National Library of Energy BETA

Sample records for gamma radiation levels

  1. Estimation of maximum permissible errors in the total gamma-spectra intensities at determination from them of level density and radiative strength functions

    E-Print Network [OSTI]

    A. M. Sukhovoj; V. A. Khitrov

    2010-09-24

    From a comparison of the total gamma-spectra calculated for different functional dependencies of level density and radiative strength functions, there were obtained both their square root relative differences and analogous data for the used parameters. The analysis of these data showed that the total uncertainty in determination of gamma-spectra intensities which is necessary to obtain reliable values of parameters of cascade gamma-decay, most probably, must not exceed one percent.

  2. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1995-10-17

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  3. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1994-08-16

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  4. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1995-01-01

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  5. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1994-01-01

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  6. Apparatus and method for detecting gamma radiation

    DOE Patents [OSTI]

    Sigg, R.A.

    1994-12-13

    A high efficiency radiation detector is disclosed for measuring X-ray and gamma radiation from small-volume, low-activity liquid samples with an overall uncertainty better than 0.7% (one sigma SD). The radiation detector includes a hyperpure germanium well detector, a collimator, and a reference source. The well detector monitors gamma radiation emitted by the reference source and a radioactive isotope or isotopes in a sample source. The radiation from the reference source is collimated to avoid attenuation of reference source gamma radiation by the sample. Signals from the well detector are processed and stored, and the stored data is analyzed to determine the radioactive isotope(s) content of the sample. Minor self-attenuation corrections are calculated from chemical composition data. 4 figures.

  7. Apparatus and method for detecting gamma radiation

    DOE Patents [OSTI]

    Sigg, Raymond A. (Martinez, GA)

    1994-01-01

    A high efficiency radiation detector for measuring X-ray and gamma radiation from small-volume, low-activity liquid samples with an overall uncertainty better than 0.7% (one sigma SD). The radiation detector includes a hyperpure germanium well detector, a collimator, and a reference source. The well detector monitors gamma radiation emitted by the reference source and a radioactive isotope or isotopes in a sample source. The radiation from the reference source is collimated to avoid attenuation of reference source gamma radiation by the sample. Signals from the well detector are processed and stored, and the stored data is analyzed to determine the radioactive isotope(s) content of the sample. Minor self-attenuation corrections are calculated from chemical composition data.

  8. Composition and apparatus for detecting gamma radiation

    DOE Patents [OSTI]

    Hofstetter, K.J.

    1994-08-09

    A gamma radiation detector and a radioluminescent composition for use therein. The detector includes a radioluminescent composition that emits light in a characteristic wavelength region when exposed to gamma radiation, and means for detecting said radiation. The composition contains a scintillant such as anglesite (PbSO[sub 4]) or cerussite (PbCO[sub 3]) incorporated into an inert, porous glass matrix via a sol-gel process. Particles of radiation-sensitive scintillant are added to, a sol solution. The mixture is polymerized to form a gel, then dried under conditions that preserve the structural integrity and radiation sensitivity of the scintillant. The final product is a composition containing the uniformly-dispersed scintillant in an inert, optically transparent and highly porous matrix. The composition is chemically inert and substantially impervious to environmental conditions including changes in temperature, air pressure, and so forth. It can be fabricated in cylinders, blocks with holes therethrough for flow of fluid, sheets, surface coatings, pellets or other convenient shapes. 3 figs.

  9. Field Deployable Gamma Radiation Detectors for DHS Use

    SciTech Connect (OSTI)

    Sanjoy Mukhopadhyay

    2007-08-31

    Recently, the U.S. Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS’s requirements in terms of sensitivity, resolution, response time and reach back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron’s identiFINDER™, which primarily uses sodium iodide crystals (3.18-cm x 2.54-cm cylinders) as gamma detector, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack™ that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity (comparable to that of a 7.62-cm x 7.62-cm sodium iodide crystal at low gamma energy ranging from 30 keV to 3,000 keV), better resolution (< 3.0 percent at 662 keV), faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system auto triggers saving of relevant spectral data and software-triggers the digital camera to take a snapshot. The spectral data including in situ analysis and the imagery data will be packaged in a suitable format and sent to a command post using an imbedded cell phone.

  10. Field Deployable Gamma Radiation Detectors for DHS Use

    SciTech Connect (OSTI)

    Sanjoy Mukhopadhyay

    2007-08-01

    Recently, the Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial off-the-shelf and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS requirements in terms of sensitivity, resolution, response time, and reach-back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron's identiFINDER{trademark}, which primarily uses sodium iodide crystals (3.18 x 2.54cm cylinders) as gamma detectors, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack{trademark} that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity, better resolution, and faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation, and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system automatically triggers the saving of relevant spectral data and software-triggers the digital camera to take a snapshot. The spectral data including in situ analysis and the imagery data will be packaged in a suitable format and sent to a command post using an imbedded cell phone.

  11. PROBING THE COSMIC X-RAY AND MeV GAMMA-RAY BACKGROUND RADIATION...

    Office of Scientific and Technical Information (OSTI)

    ASTROPHYSICS; BACKGROUND RADIATION; BLACK HOLES; CORRELATIONS; COSMIC PHOTONS; GALAXY NUCLEI; GAMMA RADIATION; HARD X RADIATION; KEV RANGE; MEV RANGE; QUASARS; SEYFERT...

  12. Radiative Transfer Models for Gamma-Ray Bursts

    E-Print Network [OSTI]

    Vurm, Indrek

    2015-01-01

    We present global radiative transfer models for heated relativistic jets. The simulations include all relevant radiative processes, starting deep in the opaque zone and following the evolution of radiation to and beyond the photosphere of the jet. The transfer models are compared with three gamma-ray bursts GRB 990123, GRB 090902B, and GRB 130427A, which have well-measured and different spectra. The models provide good fits to the observed spectra in all three cases. The fits give estimates for the jet magnetization parameter $\\varepsilon_{\\rm B}$ and the Lorentz factor $\\Gamma$. In the small sample of three bursts, $\\varepsilon_{\\rm B}$ varies between 0.01 and 0.1, and $\\Gamma$ varies between 340 and 1200.

  13. On the origin of Gamma Ray Burst radiation

    E-Print Network [OSTI]

    G. Ghisellini

    2001-01-17

    In the standard internal shock model, the observed X and gamma-ray radiation is assumed to be produced by synchrotron emission. I will show that there are serious problems with this interpretation, calling for other radiation mechanisms, such as quasi-thermal Comptonization and/or Compton drag processes, or both. These new ideas can have important consequences on the more general internal shock scenario, and can be tested by future observations.

  14. Integrated beta and gamma radiation dose calculations for the ferrocyanide waste tanks

    SciTech Connect (OSTI)

    Parra, S.A.

    1994-11-30

    This report contains the total integrated beta and gamma radiation doses in all the ferrocyanide waste tanks. It also contains estimated gamma radiation dose rates for all single-shell waste tanks containing a liquid observation well.

  15. Gamma Radiation & X-Rays

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journal Article)ForthcomingGENERAL ASSIGNMENTGame-Changing AdvancementsGamma

  16. Gamma-ray decay of levels in /sup 53/Cr

    SciTech Connect (OSTI)

    Dickens, J.K.; Larson, D.C.

    1987-11-01

    Gamma-ray decay of levels in the stable isotope /sup 53/Cr has been studied using /sup 53/Cr(n,n'..gamma..) reactions for incident neutron energies between threshold and 10 MeV. Of the 65 gamma rays or gamma-ray groups observed for neutron interactions with /sup 53/Cr, 50 have been placed or tentatively placed among 34 levels in /sup 53/Cr up to an excitation energy of 4.36 MeV. Deduced branching ratios are in reasonable agreement with previous measurements except for decay of the E/sub x/ = 1537-keV level. For the decay of the E/sub x/ = 1537-keV level we are unable to explain variations in the branching ratios of the transition gamma rays as a function of incident neutron energy within the framework of the presently known level structure of /sup 53/Cr and suggest the possibility of a second energy level at E/sub x/ = 1537 keV. 59 refs., 13 figs., 2 tabs.

  17. Low Level Radiation SEAB Ltr. to Moniz

    Office of Environmental Management (EM)

    on how DOE should pursue research on the question of a 'linear' or 'threshold' low-level radiation exposure model. Should DOE continue its efforts on this subject or...

  18. Annihilation type rare radiative $B_{(s)}\\to V\\gamma$ decays

    E-Print Network [OSTI]

    Kozachuk, Anastasiya; Nikitin, Nikolai

    2015-01-01

    We obtain predictions for a number of radiative decays $B_{(s)}\\to V\\gamma$, $V$ the vector meson, which proceed through the weak-annihilation mechanism. Within the factorization approximation, we take into account the photon emission from the $B$-meson loop and from the vector-meson loop; the latter subprocesses were not considered in the previous analyses but are found to have sizeable impact on the $B_{(s)}\\to V\\gamma$ decay rate. The highest branching ratios for the weak-annihilation reactions reported here are ${\\cal B}(\\bar B^0_s\\to J/\\psi\\gamma)=1.5\\cdot 10^{-7}$ and ${\\cal B}(B^-\\to \\bar D_s^{*-}\\gamma)=1.7\\cdot 10^{-7}$, the estimated accuracy of these predictions being at the level of 20\\%.

  19. HEALTH EFFECTS OF LOW-LEVEL IONIZING RADIATION

    E-Print Network [OSTI]

    Fabrikant, Jacob I.

    2012-01-01

    any exposure to radiation at low levels of dose carries some1 as the dose of radiation increases above very low levels,any exposure to radiation at low levels of dose carries some

  20. Gamma thermometer based reactor core liquid level detector

    DOE Patents [OSTI]

    Burns, Thomas J. (Knoxville, TN)

    1983-01-01

    A system is provided which employs a modified gamma thermometer for determining the liquid coolant level within a nuclear reactor core. The gamma thermometer which normally is employed to monitor local core heat generation rate (reactor power), is modified by thermocouple junctions and leads to obtain an unambiguous indication of the presence or absence of coolant liquid at the gamma thermometer location. A signal processor generates a signal based on the thermometer surface heat transfer coefficient by comparing the signals from the thermocouples at the thermometer location. The generated signal is a direct indication of loss of coolant due to the change in surface heat transfer when coolant liquid drops below the thermometer location. The loss of coolant indication is independent of reactor power at the thermometer location. Further, the same thermometer may still be used for the normal power monitoring function.

  1. EFFECTS OF GAMMA RADIATION ON ELECTROCHEMICAL PROPERTIES OF IONIC LIQUIDS

    SciTech Connect (OSTI)

    Visser, A; Nicholas Bridges, N; Thad Adams, T; John Mickalonis, J; Mark02 Williamson, M

    2009-04-21

    The electrochemical properties of ionic liquids (ILs) make them attractive for possible replacement of inorganic salts in high temperature molten salt electrochemical processing of nuclear fuel. To be a feasible replacement solvent, ILs need to be stable in moderate and high doses of radiation without adverse chemical and physical effects. Here, we exposed seven different ILs to a 1.2 MGy dose of gamma radiation to investigate their physical and chemical properties as they related to radiological stability. The azolium-based ILs experienced the greatest change in appearance, but these ILs were chemically more stable to gamma radiation than some of the other classes of ILs tested, due to the presence of aromatic electrons in the azolium ring. All the ILs exhibited a decrease in their conductivity and electrochemical window (at least 1.1 V), both of which could affect the utility of ILs in electrochemical processing. The concentration of the irradiation decomposition products was less than 3 mole %, with no impurities detectable using NMR techniques.

  2. Gravitational radiation from long gamma-ray bursts

    E-Print Network [OSTI]

    Maurice H. P. M. van Putten

    2001-02-11

    Long gamma-ray bursts (GRBs) are probably powered by high-angular momentum black hole-torus systems in suspended accretion. The torus will radiate gravitational waves as non-axisymmetric instabilities develop. The luminosity in gravitational-wave emissions is expected to compare favorably with the observed isotropic equivalent luminosity in GRB-afterglow emissions. This predicts that long GRBs are potentially the most powerful LIGO/VIRGO burst-sources in the Universe. Their frequency-dynamics is characterized by a horizontal branch in the $\\dot{f}(f)-$diagram.

  3. This work centers around a state of the art gamma and neutron radiation detector, which is able to display radiation information about its surrounding at every second. Information about the count

    E-Print Network [OSTI]

    Abidi, Mongi A.

    ABSTRACT This work centers around a state of the art gamma and neutron radiation detector, which is able to display radiation information about its surrounding at every second. Information about the count level is displayed along with the energy range of the detected radiation. Currently, similar

  4. Neutron and gamma radiation shielding material, structure, and process of making structure

    DOE Patents [OSTI]

    Hondorp, Hugh L. (Princeton Junction, NJ)

    1984-01-01

    The present invention is directed to a novel neutron and gamma radiation elding material consisting of 95 to 97 percent by weight SiO.sub.2 and 5 to 3 percent by weight sodium silicate. In addition, the method of using this composition to provide a continuous neutron and gamma radiation shielding structure is disclosed.

  5. Estimating GroundEstimating Ground--Level Solar RadiationLevel Solar Radiation and Evapotranspiration In Puerto Ricoand Evapotranspiration In Puerto Rico

    E-Print Network [OSTI]

    Gilbes, Fernando

    Estimating GroundEstimating Ground--Level Solar RadiationLevel Solar Radiation radiation, therefore, solar radiation measurements throughout the island are essential. #12;Currently, including solar radiation ·In PR, solar radiation is only available at selected locations. · The majority

  6. Gravitational Radiation from Gamma-Ray Burst Progenitors

    E-Print Network [OSTI]

    Shiho Kobayashi; Peter Meszaros

    2003-02-11

    We study gravitational radiation from various proposed gamma-ray burst (GRB) progenitor models, in particular compact mergers and massive stellar collapses. These models have in common a high angular rotation rate, and the final stage involves a rotating black hole and accretion disk system. We consider the in-spiral, merger and ringing phases, and for massive collapses we consider the possible effects of asymmetric collapse and break-up, as well bar-mode instabilities in the disks. We calculate the strain and frequency of the gravitational waves expected from various progenitors, at distances based on occurrence rate estimates. Based on simplifying assumptions, we give estimates of the probability of detection of gravitational waves by the advanced LIGO system from the different GRB scenarios.

  7. Calorimetric calibration of pyroelectric gamma-radiation detectors

    SciTech Connect (OSTI)

    Strakovskaya, R.Y.; Sras', A.G.

    1985-07-01

    A method has been devised for calibrating a pyroelectric dosimeter, which is based on comparing the readings obtained with it in a gamma-ray beam with the readings of an integral calorimeter under stationary conditions, with the latter previously calibrated from Joule heat. The calorimeter used was in the form of a closed shell, whose overall thermo-emf was independent of the spatial distribution of the heat sources in it, the value being proportional to the integral heat flux through the shell. Measurements were made not only with a quasiisotropic radiation field but also in directed fields. The overall error in calibrating the pyroelectric detectors by this method was less than or equal to plus or minus 10%.

  8. Population doses from environmental gamma radiation in Iraq

    SciTech Connect (OSTI)

    Marouf, B.A.; Mohamad, A.S.; Taha, J.S.; al-Haddad, I.K. (Iraq Atomic Energy Commission, Nuclear Research Center, Tuwaitha, Baghdad, (Iraq))

    1992-05-01

    The exposure rates due to external gamma radiation were measured in 11 Iraqi governerates. Measurements were performed with an Environmental Monitoring System (RSS-111) in open air 1 m above the ground. The average absorbed dose rate in each governerate was as follows (number x 10(-2) microGy h-1): Babylon (6.0), Kerbala (5.3), Al-Najaf (5.4), Al-Kadysia (6.5), Wasit (6.5), Diala (6.5), Al-Anbar (6.5), Al-Muthana (6.6), Maisan (6.8), Thee-Kar (6.6), and Al-Basrah (6.5). The collective doses to the population living in these governerates were 499, 187, 239, 269, 262, 458, 384, 153, 250, 450, and 419 person-Sv, respectively.

  9. On the omnipresent background gamma radiation of the continuous spectrum

    E-Print Network [OSTI]

    R. Banjanac; D. Maleti?; D. Jokovi?; N. Veselinovi?; A. Dragi?; V. Udovi?i?; I. Ani?in

    2013-05-14

    The background spectrum of a germanium detector, shielded from the radiations arriving from the lower and open for the radiations arriving from the upper hemisphere is studied, both in a ground level and in an underground laboratory. It is established that the continuous portion of this background spectrum is mostly due to the radiations that arrive from the upper hemisphere of the continuous spectrum similar to the instrumental one. The intensity of this radiation of an average energy of about 120 keV is estimated to about 8000 photons/m2s 2\\pi srad in a ground level laboratory, and to about 5000 photons/m2s 2\\pi srad at the depth of 25 m.w.e. Rough estimates of the dose that it contributes to the skin are about 1.5 nSv/h and 1 nSv/h respectively. Simulations by GEANT4 and CORSIKA demonstrate that this radiation is both of cosmic and terrestrial origin, mixed in proportion that still has to be determined.

  10. On the omnipresent background gamma radiation of the continuous spectrum

    E-Print Network [OSTI]

    Banjanac, R; Jokovi?, D; Veselinovi?, N; Dragi?, A; Udovi?i?, V; Ani?in, I

    2013-01-01

    The background spectrum of a germanium detector, shielded from the radiations arriving from the lower and open for the radiations arriving from the upper hemisphere is studied, both in a ground level and in an underground laboratory. It is established that the continuous portion of this background spectrum is mostly due to the radiations that arrive from the upper hemisphere of the continuous spectrum similar to the instrumental one. The intensity of this radiation of an average energy of about 120 keV is estimated to about 8000 photons/m2s 2\\pi srad in a ground level laboratory, and to about 5000 photons/m2s 2\\pi srad at the depth of 25 m.w.e. Rough estimates of the dose that it contributes to the skin are about 1.5 nSv/h and 1 nSv/h respectively. Simulations by GEANT4 and CORSIKA demonstrate that this radiation is both of cosmic and terrestrial origin, mixed in proportion that still has to be determined.

  11. ON THE KINETIC ENERGY AND RADIATIVE EFFICIENCY OF GAMMA-RAY BURSTS Nicole M. Lloyd-Ronning1

    E-Print Network [OSTI]

    Zhang, Bing

    ON THE KINETIC ENERGY AND RADIATIVE EFFICIENCY OF GAMMA-RAY BURSTS Nicole M. Lloyd-Ronning1 of 17 gamma-ray bursts (GRBs) during the afterglow phase and ac- counting for radiative losses, we the implications of these results for the GRB radiation and jet models. Subject headinggs: gamma rays: bursts

  12. Observation of the radiative decay D*+-> D+gamma

    E-Print Network [OSTI]

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Zhou, L.

    1998-05-01

    We have observed a signal for the decay D*(+) --> D(+)gamma at a significance of 4 standard deviations. From the measured branching ratio B(D*(+) --> D(+)gamma)/B(D*(+) --> D(+)pi(0)) = 0.055 +/- 0.014 +/- 0.010 we find B(D*(+) --> D(+)gamma) = 0...

  13. Virtuality Distributions in application to gamma gamma* to pi^0 Transition Form Factor at Handbag Level

    SciTech Connect (OSTI)

    Radyushkin, Anatoly V.

    2014-07-01

    We outline basics of a new approach to transverse momentum dependence in hard processes. As an illustration, we consider hard exclusive transition process gamma*gamma -> to pi^0 at the handbag level. Our starting point is coordinate representation for matrix elements of operators (in the simplest case, bilocal O(0,z)) describing a hadron with momentum p. Treated as functions of (pz) and z^2, they are parametrized through a virtuality distribution amplitude (VDA) Phi (x, sigma), with x being Fourier-conjugate to (pz) and sigma Laplace-conjugate to z^2. For intervals with z^+=0, we introduce transverse momentum distribution amplitude (TMDA) Psi (x, k_\\perp), and write it in terms of VDA Phi (x, \\sigma). The results of covariant calculations, written in terms of Phi (x sigma) are converted into expressions involving Psi (x, k_\\perp. Starting with scalar toy models, we extend the analysis onto the case of spin-1/2 quarks and QCD. We propose simple models for soft VDAs/TMDAs, and use them for comparison of handbag results with experimental (BaBar and BELLE) data on the pion transition form factor. We also discuss how one can generate high-k_\\perp tails from primordial soft distributions.

  14. A ground level gamma-ray burst observed in association with rocket-triggered lightning

    E-Print Network [OSTI]

    Florida, University of

    A ground level gamma-ray burst observed in association with rocket-triggered lightning J. R. Dwyer 2004; published 13 March 2004. [1] We report the observation of an intense gamma-ray burst observed lightning channel with gamma-ray energies extending up to more than 10 MeV. The burst consisted of 227

  15. Attosecond gamma-ray pulses via nonlinear Compton scattering in the radiation dominated regime

    E-Print Network [OSTI]

    Li, Jian-Xing; Galow, Benjamin J; Keitel, Christoph H

    2015-01-01

    The interaction of a relativistic electron bunch with a counter-propagating tightly-focused laser beam is investigated for intensities when the dynamics is strongly affected by its own radiation. The Compton scattering spectra of gamma-radiation are evaluated employing a semiclassical description for the laser-driven electron dynamics and a quantum electrodynamical description for the photon emissions. We show for laser facilities under construction that gamma-ray bursts of few hundred attoseconds and dozens of megaelectronvolt photon energies may be detected in the near-backwards direction of the initial electron motion. Tight focussing of the laser beam and radiation reaction are demonstrated to be jointly responsible for such short gamma-ray bursts which are independent of both duration of electron bunch and laser pulse. Furthermore, the stochastic nature of the gamma-photon emission features signatures in the resulting gamma-ray comb in the case of the application of a multi-cycle laser pulse.

  16. Detection system for high-resolution gamma radiation spectroscopy with neutron time-of-flight filtering

    DOE Patents [OSTI]

    Dioszegi, Istvan; Salwen, Cynthia; Vanier, Peter

    2014-12-30

    A .gamma.-radiation detection system that includes at least one semiconductor detector such as HPGe-Detector, a position-sensitive .alpha.-Detector, a TOF Controller, and a Digitizer/Integrator. The Digitizer/Integrator starts to process the energy signals of a .gamma.-radiation sent from the HPGe-Detector instantly when the HPGe-Detector detects the .gamma.-radiation. Subsequently, it is determined whether a coincidence exists between the .alpha.-particles and .gamma.-radiation signal, based on a determination of the time-of-flight of neutrons obtained from the .alpha.-Detector and the HPGe-Detector. If it is determined that the time-of-flight falls within a predetermined coincidence window, the Digitizer/Integrator is allowed to continue and complete the energy signal processing. If, however, there is no coincidence, the Digitizer/Integrator is instructed to be clear and reset its operation instantly.

  17. Branching fractions and CP-violating asymmetries in radiative B decays to eta K gamma

    E-Print Network [OSTI]

    Zhao, M.

    We present measurements of the CP-violation parameters S and C for the radiative decay B0-->etaKS0gamma; for B-->etaKgamma we also measure the branching fractions and for B+-->etaK+gamma the time-integrated charge asymmetry ...

  18. Flash polymerization of silicone oils using gamma radiation for conserving waterlogged wood 

    E-Print Network [OSTI]

    Gidden, Richmond Paul

    1996-01-01

    the SFD-I /SFD-5 mix. These bulked samples were exposed to gamma radiation emitted from a nuclear research reactor and received gamma doses ranging from 30 Gy to 228 Gy with dose rates ranging from 0.6 Gy/min to 5.1 Gy/min. Following irradiation, thin...

  19. Constraining |V(td)|/|V(ts)| Using Radiative Penguin B -> V(K*/rho/omega)gamma Decays

    SciTech Connect (OSTI)

    Tan, Ping; /Wisconsin U., Madison

    2006-03-08

    Exclusive radiative penguin B decays, B {yields} (K*{sup 0}/K*{sup +}) and B {yields} ({rho}/{omega}){gamma}, are flavor-changing neutral-current (FCNC) processes. Studies of these decays are of special interest in testing Standard Model (SM) predictions and searching for other beyond-the-SM FCNC interactions. Using 89 x 10{sup 6} B{bar B} pairs from BABAR, we measure the branching fraction ({Beta}), CP-asymmetry ({Alpha}), and isospin asymmetry ({Delta}{sub 0-}) of B {yields} (K*{sup 0}/K*{sup +}){gamma} as follows: {Beta}(B{sup 0} {yields} K*{sup 0}{gamma}) = 3.92 {+-} 0.20(stat.) {+-} 0.24(syst.); {Beta}(B{sup +} {yields} K*{sup +}{gamma}) = 3.87 {+-} 0.28(stat.) {+-} 0.26(syst.); {Alpha}(B {yields} K*{gamma}) = -0.013 {+-} 0.36(stat.) {+-} 0.10(syst.); {Delta}{sub 0-}(B {yields} K*{gamma}) = 0.050 {+-} 0.045(stat.) {+-} 0.028(syst.) {+-} 0.024(R{sup +/0}). The 90% confidence intervals for the CP-asymmetry and the isospin-asymmetry in the B {yields} K*{gamma} decay are given as: -0.074 < {Alpha}(B {yields} K*{gamma}) < 0.049, -0.046 < {Delta}{sub 0-} (B {yields} K*{gamma}) < 0.146. We also search for B {yields} ({rho}/{omega}){gamma} decays using 211 x 10{sup 6} B{bar B} pairs from BABAR. No evidence for these decays is found. We set the upper limits at 90% confidence level for these decays: {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) < 0.4 x 10{sup -6}; {Beta}(B{sup +}{yields} {rho}{sup =}{gamma}) < 1.8 x 10{sup -6}; {Beta}(B{sup 0} {yields} {omega}{gamma}) < 1.0 x 10{sup -6}; {bar {Beta}}(B {yields} ({rho}/{omega}){gamma}) < 1.2 x 10{sup -6}. These results are in good agreement with the SM predictions. The branching fractions of these decays are then used to constrain the ratio |V{sub td}|/|V{sub ts}|.

  20. Radiation levels on empty cylinders containing heel material

    SciTech Connect (OSTI)

    Shockley, C.W. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    Empty UF{sub 6} cylinders containing heel material were found to emit radiation levels in excess of 200 mr/hr, the maximum amount stated in ORO-651. The radiation levels were as high as 335 mr/hr for thick wall (48X and 48Y) cylinders and 1050 mr/hr for thin wall (48G and 48H) cylinders. The high readings were found only on the bottom of the cylinders. These radiation levels exceeded the maximum levels established in DOT 49 CFR, Part 173.441 for shipment of cylinders. Holding periods of four weeks for thick-wall cylinders and ten weeks for thin-wall cylinders were established to allow the radiation levels to decay prior to shipment.

  1. A Grey Radiative Transfer Procedure For Gamma-ray Transfer in Supernovae

    E-Print Network [OSTI]

    David J. Jeffery

    1998-11-23

    The gamma-ray transfer in supernovae for the purposes of energy deposition in the ejecta can be approximated fairly accurately as frequency-integrated (grey) radiative transfer using a mean opacity as shown by Swartz, Sutherland, & Harkness (SSH). In SSH's grey radiative transfer procedure (unoptimized) the mean opacity is a pure absorption opacity and it is a constant aside from a usually weak composition dependence. In this paper, we present a variation on the SSH procedure which uses multiple mean opacities which have both absorption and scattering components. There is a mean opacity for each order of Compton scattering. A local-state (LS) approximation permits an analytic solution for the gamma-ray transfer of scattered gamma-ray fields. The LS approximation is admittedly crude, but the scattered fields are always of lesser importance to the energy deposition. We call our procedure the LS grey radiative transfer procedure or LS procedure for short. For a standard Type Ia supernova (SN Ia) model the uncertainty in gamma-ray energy deposition is estimated to be of order 10 % or less. The LS procedure code used for this paper can be obtained by request from the author. For completeness and easy reference, we include in this paper a review of the gamma-ray opacities important in supernovae, a discussion of the appropriate mean opacity prescription, and a discussion of the errors arising from neglecting time-dependent and non-static radiative transfer effects.

  2. Gadolinium-doped water cerenkov-based neutron and high energy gamma-ray detector and radiation portal monitoring system

    SciTech Connect (OSTI)

    Dazeley, Steven A; Svoboda, Robert C; Bernstein, Adam; Bowden, Nathaniel

    2013-02-12

    A water Cerenkov-based neutron and high energy gamma ray detector and radiation portal monitoring system using water doped with a Gadolinium (Gd)-based compound as the Cerenkov radiator. An optically opaque enclosure is provided surrounding a detection chamber filled with the Cerenkov radiator, and photomultipliers are optically connected to the detect Cerenkov radiation generated by the Cerenkov radiator from incident high energy gamma rays or gamma rays induced by neutron capture on the Gd of incident neutrons from a fission source. The PMT signals are then used to determine time correlations indicative of neutron multiplicity events characteristic of a fission source.

  3. On the connection between gamma and radio radiation spectra in pulsars

    E-Print Network [OSTI]

    V. M. Kontorovich; A. B. Flanchik

    2007-12-29

    The model of pulsar radio emission is discussed in which a coherent radio emis-sion is excited in a vacuum gap above polar cap of neutron star. Pulsar X and gamma radiation are considered as the result of low-frequency radio emission inverse Comp-ton scattering on ultra relativistic electrons accelerated in the gap. The influence of the pulsar magnetic field on Compton scattering is taken into account. The relation of radio and gamma radiation spectra has been found in the framework of the model.

  4. LOW-LEVEL RADIATION HEALTH EFFECTS: PROGRAMS AND PANEL DISCUSSION

    E-Print Network [OSTI]

    Shlyakhter, Ilya

    41 LOW-LEVEL RADIATION HEALTH EFFECTS: PROGRAMS AND PANEL DISCUSSION Cosponsored by the Biology. The reduction was presumably due to the reduced effects at low dose rate. THE DATA SETS In the former USSR dose: Of those we expect up to 50 to develop cancers due to radiation. 2. The 25 000 people evacuated

  5. Microbiological, chemical, and sensory quality changes in Pico de gallo as affected by gamma radiation 

    E-Print Network [OSTI]

    Miller, Gerald Howard

    1994-01-01

    by radiation and storage. Pectin solubility was affected by radiation treatment and storage. Radiation resulted in conversion of CSP to NXP. Levels of WSP and NXP increased in both treatments during storage, while levels of CSP and OHSP decreased. Pectins were...

  6. Radiation detection system for portable gamma-ray spectroscopy

    DOE Patents [OSTI]

    Rowland, Mark S. (Alamo, CA); Howard, Douglas E. (Livermore, CA); Wong, James L. (Dublin, CA); Jessup, James L. (Tracy, CA); Bianchini, Greg M. (Livermore, CA); Miller, Wayne O. (Livermore, CA)

    2006-06-20

    A portable gamma ray detection apparatus having a gamma ray detector encapsulated by a compact isolation structure having at least two volumetrically-nested enclosures where at least one is a thermal shield. The enclosures are suspension-mounted to each other to successively encapsulate the detector without structural penetrations through the thermal shields. A low power cooler is also provided capable of cooling the detector to cryogenic temperatures without consuming cryogens, due to the heat load reduction by the isolation structure and the reduction in the power requirements of the cooler. The apparatus also includes a lightweight portable power source for supplying power to the apparatus, including to the cooler and the processing means, and reducing the weight of the apparatus to enable handheld operation or toting on a user's person.

  7. LOW TEMPERATURE PHYSICS The effect of neutron and gamma radiation on

    E-Print Network [OSTI]

    McDonald, Kirk

    LOW TEMPERATURE PHYSICS The effect of neutron and gamma radiation on magnet components Michael University of Technology Atominstitut, Vienna, Austria RESMM Workshop, Fermilab, 14 February 2012 #12;LOW. Hengstberger, R. Prokopec, M. Zehetmayer PhD students: T. Baumgartner, M. Chudy, J. Emhofer #12;LOW TEMPERATURE

  8. Astrophysical factor for the radiative capture reaction alpha+d->Li-6+gamma 

    E-Print Network [OSTI]

    Mukhamedzhanov, AM; Schmitt, R. P.; Tribble, Robert E.; Sattarov, A.

    1995-01-01

    We consider the radiative capture process alpha+d-->Li-6+gamma at energies, E(c.m.)less than or equal to 300 keV, that are relevant for astrophysical processes. Due to the peripheral character of the reaction, the overall normalization...

  9. Ground-level ozone following astrophysical ionizing radiation events: an additional biological hazard?

    E-Print Network [OSTI]

    Thomas, Brian C

    2015-01-01

    Astrophysical ionizing radiation events such as supernovae, gamma-ray bursts, and solar proton events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in solar UV radiation at Earth's surface and in the upper levels of the ocean. Other work has also considered the potential impact of nitric acid rainout, concluding that no significant threat is likely. Not yet studied to-date is the potential impact of ozone produced in the lower atmosphere following an ionizing radiation event. Ozone is a known irritant to organisms on land and in water and therefore may be a significant additional hazard. Using previously completed atmospheric chemistry modeling we have examined the amount of ozone produced in the lower atmosphere for the case of a gamma-ray burst and find that the values are too small to pose a significant additional threat to the biosphere. These results may be extended to other ionizing radiation events, including supe...

  10. THE PHOTOSPHERIC RADIATION MODEL FOR THE PROMPT EMISSION OF GAMMA-RAY BURSTS: INTERPRETING FOUR OBSERVED CORRELATIONS

    SciTech Connect (OSTI)

    Fan Yizhong; Wei Daming; Zhang Fuwen [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Zhang Binbin, E-mail: yzfan@pmo.ac.cn, E-mail: dmwei@pmo.ac.cn, E-mail: fwzhang@pmo.ac.cn, E-mail: bbzhang@psu.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

    2012-08-10

    We show that the empirical E{sub p}-L, {Gamma}-L, E{sub p}-{Gamma}, and {eta}-bar{sub {gamma}}-E{sub p} correlations (where L is the time-averaged luminosity of the prompt emission, E{sub p} is the spectral peak energy, {Gamma} is the bulk Lorentz factor, and {eta}-bar{sub {gamma}} is the emission efficiency of gamma-ray bursts, GRBs) are well consistent with the relations between the analogous parameters predicted in the photospheric radiation model of the prompt emission of GRBs. The time-resolved thermal radiation of GRB 090902B does follow the E{sub p}-L and {Gamma}-L correlations. A reliable interpretation of the four correlations in alternative models is still lacking. These may point toward a photospheric origin of prompt emission of some GRBs.

  11. High-efficiency scintillation detector for combined detection of thermal and fast neutrons and gamma radiation

    DOE Patents [OSTI]

    Chiles, M.M.; Mihalczo, J.T.; Blakeman, E.D.

    1987-02-27

    A scintillation based radiation detector for the combined detection of thermal neutrons, high-energy neutrons and gamma rays in a single detecting unit. The detector consists of a pair of scintillators sandwiched together and optically coupled to the light sensitive face of a photomultiplier tube. A light tight radiation pervious housing is disposed about the scintillators and a portion of the photomultiplier tube to hold the arrangement in assembly and provides a radiation window adjacent the outer scintillator through which the radiation to be detected enters the detector. The outer scintillator is formed of a material in which scintillations are produced by thermal-neutrons and the inner scintillator is formed of a material in which scintillations are produced by high-energy neutrons and gamma rays. The light pulses produced by events detected in both scintillators are coupled to the photomultiplier tube which produces a current pulse in response to each detected event. These current pulses may be processed in a conventional manner to produce a count rate output indicative of the total detected radiation event count rate. Pulse discrimination techniques may be used to distinguish the different radiations and their energy distribution.

  12. High-efficiency scintillation detector for combined of thermal and fast neutrons and gamma radiation

    DOE Patents [OSTI]

    Chiles, Marion M. (Knoxville, TN); Mihalczo, John T. (Oak Ridge, TN); Blakeman, Edward D. (Oak Ridge, TN)

    1989-01-01

    A scintillation based radiation detector for the combined detection of thermal neutrons, high-energy neutrons and gamma rays in a single detecting unit. The detector consists of a pair of scintillators sandwiched together and optically coupled to the light sensitive face of a photomultiplier tube. A light tight radiation pervious housing is disposed about the scintillators and a portion of the photomultiplier tube to hold the arrangement in assembly and provides a radiation window adjacent the outer scintillator through which the radiation to be detected enters the detector. The outer scintillator is formed of a material in which scintillations are produced by thermal-neutrons and the inner scintillator is formed of a material in which scintillations are produced by high-energy neutrons and gamma rays. The light pulses produced by events detected in both scintillators are coupled to the photomultiplier tube which produces a current pulse in response to each detected event. These current pulses may be processed in a conventional manner to produce a count rate output indicative of the total detected radiation even count rate. Pulse discrimination techniques may be used to distinguish the different radiations and their energy distribution.

  13. The Contribution of Tissue Level Organization to Genomic Stability Following Low Dose/Low Dose Rate Gamma and Proton Irradiation

    SciTech Connect (OSTI)

    Cheryl G. Burrell, Ph.D.

    2012-05-14

    The formation of functional tissue units is necessary in maintaining homeostasis within living systems, with individual cells contributing to these functional units through their three-dimensional organization with integrin and adhesion proteins to form a complex extra-cellular matrix (ECM). This is of particular importance in those tissues susceptible to radiation-induced tumor formation, such as epithelial glands. The assembly of epithelial cells of the thyroid is critical to their normal receipt of, and response to, incoming signals. Traditional tissue culture and live animals present significant challenges to radiation exposure and continuous sampling, however, the production of bioreactor-engineered tissues aims to bridge this gap by improve capabilities in continuous sampling from the same functional tissue, thereby increasing the ability to extrapolate changes induced by radiation to animals and humans in vivo. Our study proposes that the level of tissue organization will affect the induction and persistence of low dose radiation-induced genomic instability. Rat thyroid cells, grown in vitro as 3D tissue analogs in bioreactors and as 2D flask grown cultures were exposed to acute low dose (1, 5, 10 and 200 cGy) gamma rays. To assess immediate (6 hours) and delayed (up to 30 days) responses post-irradiation, various biological endpoints were studied including cytogenetic analyses, apoptosis analysis and cell viability/cytotoxicity analyses. Data assessing caspase 3/7 activity levels show that, this activity varies with time post radiation and that, overall, 3D cultures display more genomic instability (as shown by the lower levels of apoptosis over time) when compared to the 2D cultures. Variation in cell viability levels were only observed at the intermediate and late time points post radiation. Extensive analysis of chromosomal aberrations will give further insight on the whether the level of tissue organization influences genomic instability patterns after low dose radiation exposure. Cells viability/cytotoxicity analysis data are currently being analyzed to determine how these endpoints are affected under our experimental conditions. The results from this study will be translatable to risk assessment for assigning limits to radiation workers, pre-dosing for more effective radiotherapy and the consequences of long duration space flight. The data from this study has been presented a various scientific meetings/workshops and a manuscript, containing the findings, is currently being prepared for publication. Due to unforeseen challenges in collecting the data and standardizing experimental procedures, the second and third aims have not been completed. However, attempts will be made, based on the availability of funds, to continue this project so that these aims can be satisfied.

  14. A New Natural Gamma Radiation Measurement System for Marine Sediment and Rock Analysis

    E-Print Network [OSTI]

    Vasiliev, M A; Chubarian, G; Olsen, R; Bennight, C; Cobine, T; Fackler, D; Hastedt, M; Houpt, D; Mateo, Z; Vasilieva, Y B

    2010-01-01

    A new high-efficiency and low-background system for the measurement of natural gamma radioactivity in marine sediment and rock cores retrieved from beneath the seabed was designed, built, and installed on the JOIDES Resolution research vessel. The system includes eight large NaI(Tl) detectors that measure adjacent intervals of the core simultaneously, maximizing counting times and minimizing statistical error for the limited measurement times available during drilling expeditions. Effect to background ratio is maximized with passive lead shielding, including both ordinary and low-activity lead. Large-area plastic scintillator active shielding filters background associated with the high-energy part of cosmic radiation. The new system has at least an order of magnitude higher statistical reliability and significantly enhances data quality compared to other offshore natural gamma radiation (NGR) systems designed to measure geological core samples. Reliable correlations and interpretations of cored intervals are ...

  15. PHOTOSPHERIC EMISSION AS THE DOMINANT RADIATION MECHANISM IN LONG-DURATION GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Lazzati, Davide [Department of Physics, NC State University, 2401 Stinson Drive, Raleigh, NC 27695-8202 (United States); Morsony, Brian J. [Department of Astronomy, University of Wisconsin-Madison, 3321 Sterling Hall, 475 N. Charter Street, Madison WI 53706-1582 (United States); Margutti, Raffaella [Harvard-Smithsonian Center for Astrophysics, ITC, 60 Garden Street, Cambridge, MA 02138 (United States); Begelman, Mitchell C. [JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309-0440 (United States)

    2013-03-10

    We present the results of a set of numerical simulations of long-duration gamma-ray burst jets associated with massive, compact stellar progenitors. The simulations extend to large radii and allow us to locate the region in which the peak frequency of the advected radiation is set before the radiation is released at the photosphere. Light curves and spectra are calculated for different viewing angles as well as different progenitor structures and jet properties. We find that the radiation released at the photosphere of matter-dominated jets is able to reproduce the observed Amati and energy-Lorentz factor correlations. Our simulations also predict a correlation between the burst energy and the radiative efficiency of the prompt phase, consistent with observations.

  16. Method for detecting water equivalent of snow using secondary cosmic gamma radiation

    DOE Patents [OSTI]

    Condreva, K.J.

    1997-01-14

    Water equivalent of accumulated snow determination by measurement of secondary background cosmic radiation attenuation by the snowpack. By measuring the attenuation of 3-10 MeV secondary gamma radiation it is possible to determine the water equivalent of snowpack. The apparatus is designed to operate remotely to determine the water equivalent of snow in areas which are difficult or hazardous to access during winter, accumulate the data as a function of time and transmit, by means of an associated telemetry system, the accumulated data back to a central data collection point for analysis. The electronic circuitry is designed so that a battery pack can be used to supply power. 4 figs.

  17. Method for detecting water equivalent of snow using secondary cosmic gamma radiation

    DOE Patents [OSTI]

    Condreva, Kenneth J. (1420 Fifth St., Livermore, Alameda County, CA 94550)

    1997-01-01

    Water equivalent of accumulated snow determination by measurement of secondary background cosmic radiation attenuation by the snowpack. By measuring the attentuation of 3-10 MeV secondary gamma radiation it is possible to determine the water equivalent of snowpack. The apparatus is designed to operate remotely to determine the water equivalent of snow in areas which are difficult or hazardous to access during winter, accumulate the data as a function of time and transmit, by means of an associated telemetry system, the accumulated data back to a central data collection point for analysis. The electronic circuitry is designed so that a battery pack can be used to supply power.

  18. Gamma ray bursts may be blueshifted bundles of the relic radiation

    E-Print Network [OSTI]

    Andrzej Krasi?ski

    2015-02-02

    A hypothesis is proposed that the gamma-ray bursts (GRBs) may arise by blueshifting the emission radiation of hydrogen and helium generated during the last scattering epoch. The blueshift mechanism is provided by such a Lema\\^{\\i}tre -- Tolman (L--T) model, in which the bang-time function $t_B(r)$ is not everywhere constant. Blueshift arises on \\textit{radial} rays that are emitted over regions where $\\dril{t_B} r \

  19. Gamma ray bursts may be blueshifted bundles of the relic radiation

    E-Print Network [OSTI]

    Andrzej Krasi?ski

    2015-09-22

    A hypothesis is proposed that the gamma-ray bursts (GRBs) may arise by blueshifting the emission radiation of hydrogen and helium generated during the last scattering epoch. The blueshift mechanism is provided by such a Lema\\^itre -- Tolman (L--T) model, in which the bang-time function $t_B(r)$ is not everywhere constant. Blueshift arises on \\textit{radial} rays that are emitted over regions where $\\dril{t_B} r \

  20. Time correlation of cosmic-ray-induced neutrons and gamma rays at sea level

    E-Print Network [OSTI]

    Harilal, S. S.

    Time correlation of cosmic-ray-induced neutrons and gamma rays at sea level G. Miloshevsky n , A and evaporation processes of air nuclei are time-correlated. The occurrence of their counts in a fixed time interval is not a random (Poisson) distribution, but rather time-correlated bursts of counts

  1. 1989 neutron and gamma personnel dosimetry intercomparison study using RADCAL (Radiation Calibration Laboratory) sources

    SciTech Connect (OSTI)

    Sims, C.S.; Casson, W.H.; Patterson, G.R. ); Murakami, H. . Dept. of Health Physics); Liu, J.C. )

    1990-10-01

    The fourteenth Personnel Dosimetry Intercomparison Study (i.e., PDIS 14) was conducted during May 1-5, 1989. A total of 48 organizations (33 from the US and 15 from abroad) participated in PDIS 14. Participants submitted by mail a total of 1,302 neutron and gamma dosimeters for this mixed field study. The type of neutron dosimeter and the percentage of participants submitting that type are as follows: TLD-albedo (40%), direct interaction TLD (22%), track (20%), film (7%), combination (7%), and bubble detectors (4%). The type of gamma dosimeter and the percentage of participants submitting that type are as follows: TLD (84%) and film (16%). Radiation sources used in the six PDIS 14 exposures included {sup 252}Cf moderated by 15-cm D{sub 2}O, {sup 252}Cf moderated by 15-cm polyethylene (gamma-enhanced with {sup 137}Cs), and {sup 238}PuBe. Neutron dose equivalents ranged from 0.44--2.63 mSv and gamma doses ranged from 0. 01-1.85 mSv. One {sup 252}Cf(D{sub 2}O) exposure was performed at a 60{degree} angle of incidence (most performance tests are at perpendicular incidence). The average neutron dosimeter response for this exposure was 70% of that at normal incidence. The average gamma dosimeter response was 96% of that at normal incidence. A total of 70% of individual reported neutron dosimeter measurements were within {plus minus}50% of reference values. If the 0.01 mSv data are omitted, approximately 90% of the individual reported gamma measurements were within {plus minus}50% of reference values. 33 refs., 9 figs., 27 tabs.

  2. Gamma spectroscopic measurements using the PID350 pixelated CdTe radiation detector

    E-Print Network [OSTI]

    K. Karafasoulis; K. Zachariadou; S. Seferlis; I. Papadakis; D. Loukas; C. Lambropoulos; C. Potiriadis

    2010-11-15

    Spectroscopic measurements are presented using the PID350 pixelated gamma radiation detectors. A high-speed data acquisition system has been developed in order to reduce the data loss during the data reading in case of a high flux of photons. A data analysis framework has been developed in order to improve the resolution of the acquired energy spectra, using specific calibration parameters for each PID350's pixel. Three PID350 detectors have been used to construct a stacked prototype system and spectroscopic measurements have been performed in order to test the ability of the prototype to localize radioactive sources.

  3. SIMILAR RADIATION MECHANISM IN GAMMA-RAY BURSTS AND BLAZARS: EVIDENCE FROM TWO LUMINOSITY CORRELATIONS

    SciTech Connect (OSTI)

    Wang, F. Y.; Yi, S. X.; Dai, Z. G. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

    2014-05-01

    Active galactic nuclei and gamma-ray bursts (GRBs) are powerful astrophysical events with relativistic jets. In this Letter, the broadband spectral properties of GRBs and well-observed blazars are compared. The distribution of GRBs is consistent with the well-known blazar sequence including the ?L {sub ?}(5 GHz) – ?{sub RX} and ?L {sub ?}(5 GHz) – ?{sub peak} correlations, where ?{sub RX} is defined as the broadband spectral slope in radio-to-X-ray bands, and ?{sub peak} is defined as the spectral peak frequency. Moreover, GRBs occupy the low radio luminosity end of these sequences. These two correlations suggest that GRBs could have a radiation process, i.e., synchrotron radiation, similar to blazars both in the prompt emission and afterglow phases.

  4. Gamma watermarking

    DOE Patents [OSTI]

    Ishikawa, Muriel Y.; Wood, Lowell L.; Lougheed, Ronald W.; Moody, Kenton J.; Wang, Tzu-Fang

    2004-05-25

    A covert, gamma-ray "signature" is used as a "watermark" for property identification. This new watermarking technology is based on a unique steganographic or "hidden writing" digital signature, implemented in tiny quantities of gamma-ray-emitting radioisotopic material combinations, generally covertly emplaced on or within an object. This digital signature may be readily recovered at distant future times, by placing a sensitive, high energy-resolution gamma-ray detecting instrument reasonably precisely over the location of the watermark, which location may be known only to the object's owner; however, the signature is concealed from all ordinary detection means because its exceedingly low level of activity is obscured by the natural radiation background (including the gamma radiation naturally emanating from the object itself, from cosmic radiation and material surroundings, from human bodies, etc.). The "watermark" is used in object-tagging for establishing object identity, history or ownership. It thus may serve as an aid to law enforcement officials in identifying stolen property and prosecuting theft thereof. Highly effective, potentially very low cost identification-on demand of items of most all types is thus made possible.

  5. FMC-based Neutron and Gamma Radiation Monitoring Module for xTCA Applications

    E-Print Network [OSTI]

    Kozak, T; Napieralski, A

    2012-01-01

    The machines used in High Energy Physics (HEP) experiments, such as accelerators or tokamaks, are sources of gamma and neutron radiation fields. The radiation has a negative influence on electronics and can lead to the incorrect functioning of complex control and diagnostic system designed for HEP machines. Therefore, in most cases the electronic equipments is installed in radiation-safe areas, but in some cases this rule is omitted to decrease costs of the project. The European X-ray Free Electron Laser (E-XFEL), being under construction at DESY research center, is a good example. The E-XFEL uses single tunnel and part of the electronic system will be installed next to main beam pipe and exposed to radiation. The modern Advanced/Micro Telecommunications Computing Architecture (ATCA/?TCA) standards are foreseen as a base for control and diagnostic system for this new project. These flexible standards provide high reliability, availability and usability for the system which can be decreased by negative influe...

  6. SOLIDIFICATION TESTING FOR A HIGH ACTIVITY WASTESTREAM FROM THE SAVANNAH RIVER SITE USING GROUT AND GAMMA RADIATION SHEILDING MATERIALS - 10017

    SciTech Connect (OSTI)

    Burns, H.

    2009-11-10

    The U.S. Department of Energy (DOE) tasked MSE Technology Applications, Inc. (MSE) with evaluating grouts that include gamma radiation shielding materials to solidify surrogates of liquid aqueous radioactive wastes from across the DOE Complex. The Savannah River Site (SRS) identified a High Activity Waste (HAW) that will be treated and solidified at the Waste Solidification Building (WSB) for surrogate grout testing. The HAW, which is produced at the Mixed Oxide Fuel Fabrication Facility (MFFF), is an acidic aqueous wastestream generated by the alkaline treatment process and the aqueous purification process. The HAW surrogate was solidified using Portland cement with and without the inclusion of different gamma radiation shielding materials to determine the shielding material that is the most effective to attenuate gamma radiation for this application.

  7. State background-radiation levels: results of measurements taken during 1975-1979

    SciTech Connect (OSTI)

    Myrick, T.E.; Berven, B.A.; Haywood, F.F.

    1981-11-01

    Background radiation levels across the United States have been measured by the Off-Site Pollutant Measurements Group of the Health and Safety Research Division at Oak Ridge National Laboratory (ORNL). These measurements have been conducted as part of the ORNL program of radiological surveillance at inactive uranium mills and sites formerly utilized during Manhattan Engineer District and early Atomic Energy Commission projects. The measurements included determination of /sup 226/Ra, /sup 232/Th, and /sup 238/U concentrations in surface soil samples and measurement of external gamma-ray exposure rates at 1 m above the ground surface at the location of soil sampling. This information is being utilized for comparative purposes to determine the extent of contamination present at the survey sites and surrounding off-site areas. The sampling program to date has provided background information at 356 locations in 33 states. External gamma-ray exposure rates were found to range from less than 1 to 34 ..mu..R/h, with an US average of 8.5 ..mu..R/h. The nationwide average concentrations of /sup 226/Ra, /sup 232/Th, and /sup 238/U in surface soil were determined to be 1.1, 0.98, and 1.0 pCi/g, respectively.

  8. Real-Time Airborne Gamma-Ray Background Estimation Using NASVD with MLE and Radiation Transport for Calibration

    SciTech Connect (OSTI)

    Kulisek, Jonathan A.; Schweppe, John E.; Stave, Sean C.; Bernacki, Bruce E.; Jordan, David V.; Stewart, Trevor N.; Seifert, Carolyn E.; Kernan, Warnick J.

    2015-06-01

    Helicopter-mounted gamma-ray detectors can provide law enforcement officials the means to quickly and accurately detect, identify, and locate radiological threats over a wide geographical area. The ability to accurately distinguish radiological threat-generated gamma-ray signatures from background gamma radiation in real time is essential in order to realize this potential. This problem is non-trivial, especially in urban environments for which the background may change very rapidly during flight. This exacerbates the challenge of estimating background due to the poor counting statistics inherent in real-time airborne gamma-ray spectroscopy measurements. To address this, we have developed a new technique for real-time estimation of background gamma radiation from aerial measurements. This method is built upon on the noise-adjusted singular value decomposition (NASVD) technique that was previously developed for estimating the potassium (K), uranium (U), and thorium (T) concentrations in soil post-flight. The method can be calibrated using K, U, and T spectra determined from radiation transport simulations along with basis functions, which may be determined empirically by applying maximum likelihood estimation (MLE) to previously measured airborne gamma-ray spectra. The method was applied to both measured and simulated airborne gamma-ray spectra, with and without man-made radiological source injections. Compared to schemes based on simple averaging, this technique was less sensitive to background contamination from the injected man-made sources and may be particularly useful when the gamma-ray background frequently changes during the course of the flight.

  9. FY06 Annual Report: Amorphous Semiconductors for Gamma Radiation Detection (ASGRAD)

    SciTech Connect (OSTI)

    Johnson, Bradley R.; Riley, Brian J.; Crum, Jarrod V.; Sundaram, S. K.; Henager, Charles H.; Zhang, Yanwen; Shutthanandan, V.

    2007-01-01

    We describe progress in the development of new materials for portable, room-temperature, gamma-radiation detection at Pacific Northwest National Laboratory at the Hanford Site in Washington State. High Z, high resistivity, amorphous semiconductors are being designed for use as solid-state detectors at near ambient temperatures; principles of operation are analogous to single-crystal semiconducting detectors. Amorphous semiconductors have both advantages and disadvantages compared to single crystals, and this project is developing methods to mitigate technical problems and design optimized material for gamma detection. Several issues involved in the fabrication of amorphous semiconductors are described, including reaction thermodynamics and kinetics, the development of pyrolytic coating, and the synthesis of ingots. The characterization of amorphous semiconductors is described, including sectioning and polishing protocols, optical microscopy, X-ray diffraction, scanning electron microscopy, optical spectroscopy, particle-induced X-ram emission, Rutherford backscattering, and electrical testing. Then collaboration with the University of Illinois at Urbana-Champaign is discussed in the areas of Hall-effect measurements and current voltage data. Finally, we discuss the strategy for continuing the program.

  10. Gamma bursts

    SciTech Connect (OSTI)

    Colgate, S.A.; Petschek, A.G.

    1982-12-09

    The origin of cosmic gamma bursts is discussed. Radiation thermalization in magnetic fields, spectral mechanisms, and charge separation and photon heating are discussed. (GHT)

  11. Analysis of Gamma Radiation from a Radon Source: Indications of a Solar Influence

    E-Print Network [OSTI]

    Peter A. Sturrock; Gideon Steinitz; Ephraim Fischbach; Daniel Javorsek, II; Jere H. Jenkins

    2012-05-01

    This article presents an analysis of about 29,000 measurements of gamma radiation associated with the decay of radon in a sealed container at the Geological Survey of Israel (GSI) Laboratory in Jerusalem between 28 January 2007 and 10 May 2010. These measurements exhibit strong variations in time of year and time of day, which may be due in part to environmental influences. However, time-series analysis reveals a number of periodicities, including two at approximately 11.2 year$^{-1}$ and 12.5 year$^{-1}$. We have previously found these oscillations in nuclear-decay data acquired at the Brookhaven National Laboratory (BNL) and at the Physikalisch-Technische Bundesanstalt (PTB), and we have suggested that these oscillations are attributable to some form of solar radiation that has its origin in the deep solar interior. A curious property of the GSI data is that the annual oscillation is much stronger in daytime data than in nighttime data, but the opposite is true for all other oscillations. This may be a systematic effect but, if it is not, this property should help narrow the theoretical options for the mechanism responsible for decay-rate variability.

  12. The effects of chronic gamma radiation on the peripheral blood of Spanish goats 

    E-Print Network [OSTI]

    Leidy, Ross Bennett

    1966-01-01

    level then st ths lower level of radiation. Lasher et sl (1965) observed male snd female hLy-1 mice in groups varying fram six to 500 en%oslo that were exposed to continuous doses of 12 ~ flies 52 ' 43g 56' 74y 97 J '125 ~ snd 220 r/dsy snd secrif... or no cytoplasm around the cell edge) progressively disdnished to about 100 cells/mm5, Total lycpbocytes fell from about 9, 200/ma5 to 1, 000/car, During ECI there uas frequently sn exponeatisl decrease in lymphocyte count follooed by sons recovery before...

  13. SEAB Letter on Low-Level Radiation Research | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Secretary of Energy Advisory Board (SEAB) transmitted a letter to the Department regarding its perspective on how DOE should pursue research on low-level radiation. SEAB recommends...

  14. Detection of embedded radiation sources using temporal variation of gamma spectral data.

    SciTech Connect (OSTI)

    Shokair, Isaac R.

    2011-09-01

    Conventional full spectrum gamma spectroscopic analysis has the objective of quantitative identification of all the isotopes present in a measurement. For low energy resolution detectors, when photopeaks alone are not sufficient for complete isotopic identification, such analysis requires template spectra for all the isotopes present in the measurement. When many isotopes are present it is difficult to make the correct identification and this process often requires many trial solutions by highly skilled spectroscopists. This report investigates the potential of a new analysis method which uses spatial/temporal information from multiple low energy resolution measurements to test the hypothesis of the presence of a target spectrum of interest in these measurements without the need to identify all the other isotopes present. This method is referred to as targeted principal component analysis (TPCA). For radiation portal monitor applications, multiple measurements of gamma spectra are taken at equally spaced time increments as a vehicle passes through the portal and the TPCA method is directly applicable to this type of measurement. In this report we describe the method and investigate its application to the problem of detection of a radioactive localized source that is embedded in a distributed source in the presence of an ambient background. Examples using simulated spectral measurements indicate that this method works very well and has the potential for automated analysis for RPM applications. This method is also expected to work well for isotopic detection in the presence of spectrally and spatially varying backgrounds as a result of vehicle-induced background suppression. Further work is needed to include effects of shielding, to understand detection limits, setting of thresholds, and to estimate false positive probability.

  15. Abstract--We have recently completed a large-area, coded-aperture, gamma-ray imager for use in searching for radiation

    E-Print Network [OSTI]

    Horn, Berthold K.P.

    - strument [2] that makes a map of the radiation field as it trav- erses a region. The pixel size of the map in searching for radiation sources. The instrument was constructed to verify that weak point sources can sufficient radiation can reach a large gamma-ray detec- tor from a small source to make detection possible

  16. ESTIMATING GROUND-LEVEL SOLAR RADIATION AND EVAPOTRANSPIRATION IN PUERTO RICO

    E-Print Network [OSTI]

    Gilbes, Fernando

    1 ESTIMATING GROUND-LEVEL SOLAR RADIATION AND EVAPOTRANSPIRATION IN PUERTO RICO USING SATELLITE between the methods. A comparison between estimated and observed solar radiation is also presented for the period April 1 through June 21, 2009, which indicates a need for calibration of the solar radiation

  17. Energy resolution in semiconductor gamma radiation detectors using heterojunctions and methods of use and preparation thereof

    DOE Patents [OSTI]

    Nikolic, Rebecca J.; Conway, Adam M.; Nelson, Art J.; Payne, Stephen A.

    2012-09-04

    In one embodiment, a system comprises a semiconductor gamma detector material and a hole blocking layer adjacent the gamma detector material, the hole blocking layer resisting passage of holes therethrough. In another embodiment, a system comprises a semiconductor gamma detector material, and an electron blocking layer adjacent the gamma detector material, the electron blocking layer resisting passage of electrons therethrough, wherein the electron blocking layer comprises undoped HgCdTe. In another embodiment, a method comprises forming a hole blocking layer adjacent a semiconductor gamma detector material, the hole blocking layer resisting passage of holes therethrough. Additional systems and methods are also presented.

  18. Tritium: a model for low level long-term ionizing radiation exposure

    SciTech Connect (OSTI)

    Carsten, A.L.

    1984-01-01

    The somatic, cytogenetic and genetic effects of single and chronic tritiated water (HTO) ingestion in mice was investigated. This study serves not only as an evaluation of tritium toxicity (TRITOX) but due to its design involving long-term low concentration ingestion of HTO may serve as a model for low level long-term ionizing radiation exposure in general. Long-term studies involved animals maintained on HTO at concentrations of 0.3 ..mu..Ci/ml, 1.0 ..mu..Ci/ml, 3.0 ..mu..Ci/ml or depth dose equivalent chronic external exposures to /sup 137/Cs gamma rays. Maintenance on 3.0 ..mu..Ci/ml resulted in no effect on growth, life-time shortening or bone marrow cellularity, but did result in a reduction of bone marrow stem cells, an increase in DLM's in second generation animals maintained on this regimen and cytogenetic effects as indicated by increased sister chromatid exchanges (SCE's) in bone marrow cells, increased chromosome aberrations in the regenerating liver and an increase in micronuclei in red blood cells. Biochemical and microdosimetry studies showed that animals placed on the HTO regimen reached tritium equilibrium in the body water in approximately 17 to 21 days with a more gradual increase in bound tritium. When animals maintained for 180 days on 3.0 ..mu..Ci/ml HTO were placed on a tap water regimen, the tritium level in tissue dropped from the equilibrium value of 2.02 ..mu..Ci/ml before withdrawal to 0.001 ..mu..Ci/ml at 28 days. 18 references.

  19. Effects of chronic gamma radiation on seed production in an oak...

    Office of Scientific and Technical Information (OSTI)

    of radiation, but were sporadic in appearance. It more is suggested that many of the radiation damaged acorns abscised from the tree and thus escaped detection. (auth) less...

  20. Gamma-Ray Signatures for State-Of-Health Analysis and Monitoring of Widely-Arrayed Radiation Portal Monitor Systems

    SciTech Connect (OSTI)

    Woodring, Mitchell L.; Ely, James H.; Angel, Linda K.; Wright, Ingrid H.; Eslinger, Melany A.; Pospical, A. Jill; Ellis, John E.

    2008-05-15

    Pacific Northwest National Laboratory (PNNL) has deployed a large array of radiation portal monitors for the Department of Homeland Security U.S. Customs and Border Protection. These portal monitors scan incoming vehicles crossing the U.S. border and shipping containers leaving international ports for radioactive material via gamma-ray and neutron detection. Data produced and captured by these systems are recorded for every vehicle related to radiation signature, sensor/system status, and local background, as well as a host of other variables. Within the Radiation Portal Monitor Project at PNNL, state-of-health observation and analysis for the whole RPM system using these data to determine functionality and performance is being developed. (PIET-43741-TM-492)

  1. Transport and noise properties of Si nanowire channels with different lengths before and after gamma radiation treatment

    SciTech Connect (OSTI)

    Li, Jing; Vitusevich, Svetlana; Pud, Sergii; Sydoruk, Viktor; Offenhäusser, Andreas; Petrychuk, Mykhailo; Danilchenko, Boris

    2013-12-04

    The transport properties of Si nanowire (NW) structures fabricated on the basis of silicon on insulator (SOI) wafers were studied using noise spectroscopy before and after treatment with small doses of gamma radiation. The total resistance obtained from the I-V characteristics of Si NW structures scaled perfectly with length. Normalized flicker noise demonstrated 1/L{sup 2} dependence, which is a characteristic of dominant noise contribution from near-contact regions. The behavior changed to 1/L dependence after a small dose (1×10{sup 4} Gy) of gamma radiation treatment. Comparison of the random telegraph signal (RTS) noise parameters in the samples with small lengths before and after the treatment revealed a decrease in RTS amplitude and a shift to a lower frequency range after gamma irradiation. These results confirmed that the main changes in the samples were related to strain relaxation near-contact regions. In addition, such treatment resulted in a considerable decrease in the scattering data of device parameters.

  2. The Observation of the Weak Radiative Hyperon Decay XI0 ---> Lambda0 pi0 gamma at KTeV/E799, Fermilab

    SciTech Connect (OSTI)

    Ping, Huican

    2005-01-01

    The large sample of {Xi}{sup 0} hyperons available at KTeV 799 provides an opportunity to search for the Weak Radiative Hyperon Decay {Xi}{sup 0} {yields} {Lambda}{sup 0}{pi}{sup 0}{gamma}. They present a branching fraction measurement of {Xi}{sup 0} {yields} {Lambda}{sup 0}{pi}{sup 0}{gamma} based on the E799-II experiment data-taking in 1999 at KTeV, Fermilab. They used the principal decay of {Xi}{sup 0} {yields} {Lambda}{sup 0}{pi}{sup 0} where {Lambda} decays to a proton and a {pi}{sup -} as the flux normalization mode. This is the first observation of this interesting decay mode. 4 candidate events are found in the data. The branching ratio at 90% confidence level has been measured to be (1.67{sub -0.80}{sup +1.45}(stat.) {+-} 0.50(syst.)) x 10{sup -5} or (1.67{sub -0.69}{sup +1.16}(stat.) {+-} 0.50(syst.)) x 10{sup -5} at 68.27% confidence level.

  3. Cherenkov radiation conversion and collection considerations for a gamma bang time/reaction history diagnostic for the NIF

    SciTech Connect (OSTI)

    Herrmann, Hans W.; Mack, Joseph M.; Young, Carlton S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Malone, Robert M. [National Security Technologies, Los Alamos Operations, Los Alamos, New Mexico 87544 (United States); Stoeffl, Wolfgang [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Horsfield, Colin J. [Atomic Weapons Establishment, Aldermaston (United Kingdom)

    2008-10-15

    Bang time and reaction history measurements are fundamental components of diagnosing inertial confinement fusion (ICF) implosions and will be essential contributors to diagnosing attempts at ignition on the National Ignition Facility (NIF). Fusion gammas provide a direct measure of fusion interaction rate without being compromised by Doppler spreading. Gamma-based gas Cherenkov detectors that convert fusion gamma rays to optical Cherenkov photons for collection by fast recording systems have been developed and fielded at Omega. These systems have established their usefulness in illuminating ICF physics in several experimental campaigns. Bang time precision better than 25 ps has been demonstrated, well below the 50 ps accuracy requirement defined by the NIF system design requirements. A comprehensive, validated numerical study of candidate systems is providing essential information needed to make a down selection based on optimization of sensitivity, bandwidth, dynamic range, cost, and NIF logistics. This paper presents basic design considerations arising from the two-step conversion process from {gamma} rays to relativistic electrons to UV/visible Cherenkov radiation.

  4. Projection of needs for gamma radiation sources and other radioisotopes and assessment of alternatives for providing radiation sources

    SciTech Connect (OSTI)

    Ross, W.A.; Jensen, G.A.; Clark, L.L.; Eakin, D.E.; Jarrett, J.H.; Katayama, Y.B.; McKee, R.W.; Morgan, L.G.; Nealey, S.M.; Platt, A.M.; Tingey, G.L.

    1989-06-01

    Pacific Northwest Laboratory reviewed the projected uses and demands for a variety of nuclear byproducts. Because the major large-scale near-term demand is for gamma irradiation sources, this report concentrates on the needs for gamma sources and evaluates the options for providing the needed material. Projections of possible growth in the irradiation treatment industry indicate that there will be a need for 180 to 320 MCi of /sup 60/Co (including /sup 137/Cs equivalent) in service in the year 2000. The largest current and projected use of gamma irradiation is for the sterilization of medical devices and disposable medical supplies. Currently, 40% of US disposable medical products are treated by irradiation, and within 10 years it is expected that 90% will be treated in this manner. Irradiation treatment of food for destruction of pathogens or parasites, disinfestation, or extension of allowable storage periods is estimated to require an active inventory of 75 MCi of /sup 60/Co-equivalent gamma source in about a decade. 90 refs., 7 figs., 25 tabs.

  5. Hanford waste treatment plant Immobilized High Level Waste (IHLW) canister radiation dose rate and radiolytic heat load analysis

    SciTech Connect (OSTI)

    PIERSON, R.M.

    2003-09-02

    This document provides an analysis of anticipated radiation dose rates and heat loads for immobilized high level waste (IHW) canisters

  6. Vacuum - induced stationary entanglement in radiatively coupled three - level atoms

    E-Print Network [OSTI]

    L. Derkacz; L. Jakobczyk

    2008-05-05

    We consider a pair of three - level atoms interacting with a common vacuum and analyze the process of entanglement production due to spontaneous emission. We show that in the case of closely separated atoms, collective damping can generate robust entanglement of the asymptotic states.

  7. On the conversion of blast wave energy into radiation in active galactic nuclei and gamma-ray bursts

    E-Print Network [OSTI]

    Martin Pohl; Reinhard Schlickeiser

    1999-11-24

    It has been suggested that relativistic blast waves may power the jets of AGN and gamma-ray bursts (GRB). We address the important issue how the kinetic energy of collimated blast waves is converted into radiation. It is shown that swept-up ambient matter is quickly isotropised in the blast wave frame by a relativistic two-stream instability, which provides relativistic particles in the jet without invoking any acceleration process. The fate of the blast wave and the spectral evolution of the emission of the energetic particles is therefore solely determined by the initial conditions. We compare our model with existing multiwavelength data of AGN and find remarkable agreement.

  8. Radiation-Induced Carcinogenesis: Mechanistically Based Differences between Gamma-Rays and Neutrons, and

    E-Print Network [OSTI]

    Brenner, David Jonathan

    . For radiation doses which are sufficiently low to avoid substantial cell killing, sparsely ionizing radiation dose/dose rate. Sparsely ionizing radiation (e.g. c-rays) generally produces linear or upwardly curving dose responses at low doses, and the risk decreases when the dose rate is reduced (direct dose rate

  9. Activation of a c-K-ras oncogene by somatic mutation in mouse lymphomas induced by gamma radiation

    SciTech Connect (OSTI)

    Guerrero, I.; Villasante, A.; Corces, V.; Pellicer, A.

    1984-09-14

    Mouse tumors induced by gamma radiation are a useful model system for oncogenesis. DNA from such tumors contains an activated K-ras oncogene that can transform NIH 3T3 cells. This report describes the cloning of a fragment of the mouse K-ras oncogene containing the first exon from both a transformant in rat-2 cells and the brain of the same mouse that developed the tumor. Hybrid constructs containing one of the two pieces were made and only the plasmid including the first exon from the transformant gave rise to foci in NIH 3T3 cells. There was only a single base difference (G----A) in the exonic sequence, which changed glycine to aspartic acid in the transformant. By use of a synthetic oligonucleotide the presence of the mutation was demonstrated in the original tumor, ruling out modifications during DNA-mediated gene transfer and indicating that the alteration was present in the thymic lymphoma but absent from other nonmalignant tissue. The results are compatible with gamma radiation being a source of point mutations.

  10. Hand-held, mechanically cooled, radiation detection system for gamma-ray spectroscopy

    DOE Patents [OSTI]

    Burks, Morgan Thomas; Eckels, Joel Del

    2010-06-08

    In one embodiment, a radiation detection system is provided including a radiation detector and a first enclosure encapsulating the radiation detector, the first enclosure including a low-emissivity infra-red (IR) reflective coating used to thermally isolate the radiation detector. Additionally, a second enclosure encapsulating the first enclosure is included, the first enclosure being suspension mounted to the second enclosure. Further, a cooler capable of cooling the radiation detector is included. Still yet, a first cooling interface positioned on the second enclosure is included for coupling the cooler and the first enclosure. Furthermore, a second cooling interface positioned on the second enclosure and capable of coupling the first enclosure to a cooler separate from the radiation detection system is included. Other embodiments are also presented.

  11. Photon statistics of radiation in an incoherently pumped three-level cascade system

    E-Print Network [OSTI]

    Ahmed, Shaik; Singh, Suneel; Lakshmi, P Anantha

    2014-01-01

    We study the intensity-intensity correlations of the radiation emitted on probe transition in a three level cascade electromagnetically induced transparency (EIT) scheme. By applying an incoherent pump, we also monitor further changes in the characteristics of the emitted radiation. It is found that application of even a very weak incoherent pump can significantly alter the characteristics of the emitted radiation, even though the EIT characteristics remain unaltered. Our study demonstrates that for certain range of parameter values, the two photon correlation function in the probe transition oscillates between classical and non-classical domains.

  12. Photon statistics of radiation in an incoherently pumped three-level cascade system

    E-Print Network [OSTI]

    Shaik Ahmed; Preethi N. Wasnik; Suneel Singh; P. Anantha Lakshmi

    2014-09-03

    We study the intensity-intensity correlations of the radiation emitted on probe transition in a three level cascade electromagnetically induced transparency (EIT) scheme. By applying an incoherent pump, we also monitor further changes in the characteristics of the emitted radiation. It is found that application of even a very weak incoherent pump can significantly alter the characteristics of the emitted radiation, even though the EIT characteristics remain unaltered. Our study demonstrates that for certain range of parameter values, the two photon correlation function in the probe transition oscillates between classical and non-classical domains.

  13. Strategy to detect the gravitational radiation counterpart of gamma-ray bursts

    E-Print Network [OSTI]

    S. Bonazzola; E. Gourgoulhon

    1998-01-20

    Both observational and theoretical rates of binary neutron star coalescence give low prospects for detection of a single event by the initial LIGO/VIRGO interferometers. However, by utilizing at the best all the a priori information on the expected signal, a positive detection can be achieved. This relies on the hypothesis that $\\gamma$-ray bursts are the electromagnetic signature of neutron star coalescences. The information about the direction of the source can then be used to add in phase the signals from different detectors in order (i) to increase the signal-to-noise ratio and (ii) to make the noise more Gaussian. Besides, the information about the time of arrival can be used to drastically decrease the observation time and thereby the false alarm rate. Moreover the fluence of the $\\gamma$-ray emission gives some information about the amplitude of the gravitational signal. One can then add the signals from $\\sim 10^4$ observation boxes ($\\sim$ number of $\\gamma$-ray bursts during 10 years) to yield a positive detection. Such a detection, based on the Maximum a Posteriori Probability Criterium, is a minimal one, in the sense that no information on the position and time of the events, nor on any parameter of the model, is collected. The advantage is that this detection requires an improvement of the detector sensitivity by a factor of only $\\sim 1.5$ with respect to the initial LIGO/VIRGO interferometers, and that, if positive, it will confirm the $\\gamma$-ray burst model.

  14. Effects of High Dietary Iron and Gamma Radiation on Oxidative Stress and Bone 

    E-Print Network [OSTI]

    Yuen, Evelyn P

    2013-04-19

    Astronauts in space flight missions are exposed to increased iron (Fe) stores and galactic cosmic radiation, both of which independently induce oxidative stress. Oxidative stress can result in protein, lipid, and DNA oxidation. Recent evidence has...

  15. Handheld CZT radiation detector

    DOE Patents [OSTI]

    Murray, William S.; Butterfield, Kenneth B.; Baird, William

    2004-08-24

    A handheld CZT radiation detector having a CZT gamma-ray sensor, a multichannel analyzer, a fuzzy-logic component, and a display component is disclosed. The CZT gamma-ray sensor may be a coplanar grid CZT gamma-ray sensor, which provides high-quality gamma-ray analysis at a wide range of operating temperatures. The multichannel analyzer categorizes pulses produce by the CZT gamma-ray sensor into channels (discrete energy levels), resulting in pulse height data. The fuzzy-logic component analyzes the pulse height data and produces a ranked listing of radioisotopes. The fuzzy-logic component is flexible and well-suited to in-field analysis of radioisotopes. The display component may be a personal data assistant, which provides a user-friendly method of interacting with the detector. In addition, the radiation detector may be equipped with a neutron sensor to provide an enhanced mechanism of sensing radioactive materials.

  16. Sub-photospheric, radiation-mediated shocks in gamma-ray bursts: Multiple shock emission and the band spectrum

    SciTech Connect (OSTI)

    Keren, Shai; Levinson, Amir, E-mail: Levinson@wise.tau.ac.il [School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)

    2014-07-10

    We compute the time-integrated, thermal emission produced by a series of radiation-mediated shocks that emerge from the photosphere of a gamma-ray burst outflow. We show that for a sufficiently broad distribution of shock strengths, the overall shape of the time-integrated spectral energy distribution below the peak is a power law, ?E{sub ?}??{sup ?}, with a slope of 1 < ? < 2. A substructure in the spectral energy distribution (SED) can also be produced in this model for certain choices of the shock train distribution. In particular, we demonstrate that our model can reproduce the double-peak SED observed in some bursts, in events where a strong shock is followed by a sequence of sufficiently weaker ones.

  17. A kinetic model of tumor growth and its radiation response with an application to Gamma Knife stereotactic radiosurgery

    E-Print Network [OSTI]

    Watanabe, Yoichi; Leder, Kevin Z; Hui, Susanta K

    2015-01-01

    We developed a mathematical model to simulate the growth of tumor volume and its response to a single fraction of high dose irradiation. We made several key assumptions of the model. Tumor volume is composed of proliferating (or dividing) cancer cells and non-dividing (or dead) cells. Tumor growth rate (or tumor volume doubling time, Td) is proportional to the ratio of the volumes of tumor vasculature and the tumor. The vascular volume grows slower than the tumor by introducing the vascular growth retardation factor, theta. Upon irradiation the proliferating cells gradually die over a fixed time period after irradiation. Dead cells are cleared away with cell clearance time, Tcl. The model was applied to simulate pre-treatment growth and post-treatment radiation response of rat rhabdomyosarcoma tumor and metastatic brain tumors of five patients who were treated by Gamma Knife stereotactic radiosurgery (GKSRS). By selecting appropriate model parameters, we showed the temporal variation of the tumors for both th...

  18. Determination and Mitigation of Precipitation Effects on Portal Monitor Gamma Background Levels 

    E-Print Network [OSTI]

    Revis, Stephen

    2012-07-16

    apart, as seen in Fig. 1. Each of these columns contains two 3He neutron detector units and two Polyvinyl Toluene (PVT) plastic scintillator gamma ray detection units. The 3He detector units consist of two 3He tubes encased in a white polyethylene... moderator, while the PVT detector units consist of a single, large rectangular prism of PVT, which is covered in black plastic to prevent ordinary visible light from affecting the detector. In Fig. 2, the PVT detector unit can be seen on the lower left...

  19. Effect of gamma radiation on selected functional and physical properties of liquid egg white 

    E-Print Network [OSTI]

    Ball, Hershell Ray

    1966-01-01

    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o 14 4 The relative protein composition of egg white (Warner, 1954 ) . . . . . . . . . . . . . . . ~ . . . . . . . . . . . ~ 22 5 Analysis of variance for beating time . . ~. . . . . . . . 30 6 Multiple regression analysis of beating time... . . . . . . . . . . . . . . . . . . . . , . . 42 5 Illustration of textural difference &. . . . . . . . . . . 46 6 Typical electrophoretic patterns obtained . . . . . . 76 C HL PTER I GENERA L CONSIDERATIONS Introduction The use of ionizing radiation in the processing of foods has been...

  20. Energy levels and radiative rates for transitions in Cr-like Co IV and Ni V

    E-Print Network [OSTI]

    Aggarwal, K M; Karpuškien?, R; Keenan, F P; Kisielius, R; Stancalie, V

    2015-01-01

    We report calculations of energy levels and radiative rates ($A$-values) for transitions in Cr-like Co IV and Ni V. The quasi-relativistic Hartree-Fock (QRHF) code is adopted for calculating the data although GRASP (general-purpose relativistic atomic structure package) and flexible atomic code (FAC) have also been employed for comparison purposes. No radiative rates are available in the literature to compare with our results, but our calculated energies are in close agreement with those compiled by NIST for a majority of the levels. However, there are discrepancies for a few levels of up to 3\\%. The $A$-values are listed for all significantly contributing E1, E2 and M1 transitions, and the corresponding lifetimes reported, although unfortunately no previous theoretical or experimental results exist to compare with our data.

  1. Gamma ray measurements with photoconductive detectors using a...

    Office of Scientific and Technical Information (OSTI)

    AND TECHNOLOGY; ARGON; BREMSSTRAHLUNG; DEUTERIUM; DIAMONDS; GALLIUM ARSENIDES; GAMMA DETECTION; GAMMA RADIATION; HYDROGEN; MEV RANGE; NEON; PHOTOCONDUCTORS; PHOTOMULTIPLIERS;...

  2. Low Dose Radiation Response Curves, Networks and Pathways in Human Lymphoblastoid Cells Exposed from 1 to 10 cGy of Acute Gamma Radiation

    E-Print Network [OSTI]

    Wyrobek, A. J.

    2011-01-01

    Low Dose Radiation Response Curves, Networks and Pathways inbrain response to low- dose radiation exposure involves245-257. G. Bauer, Low dose radiation and intercellular

  3. Low-level determination of plutonium by gamma and L x-ray spectroscopy

    SciTech Connect (OSTI)

    Nitsche, H.; Gatti, R.C.; Lee, S.C.

    1991-04-01

    we have developed an analytical method for detection of {sup 239}Pu in aqueous samples at concentrations as low as 10{sup {minus}10} M. This nuclear counting technique utilizes the uranium L X-rays, which follow the alpha decay of plutonium. Because L X-rays are specific for the element and not for the individual isotopes, the isotopic composition of the plutonium sample must be known. The counting efficiency in the 11--23 keV range is determined from a plutonium standard, and the concentration of the sample is then calculated from the L X-ray count and the isotopic composition. The total L X-ray count is corrected for possible contributions from other radionuclides present as impurities by measuring the low-energy gamma spectrum for each contaminant to establish specific photon/X-ray ratios. The ratios are important when {sup 241}Pu and {sup 242}Pu are measured, because the respective decay chain members produce non-U L X-rays. This new method can replace the use of labor-intensive radiochemical separation techniques and elaborate activation methods for analysis of {sup 239}Pu in aqueous samples. It is also applicable for assaying plutonium in liquid wastes that pose possible hazards to the environment.

  4. Studies in feed spoilage: prevention of spoilage in ground corn by gamma radiation 

    E-Print Network [OSTI]

    Webb, Billy Dean

    1959-01-01

    xespectively fox complete inactivation, 6 Number of Or anisms- Several studies have been carried out to determine the radiation dose requix'ed to sterilise a food when various concentrations of the spores were present. Kempep Gxaikoski, and Gillies (1954...) reported the dosage of gams- rays requiired to sterilize meat inoculated with vary- 19 *tt 1: P ftl tdi Bt. lt . 11 d 9 *qt d to sterilise the meat incxeased fx'om 2, 5 x 10 to 4. 0 x 10 rep as the con- 6 centration of spox'es of Glostridlum botulinum...

  5. Induction of mutations resistant to maize dwarf mosaic virus in Sorghum bicolor using gamma radiation 

    E-Print Network [OSTI]

    Pye, Quentin Niel

    1977-01-01

    sterilised seeds (50) from each treatment level (contml, 20, 35 and 50 krad. ) were placed on moist filter paper in sterile petri- dishes and maintained at a temperature of 23 C. The filter paper was kept moist. Germination counts. were taken 14 days after...

  6. Hubble diagrams of soft and hard radiation sources in the graviton background: to an apparent contradiction between supernova 1a and gamma-ray burst observations

    E-Print Network [OSTI]

    Michael A. Ivanov

    2007-01-10

    In the sea of super-strong interacting gravitons, non-forehead collisions with gravitons deflect photons, and this deflection may differ for soft and hard radiations. As a result, the Hubble diagram would not be a universal function and it will have a different view for such sources as supernovae in visible light and gamma-ray bursts. Observations of these two kinds are compared here with the limit cases of the Hubble diagram.

  7. Measured Radiation and Background Levels During Transmission of Megawatt Electron Beams Through Millimeter Apertures

    SciTech Connect (OSTI)

    Alarcon, Ricardo [Arizona State University, Glendale, AZ (United States); Balascuta, S. [Arizona State University, Glendale, AZ (United States); Benson, Stephen V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Bertozzi, William [Massachusetts Institute of Technology, Cambridge, MA (United States); Boyce, James R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Cowan, Ray [Massachusetts Institute of Technology, Cambridge, MA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Evtushenko, Pavel [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Fisher, P. [Massachusetts Institute of Technology, Cambridge, MA (United States); Ihloff, Ernest E. [Hampton University, Hampton, VA (United States); Kalantarians, Narbe [Hampton University, Hampton, VA (United States); Kelleher, Aidan Michael [Massachusetts Institute of Technology, Cambridge, MA (United States); Krossler, W. J. [William and Mary College, Williamsburg, VA (United States); Legg, Robert A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Long, Elena [University of New Hampshire, Durham, NH (United States); Milner, Richard [Massachusetts Institute of Technology, Cambridge, MA (United States); Neil, George R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Ou, Longwu [Massachusetts Institute of Technology, Cambridge, MA (United States); Schmookler, Barack Abraham [Massachusetts Institute of Technology, Cambridge, MA (United States); Tennant, Christopher D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Tschalar, C. [Massachusetts Institute of Technology, Cambridge, MA (United States); Williams, Gwyn P. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhang, Shukui [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2013-11-01

    We report measurements of photon and neutron radiation levels observed while transmitting a 0.43 MW electron beam through millimeter-sized apertures and during beam-off, but accelerating gradient RF-on, operation. These measurements were conducted at the Free-Electron Laser (FEL) facility of the Jefferson National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an energy-recovery linear accelerator. The beam was directed successively through 6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a maximum current of 4.3 mA (430 kW beam power). This study was conducted to characterize radiation levels for experiments that need to operate in this environment, such as the proposed DarkLight Experiment. We find that sustained transmission of a 430 kW continuous-wave (CW) beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, multipactoring inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation when the machine is tuned for 130 MeV operation.

  8. Calculation of the total gamma-spectra of the fast neutrons capture in the isotopes 117,119Sn for the different parameters of cascade gamma-decay

    E-Print Network [OSTI]

    A. M. Sukhovoj; V. A. Khitrov

    2008-09-15

    The gamma-spectra were calculated for the set of different level densities and radiative strength functions. The sufficiently precise reproduction of the experiment is impossible without taking into account the influence of the process of the nucleons Cooper pairs breaking on any nuclei cascade gamma-decay parameters.

  9. Influence of irradiation with {gamma}-ray photons on the photoluminescence of Cd{sub 0.9}Zn{sub 0.1}Te crystals preliminarily subjected to the intense radiation of a neodymium laser

    SciTech Connect (OSTI)

    Glinchuk, K. D.; Medvid', A. P.; Mychko, A. M.; Naseka, Yu. M.; Prokhorovich, A. V.; Strilchuk, O. M.

    2013-04-15

    The effect of the preliminary treatment of Cd{sub 0.9}Zn{sub 0.1}Te crystals with high-power pulses of neodymium laser radiation (the power density is {<=}1.8 MW/cm{sup 2}, at a wavelength of 532 nm) on the low-temperature (5 K) photoluminescence induced by {gamma}-ray radiation (the dose was {Phi}{sub {gamma}} = 5 kGy) is studied. The luminescence bands are related to radiation-stimulated donor-acceptor pairs, which include shallow neutral donors and neutral cadmium vacancies stimulated by {gamma}-ray irradiation, the transition of free electrons to neutral cadmium vacancies formed by radiation, and the annihilation of excitons bound to the above vacancies. It is shown that, in the crystals preliminarily treated with laser radiation, the intensity of the {gamma}-ray-stimulated luminescence bands is significantly lower than in crystals not subjected to laser radiation. This fact is accounted for by a decrease in the concentration of cadmium vacancies generated by the {gamma}-ray radiation as a result of their annihilation during the course of their interaction with laser-stimulated defects, in particular, as a consequence of their recombination at laser-stimulated interstitial cadmium atoms.

  10. Radiative lifetime and energy of the low-energy isomeric level in $^{229}$Th

    E-Print Network [OSTI]

    Tkalya, E V; Jeet, Justin; Hudson, Eric R

    2015-01-01

    We estimate the range of the radiative lifetime and energy of the anomalous, low-energy $3/2^+(7.8 \\pm 0.5$ eV) state in the $^{229}$Th nucleus. Our phenomenological calculations are based on the available experimental data for the intensities of $M1$ and $E2$ transitions between excited levels of the $^{229}$Th nucleus in the $K^{\\pi}[Nn_Z\\Lambda]=5/2^+[633]$ and $3/2^+[631]$ rotational bands. We also discuss the influence of certain branching coefficients, which affect the currently accepted measured energy of the isomeric state. From this work, we establish a favored region where the transition lifetime and energy should lie at roughly the 90% confidence level. We also suggest new nuclear physics measurements, which would significantly reduce the ambiguity in the present data.

  11. THE BEIR-III REPORT AND THE HEALTH EFFECTS OF LOW-LEVEL RADIATION

    E-Print Network [OSTI]

    Fabrikant, J.I.

    2010-01-01

    the body exposed to very low radiation doses and dose rates.carcinogenic risk of low-dose, low-LET radiation is subjectbe made for low- dose, low-LET radiation. It is for these

  12. THE HEALTH EFFECTS IN WOMEN EXPOSED TO LOW-LEVELS OF IONIZING RADIATION

    E-Print Network [OSTI]

    Fabrikant, J.I.

    2010-01-01

    cancer following low-dose radiation exposure. Radiology 131:is the matter of low-dose radiation and the pregnant woman.considered incorrect; low-dose radiation can cause cancer,

  13. Symmetry Adapted Coherent States for Three-Level Atoms Interacting with One-Mode Radiation

    E-Print Network [OSTI]

    R. López-Peña; S. Cordero; E. Nahmad-Achar; O. Castaños

    2015-10-21

    We introduce a combination of coherent states as variational test functions for the atomic and radiation sectors to describe a system of Na three- level atoms interacting with a one-mode quantised electromagnetic field, with and without the rotating wave approximation, which preserves the symmetry presented by the Hamiltonian. These provide us with the possibility of finding analytical solutions for the ground and first excited states. We study the properties of these solutions for the V-configuration in the double resonance condition, and calculate the expectation values of the number of photons, the atomic populations, the total number of excitations, and their corresponding fluctuations. We also calculate the photon number distribution and the linear entropy of the reduced density matrix to estimate the entanglement between matter and radiation. For the first time, we exhibit analytical expressions for all of these quantities, as well as an analytical description for the phase diagram in parameter space, which distinguishes the normal and collective regions, and which gives us all the quantum phase transitions of the ground state from one region to the other as we vary the interaction parameters (the matter-field coupling constants) of the model, in functional form.

  14. Radiative Heating of the ISCCP Upper Level Cloud Regimes and its Impact on the Large-scale Tropical Circulation

    SciTech Connect (OSTI)

    Li, Wei; Schumacher, Courtney; McFarlane, Sally A.

    2013-01-31

    Radiative heating profiles of the International Satellite Cloud Climatology Project (ISCCP) cloud regimes (or weather states) were estimated by matching ISCCP observations with radiative properties derived from cloud radar and lidar measurements from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) sites at Manus, Papua New Guinea, and Darwin, Australia. Focus was placed on the ISCCP cloud regimes containing the majority of upper level clouds in the tropics, i.e., mesoscale convective systems (MCSs), deep cumulonimbus with cirrus, mixed shallow and deep convection, and thin cirrus. At upper levels, these regimes have average maximum cloud occurrences ranging from 30% to 55% near 12 km with variations depending on the location and cloud regime. The resulting radiative heating profiles have maxima of approximately 1 K/day near 12 km, with equal heating contributions from the longwave and shortwave components. Upper level minima occur near 15 km, with the MCS regime showing the strongest cooling of 0.2 K/day and the thin cirrus showing no cooling. The gradient of upper level heating ranges from 0.2 to 0.4 K/(day?km), with the most convectively active regimes (i.e., MCSs and deep cumulonimbus with cirrus) having the largest gradient. When the above heating profiles were applied to the 25-year ISCCP data set, the tropics-wide average profile has a radiative heating maximum of 0.45Kday-1 near 250 hPa. Column-integrated radiative heating of upper level cloud accounts for about 20% of the latent heating estimated by the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). The ISCCP radiative heating of tropical upper level cloud only slightly modifies the response of an idealized primitive equation model forced with the tropics-wide TRMM PR latent heating, which suggests that the impact of upper level cloud is more important to large-scale tropical circulation variations because of convective feedbacks rather than direct forcing by the cloud radiative heating profiles. However, the height of the radiative heating maxima and gradient of the heating profiles are important to determine the sign and patterns of the horizontal circulation anomaly driven by radiative heating at upper levels.

  15. Miniaturized radiation chirper

    DOE Patents [OSTI]

    Umbarger, C. John (Los Alamos, NM); Wolf, Michael A. (Los Alamos, NM)

    1980-01-01

    The disclosure relates to a miniaturized radiation chirper for use with a small battery supplying on the order of 5 volts. A poor quality CdTe crystal which is not necessarily suitable for high resolution gamma ray spectroscopy is incorporated with appropriate electronics so that the chirper emits an audible noise at a rate that is proportional to radiation exposure level. The chirper is intended to serve as a personnel radiation warning device that utilizes new and novel electronics with a novel detector, a CdTe crystal. The resultant device is much smaller and has much longer battery life than existing chirpers.

  16. Level Crossing Analysis of Cosmic Microwave Background Radiation: A method for detecting cosmic strings

    E-Print Network [OSTI]

    M. Sadegh Movahed; Shahram Khosravi

    2011-03-01

    In this paper we study the footprint of cosmic string as the topological defects in the very early universe on the cosmic microwave background radiation. We develop the method of level crossing analysis in the context of the well-known Kaiser-Stebbins phenomenon for exploring the signature of cosmic strings. We simulate a Gaussian map by using the best fit parameter given by WMAP-7 and then superimpose cosmic strings effects on it as an incoherent and active fluctuations. In order to investigate the capability of our method to detect the cosmic strings for the various values of tension, $G\\mu$, a simulated pure Gaussian map is compared with that of including cosmic strings. Based on the level crossing analysis, the superimposed cosmic string with $G\\mu\\gtrsim 4\\times 10^{-9}$ in the simulated map without instrumental noise and the resolution $R=1'$ could be detected. In the presence of anticipated instrumental noise the lower bound increases just up to $G\\mu\\gtrsim 5.8\\times 10^{-9}$.

  17. RADIATION MECHANISM AND JET COMPOSITION OF GAMMA-RAY BURSTS AND GeV-TeV-SELECTED RADIO-LOUD ACTIVE GALACTIC NUCLEI

    SciTech Connect (OSTI)

    Zhang Jin; Lu Ye; Zhang Shuangnan; Liang Enwei; Sun Xiaona; Zhang Bing

    2013-09-01

    Gamma-ray bursts (GRBs) and GeV-TeV-selected radio-loud active galactic nuclei (AGNs) are compared based on our systematic modeling of the observed spectral energy distributions of a sample of AGNs with a single-zone leptonic model. We show that the correlation between the jet power (P{sub jet}) and the prompt gamma-ray luminosity (L{sub jet}) of GRBs is consistent, within the uncertainties, with the correlation between jet power and the synchrotron peak luminosity (L{sub s,jet}) of flat spectrum radio quasars (FSRQs). Their radiation efficiencies ({epsilon}) are also comparable (>10% for most sources), which increase with the bolometric jet luminosity (L{sub bol,jet}) for FSRQs and with the L{sub jet} for GRBs with similar power-law indices. BL Lac objects (BL Lacs) do not follow the P{sub jet}-L{sub s,jet} relation of FSRQs. They have lower {epsilon} and L{sub bol,jet} values than FSRQs, and a tentative L{sub bol,jet}-{epsilon} relation is also found, with a power-law index different from that of the FSRQs. The magnetization parameters ({sigma}) of FSRQs are on average larger than that of BL Lacs. They are anti-correlated with {epsilon} for the FSRQs, but positively correlated with {epsilon} for the BL Lacs. GeV narrow-line Seyfert 1 galaxies potentially share similar properties with FSRQs. Based on the analogy between GRBs and FSRQs, we suggest that the prompt gamma-ray emission of GRBs is likely produced by the synchrotron process in a magnetized jet with high radiation efficiency, similar to FSRQs. The jets of BL Lacs, on the other hand, are less efficient and are likely more matter-dominated.

  18. Electroreflectance study of the effect of {gamma} radiation on the optical properties of epitaxial GaN films

    SciTech Connect (OSTI)

    Belyaev, A. E.; Klyui, N. I. Konakova, R. V.; Lukyanov, A. N.; Danilchenko, B. A.; Sveshnikov, J. N.; Klyui, A. N.

    2012-03-15

    Experimental data on the electroreflectance spectra of {gamma}-irradiated epitaxial GaN films on sapphire are reported. The irradiation doses are 10{sup 5}-2 Multiplication-Sign 10{sup 6} rad. The theoretical electroreflectance spectra calculated on the basis of a model of three types of transitions are in agreement with experimental data with reasonable accuracy. The energies and broadenings of the transitions derived in the context of the model give grounds to infer that, in the GaN films, there are internal stresses dependent on the {gamma}-irradiation dose.

  19. Cold neutron prompt gamma activation analysis, a non-destructive technique for hydrogen level assessment in zirconium alloys

    E-Print Network [OSTI]

    Motta, Arthur T.

    assessment in zirconium alloys Adrien Couet a, , Arthur T. Motta a , Robert J. Comstock b , Rick L. Paul c to quantitatively assess hydrogen concentration in zirconium alloys. The technique, called Cold Neutron Prompt Gamma. Introduction With increased burnups and longer life times in nuclear reac- tors, uniform corrosion of zirconium

  20. Electrode level Monte Carlo model of radiation damage effects on astronomical CCDs

    E-Print Network [OSTI]

    Prod'homme, T; Lindegren, L; Short, A D T; Brown, S W

    2011-01-01

    Current optical space telescopes rely upon silicon Charge Coupled Devices (CCDs) to detect and image the incoming photons. The performance of a CCD detector depends on its ability to transfer electrons through the silicon efficiently, so that the signal from every pixel may be read out through a single amplifier. This process of electron transfer is highly susceptible to the effects of solar proton damage (or non-ionizing radiation damage). This is because charged particles passing through the CCD displace silicon atoms, introducing energy levels into the semi-conductor bandgap which act as localized electron traps. The reduction in Charge Transfer Efficiency (CTE) leads to signal loss and image smearing. The European Space Agency's astrometric Gaia mission will make extensive use of CCDs to create the most complete and accurate stereoscopic map to date of the Milky Way. In the context of the Gaia mission CTE is referred to with the complementary quantity Charge Transfer Inefficiency (CTI = 1-CTE). CTI is an ...

  1. Semiquantitative Analysis Using Thallium-201 SPECT for Differential Diagnosis Between Tumor Recurrence and Radiation Necrosis After Gamma Knife Surgery for Malignant Brain Tumors

    SciTech Connect (OSTI)

    Matsunaga, Shigeo; Shuto, Takashi; Takase, Hajime; Ohtake, Makoto; Tomura, Nagatsuki; Tanaka, Takahiro; Sonoda, Masaki

    2013-01-01

    Purpose: Semiquantitative analysis of thallium-201 chloride single photon emission computed tomography ({sup 201}Tl SPECT) was evaluated for the discrimination between recurrent brain tumor and delayed radiation necrosis after gamma knife surgery (GKS) for metastatic brain tumors and high-grade gliomas. Methods and Materials: The medical records were reviewed of 75 patients, including 48 patients with metastatic brain tumor and 27 patients with high-grade glioma who underwent GKS in our institution, and had suspected tumor recurrence or radiation necrosis on follow-up neuroimaging and deteriorating clinical status after GKS. Analysis of {sup 201}Tl SPECT data used the early ratio (ER) and the delayed ratio (DR) calculated as tumor/normal average counts on the early and delayed images, and the retention index (RI) as the ratio of DR to ER. Results: A total of 107 tumors were analyzed with {sup 201}Tl SPECT. Nineteen lesions were removed surgically and histological diagnoses established, and the other lesions were evaluated with follow-up clinical and neuroimaging examinations after GKS. The final diagnosis was considered to be recurrent tumor in 65 lesions and radiation necrosis in 42 lesions. Semiquantitative analysis demonstrated significant differences in DR (P=.002) and RI (P<.0001), but not in ER (P=.372), between the tumor recurrence and radiation necrosis groups, and no significant differences between metastatic brain tumors and high-grade gliomas in all indices (P=.926 for ER, P=.263 for DR, and P=.826 for RI). Receiver operating characteristics analysis indicated that RI was the most informative index with the optimum threshold of 0.775, which provided 82.8% sensitivity, 83.7% specificity, and 82.8% accuracy. Conclusions: Semiquantitative analysis of {sup 201}Tl SPECT provides useful information for the differentiation between tumor recurrence and radiation necrosis in metastatic brain tumors and high-grade gliomas after GKS, and the RI may be the most valuable index for this purpose.

  2. Radiation from Small-Scale Magnetic Field Turbulence: Implications for Gamma-Ray Bursts and Laboratory Astrophysical Plasmas

    E-Print Network [OSTI]

    Reynolds, Sarah J

    2012-05-31

    Relativistic charged particles moving within regions of small-scale magnetic field turbulence radiate as they undergo transverse accelerations reflective of the magnetic field variation along the particle's path. For a ...

  3. THE IMPACT OF THE 1980 BEIR-III REPORT ON LOW-LEVEL RADIATION RISK ASSESSMENT, RADIATION PROTECTION GUIDES, AND PUBLIC HEALTH POLICY

    E-Print Network [OSTI]

    Fabrikant, J.I.

    2010-01-01

    National Council on Radiation Protection and Measurements.of the Current State of Radiation Protection Philosophy.National Council on Radiation Protection and Measurements.

  4. Perspective of monochromatic gamma-ray line detection with the High Energy cosmic-Radiation Detection (HERD) facility onboard China's Space Station

    E-Print Network [OSTI]

    Huang, Xiaoyuan; Tsai, Yue-Lin Sming; Xu, Ming; Yuan, Qiang; Chang, Jin; Dong, Yong-Wei; Hu, Bing-Liang; Lü, Jun-Guang; Wang, Le; Wu, Bo-Bing; Zhang, Shuang-Nan

    2015-01-01

    HERD is the High Energy cosmic-Radiation Detection instrument proposed to operate onboard China's space station in the 2020s. It is designed to detect energetic cosmic ray nuclei, leptons and photons with a high energy resolution ($\\sim1\\%$ for electrons and photons and $20\\%$ for nuclei) and a large geometry factor ($>3\\, m^2sr$ for electrons and diffuse photons and $>2\\, m^2sr$ for nuclei). In this work we discuss the capability of HERD to detect monochromatic $\\gamma$-ray lines, based on simulations of the detector performance. It is shown that HERD will be one of the most sensitive instruments for monochromatic $\\gamma$-ray searches at energies between $\\sim10$ to a few hundred GeV. Above hundreds of GeV, Cherenkov telescopes will be more sensitive due to their large effective area. As a specific example, we show that a good portion of the parameter space of a supersymmetric dark matter model can be probed with HERD.

  5. Gamma ray bursts ROBERT S MACKAY

    E-Print Network [OSTI]

    Rourke, Colin

    Gamma ray bursts ROBERT S MACKAY COLIN ROURKE We propose that a gamma ray burst is a kinematic Gamma ray bursts are intense flashes of electromagnetic radiation of cosmic origin lasting from ten accepted mechanism. We propose that a gamma ray burst is simply a kinematic effect, namely the effect

  6. Search for Invisible Decays of a Light Scalar in Radiative Transitions Y(3S)->gamma A0

    SciTech Connect (OSTI)

    Aubert, B

    2008-11-05

    We search for a light scalar particle produced in single-photon decays of the {Upsilon}(3S) resonance through the process {Upsilon}(3S) {yields} {gamma} + A{sup 0}, A{sup 0} {yields} invisible. Such an object appears in Next-to-Minimal Supersymmetric extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. If, in addition, there exists a light, stable neutralino, decays of A{sup 0} could be preferentially to an invisible final state. We search for events with a single high-energy photon and a large missing mass, consistent with a 2-body decay of {Upsilon}(3S). We find no evidence for such processes in a sample of 122 x 10{sup 6} {Upsilon}(3S) decays collected by the BABAR collaboration at the PEP-II B-factory, and set 90% C.L. upper limits on the branching fraction {Beta}({Upsilon}(3S) {yields} {gamma}A{sup 0}) x {Beta}(A{sup 0} {yields} invisible) at (0.7-31) x 10{sup -6} in the mass range m{sub A{sup 0}} {le} 7.8 GeV. The results are preliminary.

  7. Low Dose Radiation Response Curves, Networks and Pathways in Human Lymphoblastoid Cells Exposed from 1 to 10 cGy of Acute Gamma Radiation

    SciTech Connect (OSTI)

    Wyrobek, A. J.; Manohar, C. F.; Nelson, D. O.; Furtado, M. R.; Bhattacharya, M. S.; Marchetti, F.; Coleman, M.A.

    2011-04-18

    We investigated the low dose dependency of the transcriptional response of human cells to characterize the shape and biological functions associated with the dose response curve and to identify common and conserved functions of low dose expressed genes across cells and tissues. Human lymphoblastoid (HL) cells from two unrelated individuals were exposed to graded doses of radiation spanning the range of 1-10 cGy were analyzed by transcriptome profiling, qPCR and bioinformatics, in comparison to sham irradiated samples. A set of {approx}80 genes showed consistent responses in both cell lines; these genes were associated with homeostasis mechanisms (e.g., membrane signaling, molecule transport), subcellular locations (e.g., Golgi, and endoplasmic reticulum), and involved diverse signal transduction pathways. The majority of radiation-modulated genes had plateau-like responses across 1-10 cGy, some with suggestive evidence that transcription was modulated at doses below 1 cGy. MYC, FOS and TP53 were the major network nodes of the low-dose response in HL cells. Comparison our low dose expression findings in HL cells with those of prior studies in mouse brain after whole body exposure, in human keratinocyte cultures, and in endothelial cells cultures, indicates that certain components of the low dose radiation response are broadly conserved across cell types and tissues, independent of proliferation status.

  8. System level latchup mitigation for single event and transient radiation effects on electronics

    DOE Patents [OSTI]

    Kimbrough, Joseph Robert (Pleasanton, CA); Colella, Nicholas John (Livermore, CA)

    1997-01-01

    A "blink" technique, analogous to a person blinking at a flash of bright light, is provided for mitigating the effects of single event current latchup and prompt pulse destructive radiation on a micro-electronic circuit. The system includes event detection circuitry, power dump logic circuitry, and energy limiting measures with autonomous recovery. The event detection circuitry includes ionizing radiation pulse detection means for detecting a pulse of ionizing radiation and for providing at an output terminal thereof a detection signal indicative of the detection of a pulse of ionizing radiation. The current sensing circuitry is coupled to the power bus for determining an occurrence of excess current through the power bus caused by ionizing radiation or by ion-induced destructive latchup of a semiconductor device. The power dump circuitry includes power dump logic circuitry having a first input terminal connected to the output terminal of the ionizing radiation pulse detection circuitry and having a second input terminal connected to the output terminal of the current sensing circuitry. The power dump logic circuitry provides an output signal to the input terminal of the circuitry for opening the power bus and the circuitry for shorting the power bus to a ground potential to remove power from the power bus. The energy limiting circuitry with autonomous recovery includes circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential. The circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential includes a series FET and a shunt FET. The invention provides for self-contained sensing for latchup, first removal of power to protect latched components, and autonomous recovery to enable transparent operation of other system elements.

  9. System level latchup mitigation for single event and transient radiation effects on electronics

    DOE Patents [OSTI]

    Kimbrough, J.R.; Colella, N.J.

    1997-09-30

    A ``blink`` technique, analogous to a person blinking at a flash of bright light, is provided for mitigating the effects of single event current latchup and prompt pulse destructive radiation on a micro-electronic circuit. The system includes event detection circuitry, power dump logic circuitry, and energy limiting measures with autonomous recovery. The event detection circuitry includes ionizing radiation pulse detection means for detecting a pulse of ionizing radiation and for providing at an output terminal thereof a detection signal indicative of the detection of a pulse of ionizing radiation. The current sensing circuitry is coupled to the power bus for determining an occurrence of excess current through the power bus caused by ionizing radiation or by ion-induced destructive latchup of a semiconductor device. The power dump circuitry includes power dump logic circuitry having a first input terminal connected to the output terminal of the ionizing radiation pulse detection circuitry and having a second input terminal connected to the output terminal of the current sensing circuitry. The power dump logic circuitry provides an output signal to the input terminal of the circuitry for opening the power bus and the circuitry for shorting the power bus to a ground potential to remove power from the power bus. The energy limiting circuitry with autonomous recovery includes circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential. The circuitry for opening the power bus and circuitry for shorting the power bus to a ground potential includes a series FET and a shunt FET. The invention provides for self-contained sensing for latchup, first removal of power to protect latched components, and autonomous recovery to enable transparent operation of other system elements. 18 figs.

  10. HELLE: Health Effects of Low Level Exposures/ Gezondheidseffecten van lage blootstellingniveaus [International workshop: Influence of low level exposures to chemicals and radiation on human and ecological health

    SciTech Connect (OSTI)

    Schoten, Eert

    1998-11-26

    The Health Council is closely involved in establishing the scientific foundation of exposure limits for substances and radiation in order to protect public health. Through the years, the Council has contributed to the formulation of principles and procedures, both for carcinogenic and for noncarcinogenic agents. As a rule, the discussion with regard to the derivation of health-based recommended exposure limits centers around the appropriateness of extrapolation methods (What can be inferred from data on high exposure levels and on experimental animals?). Generally speaking, there is a lack of direct information on the health effects of low levels of exposure. Effects at these levels cannot usually be detected by means of traditional animal experiments or epidemiological research. The capacity of these analytical instruments to distinguish between ''signal'' and ''noise'' is inadequate in most cases. Annex B of this report contains a brief outline of the difficulties and the established methods for tackling this problem. In spite of this, the hope exists that the posited weak signals, if they are indeed present, can be detected by other means. The search will have to take place on a deeper level. In other words, effort must be made to discover what occurs at underlying levels of biological organization when organisms are exposed to low doses of radiation or substances. Molecular and cell biology provide various methods and techniques which give an insight into the processes within the cell. This results in an increase in the knowledge about the molecular and cellular effects of exposure to agents, or stated differently, the working mechanisms which form the basis of the health effects. Last year, the Health Council considered that the time was ripe to take stock of the state of knowledge in this field. To this end, an international working conference was held from 19 to 21 October 1997, entitled ''Health Effects of Low Level Exposures: Scientific Developments and Perspectives for Risk Assessment''. The central question was the extent to which the sometimes fast-growing knowledge about molecular and cellular effects offers the desired basis for extrapolation. Against this setting, a number of more specific questions which have been hotly debated for some time were also addressed. One of the primary questions concerned the traditional but increasingly questioned division between stochastic and non-stochastic working agents, and the corresponding division between exposure-effect relations without a threshold and with a threshold. Thoughts were also exchanged on what is often referred to as hormesis: the notion that low levels of exposure could actually improve health. For the purpose of illuminating the many aspects of these issues, experts from a number of areas were invited. In addition to this, three agents were selected to serve as points of crystallization for the general debate: ionizing radiation, ultraviolet (UV) radiation and dioxins. The present report calls attention to a selection of issues which emerged during the discussions on the above-mentioned central topic. Various more detailed questions and the wider context of the points considered are described at greater length in the enclosed conference report and in the background documents attached to the report. What follows is a series of considerations regarding the scientific basis for the derivation of recommended exposure levels, viewed in the light of current procedures and against the background of the work of the Health Council. In the preparation of the following comments and recommendations, various Dutch experts have been consulted.

  11. Distributions of gamma-ray bursts and blazars in the L {sub p}-E {sub p}-plane and possible implications for their radiation physics

    SciTech Connect (OSTI)

    Lyu, Fen; Liang, En-Wei; Liang, Yun-Feng; Sun, Xiao-Na; Lu, Rui-Jing; Zhang, Bing [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning 530004 (China); Wu, Xue-Feng [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Zhang, Jin, E-mail: lew@gxu.edu.cn, E-mail: xfwu@pmo.ac.cn, E-mail: zhang@physics.unlv.edu [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2014-09-20

    We present a spectral analysis for a sample of redshift-known gamma-ray bursts (GRBs) observed with Fermi/GBM. Together with the results derived from our systematical spectral energy distribution modeling with the leptonic models for a Fermi/LAT blazar sample, we compare the distributions of the GRBs and the blazars by plotting the synchrotron peak luminosity (L {sub s}) and the corresponding peak photon energy E {sub s} of blazars in the L {sub p}-E {sub p}-plane of GRBs, where L {sub p} and E {sub p} are the peak luminosity and peak photon energy of the GRB time-integrated ?f {sub ?} spectrum, respectively. The GRBs are in the high-L {sub p}, high-E {sub p} corner of the plane and a tight L {sub p}-E {sub p} relation is found, i.e., L{sub p}?E{sub p}{sup 2.13{sub ?}{sub 0}{sub .}{sub 4}{sub 6}{sup +{sup 0{sup .{sup 5{sup 4}}}}}}. Both flat spectrum radio quasars (FSRQs) and low-synchrotron peaking BL Lac objects (LBLs) are clustered in the low-E {sub p}, low-L {sub p} corner. Intermediate- and high-synchrotron peaking BL Lac objects (IBLs and HBLs) have E {sub s} ? 2 × 10{sup –3}-10{sup 2} keV and L {sub s} ? 10{sup 44}-10{sup 47} erg s{sup –1}, but no dependence of L {sub s} on E {sub s} is found. We show that the tight L{sub p} -E{sub p} relation of GRBs is potentially explained with the synchrotron radiation of fast-cooling electrons in a highly magnetized ejecta, and the weak anti-correlation of L {sub s}-E {sub s} for FSRQs and LBLs may be attributed to synchrotron radiation of slow-cooling electrons in a moderately magnetized ejecta. The distributions of IBLs and HBLs in the L {sub p}-E {sub p}-plane may be interpreted with synchrotron radiation of fast-cooling electrons in a matter-dominated ejecta. These results may present a unified picture for the radiation physics of relativistic jets in GRBs and blazars within the framework of the leptonic synchrotron radiation models.

  12. Multi-level effects of low dose rate ionizing radiation on southern toad, Anaxyrus [Bufo] terrestris

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stark, Karolina; Scott, David E.; Tsyusko, Olga; Coughlin, Daniel P.; Hinton, Thomas G.; Amendola, Roberto

    2015-04-30

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development –embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of ¹³?Cs at 0.13, 2.4, 21, and 222 mGy d?¹, resulting in total doses up to 15.8 Gy. Radiation treatments did notmore »affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21mGy d?¹ and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.« less

  13. Multi-level effects of low dose rate ionizing radiation on southern toad, Anaxyrus [Bufo] terrestris

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stark, Karolina [Stockholm Univ. (Sweden); Univ. of Georgia, Aiken, SC (United States); Scott, David E. [Univ. of Georgia, Aiken, SC (United States); Tsyusko, Olga [Univ. of Georgia, Aiken, SC (United States); Univ. of Kentucky, Lexington, KY (United States); Coughlin, Daniel P. [Univ. of Georgia, Aiken, SC (United States); Hinton, Thomas G. [Univ. of Georgia, Aiken, SC (United States); Inst. of Radiation Protection and Nuclear Safety, Cadarache (France); Amendola, Roberto [ENEA, (Italy)

    2015-04-30

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development –embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of ¹³?Cs at 0.13, 2.4, 21, and 222 mGy d?¹, resulting in total doses up to 15.8 Gy. Radiation treatments did not affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21mGy d?¹ and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.

  14. The Association between Cancers and Low Level Radiation: an evaluation of the epidemiological evidence at the Hanford Nuclear Weapons Facility

    E-Print Network [OSTI]

    Britton, Julie

    2010-01-01

    between leukemia and low dose radiation is critical evidenceassociations between low dose radiation and cancer might notrelationship exists with low dose radiation. In addition,

  15. Gamma Ray Pulsars: Observations

    E-Print Network [OSTI]

    David J. Thompson

    2001-01-03

    High-energy gamma rays are a valuable tool for studying particle acceleration and radiation in the magnetospheres of energetic pulsars. The six or more pulsars seen by CGRO/EGRET show that: the light curves usually have double-peak structures (suggesting a broad cone of emission); gamma rays are frequently the dominant component of the radiated power; and all the spectra show evidence of a high-energy turnover. Unless a new pulsed component appears at higher energies, progress in gamma-ray pulsar studies will be greatest in the 1-20 GeV range. Ground-based telescopes whose energy ranges extend downward toward 10 GeV should make important measurements of the spectral cutoffs. The Gamma-ray Large Area Space Telescope (GLAST), now in planning for a launch in 2005, will provide a major advance in sensitivity, energy range, and sky coverage.

  16. Simultaneous beta and gamma spectroscopy

    DOE Patents [OSTI]

    Farsoni, Abdollah T. (Corvallis, OR); Hamby, David M. (Corvallis, OR)

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  17. Assessment of Radio-Frequency Radiation Exposure Level from Selected Mobile Base Stations (MBS) in Lokoja, Kogi State, Nigeria

    E-Print Network [OSTI]

    Victor, U J Nwankwo; Dada, S S; Onugba, A A; Ushie, P

    2012-01-01

    The acquisition and use of mobile phone is tremendously increasing especially in developing countries, but not without a concern. The greater concern among the public is principally over the proximity of mobile base stations (MBS) to residential areas rather than the use of handsets. In this paper, we present an assessment of Radio-Frequency (RF) radiation exposure level measurements and analysis of radiation power density (in \\mu W/sq m) from mobile base stations relative to radial distance (in metre). The minimum average power density from individual base station in the town was about 47\\mu W/sq m while the average maximum was about 1.5mW/sq m. Our result showed that average power density of a base station decreases with increase in distance (from base station) and that radiation intensity varies from one base station to another even at the same distance away. Our result (obtained signature of power density variation) was also compared with the 'expected' signature. It was found that radiation from external...

  18. High Energy Positrons and Gamma Radiation from Decaying Constituents of a two-component Dark Atom Model

    E-Print Network [OSTI]

    K. Belotsky; M. Khlopov; C. Kouvaris; M. Laletin

    2015-08-12

    We study a two component dark matter candidate inspired by the Minimal Walking Technicolor model. Dark matter consists of a dominant SIMP-like dark atom component made of bound states between primordial helium nuclei and a doubly charged technilepton, and a small WIMP-like component made of another dark atom bound state between a doubly charged technibaryon and a technilepton. This scenario is consistent with direct search experimental findings because the dominant SIMP component interacts too strongly to reach the depths of current detectors with sufficient energy to recoil and the WIMP-like component is too small to cause significant amount of events. In this context a metastable technibaryon that decays to $e^+e^+$, $\\mu^+ \\mu^+$ and $\\tau^+ \\tau^+$ can in principle explain the observed positron excess by AMS-02 and PAMELA, while being consistent with the photon flux observed by FERMI/LAT. We scan the parameters of the model and we find the best possible fit to the latest experimental data. We find that there is a small range of parameter space that this scenario can be realised under certain conditions regarding the cosmic ray propagation and the final state radiation. This range of parameters fall inside the region where the current run of LHC can probe, and therefore it will soon be possible to either verify or exclude conclusively this model of dark matter.

  19. Health physics manual of good practices for reducing radiation exposure to levels that are as low as reasonably achievable (ALARA)

    SciTech Connect (OSTI)

    Herrington, W.N.; Higby, D.P.; Kathren,., R.L.; Merwin, S.E.; Stoetzel, G.A.

    1988-06-01

    A primary objective of the US Department of Energy (DOE) health physics and radiation protection program has been to limit radiation exposures to those levels that are as low as reasonably achievable (ALARA). As a result, the ALARA concept developed into a program and a set of operational principles to ensure that the objective was consistently met. Implementation of these principles required that a guide be produced. The original ALARA guide was issued by DOE in 1980 to promote improved understanding of ALARA concepts within the DOE community and to assist those responsible for operational ALARA activities in attaining their goals. Since 1980, additional guidance has been published by national and international organizations to provide further definition and clarification to ALARA concepts. As basic ALARA experience increased, the value and role of the original guide prompted the DOE Office of Nuclear Safety (ONS) to support a current revision. The revised manual of good practices includes six sections: 1.0 Introduction, 2.0 Administration, 3.0 Optimization, 4.0 Setting and Evaluating ALARA Goals, 5.0 Radiological Design, and 6.0 Conduct of Operations. The manual is directed primarily to contractor and DOE staff who are responsible for conduct and overview of radiation protection and ALARA programs at DOE facilities. The intent is to provide sufficient guidance such that the manual, if followed, will ensure that radiation exposures are maintained as low as reasonably achievable and will establish the basis for a formally structured and auditable program. 118 refs., 16 figs., 3 tabs.

  20. Measurement and Analysis of Radio-frequency Radiation Exposure Level from Different Mobile Base Transceiver Stations in Ajaokuta and Environs, Nigeria

    E-Print Network [OSTI]

    Ushie, P O; Bolaji, Ayinmode; Osahun, O D

    2013-01-01

    We present the result of a preliminary assessment of radio-frequency radiation exposure from selected mobile base stations in Ajaokuta environs. The Power density of RF radiation within a radial distance of 125m was measured. Although values fluctuated due to the influence of other factors, including wave interference from other electromagnetic sources around reference base stations, we show from analysis that radiation exposure level is below the standard limit (4.5W/sqm for 900MHz and 9W/sqm for 18000MHz) set by the International Commission on Non-ionizing Radiation Protection (ICNIRP) and other regulatory agencies.

  1. Gamma ray camera

    DOE Patents [OSTI]

    Perez-Mendez, Victor (Berkeley, CA)

    1997-01-01

    A gamma ray camera for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array.

  2. Gamma ray camera

    DOE Patents [OSTI]

    Perez-Mendez, V.

    1997-01-21

    A gamma ray camera is disclosed for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array. 6 figs.

  3. Perspectives of Decision-Making and Estimation of Risk in Populations Exposed to Low Levels of Ionizing Radiations

    E-Print Network [OSTI]

    Fabrikant, J.I.

    2010-01-01

    Extrapolation to low doses. Radiation Res. 71: Upton, A.C.for high LET radiations at low doses, risk values may beof radiation-induced leukemia, fow'LET, low dose: 6/rad)

  4. PROTECTIVE SURFACE COATINGS ON SEMICONDUCTOR NUCLEAR RADIATION DETECTORS

    E-Print Network [OSTI]

    Hansen, W.L.

    2010-01-01

    SEMICONDUCTOR NUCLEAR RADIATION DETECTORS W. L. Hansen, E.SEMICONDUCTOR NUCLEAR RADIATION DETECTORS* W. L. Hansen, E.suita­ bility for radiation detectors. Collimated gamma-ray

  5. Nuclear radiation-warning detector that measures impedance

    DOE Patents [OSTI]

    Savignac, Noel Felix; Gomez, Leo S; Yelton, William Graham; Robinson, Alex; Limmer, Steven

    2013-06-04

    This invention is a nuclear radiation-warning detector that measures impedance of silver-silver halide on an interdigitated electrode to detect light or radiation comprised of alpha particles, beta particles, gamma rays, X rays, and/or neutrons. The detector is comprised of an interdigitated electrode covered by a layer of silver halide. After exposure to alpha particles, beta particles, X rays, gamma rays, neutron radiation, or light, the silver halide is reduced to silver in the presence of a reducing solution. The change from the high electrical resistance (impedance) of silver halide to the low resistance of silver provides the radiation warning that detected radiation levels exceed a predetermined radiation dose threshold.

  6. Interaction of Radiation with Matter Electrons

    E-Print Network [OSTI]

    Massey, Thomas N.

    Module 2 Interaction of Radiation with Matter · Gammas · Electrons · Charged Particles · Neutron of mass. · Energy from radiation only deposited if it interacts with the material. · Only the amount;Pair Production #12;Gamma Interaction with Water #12;http://physics

  7. Gamma radiological surveys of the Oak Ridge Reservation, Paducah Gaseous Diffusion Plant, and Portsmouth Gaseous Diffusion Plant, 1990-1993, and overview of data processing and analysis by the Environmental Restoration Remote Sensing Program, Fiscal Year 1995

    SciTech Connect (OSTI)

    Smyre, J.L.; Moll, B.W.; King, A.L.

    1996-06-01

    Three gamma radiological surveys have been conducted under auspices of the ER Remote Sensing Program: (1) Oak Ridge Reservation (ORR) (1992), (2) Clinch River (1992), and (3) Portsmouth Gaseous Diffusion Plant (PORTS) (1993). In addition, the Remote Sensing Program has acquired the results of earlier surveys at Paducah Gaseous Diffusion Plant (PGDP) (1990) and PORTS (1990). These radiological surveys provide data for characterization and long-term monitoring of U.S. Department of Energy (DOE) contamination areas since many of the radioactive materials processed or handled on the ORR, PGDP, and PORTS are direct gamma radiation emitters or have gamma emitting daughter radionuclides. High resolution airborne gamma radiation surveys require a helicopter outfitted with one or two detector pods, a computer-based data acquisition system, and an accurate navigational positioning system for relating collected data to ground location. Sensors measure the ground-level gamma energy spectrum in the 38 to 3,026 KeV range. Analysis can provide gamma emission strength in counts per second for either gross or total man-made gamma emissions. Gross count gamma radiation includes natural background radiation from terrestrial sources (radionuclides present in small amounts in the earth`s soil and bedrock), from radon gas, and from cosmic rays from outer space as well as radiation from man-made radionuclides. Man-made count gamma data include only the portion of the gross count that can be directly attributed to gamma rays from man-made radionuclides. Interpretation of the gamma energy spectra can make possible the determination of which specific radioisotopes contribute to the observed man-made gamma radiation, either as direct or as indirect (i.e., daughter) gamma energy from specific radionuclides (e.g., cesium-137, cobalt-60, uranium-238).

  8. The Evaluated Gamma-ray Activation File (EGAF)

    SciTech Connect (OSTI)

    Firestone, R. B. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Molnar, G. L.; Revay, Zs.; Belgya, T. [Institute of Isotope and Surface Chemistry, H-1525, Budapest (Hungary); McNabb, D. P.; Sleaford, B. W. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

    2006-03-13

    The Evaluated Gamma-ray Activation File (EGAF), a new database of prompt and delayed neutron capture {gamma} ray cross sections, has been prepared as part of an International Atomic Energy Agency (IAEA) Coordinated Research Project to develop a 'Database of Prompt Gamma-rays from Slow Neutron Capture for Elemental Analysis'. Recent elemental {gamma}-ray cross-section measurements performed with the guided neutron beam at the Budapest Reactor have been combined with data from the literature to produce the EGAF database. EGAF contains thermal cross sections for {approx_equal}35,000 prompt and delayed {gamma}-rays from 262 isotopes. New precise total thermal radiative cross sections have been derived for many isotopes from the primary and secondary gamma-ray cross sections and additional level scheme data. An IAEA TECDOC describing the EGAF evaluation and tabulating the most prominent {gamma}-rays will be published in 2004. The TECDOC will include a CD-ROM containing the EGAF database in both ENSDF and tabular formats with an interactive viewer for searching and displaying the data. The Isotopes Project, Lawrence Berkeley National Laboratory continues to maintain and update the EGAF file. These data are available on the Internet from both the IAEA and Isotopes Project websites.

  9. A new measurement of the rare decay eta -> pi^0 gamma gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

    SciTech Connect (OSTI)

    Nefkens, B M; Prakhov, S; Aguar-Bartolom??, P; Annand, J R; Arends, H J; Bantawa, K; Beck, R; Bekrenev, V; Bergh??user, H; Braghieri, A; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F; Collicott, C; Costanza, S; Danilkin, I V; Denig, A; Demissie, B; Dieterle, M; Downie, E J; Drexler, P; Fil'kov, L V; Fix, A; Garni, S; Glazier, D I; Gregor, R; Hamilton, D; Heid, E; Hornidge, D; Howdle, D; Jahn, O; Jude, T C; Kashevarov, V L; K??ser, A; Keshelashvili, I; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Kruglov, S; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J; Maghrbi, Y; Mancel, J; Manley, D M; McNicoll, E F; Mekterovic, D; Metag, V; Mushkarenkov, A; Nikolaev, A; Novotny, R; Oberle, M; Ortega, H; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Polonski, A; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sikora, M H; Starostin, A; Strakovsky, I I; Strub, T; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Werthmueller, D; Witthauer, L

    2014-08-01

    A new measurement of the rare, doubly radiative decay eta->pi^0 gamma gamma was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Gamma(eta->pi^0 gamma gamma), on the two-photon invariant mass squared, m^2(gamma gamma), as well as a new, more precise value for the decay width, Gamma(eta->pi^0 gamma gamma) = (0.33+/-0.03_tot) eV, are based on analysis of 1.2 x 10^3 eta->pi^0 gamma gamma decays from a total of 6 x 10^7 eta mesons produced in the gamma p -> eta p reaction. The present results for dGamma(eta->pi^0 gamma gamma)/dm^2(gamma gamma) are in good agreement with previous measurements and recent theoretical calculations for this dependence.

  10. Characterization of the deep levels responsible for non-radiative recombination in InGaN/GaN light-emitting diodes

    SciTech Connect (OSTI)

    Meneghini, M. La Grassa, M.; Vaccari, S.; Meneghesso, G.; Zanoni, E.

    2014-03-17

    This paper presents an extensive investigation of the deep levels related to non-radiative recombination in InGaN/GaN light-emitting diodes (LEDs). The study is based on combined optical and deep-level transient spectroscopy measurements, carried out on LEDs with identical structure and with different values of the non-radiative recombination coefficient. Experimental data lead to the following, relevant, results: (i) LEDs with a high non-radiative recombination coefficient have a higher concentration of a trap (labeled as “e{sub 2}”) with an activation energy of 0.7 eV, which is supposed to be located close to/within the active region; (ii) measurements carried out with varying filling pulse duration suggest that this deep level behaves as a point-defect/dislocation complex. The Arrhenius plot of this deep level is critically compared with the previous literature reports, to identify its physical origin.

  11. RADIATIVE OPACITY OF IRON STUDIED USING A DETAILED LEVEL ACCOUNTING MODEL

    SciTech Connect (OSTI)

    Jin Fengtao; Zeng Jiaolong; Yuan Jianmin; Huang Tianxuan; Ding Yongkun; Zheng Zhijian

    2009-03-01

    The opacity of iron plasma in local thermodynamic equilibrium is studied using an independently developed detailed level accounting model. Atomic data are generated by solving the full relativistic Dirac-Fock equations. State mixing within one electronic configuration is considered to include part of the correlations between electrons without configuration interaction matrices that are too large being involved. Simulations are carried out and compared with several recent experimental transmission spectra in the M- and L-shell absorption regions to reveal the high accuracy of the model. The present model is also compared with the OPAL, LEDCOP and OP models for two isothermal series at T = 20 eV and T = 19.3 eV. It is found that our model is in good agreement with OPAL and LEDCOP while it has discrepancies with OP at high densities. Systematic Rosseland and Planck mean opacities in the range 10-1000 eV for temperature and 10{sup -5}-10{sup -1} g cm{sup -3} for density are also presented and compared with LEDCOP results, finding good agreement at lower temperatures but apparent differences at high temperatures where the L- and K-shell absorptions are dominant.

  12. Portable compton gamma-ray detection system

    DOE Patents [OSTI]

    Rowland, Mark S. (Alamo, CA); Oldaker, Mark E. (Pleasanton, CA)

    2008-03-04

    A Compton scattered gamma-ray detector system. The system comprises a gamma-ray spectrometer and an annular array of individual scintillators. The scintillators are positioned so that they are arrayed around the gamma-ray spectrometer. The annular array of individual scintillators includes a first scintillator. A radiation shield is positioned around the first scintillator. A multi-channel analyzer is operatively connected to the gamma-ray spectrometer and the annular array of individual scintillators.

  13. Plastic Gamma Sensors: An Application in Detection of Radioisotopes

    SciTech Connect (OSTI)

    S. Mukhopadhyay

    2003-06-01

    A brief survey of plastic scintillators for various radiation measurement applications is presented here. The utility of plastic scintillators for practical applications such as gamma radiation monitoring, real-time radioisotope detection and screening is evaluated in laboratory and field measurements. This study also reports results of Monte Carlo-type predictive responses of common plastic scintillators in gamma and neutron radiation fields. Small-size plastic detectors are evaluated for static and dynamic gamma-ray detection sensitivity of selected radiation sources.

  14. Plutonium radiation surrogate

    DOE Patents [OSTI]

    Frank, Michael I. (Dublin, CA)

    2010-02-02

    A self-contained source of gamma-ray and neutron radiation suitable for use as a radiation surrogate for weapons-grade plutonium is described. The source generates a radiation spectrum similar to that of weapons-grade plutonium at 5% energy resolution between 59 and 2614 keV, but contains no special nuclear material and emits little .alpha.-particle radiation. The weapons-grade plutonium radiation surrogate also emits neutrons having fluxes commensurate with the gamma-radiation intensities employed.

  15. TANAMI: Milliarcsecond Resolution Observations of Extragalactic Gamma-ray Sources

    E-Print Network [OSTI]

    Ojha, Roopesh; Böck, M; Booth, R; Dutka, M S; Edwards, P G; Fey, A L; Fuhrmann, L; Gaume, R A; Hase, H; Horiuchi, S; Jauncey, D L; Johnston, K J; Katz, U; Lister, M; Lovell, J E J; Müller, C; Plötz, C; Quick, J F H; Ros, E; Taylor, G B; Thompson, D J; Tingay, S J; Tosti, G; Tzioumis, A K; Wilms, J; Zensus, J A

    2010-01-01

    The TANAMI (Tracking AGN with Austral Milliarcsecond Interferometry) and associated programs provide comprehensive radio monitoring of extragalactic gamma-ray sources south of declination -30 degrees. Joint quasi-simultaneous observations between the Fermi Gamma-ray Space Telescope and ground based observatories allow us to discriminate between competing theoretical blazar emission models. High resolution VLBI observations are the only way to spatially resolve the sub-parsec level emission regions where the high-energy radiation originates. The gap from radio to gamma-ray energies is spanned with near simultaneous data from the Swift satellite and ground based optical observatories. We present early results from the TANAMI program in the context of this panchromatic suite of observations.

  16. The neutron-gamma Feynman variance to mean approach: gamma detection and total neutron-gamma detection (theory and practice)

    E-Print Network [OSTI]

    Dina Chernikova; Kåre Axell; Senada Avdic; Imre Pázsit; Anders Nordlund

    2015-01-23

    Two versions of the neutron-gamma variance to mean (Feynman-alpha method or Feynman-Y function) formula for either gamma detection only or total neutron-gamma detection, respectively, are derived and compared in this paper. The new formulas have a particular importance for detectors of either gamma photons or detectors sensitive to both neutron and gamma radiation. If applied to a plastic or liquid scintillation detector, the total neutron-gamma detection Feynman-Y expression corresponds to a situation where no discrimination is made between neutrons and gamma particles. The gamma variance to mean formulas are useful when a detector of only gamma radiation is used or when working with a combined neutron-gamma detector at high count rates. The theoretical derivation is based on the Chapman-Kolmogorov equation with inclusion of general reactions and passage intensities for neutrons and gammas, but with the inclusion of prompt reactions only. A one energy group approximation is considered. The comparison of the two different theories is made by using reaction intensities obtained in MCNPX simulations with a simplified geometry for two scintillation detectors and a 252Cf-source enclosed in a steel container. In addition, the variance to mean ratios, neutron, gamma and total neutron-gamma, are evaluated experimentally for a weak 252Cf neutron-gamma source in a steel container, a 137Cs random gamma source and a 22Na correlated gamma source. Due to the focus being on the possibility of using neutron-gamma variance to mean theories for both reactor and safeguards applications, we limited the present study to the general analytical expressions for Feynman-Y formulas.

  17. A Monte Carlo Study of the Relationship between the Time Structures of Prompt Gammas and in vivo Radiation Dose in Proton Therapy

    E-Print Network [OSTI]

    Shin, Wook-Geun; Shin, Jae-Ik; Jeong, Jong Hwi; Lee, Se Byeong

    2015-01-01

    For the in vivo range verification in proton therapy, it has been tried to measure the spatial distribution of the prompt gammas generated by the proton-induced interactions with the close relationship with the proton dose distribution. However, the high energy of the prompt gammas and background gammas are still problematic in measuring the distribution. In this study, we suggested a new method determining the in vivo range by utilizing the time structure of the prompt gammas formed with the rotation of a range modulation wheel (RMW) in the passive scattering proton therapy. To validate the Monte Carlo code simulating the proton beam nozzle, axial percent depth doses (PDDs) were compared with the measured PDDs with the varying beam range of 4.73-24.01 cm. And the relationship between the proton dose rate and the time structure of the prompt gammas was assessed and compared in the water phantom. The results of the PDD showed accurate agreement within the relative errors of 1.1% in the distal range and 2.9% in...

  18. The investigation of the gamma-gamma->WW including electromagnetic corrections at the TESLA kinematics

    E-Print Network [OSTI]

    I. Marfin; V. Mossolov; T. Shishkina

    2003-05-17

    The WW production in gamma-gamma scattering is considered in the Standard Model. The main contribution to radiative effects for the process gamma-gamma->WW has been calculating and analyzing. It is found the latter is considerable at high energies and greatly contributes to the differential cross section $d\\sigma$ at various polarizations of initial photons and final bosons. Monte-Carlo generator built based on TESLA kinematics.

  19. Composition for radiation shielding

    DOE Patents [OSTI]

    Kronberg, James W. (Aiken, SC)

    1994-01-01

    A composition for use as a radiation shield. The shield has a depleted urum core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container.

  20. Working safely in gamma radiography. A training manual for industrial radiographers

    SciTech Connect (OSTI)

    McGuire, S.A.; Peabody, C.A.

    1982-09-01

    This manual is designed for classroom training in working safely in industrial radiography using gamma sources. The purpose is to train radiographers' assistants to work safely as a qualified gamma radiographer. The contents cover the essentials of radiation, radiation protection, emergency procedures, gamma cameras, and biological effects of radiation. (ACR)

  1. X-RAYRICH GAMMA-RAY BURSTS, PHOTOSPHERES, AND VARIABILITY P. Meszaros,1,2

    E-Print Network [OSTI]

    Zhang, Bing

    X-RAY­RICH GAMMA-RAY BURSTS, PHOTOSPHERES, AND VARIABILITY P. Me´sza´ros,1,2 E. Ramirez-Ruiz,3 M. J of the observational gamma-ray variability-luminosity relation. Subject headings: gamma rays: bursts -- radiation mechanisms: nonthermal 1. INTRODUCTION Gamma-ray burst (GRB) light curves at gamma-ray ener- gies are often

  2. Radiation Transport Simulation Studies Using MCNP for a Cow Phantom to Determine an Optimal Detector Configuration for a New Livestock Portal 

    E-Print Network [OSTI]

    Joe Justina, -

    2012-10-19

    scalable gamma radiation portal monitor (RPM) which can be used to assess the level of contamination on large animals like cattle. This work employed a Monte Carlo N-Particle (MCNP) radiation transport code for the purpose. A virtual system of cow...

  3. AND NUCLEAR MEDICINE; DIAGNOSIS; DISEASES; GAMMA CAMERAS; GENETICS...

    Office of Scientific and Technical Information (OSTI)

    Converting energy to medical progress nuclear medicine NONE 62 RADIOLOGY AND NUCLEAR MEDICINE; DIAGNOSIS; DISEASES; GAMMA CAMERAS; GENETICS; NUCLEAR MEDICINE; PATIENTS; RADIATION...

  4. Radiation detector

    DOE Patents [OSTI]

    Fultz, B.T.

    1980-12-05

    Apparatus is provided for detecting radiation such as gamma rays and x-rays generated in backscatter Moessbauer effect spectroscopy and x-ray spectrometry, which has a large window for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  5. Cellular and molecular research to reduce uncertainties in estimates of health effects from low-level radiation

    SciTech Connect (OSTI)

    Elkind, M.M.; Bedford, J.; Benjamin, S.A.; Waldren, C.A. (Colorado State Univ., Fort Collins, CO (USA)); Gotchy, R.L. (Science Applications International Corp., McLean, VA (USA))

    1990-10-01

    A study was undertaken by five radiation scientists to examine the feasibility of reducing the uncertainties in the estimation of risk due to protracted low doses of ionizing radiation. In addressing the question of feasibility, a review was made by the study group: of the cellular, molecular, and mammalian radiation data that are available; of the way in which altered oncogene properties could be involved in the loss of growth control that culminates in tumorigenesis; and of the progress that had been made in the genetic characterizations of several human and animal neoplasms. On the basis of this analysis, the study group concluded that, at the present time, it is feasible to mount a program of radiation research directed at the mechanism(s) of radiation-induced cancer with special reference to risk of neoplasia due to protracted, low doses of sparsely ionizing radiation. To implement a program of research, a review was made of the methods, techniques, and instruments that would be needed. This review was followed by a survey of the laboratories and institutions where scientific personnel and facilities are known to be available. A research agenda of the principal and broad objectives of the program is also discussed. 489 refs., 21 figs., 14 tabs.

  6. Evaluation of Radiation Doses Due to Consumption of Contaminated Food Items and Calculation of Food Class-Specific Derived Intervention Levels

    SciTech Connect (OSTI)

    Heinzelman, K M; Mansfield, W G

    2010-04-27

    This document evaluates the expected radiation dose due to the consumption of several specific food classes (dairy, meat, produce, etc.) contaminated with specific radionuclides, and relates concentration levels in food to the detection abilities of typical aboratory analysis/measurement methods. The attached charts present the limiting organ dose as a function of the radionuclide concentration in a particular food class, and allow the user to compare these concentrations and doses to typical analytical detection apabilities. The expected radiation dose depends on several factors: the age of the individual; the radionuclide present in the food; the concentration of the radionuclide in the food; and the amount of food consumed. Food consumption rates for individuals of various ges were taken from the 1998 United States Food and Drug Administration (FDA) document, Accidental Radioactive Contamination of HUman Food and Animal Feeds: Recommendations for State and Local Agencies. In that document, the FDA defines the erived Intervention Level (DIL), which is the concentration of a particular radionuclide in food that if consumed could result in an individual receiving a radiation dose exceeding the Protection Action Guide (PAG) thresholds for intervention. This document also resents odified, food class specific DIL, which is calculated using a somewhat modified version of the FDA's procedure. This document begins with an overview of the FDA's DIL calculation, followed by a description of the food class specific DIL calculations, and finally charts of the radiation dose per radioactivity concentration for several food class/radionuclide combinations.

  7. Radiation monitoring during criticality at a gaseous diffusion plant

    SciTech Connect (OSTI)

    Goebel, G.R.; Hines, T.W.; Carver, A.M.

    1994-12-31

    The Paducah gaseous diffusion plant (PGDP) has two systems of radiation detection units that monitor radiation associated with a nuclear criticality accident (NCA). The primary system, the criticality accident alarm system (CAAS), is composed of several detection units that alarm when gamma-radiation levels exceed 10 mR/h. The CAAS provides the means to initiate emergency-evacuation procedures in the event of an NCA. This system is augmented with a second system of radiation detectors, which is referred to as the argon gamma graph (AGG) system. The AGG system is utilized specifically for the remote monitoring of radiation during an NCA and is a primary tool used by emergency response personnel. The remote radiation readings supplied by the AGG system provide the means to quickly locate and characterize an NCA. The centralized remote monitoring of radiation during an NCA permits important data to be collected efficiently without subjecting personnel to unknown and unquantified radiation fields. Calculations of the expected radiation readings on the AGG system were performed for a postulated NCA at four different locations at PGDP.

  8. Low Dose Gamma Irradiation Potentiates Secondary Exposure to Gamma Rays or Protons in Thyroid Tissue Analogs

    SciTech Connect (OSTI)

    Green, Lora M

    2006-05-25

    We have utilized our unique bioreactor model to produce three-dimensional thyroid tissue analogs that we believe better represent the effects of radiation in vivo than two-dimensional cultures. Our thyroid model has been characterized at multiple levels, including: cell-cell exchanges (bystander), signal transduction, functional changes and modulation of gene expression. We have significant preliminary data on structural, functional, signal transduction and gene expression responses from acute exposures at high doses (50-1000 rads) of gamma, protons and iron (Green et al., 2001a; 2001b; 2002a; 2002b; 2005). More recently, we used our DOE funding (ending Feb 06) to characterize the pattern of radiation modulated gene expression in rat thyroid tissue analogs using low-dose/low-dose rate radiation, plus/minus acute challenge exposures. Findings from these studies show that the low-dose/low-dose rate “priming” exposures to radiation invoked changes in gene expression profiles that varied with dose and time. The thyrocytes transitioned to a “primed” state, so that when the tissue analogs were challenged with an acute exposure to radiation they had a muted response (or an increased resistance) to cytopathological changes relative to “un-primed” cells. We measured dramatic differences in the primed tissue analogs, showing that our original hypothesis was correct: that low dose gamma irradiation will potentiate the repair/adaptation response to a secondary exposure. Implications from these findings are that risk assessments based on classical in vitro tissue culture assays will overestimate risk, and that low dose rate priming results in a reduced response in gene expression to a secondary challenge exposure, which implies that a priming dose provides enhanced protection to thyroid cells grown as tissue analogs. If we can determine that the effects of radiation on our tissue analogs more closely resemble the effects of radiation in vivo, then we can better estimate the risks and modify assign limits to radiation worker and astronauts. Additionally, confirmation that tissue analogs represent a realistic in vivo response to radiation will allow scientists to perform tissue relevant experiments without the expense of using animals. Confirmation of the in vivo approximation of our model will strengthen our findings from the recent completion of our DOE funding which is the subject of the current proposal.

  9. Study of galactic gamma ray sources with Milagro Jordan A. Goodman for the Milagro Collaboration

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    . The diffuse gamma radiation arising from the interaction of cosmic ray particles with matter and radiation surface brightness sources such as the diffuse gamma radiation arising from interactions of cosmic radiation with interstellar matter. In this paper we report our results on diffuse emission from

  10. Multi-level effects of low dose rate ionizing radiation on southern toad, Anaxyrus [Bufo] terrestris

    SciTech Connect (OSTI)

    Stark, Karolina; Scott, David E.; Tsyusko, Olga; Coughlin, Daniel P.; Hinton, Thomas G.; Amendola, Roberto

    2015-04-30

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development –embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of ¹³?Cs at 0.13, 2.4, 21, and 222 mGy d?¹, resulting in total doses up to 15.8 Gy. Radiation treatments did not affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21mGy d?¹ and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.

  11. CP Violating B ---> s Gamma Decay in Supersymmetric Models

    E-Print Network [OSTI]

    Chun-Khiang Chua; Xiao-Gang He; Wei-Shu Hou

    1999-02-20

    Supersymmetric models with nonuniversal down type squark masses can enrich the chiral structure and CP violating phenomena in $b\\to s\\gamma$ decays. Direct CP violation in $b\\to s \\gamma$, mixing induced CP violation in radiative $B_{d,s}$ decays (such as $B_s\\to \\phi \\gamma$ and $B_d \\to K^*_{1,2}\\gamma$), and $\\Lambda$ polarization in $\\Lambda_b \\to \\Lambda \\gamma$ can be substantially different from the Standard Model. Future experiements at $e^+ e^-$ and hadronic B factories will give important information on the underlying theory for radiative $b$ decays.

  12. Gamma radiolysis of chlorinated hydrocarbons

    SciTech Connect (OSTI)

    Arbon, R.E.; Mincher, B.J.; Meikrantz, D.H.

    1992-01-01

    This program is the Idaho National Engineering Laboratory (INEL) component of a joint collarborative effort with Lawrence Livermore National Laboratory (LLNL). The purpose of this effort is to demonstrate a viable process for breaking down hazardous halogenated organic wastes to simpler, non-hazardous waste using high energy ionizing radiation. The INEL effort focuses on the use of spent reactor fuel gamma radiation sources to decompose complex wastes such as PCBs. At LLNL, halogenated solvents such as carbon tetrachloride and trichloroethylene are being studied using accelerator radiation sources. The INEL irradiation experiments concentrated on a single PCB congener so that a limited set of decomposition reactions could be studied. The congener 2,2{prime}, 3,3{prime},4,5{prime},6,6{prime} - octachlorobiphenyl was examined following exposure to various gamma doses at the Advanced Test Reactor (AIR) spent fuel pool. The decomposition rates and products in several solvents are discussed. 3 refs.

  13. Gamma radiolysis of chlorinated hydrocarbons

    SciTech Connect (OSTI)

    Arbon, R.E.; Mincher, B.J.; Meikrantz, D.H.

    1992-08-01

    This program is the Idaho National Engineering Laboratory (INEL) component of a joint collarborative effort with Lawrence Livermore National Laboratory (LLNL). The purpose of this effort is to demonstrate a viable process for breaking down hazardous halogenated organic wastes to simpler, non-hazardous waste using high energy ionizing radiation. The INEL effort focuses on the use of spent reactor fuel gamma radiation sources to decompose complex wastes such as PCBs. At LLNL, halogenated solvents such as carbon tetrachloride and trichloroethylene are being studied using accelerator radiation sources. The INEL irradiation experiments concentrated on a single PCB congener so that a limited set of decomposition reactions could be studied. The congener 2,2{prime}, 3,3{prime},4,5{prime},6,6{prime} - octachlorobiphenyl was examined following exposure to various gamma doses at the Advanced Test Reactor (AIR) spent fuel pool. The decomposition rates and products in several solvents are discussed. 3 refs.

  14. High resistivity aluminum antimonide radiation detector

    DOE Patents [OSTI]

    Sherohman, John W. (Livermore, CA); Coombs, III, Arthur W. (Patterson, CA); Yee, Jick H. (Livermore, CA)

    2007-12-18

    Bulk Aluminum Antimonide (AlSb)-based single crystal materials have been prepared for use as ambient (room) temperature X-ray and Gamma-ray radiation detection.

  15. High resistivity aluminum antimonide radiation detector

    DOE Patents [OSTI]

    Sherohman, John W.; Coombs, III, Arthur W.; Yee, Jick H.

    2005-05-03

    Bulk Aluminum Antimonide (AlSb)-based single crystal materials have been prepared for use as ambient (room) temperature X-ray and Gamma-ray radiation detection.

  16. Radiation Damage In Reactor Cavity Concrete

    SciTech Connect (OSTI)

    Field, Kevin G; Le Pape, Yann; Naus, Dan J; Remec, Igor; Busby, Jeremy T; Rosseel, Thomas M; Wall, Dr. James Joseph

    2015-01-01

    License renewal up to 60 years and the possibility of subsequent license renewal to 80 years has established a renewed focus on long-term aging of nuclear generating stations materials, and recently, on concrete. Large irreplaceable sections of most nuclear generating stations include concrete. The Expanded Materials Degradation Analysis (EMDA), jointly performed by the Department of Energy, the Nuclear Regulatory Commission and Industry, identified the urgent need to develop a consistent knowledge base on irradiation effects in concrete [1]. Much of the historical mechanical performance data of irradiated concrete [2] does not accurately reflect typical radiation conditions in NPPs or conditions out to 60 or 80 years of radiation exposure [3]. To address these potential gaps in the knowledge base, The Electric Power Research Institute and Oak Ridge National Laboratory are working to disposition radiation damage as a degradation mechanism. This paper outlines the research program within this pathway including: (i) defining the upper bound of the neutron and gamma dose levels expected in the biological shield concrete for extended operation (80 years of operation and beyond), (ii) determining the effects of neutron and gamma irradiation as well as extended time at temperature on concrete, (iii) evaluating opportunities to irradiate prototypical concrete under accelerated neutron and gamma dose levels to establish a conservative bound and share data obtained from different flux, temperature, and fluence levels, (iv) evaluating opportunities to harvest and test irradiated concrete from international NPPs, (v) developing cooperative test programs to improve confidence in the results from the various concretes and research reactors, (vi) furthering the understanding of the effects of radiation on concrete (see companion paper) and (vii) establishing an international collaborative research and information exchange effort to leverage capabilities and knowledge.

  17. Experience of gamma-locator system using for radiation monitoring during rehabilitation works at temporal radwaste storage area of Kurchatov Institute

    SciTech Connect (OSTI)

    Ivanov, O. P.; Potapov, V. N.; Ignatov, S. M.; Smirnov, S. V.; Stepanov, V. E.; Volkovich, A. G.; Volkov, V. G. [RRC Kurchatov Institute, Moscow (Russian Federation)

    2007-07-01

    Remote monitoring of radiological conditions on large areas is important task during large-scale activity with radioactive contamination/materials. We present results of application of an automatic system for remote measurements of radiological conditions at territory of rehabilitation activity The system is scanning collimated spectrometric detector, its construction and main performance characteristics are shortly described. System, including two different measurement heads was used during three years for radiological monitoring of area rehabilitation works at temporal radwaste storage are a of RRC Kurchatov Institute. The results of its application for exposure dose rate monitoring at particular control points from separate strong sources located in the territory of activity are presented and special cases are studies in details. The method of EDR calculation in 3-D space around territory of activity and analysis of relative input of main gamma-sources into EDR are presented. The results of application of the system during rehabilitation activity at territory of temporal storage of radioactive wastes of RRC Kurchatov Institute have shown high efficiency of this system for such operations. (authors)

  18. Persistence of gamma-H2AX and 53BP1 foci in proliferating and nonproliferating human mammary epithelial cells after exposure to gamma-rays or iron ions

    SciTech Connect (OSTI)

    Groesser, Torsten; Chang, Hang; Fontenay, Gerald; Chen, James; Costes, Sylvain V.; Barcellos-Hoff, Mary Helen; Parvin, Bahram; Rydberg, Bjorn

    2010-12-22

    To investigate {gamma}-H2AX (phosphorylated histone H2AX) and 53BP1 (tumour protein 53 binding protein No. 1) foci formation and removal in proliferating and non-proliferating human mammary epithelial cells (HMEC) after exposure to sparsely and densely ionizing radiation under different cell culture conditions. HMEC cells were grown either as monolayers (2D) or in extracellular matrix to allow the formation of acinar structures in vitro (3D). Foci numbers were quantified by image analysis at various time points after exposure. Our results reveal that in non-proliferating cells under 2D and 3D cell culture conditions, iron-ion induced {gamma}-H2AX foci were still present at 72 h after exposure, although 53BP1 foci returned to control levels at 48 h. In contrast in proliferating HMEC, both {gamma}-H2AX and 53BP1 foci decreased to control levels during the 24-48 h time interval after irradiation under 2D conditions. Foci numbers decreased faster after {gamma}-ray irradiation and returned to control levels by 12 h regardless of marker, cell proliferation status, and cell culture condition. Conclusions: The disappearance of radiation induced {gamma}-H2AX and 53BP1 foci in HMEC have different dynamics that depend on radiation quality and proliferation status. Notably, the general patterns do not depend on the cell culture condition (2D versus 3D). We speculate that the persistent {gamma}-H2AX foci in iron-ion irradiated non-proliferating cells could be due to limited availability of double strand break (DSB) repair pathways in G0/G1-phase, or that repair of complex DSB requires replication or chromatin remodeling.

  19. Chapter 5. Conclusion Uranium, a naturally occurring element, contributes to low levels of natural background radiation in the

    E-Print Network [OSTI]

    5-1 Chapter 5. Conclusion Uranium, a naturally occurring element, contributes to low levels into uranium oxide or other chemical forms usable in industry. Uranium undergoes radioactive decay into a long are extracted from the earth. Protore is mined uranium ore that is not rich enough to meet the market demand

  20. GammaCam Technology Demonstration at ORNL Buildings 3026C and 3026D

    Office of Energy Efficiency and Renewable Energy (EERE)

    The GammaCam system is an effective tool for remotely identifying high gamma radiation in radioactive environments.  Its versatility allows the user to perform preliminary characterization of an...

  1. Pulsed pyroelectric crystal-powered gamma source

    SciTech Connect (OSTI)

    Chen, A. X.; Antolak, A. J.; Leung, K.-N.; Raber, T. N.; Morse, D. H. [Sandia National Laboratories, Livermore, CA 94550 (United States)

    2013-04-19

    A compact pulsed gamma generator is being developed to replace radiological sources used in commercial, industrial and medical applications. Mono-energetic gammas are produced in the 0.4 - 1.0 MeV energy range using nuclear reactions such as {sup 9}Be(d,n{gamma}){sup 10}B. The gamma generator employs an RF-driven inductively coupled plasma ion source to produce deuterium ion current densities up to 2 mA/mm{sup 2} and ampere-level current pulses can be attained by utilizing an array extraction grid. The extracted deuterium ions are accelerated to approximately 300 keV via a compact stacked pyroelectric crystal system and then bombard the beryllium target to generate gammas. The resulting microsecond pulse of gammas is equivalent to a radiological source with curie-level activity.

  2. Received 9 May 2015 | Accepted 9 Sep 2015 | Published 9 Oct 2015 High-intensity power-resolved radiation

    E-Print Network [OSTI]

    MacDonald, Mark

    to image high-intensity fast-neutron and gamma-ray fields simultaneously. This system has been deployed. Monitoring systems, such as fission chambers and rhodium detector systems are expensive and have limited high temperatures, corrosion, extreme radiation levels and miniaturization. In-core monitoring systems

  3. Gamma-Ray Bursts, Ultra High Energy Cosmic Rays, and Cosmic Gamma-Ray Background

    E-Print Network [OSTI]

    Tomonori Totani

    1999-04-13

    We argue that gamma-ray bursts (GRBs) may be the origin of the cosmic gamma-ray background radiation observed in GeV range. It has theoretically been discussed that protons may carry a much larger amount of energy than electrons in GRBs, and this large energy can be radiated in TeV range by synchrotron radiation of ultra-high-energy protons (\\sim 10^{20} eV). The possible detection of GRBs above 10 TeV suggested by the Tibet and HEGRA groups also supports this idea. If this is the case, most of TeV gamma-rays from GRBs are absorbed in intergalactic fields and eventually form GeV gamma-ray background, whose flux is in good agreement with the recent observation.

  4. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    2000-12-26

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  5. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    1998-01-01

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  6. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, W.J.; Lessing, P.A.

    1998-07-28

    A composition is disclosed for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm{sup 3} and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile. 5 figs.

  7. Gamma Ray Burst and Soft Gamma Repeaters. Spinning, Precessing Gamma Jets

    E-Print Network [OSTI]

    Daniele Fargion

    1999-06-28

    Gamma Ray Bursts as recent GRB990123 and GRB990510 are observed to occur in cosmic volumes with a corresponding output reaching, for isotropic explosions, energies as large as two solar masses annihilation. These energies are underestimated because of the neglected role of comparable ejected neutrinos bursts. These extreme power cannot be explained with any standard spherically symmetric Fireball model. A too heavy black hole or Star would be unable to coexist with the shortest millisecond time structure of Gamma ray Burst. Beaming of the gamma radiation may overcome the energy puzzle. However any mild explosive beam $(\\Omega > 10^{-2})$ should not solve the jet containment at those disruptive energies. Only extreme beaming $(\\Omega < 10^{-8})$, by a slow decaying, but long-lived precessing jet, it may coexist with characteristic Supernova energies, apparent GRBs output, statistics as well as their connection with older and nearer SGRs relics.

  8. Composition for radiation shielding

    DOE Patents [OSTI]

    Kronberg, J.W.

    1994-08-02

    A composition for use as a radiation shield is disclosed. The shield has a depleted uranium core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container. 2 figs.

  9. Radiation dose in coronary angiography and intervention: initial results from the establishment of a multi-centre diagnostic reference level in Queensland public hospitals

    SciTech Connect (OSTI)

    Crowhurst, James A; Whitby, Mark; Thiele, David; Halligan, Toni; Westerink, Adam; Crown, Suzanne; Milne, Jillian

    2014-09-15

    Radiation dose to patients undergoing invasive coronary angiography (ICA) is relatively high. Guidelines suggest that a local benchmark or diagnostic reference level (DRL) be established for these procedures. This study sought to create a DRL for ICA procedures in Queensland public hospitals. Data were collected for all Cardiac Catheter Laboratories in Queensland public hospitals. Data were collected for diagnostic coronary angiography (CA) and single-vessel percutaneous intervention (PCI) procedures. Dose area product (P{sub KA}), skin surface entrance dose (K{sub AR}), fluoroscopy time (FT), and patient height and weight were collected for 3 months. The DRL was set from the 75th percentile of the P{sub KA.} 2590 patients were included in the CA group where the median FT was 3.5 min (inter-quartile range = 2.3–6.1). Median K{sub AR} = 581 mGy (374–876). Median P{sub KA} = 3908 uGym{sup 2} (2489–5865) DRL = 5865 uGym{sup 2}. 947 patients were included in the PCI group where median FT was 11.2 min (7.7–17.4). Median K{sub AR} = 1501 mGy (928–2224). Median P{sub KA} = 8736 uGym{sup 2} (5449–12,900) DRL = 12,900 uGym{sup 2}. This study established a benchmark for radiation dose for diagnostic and interventional coronary angiography in Queensland public facilities.

  10. Appendix G. Radiation Appendix G. Radiation

    E-Print Network [OSTI]

    Pennycook, Steve

    energy, is energy in the form of waves or particles moving through space. Visi- ble light, heat, radio in the form of electromagnetic waves. Examples include gamma rays, ultraviolet light, and radio waves waves, and alpha particles are examples of radiation. When people feel warmth from sunlight

  11. Gamma Ray Bursts

    E-Print Network [OSTI]

    Stahl, Bennett

    2014-01-01

    Olson. “Observations of gamma-ray bursts of cosmic origin. ”E. Lingenfelter. “Gamma-ray bursts. ” Annual Review of652-654. Waxman, Eli. “Gamma-ray-burst afterglow: supporting

  12. The Northern Marshall Islands radiological survey: A quality control program for radiochemical and gamma spectroscopy analysis

    SciTech Connect (OSTI)

    Kehl, S.R.; Mount, M.E.; Robison, W.L.

    1995-09-01

    From 1979 to 1989, approximately 25,000 Post Northern Marshall Islands Radiological Survey (PNMIRS) samples were collected, and over 71,400 radiochemical and gamma spectroscopy analyses were performed to establish the concentration of {sup 90}Sr, {sup 137}Cs, {sup 241}Am, and plutonium isotopes in soil, vegetation, fish, and animals in the Northern Marshall Islands. While the Low Level Gamma Counting Facility (B379) in the Health and Ecological Assessment (HEA) division accounted for over 80% of all gamma spectroscopy analyses, approximately 4889 radiochemical and 5437 gamma spectroscopy analyses were performed on 4784 samples of soil, vegetation, terrestrial animal, and marine organisms by outside laboratories. Four laboratories were used by Lawrence Livermore National Laboratory (LLNL) to perform the radiochemical analyses: Thermo Analytical Norcal, Richmond, California (TMA); Nuclear Energy Services, North Carolina State University (NCSU); Laboratory of Radiation Ecology, University of Washington (LRE); and Health and Ecological Assessment (HEA) division, LLNL, Livermore, California. Additionally, LRE and NCSU were used to perform gamma spectroscopy analyses. The analytical precision and accuracy were monitored by including blind duplicates and natural matrix standards in each group of samples analyzed. On the basis of reported analytical values for duplicates and standards, 88% of the gamma and 87% of the radiochemical analyses in this survey were accepted. By laboratory, 93% of the radiochemical analyses by TMA; 88% of the gamma-ray spectrometry and 100% of the radiochemistry analyses by NCSU; 89% of the gamma spectroscopy and 87% of the radiochemistry analyses by LRE; and 90% of the radiochemistry analyses performed by HEA`s radiochemistry department were accepted.

  13. Search for $\\alpha$ decay of $^{151}$Eu to the first excited level of $^{147}$Pm using underground $\\gamma$-ray spectrometry

    E-Print Network [OSTI]

    Danevich, F A; Hult, M; Marissens, G; Tretyak, V I; Yuksel, A; 10.1140/epja/i2012-12157-7

    2013-01-01

    The alpha decay of $^{151}$Eu to the first excited level of $^{147}$Pm ($J^\\pi = 5/2^+$, $E_{exc}=91.1$ keV) was searched for at the HADES underground laboratory ($\\approx 500$ m w.e.). A sample of high purity europium oxide with mass of 303 g and a natural isotopic composition has been measured over 2232.8 h with a high energy resolution ultra-low background n-type semi-planar HPGe detector (40 cm$^3$) with sub-micron deadlayer. The new improved half-life limit has been set as $T_{1/2} \\geq 3.7\\times 10^{18}$ yr at 68% C.L. Possibilities to improve the sensitivity of the experiment, which is already near the theoretical predictions, are discussed. New half-life limit for $\\alpha$ decay of $^{153}$Eu is also set as $T_{1/2} \\geq 5.5\\times 10^{17}$ yr.

  14. On the determination of reference levels for quality assurance of flattening filter free photon beams in radiation therapy

    SciTech Connect (OSTI)

    Clivio, Alessandro; Belosi, Maria Francesca; Cozzi, Luca; Nicolini, Giorgia; Vanetti, Eugenio; Fogliata, Antonella; Bolard, Grégory; Fenoglietto, Pascal; Krauss, Harald

    2014-02-15

    Purpose: New definitions for some dosimetric parameters for use in quality assurance of flattening filter free (FFF) beams generated by medical linear accelerators have been suggested. The present study aims to validate these suggestions and to propose possible reference levels. Methods: The main characteristics of FFF photon beams were described in terms of: field size, penumbra, unflatness, slope, and peak-position parameters. Data were collected for 6 and 10 MV-FFF beams from three different Varian TrueBeam Linacs. Measurements were performed with a 2D-array (Starcheck system from PTW-Freiburg) and with the portal dosimetry method GLAaS utilizing the build-in portal imager of TrueBeam. Data were also compared to ion chamber measurements. A cross check validation has been performed on a FFF beam of 6 MV generated by a Varian Clinac-iX upgraded to FFF capability. Results : All the parameters suggested to characterize the FFF beams resulted easily measurable and little variation was observed among different Linacs. Referring to two reference field sizes of 10 × 10 and 20 × 20 cm{sup 2}, at SDD = 100 cm and d = dmax, from the portal dosimetry data, the following results (averaging X and Y profiles) were obtained. Field size: 9.95 ± 0.02 and 19.98 ± 0.03 cm for 6 MV-FFF (9.94 ± 0.02 and 19.98 ± 0.03 cm for 10 MV-FFF). Penumbra: 2.7 ± 0.3 and 2.9 ± 0.3 mm for 6 MV-FFF (3.1 ± 0.2 and 3.3 ± 0.3 for 10 MV-FFF). Unflatness: 1.11 ± 0.01 and 1.25 ± 0.01 for 6 MV-FFF (1.21 ± 0.01 and 1.50 ± 0.01 for 10 MV-FFF). Slope: 0.320 ± 0.020%/mm and 0.43 ± 0.015%/mm for 6 MV-FFF (0.657 ± 0.023%/mm and 0.795 ± 0.017%/mm for 10 MV-FFF). Peak Position ?0.2 ± 0.2 and ?0.4 ± 0.2 mm for 6 MV-FFF (?0.3 ± 0.2 and 0.7 ± 0.3 mm for 10 MV-FFF). Results would depend upon measurement depth. With thresholds set to at least 95% confidence level from the measured data and to account for possible variations between detectors and methods and experimental settings, a tolerance set of: 1 mm for field size and penumbra, 0.04 for unflatness, 0.1%/mm for slope, and 1 mm for peak position could be proposed from our data. Conclusions : The parameters proposed for the characterization and routine control of stability of profiles of FFF beams appear to be a viable solution with a strong similarity to the conventional parameters used for flattened beams. The results from three different TrueBeams and the cross-validation against a Clinac-iX suggested the possible generalization of the methods and the possibility to use common tolerances for the parameters. The data showed also the reproducibility of beam characteristics among different systems (of the same vendor) and the resulting parameter values could therefore be possibly generalized.

  15. Gamma greenhouse: A chronic facility for crops improvement and agrobiotechnology

    SciTech Connect (OSTI)

    Azhar, M. Ahsanulkhaliqin, A. W.

    2014-02-12

    Gamma irradiation is one of the most common procedures in plant mutagenesis and agrobiotechnology activities. The procedures consist of chronic and acute gamma radiation. Generally, {sup 60}Co and {sup 137}Cs are gamma radiation sources for radiation processing with relatively high energy (half-life 5.27 years for {sup 60}Co and 30.1 years for {sup 137}Cs). The energy associated with gamma radiation is high enough to break the molecular bonds and ionize atoms without affecting structure of the atomic nucleus (avoiding induction of radioactivity). The Gamma Green House (GGH) is the only chronic irradiation facility in Malaysia, located at Malaysian Nuclear Agency (Nuclear Malaysia). GGH is used for induction of mutation in plants and other biological samples at low dose radiation over period of time depending on the nature and sensitivity of the plant species. The GGH consist of circular green house with 30 meters radius, control room and irradiator with interlock system. The irradiator produces low dose gamma radiation derived from Caesium-137 radioactive source. The biological samples can be exposed to low dose radiation in days, weeks, months or years. The current irradiation rate for GGH is 2.67 Gy/hr at 1 meter from the source. Chronic gamma irradiation produces a wider mutation spectrum and useful for minimizing radiation damages towards obtaining new improved traits for research and commercial values. The prospect of the gamma greenhouse is its uses in research, educations and services on induced mutation techniques for the improvement of plant varieties and microbes. In generating awareness and attract users to the facility, Nuclear Malaysia provides wide range of irradiation services for plant species and mutagenesis consultancies to academicians, students scientists, and plant breeders, from local universities, other research institutes, and growers. Charges for irradiation and consultancy services are at nominal rates. The utilization activities of the gamma greenhouse mainly cover Research and Development, Research Collaboration, Exchange of Information, Irradiation Services, Training Programs, Education, Exchange of Scientists and Seminars/ Conferences.

  16. GAMMA-400 gamma-ray observatory

    E-Print Network [OSTI]

    Topchiev, N P; Bonvicini, V; Adriani, O; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Bakaldin, A V; Bergstrom, L; Berti, E; Bigongiari, G; Bobkov, S G; Boezio, M; Bogomolov, E A; Bonechi, L; Bongi, M; Bottai, S; Castellini, G; Cattaneo, P W; Cumani, P; Dalkarov, O D; Dedenko, G L; De Donato, C; Dogiel, V A; Finetti, N; Gascon, D; Gorbunov, M S; Gusakov, Yu V; Hnatyk, B I; Kadilin, V V; Kaplin, V A; Kaplun, A A; Kheymits, M D; Korepanov, V E; Larsson, J; Leonov, A A; Loginov, V A; Longo, F; Maestro, P; Marrocchesi, P S; Martinez, M; Menshenin, A L; Mikhailov, V V; Mocchiutti, E; Moiseev, A A; Mori, N; Moskalenko, I V; Naumov, P Yu; Papini, P; Paredes, J M; Pearce, M; Picozza, P; Rappoldi, A; Ricciarini, S; Runtso, M F; Ryde, F; Serdin, O V; Sparvoli, R; Spillantini, P; Stozhkov, Yu I; Suchkov, S I; Taraskin, A A; Tavani, M; Tiberio, A; Tyurin, E M; Ulanov, M V; Vacchi, A; Vannuccini, E; Vasilyev, G I; Ward, J E; Yurkin, Yu T; Zampa, N; Zirakashvili, V N; Zverev, V G

    2015-01-01

    The GAMMA-400 gamma-ray telescope with excellent angular and energy resolutions is designed to search for signatures of dark matter in the fluxes of gamma-ray emission and electrons + positrons. Precision investigations of gamma-ray emission from Galactic Center, Crab, Vela, Cygnus, Geminga, and other regions will be performed, as well as diffuse gamma-ray emission, along with measurements of high-energy electron + positron and nuclei fluxes. Furthermore, it will study gamma-ray bursts and gamma-ray emission from the Sun during periods of solar activity. The energy range of GAMMA-400 is expected to be from ~20 MeV up to TeV energies for gamma rays, up to 20 TeV for electrons + positrons, and up to 10E15 eV for cosmic-ray nuclei. For high-energy gamma rays with energy from 10 to 100 GeV, the GAMMA-400 angular resolution improves from 0.1{\\deg} to ~0.01{\\deg} and energy resolution from 3% to ~1%; the proton rejection factor is ~5x10E5. GAMMA-400 will be installed onboard the Russian space observatory.

  17. RadTracker: Optical Imaging of High Energy Radiation Tracks

    SciTech Connect (OSTI)

    Vernon, S P; Lowry, M E; Comaskey, B J; Heebner, J E; Kallman, J S; Richards, J B

    2007-03-02

    This project examined the possibility of extending the recently demonstrated radoptic detection approach to gamma imaging. Model simulations of the light scattering process predicted that expected signal levels were small and likely below the detection limit of large area, room-temperature detectors. A series of experiments using pulsed x-ray excitation, modulated gamma excitation and optical pump-probe methods confirmed those theoretical predictions. At present the technique does not appear to provide a viable approach to volumetric radiation detection; however, in principal, orders of magnitude improvement in the SNR can result by using designer materials to concentrate and localize the radiation-absorption induced charge, simultaneously confining the optical mode to increase 'fill' factor and overlap of the probe beam with the affected regions, and employing high speed gated imaging detectors to measure the scattered signal.

  18. A Model-Independent Search for the decay B->l nu gamma

    SciTech Connect (OSTI)

    Aubert, Bernard; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, David Nathan; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS; /more authors..

    2012-10-09

    The authors present a search for the radiative leptonic decay B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}}{gamma}, where {ell} = e, {mu}, using a data sample of 465 million B{bar B} pairs collected by the BABAR experiment. In this analysis, they fully reconstruct the hadronic decay of one of the B mesons in {Upsilon}(4S) {yields} B{sup +}B{sup -} decays, then search for evidence of B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}}{gamma} in the rest of the event. They observe no significant evidence of signal decays and report model-independent branching fraction upper limits of {Beta}(B{sup +} {yields} e{sup +}{nu}{sub e}{gamma}) < 17 x 10{sup -6}, {Beta}(B{sup +} {yields} {mu}{sup +}{nu}{sub {mu}}{gamma}) < 24 x 10{sup -6}, and {Beta}(B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}}{gamma}) < 15.6 x 10{sup -6} ({ell} = e or {mu}), all at the 90% confidence level.

  19. Cosmological dark matter annihilations into gamma-rays - a closer look

    E-Print Network [OSTI]

    Piero Ullio; Lars Bergstrom; Joakim Edsjo; Cedric Lacey

    2002-07-04

    We investigate the prospects of detecting weakly interacting massive particle (WIMP) dark matter by measuring the contribution to the extragalactic gamma-ray radiation induced, in any dark matter halo and at all redshifts, by WIMP pair annihilations into high-energy photons. We perform a detailed analysis of the distinctive spectral features of this signal, recently proposed in a short letter by three of the authors, with emphasis on the signature due to monochromatic gamma-ray yields: the combined effect of cosmological redshift and absorption along the line of sight produces sharp bumps, peaked at the rest frame energy of the lines and asymmetrically smeared to lower energies. The level of the flux depends both on the particle physics scenario for WIMP dark matter and on the question of how dark matter clusters. Uncertainties introduced by the latter are thoroughly discussed implementing a realistic model inspired by results of the state-of-the-art N-body simulations and semi-analytic modeling in the cold dark matter structure formation theory. We also address the question of the potential gamma-ray background originating from blazars, presenting a novel calculation. Comparing the signal with the background, we find that there are viable configurations, in the combined parameter space defined by the particle physics setup and the structure formation scenario, for which the WIMP induced extragalactic gamma-ray signal will be detectable in the new generation of gamma-ray telescopes such as GLAST.

  20. Application of the {gamma}SF method to palladium

    SciTech Connect (OSTI)

    Utsunomiya, H.; Akimune, H.; Yamagata, T.; Kondo, T.; Iwamoto, C.; Kamata, M.; Itoh, O. [Department of Physics, Konan University, Okamoto 8-9-1, Higashinada, Kobe 658-8501 (Japan); Goriely, S.; Daoutidis, I. [Institut d'Astronomie et d'Astrophysique, Universite Libre de Bruxelles, Campus de la Plaine, CP-226, 1050 Brussels (Belgium); Arteaga, D. P. [Institut de Physique Nucleaire, Universite Paris-Sud, IN2P3-CNRS, F-91406 Orsay Cedex (France); Harada, H.; Kitatani, F. [Japan Atomic Energy Agency, Tokai-mura, Naka, Ibaraki 319-1195 (Japan); Goko, S. [Japan Atomic Energy Agency, Tokai-mura, Naka, Ibaraki 319-1195 (Japan); Faculty of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Toyokawa, H.; Yamada, K. [National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568 (Japan); Lui, Y.-W. [Cyclotron Institute, Texas A and M University, College Station, Texas 77843 (United States); Hilaire, S. [CEA, DAM, DIF, F-91297 Arpajon (France); Koning, A. J. [Nuclear Research and Consultancy Group, P.O. Box 25, NL-1755 ZG Petten (Netherlands)

    2011-10-28

    Photoneutron cross sections were measured for {sup 108}Pd, {sup 106}Pd, and {sup 105}Pd with laser-Compton scattering {gamma}-ray beams in an application of the {gamma}SF method to a radioactive nucleus {sup 107}Pd. We present radiative neutron cross sections for {sup 107}Pd[6.5x10{sup 6} y] obtained with the {gamma}SF method.

  1. A Directional Gamma-Ray Detector Based on Scintillator Plates

    E-Print Network [OSTI]

    Hanna, D; Boyle, P; MacLeod, A M L

    2015-01-01

    A simple device for determining the azimuthal location of a source of gamma radiation, using ideas from astrophysical gamma-ray burst detection, is described. A compact and robust detector built from eight identical modules, each comprising a plate of CsI(Tl) scintillator coupled to a photomultiplier tube, can locate a point source of gamma rays with degree-scale precision by comparing the count rates in the different modules. Sensitivity to uniform environmental background is minimal.

  2. Process for gamma ray induced degradation of polychlorinated biphenyls

    DOE Patents [OSTI]

    Meikrantz, D.H.; Mincher, B.J.; Arbon, R.E.

    1998-08-25

    The invention is a process for the in-situ destruction of polychlorinated biphenyl (PCB) compounds in transformer oils and transformers. These compounds are broken down selectively by irradiation of the object or mixture using spent nuclear fuel or any isotopic source of high energy gamma radiation. For example, the level of applied dose required to decompose 400 ppm of polychlorinated biphenyl in transformer oil to less than 50 ppm is 500 kilograms. Destruction of polychlorinated biphenyls to levels of less than 50 ppm renders the transformer oil or transformer non-PCB contaminated under current regulations. Therefore, this process can be used to treat PCB contaminated oil and equipment to minimize or eliminate the generation of PCB hazardous waste. 5 figs.

  3. Process for gamma ray induced degradation of polychlorinated biphenyls

    DOE Patents [OSTI]

    Meikrantz, David H. (Idaho Falls, ID); Mincher, Bruce J. (Shelley, ID); Arbon, Rodney E. (Blackfoot, ID)

    1998-01-01

    The invention is a process for the in-situ destruction of polychlorinated biphenyl (PCB) compounds in transformer oils and transformers. These compounds are broken down selectively by irradiation of the object or mixture using spent nuclear fuel or any isotopic source of high energy gamma radiation. For example, the level of applied dose required to decompose 400 ppm of polychlorinated biphenyl in transformer oil to less than 50 ppm is 500 kilogray. Destruction of polychlorinated biphenyls to levels of less than 50 ppm renders the transformer oil or transformer non-PCB contaminated under current regulations. Therefore, this process can be used to treat PCB contaminated oil and equipment to minimize or eliminate the generation of PCB hazardous waste.

  4. Branching fraction and photon energy spectrum for b -> s gamma

    E-Print Network [OSTI]

    Ammar, Raymond G.; Bean, Alice; Besson, David Zeke; Zhao, X.

    2001-12-01

    We have measured the branching fraction and photon energy spectrum for the radiative penguin process b --> s gamma. We find B(b --> s gamma) = (3.21 +/- 0.43 +/- 0.27(-0.10)(+0.18)) x 10(-4), where the errors are statistical, ...

  5. Current Trends in Gamma Ray Detection for Radiological Emergency Response

    SciTech Connect (OSTI)

    Mukhopadhyay, S., Guss, P., Maurer, R.

    2011-08-18

    Passive and active detection of gamma rays from shielded radioactive materials, including special nuclear materials, is an important task for any radiological emergency response organization. This article reports on the current trends and status of gamma radiation detection objectives and measurement techniques as applied to nonproliferation and radiological emergencies.

  6. Gamma ray generator

    DOE Patents [OSTI]

    Firestone, Richard B; Reijonen, Jani

    2014-05-27

    An embodiment of a gamma ray generator includes a neutron generator and a moderator. The moderator is coupled to the neutron generator. The moderator includes a neutron capture material. In operation, the neutron generator produces neutrons and the neutron capture material captures at least some of the neutrons to produces gamma rays. An application of the gamma ray generator is as a source of gamma rays for calibration of gamma ray detectors.

  7. A Study of B->ccbar gamma K in the BaBar Experiment

    SciTech Connect (OSTI)

    Fulsom, Brian Gregory; /British Columbia U.

    2010-08-25

    The BABAR Collaboration is a high energy physics experiment located at the Stanford Linear Accelerator Center. The primary goal of the experiment is to study charge and parity violation in the B-meson sector, however the copious production of B mesons decaying to other final states allows for a wide-ranging physics program. In particular, one can access the charmonium system via colour-suppressed b {yields} c decays of the type B {yields} c{bar c}K. This thesis presents a study of B {yields} c{bar c}{gamma}K decays where c{bar c} includes J/{psi} and {psi}(2S), and K includes K{sup {+-}}, K{sub S}{sup 0} and K*(892). The particular emphasis is on a search for the radiative decays X(3872) {yields} J/{psi}{gamma} and X(3872) {yields} {psi}(2S){gamma}. The X(3872) state is a recently-discovered resonance of undetermined quark composition, speculatively a conventional charmonium state or exotic four-quark di-meson molecule. This research is also sensitive to the well-known radiative charmonium decays B {yields} {chi}{sub c1,2}K, which are used as verification for the analysis technique. This dissertation sets the best B {yields} {chi}{sub c1}K branching fraction measurements to date, and sees the first evidence for factorization-suppressed B{sup 0} {yields} {chi}{sub c2}K*{sup 0} decay at a level of 3.6{sigma}. It also provides evidence for X(3872) {yields} J/{psi}{gamma} and X(3872) {yields} {psi}(2S){gamma} with 3.6{sigma} and 3.3{sigma} significance, respectively. The product of branching fractions {Beta}(B{sup {+-}} {yields} X(3872)K{sup {+-}}) {center_dot} {Beta}(X(3872) {yields} J/{psi}{gamma}) = (2.8 {+-} 0.8(stat.) {+-} 0.2(syst.)) x 10{sup -6} and {Beta}(B{sup {+-}} {yields} X(3872)K{sup {+-}}) {yields} {Beta}(X(3872) {yields} {psi}(2S){gamma}) = (9.5 {+-} 2.7(stat.) {+-} 0.9(syst.)) x 10{sup -6} are measured. These results improve upon previous X(3872) {yields} J/{psi}{gamma} measurements, and represent the first evidence for X(3872) {yields} {psi}(2S){gamma}.

  8. DNA repair efficiency in germ cells and early mouse embryos and consequences for radiation-induced transgenerational genomic damage

    E-Print Network [OSTI]

    Marchetti, Francesco

    2009-01-01

    Development and the DOE Low Dose Radiation Research Program.in vivo by low doses of gamma radiation. Rad Res 156, 324-7.

  9. Time encoded radiation imaging

    DOE Patents [OSTI]

    Marleau, Peter; Brubaker, Erik; Kiff, Scott

    2014-10-21

    The various technologies presented herein relate to detecting nuclear material at a large stand-off distance. An imaging system is presented which can detect nuclear material by utilizing time encoded imaging relating to maximum and minimum radiation particle counts rates. The imaging system is integrated with a data acquisition system that can utilize variations in photon pulse shape to discriminate between neutron and gamma-ray interactions. Modulation in the detected neutron count rates as a function of the angular orientation of the detector due to attenuation of neighboring detectors is utilized to reconstruct the neutron source distribution over 360 degrees around the imaging system. Neutrons (e.g., fast neutrons) and/or gamma-rays are incident upon scintillation material in the imager, the photons generated by the scintillation material are converted to electrical energy from which the respective neutrons/gamma rays can be determined and, accordingly, a direction to, and the location of, a radiation source identified.

  10. Final deactivation project report on the High Radiation Level Analytical Facility, Building 3019B at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect (OSTI)

    1997-09-01

    The purpose of this report is to document the condition of the High Radiation Level Analytical Facility (Building 3019B) at Oak Ridge National Laboratory (ORNL) after completion of deactivation activities. This report identifies the activities conducted to place the facility in a safe and environmentally sound condition prior to transfer to the Environmental Restoration EM-40 Program. This document provides a history and description of the facility prior to the commencement of deactivation activities and documents the condition of the building after completion of all deactivation activities. Turnover items, such as the Post-Deactivation Surveillance and Maintenance (S&M) Plan, remaining hazardous materials inventory, radiological controls, safeguards and security, quality assurance, facility operations, and supporting documentation provided in the Nuclear Material and Facility Stabilization (EM-60) Turnover package are discussed. Building 3019B will require access to perform required S&M activities to maintain the building safety envelope. Building 3019B was stabilized during deactivation so that when transferred to the EM-40 Program, only a minimal S&M effort would be required to maintain the building safety envelope. Other than the minimal S&M activities the building will be unoccupied and the exterior doors locked to prevent unauthorized access. The building will be entered only to perform the required S&M until decommissioning activities begin.

  11. Actively driven thermal radiation shield

    DOE Patents [OSTI]

    Madden, Norman W. (Livermore, CA); Cork, Christopher P. (Pleasant Hill, CA); Becker, John A. (Alameda, CA); Knapp, David A. (Livermore, CA)

    2002-01-01

    A thermal radiation shield for cooled portable gamma-ray spectrometers. The thermal radiation shield is located intermediate the vacuum enclosure and detector enclosure, is actively driven, and is useful in reducing the heat load to mechanical cooler and additionally extends the lifetime of the mechanical cooler. The thermal shield is electrically-powered and is particularly useful for portable solid-state gamma-ray detectors or spectrometers that dramatically reduces the cooling power requirements. For example, the operating shield at 260K (40K below room temperature) will decrease the thermal radiation load to the detector by 50%, which makes possible portable battery operation for a mechanically cooled Ge spectrometer.

  12. Did a gamma-ray burst initiate the late Ordovician mass extinction?

    E-Print Network [OSTI]

    Jackman, Charles H.

    Did a gamma-ray burst initiate the late Ordovician mass extinction? A.L. Melott1 , B.S. Lieberman2 Abstract: Gamma-ray bursts (GRBs) produce a flux of radiation detectable across the observable Universe words: Population and evolution, mass extinction, gamma-ray burst, Ordovician, ultraviolet ozone

  13. Oak Ridge D and D Plan 3515 Project - Technology Review (2007) and GammaCam Technology Demonstration for Characterizing Building 3515 at Oak Ridge (2007)

    SciTech Connect (OSTI)

    Byrne-Kelly, D.; Hart, A.; Brown, Ch.; Jordan, D.; Phillips, E.

    2008-07-01

    This paper presents the results from the Characterization, Decontamination and Decommissioning (CD and D) Study performed by MSE Technology Application, Inc. (MSE) to assist the U.S. Department of Energy (DOE) and Oak Ridge National Laboratory (ORNL) in the preparation of a Project Execution Plan and Remediation Plan for Building 3515 at ORNL. Primary objectives of this study were to identify innovative CD and D technologies and methodologies and recommend alternatives applicable to the CD and D of Building 3515. Building 3515 is a small heavily shielded concrete and cement block structure centrally located in the Bethel Valley portion of the ORNL. The building's interior is extensively contaminated with Cesium 137 (Cs-137), the primary contaminant of concern. A previous attempt to characterize the building was limited to general interior area radiation exposure level measurements and a few surface smears gathered by inserting monitoring equipment into the building on long poles. Consequently, the spatial distribution of the gamma radiation source inside the building was not determined. A subsequent plan for D and D of the building presented a high risk of worker radiation dose in excess of as low as reasonably achievable (ALARA) because the source of the interior gamma radiation field is not completely understood and conventional practices required workers to be in close proximity of the building. As part of an initial literature search, MSE reviewed new generation gamma source characterization technologies and identified the GammaCam{sup TM} portable gamma ray imaging system as an innovative technology applicable to locating the dominant gamma ray sources within the building. The GammaCam{sup TM} gamma-ray imaging system is a commercially available technology marketed by the EDO Corporation. This system consists of a sensor head with a co-aligned camera and a portable computer. The system is designed to provide two-dimensional spatial mappings of gamma ray emitting nuclides in real time. The gamma radiation sensor and camera can be set up within or outside of the radiation field while the system operator and PC can be located 30 to 60 m (100 to 200 ft) from the sensor head. The system has been used successfully at numerous DOE and commercial nuclear facilities to precisely locate gamma radiation sources. However, literature attesting to the ability of this technology to detect radiation sources within heavily shielded structures was not available. Consequently, MSE was not certain if this technology would be capable of locating gamma ray sources within the heavily shielded Building 3515. To overcome this uncertainty, MSE sent two individuals to the EDO Corporation for training. At completion of the training, MSE leased the GammaCam{sup TM} portable system and brought it to ORNL to evaluate the capability of the system. An overview from this evaluation is summarized in this paper. (authors)

  14. Neutrino, Neutron, and Cosmic Ray Production in the External Shock Model of Gamma Ray Bursts

    E-Print Network [OSTI]

    Charles D. Dermer

    2002-04-16

    The hypothesis that ultra-high energy (>~ 10^19 eV) cosmic rays (UHECRs) are accelerated by gamma-ray burst (GRB) blast waves is assumed to be correct. Implications of this assumption are then derived for the external shock model of gamma-ray bursts. The evolving synchrotron radiation spectrum in GRB blast waves provides target photons for the photomeson production of neutrinos and neutrons. Decay characteristics and radiative efficiencies of the neutral particles that escape from the blast wave are calculated. The diffuse high-energy GRB neutrino background and the distribution of high-energy GRB neutrino events are calculated for specific parameter sets, and a scaling relation for the photomeson production efficiency in surroundings with different densities is derived. GRBs provide an intense flux of high-energy neutrons, with neutron-production efficiencies exceeding ~ 1% of the total energy release. The radiative characteristics of the neutron beta-decay electrons from the GRB "neutron bomb" are solved in a special case. Galaxies with GRB activity should be surrounded by radiation halos of ~ 100 kpc extent from the outflowing neutrons, consisting of a nonthermal optical/X-ray synchrotron component and a high-energy gamma-ray component from Compton-scattered microwave background radiation. The luminosity of sources of GRBs and relativistic outflows in L* galaxies such as the Milky Way is at the level of ~10^40+-1 ergs/s. This is sufficient to account for UHECR generation by GRBs. We briefly speculate on the possibility that hadronic cosmic rays originate from the subset of supernovae that collapse to form relativistic outflows and GRBs. (abridged)

  15. Gamma-ray shielding properties of some travertines in Turkey

    SciTech Connect (OSTI)

    Akkurt, Iskender; Guenoglu, Kadir

    2012-09-06

    The radiation is an essential phenomenon in daily life. There are various amounts of radioactivite substances in the underground and the earth was irradiated by this substances. Humans are exposed to various kind of radiation from these sources. The travertines are usually used as a coating material in buildings. In this study, the photon attenuation coefficients of some travertines have been measured using a gamma spectroscopy with NaI(Tl) detector. The measurements have been performed using {sup 60}Co source which gives 1173 and 1332 keV energies gamma rays and {sup 137}Cs source which gives 662 keV energy gamma rays and the results will be discussed.

  16. Radiation Detection Computational Benchmark Scenarios

    SciTech Connect (OSTI)

    Shaver, Mark W.; Casella, Andrew M.; Wittman, Richard S.; McDonald, Ben S.

    2013-09-24

    Modeling forms an important component of radiation detection development, allowing for testing of new detector designs, evaluation of existing equipment against a wide variety of potential threat sources, and assessing operation performance of radiation detection systems. This can, however, result in large and complex scenarios which are time consuming to model. A variety of approaches to radiation transport modeling exist with complementary strengths and weaknesses for different problems. This variety of approaches, and the development of promising new tools (such as ORNL’s ADVANTG) which combine benefits of multiple approaches, illustrates the need for a means of evaluating or comparing different techniques for radiation detection problems. This report presents a set of 9 benchmark problems for comparing different types of radiation transport calculations, identifying appropriate tools for classes of problems, and testing and guiding the development of new methods. The benchmarks were drawn primarily from existing or previous calculations with a preference for scenarios which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22. From a technical perspective, the benchmarks were chosen to span a range of difficulty and to include gamma transport, neutron transport, or both and represent different important physical processes and a range of sensitivity to angular or energy fidelity. Following benchmark identification, existing information about geometry, measurements, and previous calculations were assembled. Monte Carlo results (MCNP decks) were reviewed or created and re-run in order to attain accurate computational times and to verify agreement with experimental data, when present. Benchmark information was then conveyed to ORNL in order to guide testing and development of hybrid calculations. The results of those ADVANTG calculations were then sent to PNNL for compilation. This is a report describing the details of the selected Benchmarks and results from various transport codes.

  17. A Search for the Rare Decay $B\\rightarrow\\gamma\\gamma$

    SciTech Connect (OSTI)

    del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-06-02

    We report the result of a search for the rare decay B{sup 0} {yields} {gamma}{gamma} in 426 fb{sup -1} of data, corresponding to 226 million B{sup 0}{bar B}{sup 0} pairs, collected on the {Upsilon}(4S) resonance at the PEP-II asymmetric-energy e{sup +}e{sup -} collider using the BABAR detector. We use a maximum likelihood fit to extract the signal yield and observe 21{sub -12}{sup +13} signal events with a statistical signficance of 1.9 {sigma}. This corresponds to a branching fraction {Beta}(B{sup 0} {yields} {gamma}{gamma}) = (1.7 {+-} 1.1(stat.) {+-} 0.2(syst.)) x 10{sup -7}. Based on this result, we set a 90% confidence level upper limit of {Beta}(B{sup 0} {yields} {gamma}{gamma}) < 3.2 x 10{sup -7}.

  18. Fiber fed x-ray/gamma ray imaging apparatus

    DOE Patents [OSTI]

    Hailey, Charles J. (San Francisco, CA); Ziock, Klaus-Peter (Livermore, CA)

    1992-01-01

    X-ray/gamma ray imaging apparatus is disclosed for detecting the position, energy, and intensity of x-ray/gamma ray radiation comprising scintillation means disposed in the path of such radiation and capable of generating photons in response to such radiation; first photodetection means optically bonded to the scintillation means and capable of generating an electrical signal indicative of the intensity, and energy of the radiation detected by the scintillation means; second photodetection means capable of generating an electrical signal indicative of the position of the radiation in the radiation pattern; and means for optically coupling the scintillation means to the second photodetection means. The photodetection means are electrically connected to control and storage means which may also be used to screen out noise by rejecting a signal from one photodetection means not synchronized to a signal from the other photodetection means; and also to screen out signals from scattered radiation.

  19. Gamma Radiation Dose Rate in Air due to Terrestrial Radionuclides in Southern Brazil: Synthesis by Geological Units and Lithotypes Covered by the Serra do Mar Sul Aero-Geophysical Project

    SciTech Connect (OSTI)

    Bastos, Rodrigo O.; Appoloni, Carlos R. [Applied Nuclear Physics Laboratory-Department of Physics-CCE State University of Londrina Campus Universitario-Rodovia Celso Garcia Cid s/n, Cx. Postal 6001, CEP 86051-990, Londrina, PR (Brazil); Pinese, Jose P. P. [Department of Geosciences-CCE State University of Londrina Campus Universitario-Rodovia Celso Garcia Cid s/n, Cx. Postal 6001, CEP 86051-990, Londrina, PR (Brazil)

    2008-08-07

    The absorbed dose rates in air due to terrestrial radionuclides were estimated from aerial gamma spectrometric data for an area of 48,600 km{sup 2} in Southern Brazil. The source data was the Serra do Mar Sul Aero-Geophysical Project back-calibrated in a cooperative work among the Geological Survey of Brazil, the Geological Survey of Canada, and Paterson, Grant and Watson Ltd. The concentrations of eU (ppm), eTh (ppm) and K (%) were converted to dose rates in air (nGy{center_dot}h{sup -1}) by accounting for the contribution of each element's concentration. Regional variation was interpreted according to lithotypes and a synthesis was performed according to the basic geological units present in the area. Higher values of total dose were estimated for felsic igneous and metamorphic rocks, with average values varying up to 119{+-}24 nGy{center_dot}h{sup -1}, obtained by Anitapolis syenite body. Sedimentary, metasedimentary and metamafic rocks presented the lower dose levels, and some beach deposits reached the lowest average total dose, 18.5{+-}8.2 nGy{center_dot}h{sup -1}. Thorium gives the main average contribution in all geological units, the highest value being reached by the nebulitic gneisses of Atuba Complex, 71{+-}23 nGy{center_dot}h{sup -1}. Potassium presents the lowest average contribution to dose rate in 53 of the 72 units analyzed, the highest contribution being obtained by intrusive alkaline bodies (28{+-}12 nGy{center_dot}h{sup -1}). The general pattern of geographic dose distribution respects well the hypotheses on geo-physicochemical behavior of radioactive elements.

  20. Atomic Radiation (Illinois)

    Broader source: Energy.gov [DOE]

    This article states permissible levels of radiation in unrestricted areas, environmental standards for uranium fuel cycle and information about notification of incidents.

  1. Effect of radiation on silicon and borosilicate glass

    E-Print Network [OSTI]

    Allred, Clark L. (Clark Lane), 1972-

    2003-01-01

    A study was made that is logically divided into two parts, both involving radiation damage effects. The first is a study of the effects of neutron and gamma radiation on the dimensions of two borosilicate glasses, Pyrex® ...

  2. Spatiotemporal characterization of ionizing radiation induced DNA damage foci and their relation to chromatin organization

    E-Print Network [OSTI]

    Costes, Sylvain V

    2010-01-01

    germ cells and after low-dose gamma-radiation: relationshipsexposure to low doses of ionizing radiation. Mutat Res (after exposure to low doses of ionizing radiation. Mutat Res

  3. Discrimination of neutrons and {\\gamma}-rays in liquid scintillator based on Elman neural network

    E-Print Network [OSTI]

    Zhang, Cai-Xun; Zhao, Jian-Ling; Wang, Li; Yu, Xun-Zhen; Zhu, Jing-Jun; Xing, Hao-Yang

    2015-01-01

    A new neutron and {\\gamma} (n/{\\gamma}) discrimination method based on Elman Neural Network (ENN) was put forward to improve the n/{\\gamma} discrimination performance of liquid scintillator (LS). In this study, neutron and {\\gamma} data acquired from EJ-335 which was exposed in Am-Be radiation field was discriminated using ENN. The difference of n/{\\gamma} discrimination performance between using ENN and Back Propagation Neural Network (BPNN) is that ENN gave a improvement over BPNN in n/{\\gamma} discrimination with the increasing increasing of the Figure of Merit (FOM) from 0.907 to 0.953.

  4. Irradiation of DEPFET-like transistors with Co-60 gamma source up to 10 MRad

    E-Print Network [OSTI]

    Pablo Vázquez Regueiro; Eliseo Pérez Trigo; Pablo Rodríguez Pérez

    2011-11-18

    The Pixel Detector (PXD) of the Belle II experiment at superKEKB accelerator in Japan is based in the DEPFET technology. Two layers of 8+12 modules at a radius of 13 and 22 mm will give a spatial resolution below 10 mm. The radiation level expected in the first layer in ten years of operation is about 10 MRad of total ionizing dose. In order to study the tolerance of the DEPFET technology sixty devices were irradiated using a standard procedure like 60Co gamma source. Different doping types, channel sizes and biasing conditions were studied

  5. Gamma-ray burst data from DMSP satellites

    SciTech Connect (OSTI)

    Terrell, J.; Klebesadel, R.W.; Lee, P. ); Griffee, J.W. )

    1991-01-01

    A number of gamma-ray bursts have been detected by means of gamma-ray detectors aboard three Air Force Defense Meteorological Satellite Program (DMSP) satellites, in polar orbits at 800 km altitude. The gamma-ray data have a 2-second resolving time, and are usually telemetered in 5 energy bins in the range 50--1000 keV. Although it is not possible to detect gamma-ray bursts when the DMSP satellites are passing through the radiation belt or the South Atlantic Anomaly, or when the source is obscured by the Earth, a number of gamma-ray bursts have been detected by two or even three of the satellites. The DMSP data may be of considerable, assistance in evaluating time histories, locations, and spectra of gamma-ray bursts.

  6. Gamma-ray burst data from DMSP satellites

    SciTech Connect (OSTI)

    Terrell, J.; Klebesadel, R.W.; Lee, P.; Griffee, J.W.

    1991-12-31

    A number of gamma-ray bursts have been detected by means of gamma-ray detectors aboard three Air Force Defense Meteorological Satellite Program (DMSP) satellites, in polar orbits at 800 km altitude. The gamma-ray data have a 2-second resolving time, and are usually telemetered in 5 energy bins in the range 50--1000 keV. Although it is not possible to detect gamma-ray bursts when the DMSP satellites are passing through the radiation belt or the South Atlantic Anomaly, or when the source is obscured by the Earth, a number of gamma-ray bursts have been detected by two or even three of the satellites. The DMSP data may be of considerable, assistance in evaluating time histories, locations, and spectra of gamma-ray bursts.

  7. Cosmic Rays, Gamma-Rays, & Neutrinos in the Starburst Nuclei of Arp 220

    E-Print Network [OSTI]

    Yoast-Hull, Tova M; Zweibel, Ellen G

    2015-01-01

    The cores of Arp 220, the closest ultra-luminous infrared starburst galaxy, provide an opportunity to study interactions of cosmic rays under extreme conditions. In this paper, we model the populations of cosmic rays produced by supernovae in the central molecular zones of both starburst nuclei. We find that ~65 - 100% of cosmic rays are absorbed in these regions due to their huge molecular gas contents, and thus, the nuclei of Arp 220 nearly complete proton calorimeters. As the cosmic ray protons collide with the interstellar medium, they produce secondary electrons that are also contained within the system and radiate synchrotron emission. Using results from chi-squared tests between the model and the observed radio spectral energy distribution, we predict the emergent gamma-ray and high-energy neutrino spectra and find the magnetic field to be at milligauss levels. Because of the extremely intense far-infrared radiation fields, the gamma-ray spectrum steepens significantly at TeV energies due to gamma-gamm...

  8. Gamma-Ray Bursts: Jets and Energetics

    E-Print Network [OSTI]

    D. A. Frail

    2003-11-12

    The relativistic outflows from gamma-ray bursts are now thought to be narrowly collimated into jets. After correcting for this jet geometry there is a remarkable constancy of both the energy radiated by the burst and the kinetic energy carried by the outflow. Gamma-ray bursts are still the most luminous explosions in the Universe, but they release energies that are comparable to supernovae. The diversity of cosmic explosions appears to be governed by the fraction of energy that is coupled to ultra-relativistic ejecta.

  9. Resonance production in. gamma gamma. collisions

    SciTech Connect (OSTI)

    Renard, F.M.

    1983-04-01

    The processes ..gamma gamma.. ..-->.. hadrons can be depicted as follows. One photon creates a q anti q pair which starts to evolve; the other photon can either (A) make its own q anti q pair and the (q anti q q anti q) system continue to evolve or (B) interact with the quarks of the first pair and lead to a modified (q anti q) system in interaction with C = +1 quantum numbers. A review of the recent theoretical activity concerning resonance production and related problems is given under the following headings: hadronic C = +1 spectroscopy (q anti q, qq anti q anti q, q anti q g, gg, ggg bound states and mixing effects); exclusive ..gamma gamma.. processes (generalities, unitarized Born method, VDM and QCD); total cross section (soft and hard contributions); q/sup 2/ dependence of soft processes (soft/hard separation, 1/sup +- +/ resonances); and polarization effects. (WHK)

  10. Gamma Ray Bursts Sudden, intense flashes of gamma rays

    E-Print Network [OSTI]

    Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

    Gamma Ray Bursts #12;The Case Sudden, intense flashes of gamma rays come from nowhere and disappear with out a trace. Incredibly powerful: A single gamma ray burst is hundreds of times brighter a supernova #12;Who Vela (1960's) Looking for arms testing, found gamma ray bursts Compton Gamma Ray Observatory

  11. Parameters of Cascade Gamma-Decay of Compound-Nuclei Nd-146, Gd-156, Yb-172, Ta-182, W-184, Os-191, Th-231,233, U-239, Pu-240 from Experimental Data of Reaction $(n,?)$

    E-Print Network [OSTI]

    A. M. Sukhovoj; V. A. Khitrov

    2009-06-17

    Re-analysis of experimental data on primary gamma-transitions averaged over some energy intervals of neutron resonances has been performed. Approximation of their cumulative sums together with extrapolation of the obtained distribution to zero value allowed us to determine mean intensities of of E1- and M1-transitions, their probable number and total dispersion of intensity deviations from the mean value. The level density and sum of radiative strength functions determined in this way confirm main peculiarities of these nuclear parameters determined from intensities of the two-step gamma-cascades.

  12. Standards for Protection Against Radiation (Michigan)

    Broader source: Energy.gov [DOE]

    This rule establishes standards for protection against radiation hazards. In addition to complying with requirements set forth, every reasonable effort should be made to maintain radiation levels...

  13. Anomalous quartic boson couplings via gamma gamma --> WW and gamma gamma --> WWZ at the TESLA kinematics

    E-Print Network [OSTI]

    I. B. Marfin; V. A. Mossolov; T. V. Shishkina

    2003-04-30

    The production of two and three electroweak gauge bosons in the high-energy $\\gamma\\gamma$ collisions gives the well opportunity to probe anomalous quartic gauge boson couplings. The influence of five possible anomalous couplings on the cross sections for $W^+W^-$, $W^+W^-\\gamma$, $W^+W^-Z$ productions has been investigated at the TESLA kinematics ($\\sqrt{S}\\sim 1$ TeV). There are the reasonable discriminations between various anomalous contributions.

  14. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, Robert A. (Palo Alto, CA); Perez-Mendez, Victor (Berkeley, CA); Kaplan, Selig N. (El Cerrito, CA)

    1992-01-01

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification.

  15. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, R.A.; Perez-Mendez, V.; Kaplan, S.N.

    1992-11-17

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification. 13 figs.

  16. ON THE JITTER RADIATION

    SciTech Connect (OSTI)

    Kelner, S. R. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-6917 Heidelberg (Germany); Aharonian, F. A. [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Khangulyan, D., E-mail: skelner@rambler.ru, E-mail: Felix.Aharonian@mpi-hd.mpg.de, E-mail: khangul@astro.isas.jaxa.jp [Institute of Space and Astronautical Science/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

    2013-09-01

    In a small-scale turbulent medium, when the nonrelativistic Larmor radius R{sub L} = mc {sup 2}/eB exceeds the correlation length {lambda} of the magnetic field, the magnetic Bremsstrahlung radiation of charged relativistic particles unavoidably proceeds to the so-called jitter radiation regime. The cooling timescale of parent particles is identical to the synchrotron cooling time, thus this radiation regime can be produced with very high efficiency in different astrophysical sources characterized by high turbulence. The jitter radiation has distinct spectral features shifted toward high energies, compared to synchrotron radiation. This effect makes the jitter mechanism an attractive broad-band gamma-ray production channel, which, in highly magnetized and turbulent environments, can compete or even dominate over other high-energy radiation mechanisms. In this paper, we present a novel study of the spectral properties of the jitter radiation performed within the framework of perturbation theory. The derived general expression for the spectral power of radiation is presented in a compact and convenient form for numerical calculations.

  17. Gamma irradiation effects in W films

    SciTech Connect (OSTI)

    Claro, Luiz H.; Santos, Ingrid A.; Silva, Cassia F.

    2013-05-06

    Using the van Der Pauw methodology, the surface resistivity of irradiated tungsten films deposited on Silicon substrate was measured. The films were exposed to {gamma} radiation using a isotopic {sup 60}Co source in three irradiation stages attaining 40.35 kGy in total dose. The obtained results for superficial resistivity display a time annealing features and their values are proportional to the total dose.

  18. Lymphocyte pyknosis following cobalt - 60 gamma irradiation 

    E-Print Network [OSTI]

    Lane, Linda Kay

    1971-01-01

    Three sets of experiments were done to determine whether the lymphocytes that were leaving the peripheral blood supply immediately after receiving 200 rads or 800 rads of cobalt ? 60 gamma radiation were the same ones that would undergo pyknosis... undergo pyknosis after they leave, but the ones that do undergo pyknosis in the peripheral blood supply are not necessarily the ones that leave. &any pyknotic lymphocytes are staying and are being counted in the total lymphocyte count...

  19. Recent Advances in Understanding Radiation Damage in Reactor Cavity Concrete

    SciTech Connect (OSTI)

    Rosseel, Thomas M; Field, Kevin G; Le Pape, Yann; Remec, Igor; Giorla, Alain B; Wall, Dr. James Joseph

    2015-01-01

    License renewal up to 60 years and the possibility of subsequent license renewal to 80 years has resulted in a renewed focus on long-term aging of materials at nuclear power plants (NPPs) including concrete. Large irreplaceable sections of most nuclear generating stations include concrete. The Expanded Materials Degradation Analysis, jointly performed by the Department of Energy, the Nuclear Regulatory Commission and Nuclear Industry, identified the urgent need to develop a consistent knowledge base on irradiation effects in concrete (Graves et al., (2014)). Much of the historical mechanical performance data of irradiated concrete (Hilsdorf et al., (1978)) does not accurately reflect typical radiation conditions in NPPs or conditions out to 60 or 80 years of radiation exposure (Kontani et al., (2011)). To address these potential gaps in the knowledge base, the Electric Power Research Institute and Oak Ridge National Laboratory, are working to better understand radiation damage as a degradation mechanism. This paper outlines recent progress toward: 1) assessing the radiation environment in concrete biological shields and defining the upper bound of the neutron and gamma dose levels expected in the biological shield for extended operation, and estimating adsorbed dose, 2) evaluating opportunities to harvest and test irradiated concrete from international NPPs, 3) evaluating opportunities to irradiate prototypical concrete and its components under accelerated neutron and gamma dose levels to establish conservative bounds and inform damage models, 4) developing improved models to enhance the understanding of the effects of radiation on concrete and 5) establishing an international collaborative research and information exchange effort to leverage capabilities and knowledge including developing cooperative test programs to improve confidence in data obtained from various concretes and from accelerated irradiation experiments.

  20. Thermoluminescence and dielectric response of gamma irradiated muscovite mica

    SciTech Connect (OSTI)

    Kaur, Sukhnandan, E-mail: sukhnandanphy@gmail.com; Singh, Surinder, E-mail: sukhnandanphy@gmail.com; Singh, Lakhwant, E-mail: sukhnandanphy@gmail.com [Department of Physics, Guru Nanak Dev University, Amritsar-143005 (India); Lochab, S. P. [Inter University Accelerator Centre, New Delhi-110067 (India)

    2014-04-24

    The effect of gamma radiation dose on the thermoluminescence (TL) and dielectric properties of muscovite mica was studied. TL glow curves exhibited a single peak around 141 {sup 0}C and its activation energy was estimated to be about 0.89 eV. Different dielectric parameters like dielectric constant, dielectric loss and ac conductivity have been calculated in both pristine and gamma irradiated samples. These dielectric parameters have been studied as a function of irradiation dose.

  1. Sex-dependent Differences in Intestinal Tumorigenesis Induced in Apc1638N/+ Mice by Exposure to {gamma} Rays

    SciTech Connect (OSTI)

    Trani, Daniela; Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia; Maastricht Radiation Oncology Lab, GROW-School for Oncology and Developmental Biology, University of Maastricht ; Moon, Bo-Hyun; Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia ; Kallakury, Bhaskar; Hartmann, Dan P.; Datta, Kamal; Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia ; Fornace, Albert J.

    2013-01-01

    Purpose: The purpose of the present study was to assess the effect of 1 and 5 Gy radiation doses and to investigate the interplay of gender and radiation with regard to intestinal tumorigenesis in an adenomatous polyposis coli (APC) mutant mouse model. Methods and Materials: Apc1638N/+ female and male mice were exposed whole body to either 1 Gy or 5 Gy of {gamma} rays and euthanized when most of the treated mice became moribund. Small and large intestines were processed to determine tumor burden, distribution, and grade. Expression of proliferation marker Ki-67 and estrogen receptor (ER)-{alpha} were also assessed by immunohistochemistry. Results: We observed that, with both 1 Gy and 5 Gy of {gamma} rays, females displayed reduced susceptibility to radiation-induced intestinal tumorigenesis compared with males. As for radiation effect on small intestinal tumor progression, although no substantial differences were found in the relative frequency and degree of dysplasia of adenomas in irradiated animals compared with controls, invasive carcinomas were found in 1-Gy- and 5-Gy-irradiated animals. Radiation exposure was also shown to induce an increase in protein levels of proliferation marker Ki-67 and sex-hormone receptor ER-{alpha} in both non tumor mucosa and intestinal tumors from irradiated male mice. Conclusions: We observed important sex-dependent differences in susceptibility to radiation-induced intestinal tumorigenesis in Apc1638N/+ mutants. Furthermore, our data provide evidence that exposure to radiation doses as low as 1 Gy can induce a significant increase in intestinal tumor multiplicity as well as enhance tumor progression in vivo.

  2. Radiation physics, biophysics, and radiation biology

    SciTech Connect (OSTI)

    Hall, E.J.; Zaider, M.

    1991-05-01

    Research at the Radiological Research Laboratory is a blend of physics, chemistry, and biology, involving research at the basic level with the admixture of a small proportion of pragmatic or applied research in support of radiation protection and/or radiotherapy. Current research topics include: oncogenic transformation assays, mutation studies involving interactions between radiation and environmental contaminants, isolation, characterization and sequencing of a human repair gene, characterization of a dominant transforming gene found in C3H 10T1/2 cells, characterize ab initio the interaction of DNA and radiation, refine estimates of the radiation quality factor Q, a new mechanistic model of oncogenesis showing the role of long-term low dose medium LET radiation, and time dependent modeling of radiation induced chromosome damage and subsequent repair or misrepair.

  3. Optical gamma thermometer

    DOE Patents [OSTI]

    Koster, Glen Peter; Xia, Hua; Lee, Boon Kwee

    2013-08-06

    An optical gamma thermometer includes a metal mass having a temperature proportional to a gamma flux within a core of a nuclear reactor, and an optical fiber cable for measuring the temperature of the heated metal mass. The temperature of the heated mass may be measured by using one or more fiber grating structures and/or by using scattering techniques, such as Raman, Brillouin, and the like. The optical gamma thermometer may be used in conjunction with a conventional reactor heat balance to calibrate the local power range monitors over their useful in-service life. The optical gamma thermometer occupies much less space within the in-core instrument tube and costs much less than the conventional gamma thermometer.

  4. Appendix G. Radiation Appendix G. Radiation G-3

    E-Print Network [OSTI]

    Pennycook, Steve

    , radio waves, and alpha particles are examples of radiation. When people feel warmth from sunlight in the form of electromagnetic waves. Examples include gamma rays, ultraviolet light, and radio waves, or radiant energy, is energy in the form of waves or particles moving through space. Visi- ble light, heat

  5. Appendix F. Radiation Appendix F. Radiation F-3

    E-Print Network [OSTI]

    Pennycook, Steve

    energy, is energy in the form of waves or particles moving through space. Visi- ble light, heat, radio in the form of electromagnetic waves. Examples include gamma rays, ultraviolet light, and radio waves waves, and alpha particles are examples of radiation. When people feel warmth from sunlight

  6. CLOAKED GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Eichler, David, E-mail: eichler.david@gmail.com [Physics Department, Ben-Gurion University, Be'er-Sheva 84105 (Israel)

    2014-06-01

    It is suggested that many gamma-ray bursts (GRBs) are cloaked by an ultrarelativistic baryonic shell that has high optical depth when the photons are manufactured. Such a shell would not fully block photons reflected or emitted from its inner surface, because the radial velocity of the photons can be less than that of the shell. This avoids the standard problem associated with GRBs that the thermal component should be produced where the flow is still obscured by high optical depth. The radiation that escapes high optical depth obeys the Amati relation. Observational implications may include (1) anomalously high ratios of afterglow to prompt emission, such as may have been the case in the recently discovered PTF 11agg, and (2) ultrahigh-energy neutrino pulses that are non-coincident with detectable GRB. It is suggested that GRB 090510, a short, very hard GRB with very little afterglow, was an exposed GRB, in contrast to those cloaked by baryonic shells.

  7. Inelastic cross sections from gamma-ray measurements

    SciTech Connect (OSTI)

    Nelson, Ronald Owen [Los Alamos National Laboratory

    2010-12-06

    Measurements of gamma rays following neutron induced reactions have been studied with the Germanium Array for Neutron-induced Excitations (GEANIE) at the Los Alamos Neutron Science Center (LANSCE) for many years. Gamma-ray excitation functions and coincidence studies provide insight into nuclear reaction mechanisms as well as expanding our knowledge of energy levels and gamma-rays. Samples studied with Ge detectors at LANSCE range from Be to Pu. Fe, Cr and Ti have been considered for use as reference cross sections. An overview of the measurements and efforts to create a reliable neutron-induced gamma-ray reference cross section will be presented.

  8. Energetics of Gamma Ray Bursts

    E-Print Network [OSTI]

    Raul Jimenez; David Band; Tsvi Piran

    2001-03-16

    We determine the distribution of total energy emitted by gamma-ray bursts for bursts with fluences and distance information. Our core sample consists of eight bursts with BATSE spectra and spectroscopic redshifts. We extend this sample by adding four bursts with BATSE spectra and host galaxy R magnitudes. From these R magnitudes we calculate a redshift probability distribution; this method requires a model of the host galaxy population. From a sample of ten bursts with both spectroscopic redshifts and host galaxy R magnitudes (some do not have BATSE spectra) we find that the burst rate is proportional to the galaxy luminosity at the epoch of the burst. Assuming that the total energy emitted has a log-normal distribution, we find that the average emitted energy (assumed to be radiated isotropically) is $ = 1.3^{+1.2}_{-1.0} \\times 10^{53}$ ergs (for H$_0$ = 65 km s$^{-1}$ Mpc$^{-1}$, $\\Omega_m=0.3$ and $\\Omega_\\Lambda=0.7$); the distribution has a logarithmic width of $\\sigma_\\gamma=1.7^{+0.7}_{-0.3}$. The corresponding distribution of X-ray afterglow energy (for seven bursts) has $ = 4.0^{+1.6}_{-1.8} \\times 10^{51}$ergs and $\\sigma_X = 1.3^{+0.4}_{-0.3}$. For completeness, we also provide spectral fits for all bursts with BATSE spectra for which there were afterglow searches.

  9. Spatial Evidence for Transition Radiation in a Solar Radio Burst

    E-Print Network [OSTI]

    Gelu M. Nita; Dale E. Gary; Gregory D. Fleishman

    2005-07-10

    Microturbulence, i.e. enhanced fluctuations of plasma density, electric and magnetic fields, is of great interest in astrophysical plasmas, but occurs on spatial scales far too small to resolve by remote sensing, e.g., at ~ 1-100 cm in the solar corona. This paper reports spatially resolved observations that offer strong support for the presence in solar flares of a suspected radio emission mechanism, resonant transition radiation, which is tightly coupled to the level of microturbulence and provides direct diagnostics of the existence and level of fluctuations on decimeter spatial scales. Although the level of the microturbulence derived from the radio data is not particularly high, /n^2 ~ 10^{-5}$, it is large enough to affect the charged particle diffusion and give rise to effective stochastic acceleration. This finding has exceptionally broad astrophysical implications since modern sophisticated numerical models predict generation of much stronger turbulence in relativistic objects, e.g., in gamma-ray burst sources.

  10. DNA microarray analyses reveal a post-irradiation differential time-dependent gene expression profile in yeast cells exposed to X-rays and {gamma}-rays

    SciTech Connect (OSTI)

    Kimura, Shinzo [Laboratory of Environmental Biology, Department of Preventive Medicine, Hokkaido University School of Medicine, Sapporo 060-8638 (Japan); Ishidou, Emi [Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science and Technology (AIST) WEST, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Kurita, Sakiko [Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science and Technology (AIST) WEST, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Suzuki, Yoshiteru [Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science and Technology (AIST) WEST, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Shibato, Junko [Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science and Technology (AIST) WEST, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Rakwal, Randeep [Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science and Technology (AIST) WEST, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan)]. E-mail: rakwal-68@aist.go.jp; Iwahashi, Hitoshi [Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science and Technology (AIST) WEST, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan)

    2006-07-21

    Ionizing radiation (IR) is the most enigmatic of genotoxic stress inducers in our environment that has been around from the eons of time. IR is generally considered harmful, and has been the subject of numerous studies, mostly looking at the DNA damaging effects in cells and the repair mechanisms therein. Moreover, few studies have focused on large-scale identification of cellular responses to IR, and to this end, we describe here an initial study on the transcriptional responses of the unicellular genome model, yeast (Saccharomyces cerevisiae strain S288C), by cDNA microarray. The effect of two different IR, X-rays, and gamma ({gamma})-rays, was investigated by irradiating the yeast cells cultured in YPD medium with 50 Gy doses of X- and {gamma}-rays, followed by resuspension of the cells in YPD for time-course experiments. The samples were collected for microarray analysis at 20, 40, and 80 min after irradiation. Microarray analysis revealed a time-course transcriptional profile of changed gene expressions. Up-regulated genes belonged to the functional categories mainly related to cell cycle and DNA processing, cell rescue defense and virulence, protein and cell fate, and metabolism (X- and {gamma}-rays). Similarly, for X- and {gamma}-rays, the down-regulated genes belonged to mostly transcription and protein synthesis, cell cycle and DNA processing, control of cellular organization, cell fate, and C-compound and carbohydrate metabolism categories, respectively. This study provides for the first time a snapshot of the genome-wide mRNA expression profiles in X- and {gamma}-ray post-irradiated yeast cells and comparatively interprets/discusses the changed gene functional categories as effects of these two radiations vis-a-vis their energy levels.

  11. Offsite environmental monitoring report: Radiation monitoring around United States nuclear test areas, calendar year 1997

    SciTech Connect (OSTI)

    Davis, M.G.; Flotard, R.D.; Fontana, C.A.; Hennessey, P.A.; Maunu, H.K.; Mouck, T.L.; Mullen, A.A.; Sells, M.D.

    1999-01-01

    This report describes the Offsite Radiological Environmental Monitoring Program (OREMP) conducted during 1997 by the US Environmental Protection Agency`s (EPAs), Radiation and Indoor Environments National Laboratory, Las Vegas, Nevada. This laboratory operated an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling and analyzing milk, water, and air; by deploying and reading thermoluminescent dosimeters (TLDs); and using pressurized ionization chambers (PICs) to measure ambient gamma exposure rates with a sensitivity capable of detecting low level exposures not detected by other monitoring methods.

  12. Risk Estimation; Background Radiation (Natural and Artificial )

    E-Print Network [OSTI]

    Massey, Thomas N.

    . · This is necessary to obtain reasonable statistics on these rare events of radiation effects at low dose is based artificial and natural · response to low-level radiation. · personal background radiation level. #12;An Organism's Response to Radiation · The dose response can be linear or nonlinear and threshold or non

  13. Neutron counting and gamma spectroscopy with PVT detectors.

    SciTech Connect (OSTI)

    Mitchell, Dean James; Brusseau, Charles A.

    2011-06-01

    Radiation portals normally incorporate a dedicated neutron counter and a gamma-ray detector with at least some spectroscopic capability. This paper describes the design and presents characterization data for a detection system called PVT-NG, which uses large polyvinyl toluene (PVT) detectors to monitor both types of radiation. The detector material is surrounded by polyvinyl chloride (PVC), which emits high-energy gamma rays following neutron capture reactions. Assessments based on high-energy gamma rays are well suited for the detection of neutron sources, particularly in border security applications, because few isotopes in the normal stream of commerce have significant gamma ray yields above 3 MeV. Therefore, an increased count rate for high-energy gamma rays is a strong indicator for the presence of a neutron source. The sensitivity of the PVT-NG sensor to bare {sup 252}Cf is 1.9 counts per second per nanogram (cps/ng) and the sensitivity for {sup 252}Cf surrounded by 2.5 cm of polyethylene is 2.3 cps/ng. The PVT-NG sensor is a proof-of-principal sensor that was not fully optimized. The neutron detector sensitivity could be improved, for instance, by using additional moderator. The PVT-NG detectors and associated electronics are designed to provide improved resolution, gain stability, and performance at high-count rates relative to PVT detectors in typical radiation portals. As well as addressing the needs for neutron detection, these characteristics are also desirable for analysis of the gamma-ray spectra. Accurate isotope identification results were obtained despite the common impression that the absence of photopeaks makes data collected by PVT detectors unsuitable for spectroscopic analysis. The PVT detectors in the PVT-NG unit are used for both gamma-ray and neutron detection, so the sensitive volume exceeds the volume of the detection elements in portals that use dedicated components to detect each type of radiation.

  14. Radiation-resistant microorganism

    DOE Patents [OSTI]

    Fliermans, Carl B.

    2010-06-15

    An isolated and purified bacterium is provided which was isolated from a high-level radioactive waste site of mixed waste. The isolate has the ability to degrade a wide variety of organic contaminants while demonstrating high tolerance to ionizing radiation. The organism is uniquely suited to bioremediation of a variety or organic contaminants while in the presence of ionizing radiation.

  15. A fast algorithm for gamma evaluation in 3D

    SciTech Connect (OSTI)

    Wendling, Markus; Zijp, Lambert J.; McDermott, Leah N.; Smit, Ewoud J.; Sonke, Jan-Jakob; Mijnheer, Ben J.; Herk, Marcel van [Department of Radiation Oncology, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands)

    2007-05-15

    The {gamma}-evaluation method is a tool by which dose distributions can be compared in a quantitative manner combining dose-difference and distance-to-agreement criteria. Since its introduction, the {gamma} evaluation has been used in many studies and is on the verge of becoming the preferred dose distribution comparison method, particularly for intensity-modulated radiation therapy (IMRT) verification. One major disadvantage, however, is its long computation time, which especially applies to the comparison of three-dimensional (3D) dose distributions. We present a fast algorithm for a full 3D {gamma} evaluation at high resolution. Both the reference and evaluated dose distributions are first resampled on the same grid. For each point of the reference dose distribution, the algorithm searches for the best point of agreement according to the {gamma} method in the evaluated dose distribution, which can be done at a subvoxel resolution. Speed, computer memory efficiency, and high spatial resolution are achieved by searching around each reference point with increasing distance in a sphere, which has a radius of a chosen maximum search distance and is interpolated 'on-the-fly' at a chosen sample step size. The smaller the sample step size and the larger the differences between the dose distributions, the longer the {gamma} evaluation takes. With decreasing sample step size, statistical measures of the 3D {gamma} distribution converge. Two clinical examples were investigated using 3% of the prescribed dose as dose-difference and 0.3 cm as distance-to-agreement criteria. For 0.2 cm grid spacing, the change in {gamma} indices was negligible below a sample step size of 0.02 cm. Comparing the full 3D {gamma} evaluation and slice-by-slice 2D {gamma} evaluations ('2.5D') for these clinical examples, the {gamma} indices improved by searching in full 3D space, with the average {gamma} index decreasing by at least 8%.

  16. Soft gamma repeaters Kevin Hurley *

    E-Print Network [OSTI]

    California at Berkeley, University of

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1331 1. Introduction The soft gamma repeaters (SGRs) are sporadic sources of bursts of X- and gamma-rays), and a rather soft spectrum compared to those of cosmic gamma-ray bursts; a rough description of the spectrumReview Soft gamma repeaters Kevin Hurley * University of California, Berkeley, Space Sciences

  17. Angular Signatures of Dark Matter in the Diffuse Gamma Ray Spectrum

    SciTech Connect (OSTI)

    Hooper, Dan; Serpico, Pasquale D.; /Fermilab

    2007-02-01

    Dark matter annihilating in our Galaxy's halo and elsewhere in the universe is expected to generate a diffuse flux of gamma rays, potentially observable with next generation satellite-based experiments, such as GLAST. In this article, we study the signatures of dark matter in the angular distribution of this radiation. Pertaining to the extragalactic contribution, we discuss the effect of the motion of the solar system with respect to the cosmological rest frame, and anisotropies due to the structure of our local universe. For the gamma ray flux from dark matter in our own Galactic halo, we discuss the effects of the offset position of the solar system, the Compton-Getting effect, the asphericity of the Milky Way halo, and the signatures of nearby substructure. We explore the prospects for the detection of these features by the GLAST satellite and find that, if {approx} 10% or more of the diffuse gamma ray background observed by EGRET is the result of dark matter annihilations, then GLAST should be sensitive to anisotropies down to the 0.1% level. Such precision would be sufficient to detect many, if not all, of the signatures discussed in this paper.

  18. Sigma Gamma Tau 

    E-Print Network [OSTI]

    Unknown

    2011-08-17

    Three drums containing potentially contaminated lead bricks were assayed with the Segmented Gamma Scan Neutron Assay System (SGSNAS) at Pacific Northwest National Laboratory's (PNNL) Nondestructive Assay Center. The assay system reported...

  19. Did a gamma-ray burst initiate the late Ordovician mass extinction?

    E-Print Network [OSTI]

    Melott, Adrian L.; Lieberman, Bruce S.; Laird, C. M.; Martin, Larry D.; Medvedev, Mikhail V.; Thomas, Brian C.; Cannizzo, J. K.; Gehrels, N.; Jackman, C. H.

    2004-01-01

    Gamma-ray bursts (GRBs) produce a flux of radiation detectable across the observable Universe. A GRB within our own galaxy could do considerable damage to the Earth's biosphere; rate estimates suggest that a dangerously near GRB should occur...

  20. B [right arrow] ([rho]/[omega]) [gamma] at BaBar

    E-Print Network [OSTI]

    Köneke, Karsten, 1978-

    2007-01-01

    This document describes the measurements of the branching fractions and isospin violations of the radiative electroweak penguin decays B [right arrow] ([rho]/[omega]) [gamma] at the asymmetric energy e+e- PEP-II collider ...

  1. Radiation: Radiation Control (Indiana)

    Broader source: Energy.gov [DOE]

    It is the policy of the state to encourage the constructive uses of radiation and to control its harmful effects. This section contains regulations pertaining to the manufacture, use,...

  2. Gamma-Ray Bursts

    E-Print Network [OSTI]

    P. Meszaros

    2006-05-30

    Gamma-ray bursts are the most luminous explosions in the Universe, and their origin and mechanism are the focus of intense research and debate. More than three decades after their discovery, and after pioneering breakthroughs from space and ground experiments, their study is entering a new phase with the recently launched Swift satellite. The interplay between these observations and theoretical models of the prompt gamma ray burst and its afterglow is reviewed.

  3. A supersymmetric model of gamma ray bursts

    E-Print Network [OSTI]

    L. Clavelli; G. Karatheodoris

    2005-08-08

    We propose a model for gamma ray bursts in which a star subject to a high level of fermion degeneracy undergoes a phase transition to a supersymmetric state. The burst is initiated by the transition of fermion pairs to sfermion pairs which, uninhibited by the Pauli exclusion principle, can drop to the ground state of minimum momentum through photon emission. The jet structure is attributed to the Bose statistics of sfermions whereby subsequent sfermion pairs are preferentially emitted into the same state (sfermion amplification by stimulated emission). Bremsstrahlung gamma rays tend to preserve the directional information of the sfermion momenta and are themselves enhanced by stimulated emission.

  4. Radiation analysis devices, radiation analysis methods, and articles of manufacture

    DOE Patents [OSTI]

    Roybal, Lyle Gene

    2010-06-08

    Radiation analysis devices include circuitry configured to determine respective radiation count data for a plurality of sections of an area of interest and combine the radiation count data of individual of sections to determine whether a selected radioactive material is present in the area of interest. An amount of the radiation count data for an individual section is insufficient to determine whether the selected radioactive material is present in the individual section. An article of manufacture includes media comprising programming configured to cause processing circuitry to perform processing comprising determining one or more correction factors based on a calibration of a radiation analysis device, measuring radiation received by the radiation analysis device using the one or more correction factors, and presenting information relating to an amount of radiation measured by the radiation analysis device having one of a plurality of specified radiation energy levels of a range of interest.

  5. Spectral Properties of Black Holes in Gamma Rays

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    2005-01-14

    Black holes are the most compact objects in the universe. Therefore, matter accreting onto is likely to radiate photons of energy comparable to very high gravitational potential energy. We discuss the nature of the emitted radiation in X-rays and gamma-rays from black hole candidates. We present theoretical solutions which comprise both Keplerian and sub-Keplerian components and suggest that shocks in accretion and outflows

  6. Compton Electrons and Electromagnetic Pulse in Supernovae and Gamma-Ray Bursts

    E-Print Network [OSTI]

    J. I. Katz

    1999-08-19

    When gamma-rays emerge from a central source they may undergo Compton scattering in surrounding matter. The resulting Compton-scattered electrons radiate. Coherent radiation by such Compton electrons follows nuclear explosions above the Earth's atmosphere. Particle acceleration in instabilities produced by Compton electron currents may explain the radio emission by SN1998bw. Bounds on coherent radiation are suggested for supernovae and gamma-ray bursts; these bounds are very high, but it is unknown if coherent radiation occurs in these objects.

  7. Gamma-Ray Pulsars: Models and Predictions

    E-Print Network [OSTI]

    Alice K. Harding

    2000-12-12

    Pulsed emission from gamma-ray pulsars originates inside the magnetosphere, from radiation by charged particles accelerated near the magnetic poles or in the outer gaps. In polar cap models, the high energy spectrum is cut off by magnetic pair production above an energy that is dependent on the local magnetic field strength. While most young pulsars with surface fields in the range B = 10^{12} - 10^{13} G are expected to have high energy cutoffs around several GeV, the gamma-ray spectra of old pulsars having lower surface fields may extend to 50 GeV. Although the gamma-ray emission of older pulsars is weaker, detecting pulsed emission at high energies from nearby sources would be an important confirmation of polar cap models. Outer gap models predict more gradual high-energy turnovers at around 10 GeV, but also predict an inverse Compton component extending to TeV energies. Detection of pulsed TeV emission, which would not survive attenuation at the polar caps, is thus an important test of outer gap models. Next-generation gamma-ray telescopes sensitive to GeV-TeV emission will provide critical tests of pulsar acceleration and emission mechanisms.

  8. Influence of Extraterrestrial Radiation on Radiation Portal Monitors

    SciTech Connect (OSTI)

    Keller, Paul E.; Kouzes, Richard T.

    2009-06-01

    Cosmic radiation and solar flares can be a major source of background radiation at the Earth’s surface. This paper examines the relationship between extraterrestrial radiation and the detectable background in radiation portal monitors used for homeland security applications. Background radiation data from 13 radiation portal monitor facilities are examined and compared against external sources of data related to extraterrestrial radiation, including measurements at neutron monitors located at 53 cosmic-ray observatories around the Earth, four polar orbiting satellites, three geostationary satellites, ground-based geomagnetic field data from observatories around the Earth, a solar magnetic index, solar radio flux data, and sunspot activity data. Four-years (January 2003 through December 2006) of data are used in this study, which include the latter part of Solar Cycle 23 as solar activity was on the decline. The analysis shows a significant relationship between some extraterrestrial radiation and the background detected in the radiation portal monitors. A demonstrable decline is shown in the average gamma ray and neutron background at the radiation portal monitors as solar activity declined over the period of the study.

  9. Gamma-rays from halos around stars and the Sun

    E-Print Network [OSTI]

    Elena Orlando; Andrew Strong

    2006-10-31

    Inverse Compton scattering by relativistic electrons produces a major component of the diffuse emission from the Galaxy. The photon fields involved are the cosmic microwave background and the interstellar radiation field from stars and dust. Calculations of the inverse Compton distribution have usually assumed a smooth ISRF, but in fact a large part of the Galactic luminosity comes from the most luminous stars which are rare. Therefore we expect the ISRF, and hence the inverse Compton emission, to be clumpy at some level which could be detectable by instruments such as GLAST. Even individual nearby luminous stars could be detectable assuming just the normal cosmic-ray electron spectrum. We present the basic formalism required and give possible candidate stars to be detected, and make predictions for GLAST. Then we apply the formalism to OB associations and the Sun, showing that the IC emission produced is not negligible compared to the sensitivity of current or coming detectors. We estimate that the gamma-ray flux from the halo around the Sun contributes to the diffuse background emission at about the few percent level.

  10. Ionizing radiation induced leakage current on ultra-thin gate oxides

    SciTech Connect (OSTI)

    Scarpa, A.; Paccagnella, A.; Montera, F.; Ghibaudo, G.; Pananakakis, G.; Fuochi, P.G.

    1997-12-01

    MOS capacitors with a 4.4 nm thick gate oxide have been exposed to {gamma} radiation from a Co{sup 60} source. As a result, the authors have measured a stable leakage current at fields lower than those required for Fowler-Nordheim tunneling. This Radiation Induced Leakage Current (RILC) is similar to the usual Stress Induced Leakage Currents (SILC) observed after electrical stresses of MOS devices. They have verified that these two currents share the same dependence on the oxide field, and the RILC contribution can be normalized to an equivalent injected charge for Constant Current Stresses. They have also considered the dependence of the RILC from the cumulative radiation dose, and from the applied bias during irradiation, suggesting a correlation between RILC and the distribution of trapped holes and neutral levels in the oxide layer.

  11. Neutron-driven gamma-ray laser

    DOE Patents [OSTI]

    Bowman, Charles D. (Los Alamos, NM)

    1990-01-01

    A lasing cylinder emits laser radiation at a gamma-ray wavelength of 0.87 .ANG. when subjected to an intense neutron flux of about 400 eV neutrons. A 250 .ANG. thick layer of Be is provided between two layers of 100 .ANG. thick layer of .sup.57 Co and these layers are supported on a foil substrate. The coated foil is coiled to form the lasing cylinder. Under the neutron flux .sup.57 Co becomes .sup.58 Co by neutron absorption. The .sup.58 Co then decays to .sup.57 Fe by 1.6 MeV proton emission. .sup.57 Fe then transitions by mesne decay to a population inversion for lasing action at 14.4 keV. Recoil from the proton emission separates the .sup.57 Fe from the .sup.57 Co and into the Be, where Mossbauer emission occurs at a gamma-ray wavelength.

  12. Neutron and gamma irradiation damage to organic materials.

    SciTech Connect (OSTI)

    White, Gregory Von, II; Bernstein, Robert

    2012-04-01

    This document discusses open literature reports which investigate the damage effects of neutron and gamma irradiation on polymers and/or epoxies - damage refers to reduced physical chemical, and electrical properties. Based on the literature, correlations are made for an SNL developed epoxy (Epon 828-1031/DDS) with an expected total fast-neutron fluence of {approx}10{sup 12} n/cm{sup 2} and a {gamma} dosage of {approx}500 Gy received over {approx}30 years at < 200 C. In short, there are no gamma and neutron irradiation concerns for Epon 828-1031/DDS. To enhance the fidelity of our hypotheses, in regards to radiation damage, we propose future work consisting of simultaneous thermal/irradiation (neutron and gamma) experiments that will help elucidate any damage concerns at these specified environmental conditions.

  13. A Platinum-Enriched gamma+gamma' Two-Phase Bond Coat on Ni-Base Superalloys

    SciTech Connect (OSTI)

    Zhang, Ying [Tennessee Technological University; Pint, Bruce A [ORNL; Haynes, James A [ORNL; Wright, Ian G [ORNL

    2005-01-01

    Pt-enriched {gamma} + {gamma}{prime} two-phase coating was applied to directionally-solidified Ni-based superalloy Ren{acute e} 142 substrates with three different Hf levels (0.02, 0.76, and 1.37 wt.%). The coating was prepared by electroplating a thin layer of Pt on the superalloy followed by a diffusion treatment. The as-deposited coating exhibited a {gamma} + {gamma}{prime} two-phase microstructure with a major composition of Ni-16Al-18Pt-7Cr-9Co (in at.%) along with some incorporation of refractory elements from the substrates. Cyclic oxidation testing at 1100 C in air indicated improved oxidation resistance of the Ren{acute e} 142 alloys with the Pt-enriched {gamma} + {gamma}{prime} coatings. In addition, the oxidation resistance of both uncoated and coated alloys was proportional to the Hf content in the substrate. Compared with the single-phase {beta}-(Ni,Pt)Al coating, slightly higher mass gains and localized spallation were observed on the {gamma} + {gamma}{prime} two-phase coating, which might be due to the segregation of refractory elements and high sulfur levels in these superalloy substrates.

  14. Gamma ray bursts in their historic context

    E-Print Network [OSTI]

    Trimble, V

    2004-01-01

    Gamma Ray Bursts In Their Historic Context Virginia TrimbleMD 20742 USA Abstract. Gamma ray bursts remained essentiallyalso applies to the gamma ray bursts. First, an observation

  15. Deep-level defects introduced by 1 MeV electron radiation in AlInGaP for multijunction space solar cells

    SciTech Connect (OSTI)

    Lee, H.S.; Yamaguchi, M.; Ekins-Daukes, N. J.; Khan, A.; Takamoto, T.; Agui, T.; Kamimura, K.; Kaneiwa, M.; Imaizumi, M.; Ohshima, T.; Itoh, H.

    2005-11-01

    Presented in this paper are 1 MeV electron irradiation effects on wide-band-gap (1.97 eV) (Al{sub 0.08}Ga{sub 0.92}){sub 0.52}In{sub 0.48}P diodes and solar cells. The carrier removal rate estimated in p-AlInGaP with electron fluence is about 1 cm{sup -1}, which is lower than that in InP and GaAs. From high-temperature deep-level transient spectroscopy measurements, a deep-level defect center such as majority-carrier (hole) trap H2 (E{sub {nu}}+0.90{+-}0.05 eV) was observed. The changes in carrier concentrations ({delta}p) and trap densities as a function of electron fluence were compared, and as a result the total introduction rate, 0.39 cm{sup -1}, of majority-carrier trap centers (H1 and H2) is different from the carrier removal rate, 1 cm{sup -1}, in p-AlInGaP. From the minority-carrier injection annealing (100 mA/cm{sup 2}), the annealing activation energy of H2 defect is {delta}E=0.60 eV, which is likely to be associated with a vacancy-phosphorus Frenkel pair (V{sub p}-P{sub i}). The recovery of defect concentration and carrier concentration in the irradiated p-AlInGaP by injection relates that a deep-level defect H2 acts as a recombination center as well as compensator center.

  16. Apparatuses and methods for detecting, identifying and quantitating radioactive nuclei and methods of distinguishing neutron stimulation of a radiation particle detector from gamma-ray stimulation of a detector

    DOE Patents [OSTI]

    Cole, Jerald D. (Idaho Falls, ID); Drigert, Mark W. (Idaho Falls, ID); Reber, Edward L. (Idaho Falls, ID); Aryaeinejad, Rahmat (Idaho Falls, ID)

    2001-01-01

    In one aspect, the invention encompasses a method of detecting radioactive decay, comprising: a) providing a sample comprising a radioactive material, the radioactive material generating decay particles; b)providing a plurality of detectors proximate the sample, the detectors comprising a first set and a second set, the first set of the detectors comprising liquid state detectors utilizing liquid scintillation material coupled with photo tubes to generate a first electrical signal in response to decay particles stimulating the liquid scintillation material, the second set of the detectors comprising solid state detectors utilizing a crystalline solid to generate a second electrical signal in response to decay particles stimulating the crystalline solid; c) stimulating at least one of the detectors to generate at least one of the first and second electrical signals, the at least one of the first and second electrical signals being indicative of radioactive decay in the sample. In another aspect, the invention encompasses an apparatus for identifying and quantitating radioactive nuclei of a sample comprising radioactive material that decays to generate neutrons and high-energy .gamma.-rays.

  17. Measurement of ISR-FSR interference in the processes e+ e- --> mu+ mu- gamma and e+ e- --> pi+ pi- gamma

    E-Print Network [OSTI]

    BABAR Collaboration

    2015-08-17

    Charge asymmetry in processes e+ e- --> mu+ mu- gamma and e+ e- --> pi+ pi- gamma is measured using 232 fb-1 of data collected with the BABAR detector at center-of-mass energies near 10.58 GeV. An observable is introduced and shown to be very robust against detector asymmetries while keeping a large sensitivity to the physical charge asymmetry that results from the interference between initial and final state radiation. The asymmetry is determined as afunction of the invariant mass of the final-state tracks from production threshold to a few GeV/c2. It is compared to the expectation from QED for e+ e- --> mu+ mu- gamma and from theoretical models for e+ e- --> pi+ pi- gamma. A clear interference pattern is observed in e+ e- --> pi+ pi- gamma, particularly in the vicinity of the f_2(1270) resonance. The inferred rate of lowest order FSR production is consistent with the QED expectation for e+ e- --> mu+ mu- gamma, and is negligibly small for e+ e- --> pi+ pi- gamma.

  18. Measurement of ISR-FSR interference in the processes e+ e- --> mu+ mu- gamma and e+ e- --> pi+ pi- gamma

    E-Print Network [OSTI]

    ,

    2015-01-01

    Charge asymmetry in processes e+ e- --> mu+ mu- gamma and e+ e- --> pi+ pi- gamma is measured using 232 fb-1 of data collected with the BABAR detector at center-of-mass energies near 10.58 GeV. An observable is introduced and shown to be very robust against detector asymmetries while keeping a large sensitivity to the physical charge asymmetry that results from the interference between initial and final state radiation. The asymmetry is determined as afunction of the invariant mass of the final-state tracks from production threshold to a few GeV/c2. It is compared to the expectation from QED for e+ e- --> mu+ mu- gamma and from theoretical models for e+ e- --> pi+ pi- gamma. A clear interference pattern is observed in e+ e- --> pi+ pi- gamma, particularly in the vicinity of the f_2(1270) resonance. The inferred rate of lowest order FSR production is consistent with the QED expectation for e+ e- --> mu+ mu- gamma, and is negligibly small for e+ e- --> pi+ pi- gamma.

  19. Polarization mesurements of gamma ray bursts and axion like particles

    E-Print Network [OSTI]

    Andre Rubbia; Alexander Sakharov

    2008-09-03

    A polarized gamma ray emission spread over a sufficiently wide energy band from a strongly magnetized astrophysical object like gamma ray bursts (GRBs) offers an opportunity to test the hypothesis of axion like particles (ALPs). Based on evidences of polarized gamma ray emission detected in several gamma ray bursts we estimated the level of ALPs induced dichroism, which could take place in the magnetized fireball environment of a GRB. This allows to estimate the sensitivity of polarization measurements of GRBs to the ALP-photon coupling. This sensitivity $\\gag\\le 2.2\\cdot 10^{-11} {\\rm GeV^{-1}}$ calculated for the ALP mass $m_a=10^{-3}~{\\rm eV}$ and MeV energy spread of gamma ray emission is competitive with the sensitivity of CAST and becomes even stronger for lower ALPs masses.

  20. Parameters of Distribution of the Primary Gamma-Transition Intensities Following Resonance Neutron Capture and Some Properties of Compound Nuclei $^{157,159}$Gd

    E-Print Network [OSTI]

    A. M. Sukhovoj; V. A. Khitrov

    2009-06-16

    The re-analysis of the published experimental data on the primary gamma-transition intensities following neutron capture in different groups of neutron resonances in $^{156,158}$Gd has been performed. There are determined the most probable values of sum of E1 and M1 primary transitions, numbers of excited by them levels of both parities, ratios of radiative strength functions k(M1)/k(E1), dispersions of deviations of random values of intensities from the average and ratios of mean intensities of primary transitions to levels J=5/2 with respect to analogous data for J=1/2 and 3/2 (capture of the 24 keV neutrons) in narrow excitation energy intervals. All the data on level density and sums of radiative strength functions confirm the presence of clearly expressed step-like structure in level density below 3 MeV and general trend in change in strength functions as changing primary gamma-transition energy. Variations of distribution dispersions and, especially, ratio k(M1)/k(E1) (or $k(E1)/k(M1)$) at changing excitation energy point to strong change in structure of these nuclei above 1.0-1.5 MeV.

  1. Results of mobile gamma scanning activities in St. Louis, Missouri

    SciTech Connect (OSTI)

    Rodriguez, R E; Witt, D A; Cottrell, W D; Carrier, R F

    1991-06-01

    From 1942 through approximately 1966, the Mallinckrodt Chemical Works operated four plants in St. Louis, Missouri, for the Manhattan Engineer District and the Atomic Energy Commission. A variety of production processes using uranium- and radium-bearing ore materials were performed at the plants. It is the policy of the DOE to verify that radiological conditions at such sites or facilities comply with current DOE guidelines. Guidelines for release and use of such sites have become more stringent as research has provided more information since previous cleanups. The Formerly Utilized Sites Remedial Action Program (FUSRAP) was established as part of that effort to confirm the closeout status of facilities under contract to agencies preceding DOE during early nuclear energy development. Under the FUSRAP program, the Mallinckrodt properties have been previously investigated to determine the extent of on-site radiological contamination. At the request of DOE, Oak Ridge National Laboratory (ORNL) conducted a survey in May 1990, of public roadways and suspected haul routes between the Mallinckrodt plant and storage sites in St. Louis to ensure that no residual radioactive materials were conveyed off-site. A mobile gamma scanning van with an on-board computer system was used to identify possible anomalies. Suspect areas are those displaying measurements deviating from gamma exposure rates identified as typical for radiologically unenhanced areas in the vicinity of the areas of interest. The instrumentation highlighted three anomaly locations each of which measured less than 1m{sup 2} in size. None of the slightly elevated radiation levels originated from material associated with former AEC-related processing operations in the area. The anomalies resulted from elevated concentrations of radionuclides present in phosphate fertilizers, increased thorium in road-base gravel, and emanations from the radioactive storage site near the Latty Avenue airport. 9 refs., 3 figs.

  2. Determination of thermal neutron capture gamma yields

    E-Print Network [OSTI]

    Harper, Thomas Lawrence

    1969-01-01

    A method of analysing Ge(Li) thermal neutron capture gamma spectra to obtain total gamma yields has been developed. Tie method determines both the yields from the well resolved gamma peaks in a spectrum as well as the gamma ...

  3. Determination of thermal neutron capture gamma yields.

    E-Print Network [OSTI]

    Harper, Thomas Lawrence

    1969-01-01

    A method of analysing Ge(Li) thermal neutron capture gamma spectra to obtain total gamma yields has been developed. Tie method determines both the yields from the well resolved gamma peaks in a spectrum as well as the gamma ...

  4. Radiation tolerance of piezoelectric bulk single-crystal aluminum nitride

    SciTech Connect (OSTI)

    David A. Parks; Bernhard R. Tittmann

    2014-07-01

    For practical use in harsh radiation environments, we pose selection criteria for piezoelectric materials for nondestructive evaluation (NDE) and material characterization. Using these criteria, piezoelectric aluminum nitride is shown to be an excellent candidate. The results of tests on an aluminumnitride-based transducer operating in a nuclear reactor are also presented. We demonstrate the tolerance of single-crystal piezoelectric aluminum nitride after fast and thermal neutron fluences of 1.85 × 1018 neutron/cm2 and 5.8 × 1018 neutron/cm2, respectively, and a gamma dose of 26.8 MGy. The radiation hardness of AlN is most evident from the unaltered piezoelectric coefficient d33, which measured 5.5 pC/N after a fast and thermal neutron exposure in a nuclear reactor core for over 120 MWh, in agreement with the published literature value. The results offer potential for improving reactor safety and furthering the understanding of radiation effects on materials by enabling structural health monitoring and NDE in spite of the high levels of radiation and high temperatures, which are known to destroy typical commercial ultrasonic transducers.

  5. Gamma Ray Bursts

    E-Print Network [OSTI]

    Peter Mészáros

    2012-04-12

    Gamma-ray bursts have been detected at photon energies up to tens of GeV. We review some recent developments in the X-ray to GeV photon phenomenology in the light of Swift and Fermi observations, and some of the theoretical models developed to explain them, with a view towards implications for C.T.A.

  6. Are gamma-ray bursts cosmological?

    E-Print Network [OSTI]

    Horvath, I

    2015-01-01

    Gamma-ray burst sources are distributed with a high level of isotropy, which is compatible with either a cosmological origin or an extended Galactic halo origin. The brightness distribution is another indicator used to characterize the spatial distribution in distance. In this paper the author discusses detailed fits of the BATSE gamma-ray burst peak-flux distributions with Friedmann models taking into account possible density evolution and standard candle luminosity functions. A chi-square analysis is used to estimate the goodness of the fits and the author derives the significance level of limits on the density evolution and luminosity function parameters. Cosmological models provide a good fit over a range of parameter space which is physically reasonable

  7. Instructions for calibrating gamma detectors using the Canberra-Nuclear Data Genie Gamma Spectroscopy System

    SciTech Connect (OSTI)

    Brunk, J.L.

    1995-09-01

    A straight forward protocol provides a way to guide the calibration of a gamma detector for a particular geometry and material. Several programs have used the Low Level Gamma Counting Facility of the Health and Ecological Assessment Division of the Lawrence Livermore National Laboratory to count a variety of large environmental samples contained in several unique geometries. The equipment and calibration requirements needed to analyze these types of samples are explained. This document describes the calibration protocol that has been developed and describes how it is used to calibrate the detectors.

  8. EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS

    SciTech Connect (OSTI)

    Clark, E.

    2011-09-22

    Two formulations of EPDM elastomer, one substituting a UV stabilizer for the normal antioxidant in this polymer, and the other the normal formulation, were synthesized and samples of each were exposed to gamma irradiation in initially pure deuterium gas to compare their radiation stability. Stainless steel containers having rupture disks were designed for this task. After 130 MRad dose of cobalt-60 radiation in the SRNL Gamma Irradiation Facility, a significant amount of gas was created by radiolysis; however the composition indicated by mass spectroscopy indicated an unexpected increase in the total amount deuterium in both formulations. The irradiated samples retained their ductility in a bend test. No change of sample weight, dimensions, or density was observed. No change of the glass transition temperature as measured by dynamic mechanical analysis was observed, and most of the other dynamic mechanical properties remained unchanged. There appeared to be an increase in the storage modulus of the irradiated samples containing the UV stabilizer above the glass transition, which may indicate hardening of the material by radiation damage. Polymeric materials become damaged by exposure over time to ionizing radiation. Despite the limited lifetime, polymers have unique engineering material properties and polymers continue to be used in tritium handling systems. In tritium handling systems, polymers are employed mainly in joining applications such as valve sealing surfaces (eg. Stem tips, valve packing, and O-rings). Because of the continued need to employ polymers in tritium systems, over the past several years, programs at the Savannah River National Laboratory have been studying the effect of tritium on various polymers of interest. In these studies, samples of materials of interest to the SRS Tritium Facilities (ultra-high molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, Teflon{reg_sign}), Vespel{reg_sign} polyimide, and the elastomer ethylene propylene diene monomer (EPDM)) have been exposed in closed containers to tritium gas initially at 1 atmosphere pressure. These studies have demonstrated the degradation of properties when exposed to tritium gas. Also, the radiolytic production of significant amounts of hydrogen has been observed for UHMW-PE and EPDM. The study documented in this report exposes two similar formulations of EPDM elastomer to gamma irradiation in a closed container backfilled with deuterium. Deuterium is chemically identical to protium and tritium, but allows the identification of protium that is radiolytically produced from the samples. The goal of this program is to compare and contrast the response of EPDM exposure to two different types of ionizing radiation in a similar chemical environment.

  9. A Plasma Instability Theory of Gamma-Ray Burst Emission

    E-Print Network [OSTI]

    J. J. Brainerd

    1999-04-02

    A plasma instability theory is presented for the prompt radiation from gamma-ray bursts. In the theory, a highly relativistic shell interacts with the interstellar medium through the filamentation and the two-stream instabilities to convert bulk kinetic energy into electron thermal energy and magnetic field energy. The processes are not efficient enough to satisfy the Rankine-Hugoniot conditions, so a shock cannot form through this mechanism. Instead, the interstellar medium passes through the shell, with the electrons radiating during this passage. Gamma-rays are produced by synchrotron self-Compton emission. Prompt optical emission is also produced through this mechanism, while prompt radio emission is produced through synchrotron emission. The model timescales are consistent with the shortest burst timescales. To emit gamma-rays, the shell's bulk Lorentz factor must be greater than approximately 1000. For the radiative processes to be efficient, the interstellar medium density must satisfy a lower limit that is a function of the bulk Lorentz factor. Because the limits operate as selection effects, bursts that violate them constitute new classes. In particular, a class of optical and ultraviolet bursts with no gamma-ray emission should exist. The lower limit on the density of the interstellar medium is consistent with the requirements of the Compton attenuation theory, providing an explanation for why all burst spectra appear to be attenuated. Several tests of the theory are discussed, as are the next theoretical investigations that should be conducted.

  10. A Search for Gamma-Ray Bursts and Pulsars, and the Application of Kalman Filters to Gamma-Ray Reconstruction

    E-Print Network [OSTI]

    B. B. Jones

    2002-02-04

    Part I describes the analysis of periodic and transient signals in EGRET data. A method to search for the transient flux from gamma-ray bursts independent of triggers from other gamma-ray instruments is developed. Several known gamma-ray bursts were independently detected, and there is evidence for a previously unknown gamma-ray burst candidate. Statistical methods using maximum likelihood and Bayesian inference are developed and implemented to extract periodic signals from gamma-ray sources in the presence of significant astrophysical background radiation. The analysis was performed on six pulsars and three pulsar candidates. The three brightest pulsars, Crab, Vela, and Geminga, were readily identified, and would have been detected independently in the EGRET data without knowledge of the pulse period. No significant pulsation was detected in the three pulsar candidates. Eighteen X-ray binaries were examined. None showed any evidence of periodicity. In addition, methods for calculating the detection threshold of periodic flux modulation were developed. The future hopes of gamma-ray astronomy lie in the development of the Gamma-ray Large Area Space Telescope, or GLAST. Part II describes the development and results of the particle track reconstruction software for a GLAST science prototype instrument beam test. The Kalman filtering method of track reconstruction is introduced and implemented. Monte Carlo simulations, very similar to those used for the full GLAST instrument, were performed to predict the instrumental response of the prototype. The prototype was tested in a gamma-ray beam at SLAC. The reconstruction software was used to determine the incident gamma-ray direction. It was found that the simulations did an excellent job of representing the actual instrument response.

  11. Interaction region for gamma-gamma, gamma-electron collisions at linear colliders

    E-Print Network [OSTI]

    Valery Telnov

    2002-07-29

    Photon colliders (gamma-gamma, gamma-electron) are based on backward Compton scattering of laser light off the high energy electrons in linear colliders. All projects of linear colliders include this option. In this paper physics motivation, possible parameters and some interaction region aspects of photon colliders are discussed.

  12. Constraints on GRB TeV Emission from the GeV Extragalactic Diffuse Gamma-Ray Flux

    E-Print Network [OSTI]

    Casanova, S; Zhang, B; Zhang, Bing

    2006-01-01

    TeV gamma rays emitted by GRBs are converted into electron-positron pairs via interactions with the extragalactic infrared radiation fields. In turn the pairs produced, whose trajectories are randomized by magnetic fields, will inverse Compton scatter off the cosmic microwave background photons. The beamed TeV gamma ray flux from GRBs is thus transformed into a GeV isotropic gamma ray flux, which contributes to the total extragalactic gamma-ray background emission. Assuming a model for the extragalactic radiation fields, for the GRB redshift distribution and for the GRB luminosity function, we use the measured GeV extragalactic gamma-ray flux to set upper limits on the GRB emission in TeV gamma rays that is predicted in several models.

  13. A Search for the B^0 to e^+ e^- \\gamma and B^0 to \\mu^+ \\mu^- \\gamma Decays

    SciTech Connect (OSTI)

    Aubert, B.

    2006-09-27

    With the BABAR detector at the PEP-II asymmetric B Factory at SLAC, they present the first search for the decays B{sup 0} {yields} {ell}{sup +}{ell}{sup -}{gamma} ({ell} = e, {mu}). Using a data set of 292 fb{sup -1} collected at the {Upsilon}(4S) resonance, they find no significant signal and set the following branching fraction upper limits at 90% confidence level: {Beta}(B{sup 0} {yields} e{sup +}e{sup -}{gamma}) < 0.7 x 10{sup -7} and {Beta}(B{sup 0} {yields} {mu}{sup +}{mu}{sup -}{gamma}) < 3.4 x 10{sup -7}.

  14. Model-Independent Results for the Decay B \\to L Nu(L) Gamma at BaBar

    SciTech Connect (OSTI)

    Lindemann, D.M.; /McGill U.

    2012-04-09

    We present a search for the radiative leptonic decays B{sub +} {yields} e{sup +} {nu}{sub e}{gamma} and B{sup +} {yields} {mu}{sup +}{nu}{sub {mu}}{gamma} using data collected by the BABAR detector at the PEP-II B factory. We fully reconstruct the hadronic decay of one of the B mesons in {Upsilon}(4S) {yields} B{sup +}B{sup -} and then search for evidence of the signal decay within the rest of the event. This method provides clean kinematic information on the signal's missing energy and high momentum photon and lepton, and allows for a model-independent analysis of this decay. Using a data sample of 465 million B-meson pairs, we obtain sensitivity to branching fractions of the same order as predicted by the Standard Model. We report a model-independent branching fraction upper limit of {Beta}(B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}}{gamma}) < 15.6 x 10{sup -6} ({ell} = e or {mu}) at the 90% confidence level.

  15. Testing the millisecond pulsar scenario of the Galactic center gamma-ray excess with very high energy gamma-rays

    E-Print Network [OSTI]

    Qiang Yuan; Kunihito Ioka

    2015-02-09

    The recent analyses of the Fermi Large Area Telescope data show an extended GeV $\\gamma$-ray excess on top of the expected diffuse background in the Galactic center region, which can be explained with annihilating dark matter or a population of millisecond pulsars (MSPs). We propose to observe the very high energy $\\gamma$-rays for distinguishing the MSP scenario from the dark matter scenario. The GeV $\\gamma$-ray MSPs should release most energy to the relativistic $e^{\\pm}$ wind, which will diffuse in the Galaxy and radiate TeV $\\gamma$-rays through inverse Compton scattering and bremsstrahlung processes. By calculating the spectrum and spatial distribution, we show that such emission is detectable with the next generation very high energy $\\gamma$-ray observatory, the Cherenkov Telescope Array (CTA), under reasonable model parameters. It is essential to search for the multi-wavelength counterparts to the GeV $\\gamma$-ray excess for solving this mystery in the high energy universe.

  16. Danger radiations

    ScienceCinema (OSTI)

    None

    2011-04-25

    Le conférencier Mons.Hofert parle des dangers et risques des radiations, le contrôle des zones et les précautions à prendre ( p.ex. film badge), comment mesurer les radiations etc.

  17. Radiation absorption properties of different plaster samples

    SciTech Connect (OSTI)

    Akkurt, Iskender; Guenoglu, Kadir; Mavi, Betuel; K Latin-Small-Letter-Dotless-I l Latin-Small-Letter-Dotless-I ncarslan, Semsettin; Seven, Aysun

    2012-09-06

    Although the plaster is one of the oldest known synthetic building materials, nowadays, it is used as interior coating of walls and ceilings of buildings. Thus measuring its radiation shielding properties is vital. For this purpose, radiation absorption properties of different plaster samples in this study. The measurements have been performed using gamma spectrometer system which connected to 3'' Multiplication-Sign 3''NaI (TI) detector.

  18. LASER-PLASMA-ACCELERATOR-BASED GAMMA GAMMA COLLIDERS

    E-Print Network [OSTI]

    Schroeder, C. B.

    2010-01-01

    LASER-PLASMA-ACCELERATOR-BASED ?? COLLIDERS ? C. B.linear col- lider based on laser-plasma-accelerators arediscussed, and a laser-plasma-accelerator-based gamma-

  19. Low Level Radiation SEAB Ltr. to Moniz

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousand CubicResourcelogoFeet)Low Energy

  20. Fermi GBM Observations of Terrestrial Gamma-ray Flashes

    SciTech Connect (OSTI)

    Briggs, Michael S. [CSPAR, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States)

    2011-09-21

    Terrestrial Gamma-ray Flashes are short pulses of energetic radiation associated with thunderstorms and lightning. While the Gamma-ray Burst Monitor (GBM) on Fermi was designed to observe gamma-ray bursts, its large BGO detectors are excellent for observing TGFs. Using GBM, TGF pulses are seen to either be symmetrical or have faster rise time than fall times. Some TGFs are resolved into double, partially overlapping pulses. Using ground-based radio observations of lightning from the World Wide Lightning Location Network (WWLLN), TGFs and their associated lightning are found to be simultaneous to {approx_equal}40 {mu} s. The lightning locations are typically within 300 km of the sub-spacecraft point.

  1. A grey gamma-ray transfer procedure for supernovae

    E-Print Network [OSTI]

    David J Jeffery

    1998-02-17

    The gamma-ray transfer in supernovae for the purposes of energy deposition in the ejecta can be approximated as grey radiative transfer using mean opacities. In past work there is a single pure absorption mean opacity which is a free parameter. Accurate results can be obtained by varying this mean opacity to fit the results of more accurate procedures. In this paper, we present a grey gamma-ray transfer procedure for energy deposition in which there are multiple mean opacities that are not free parameters and that have both absorption and scattering components. This procedure is based on a local-state (LS) approximation, and so we call it the LS grey gamma-ray transfer procedure or LS procedure for short.

  2. Radiation Center and TRIGA Reactor Annual Report

    E-Print Network [OSTI]

    Specification 6.7(e). B. Battelle Energy Alliance, LLC; Subcontract Award No. 00074510. C. Oregon Department of Energy, OOE Rule No. 345-030-010. Submitted by: Steve R. Reese, Director Radiation Center Oregon State Concentration of the Total Net Beta Radioactivity 44 V 13 Beta-Gamma Concentration and Range of LLD Values 45 V

  3. EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS (REVISION 1)

    SciTech Connect (OSTI)

    Clark, E.

    2013-09-13

    Two formulations of EPDM elastomer, one substituting a UV stabilizer for the normal antioxidant in this polymer, and the other the normal formulation, were synthesized and samples of each were exposed to gamma irradiation in initially pure deuterium gas to compare their radiation stability. Stainless steel containers having rupture disks were designed for this task. After 130 MRad dose of cobalt-60 radiation in the SRNL Gamma Irradiation Facility, a significant amount of gas was created by radiolysis; however the composition indicated by mass spectroscopy indicated an unexpected increase in the total amount deuterium in both formulations. The irradiated samples retained their ductility in a bend test. No change of sample weight, dimensions, or density was observed. No change of the glass transition temperature as measured by dynamic mechanical analysis was observed, and most of the other dynamic mechanical properties remained unchanged. There appeared to be an increase in the storage modulus of the irradiated samples containing the UV stabilizer above the glass transition, which may indicate hardening of the material by radiation damage. Revision 1 adds a comparison with results of a study of tritium exposed EPDM. The amount of gas produced by the gamma irradiation was found to be equivalent to about 280 days exposure to initially pure tritium gas at one atmosphere. The glass transition temperature of the tritium exposed EPDM rose about 10 ?C. over 280 days, while no glass transition temperature change was observed for gamma irradiated EPDM. This means that gamma irradiation in deuterium cannot be used as a surrogate for tritium exposure.

  4. RADIATION EFFECTS ON EPOXY CARBON FIBER COMPOSITE

    SciTech Connect (OSTI)

    Hoffman, E

    2008-05-30

    Carbon fiber-reinforced bisphenol-A epoxy matrix composite was evaluated for gamma radiation resistance. The composite was exposed to total gamma doses of 50, 100, and 200 Mrad. Irradiated and baseline samples were tested for tensile strength, hardness and evaluated using FTIR (Fourier transform infrared) spectroscopy and DSC (differential scanning calorimetry) for structural changes. Scanning electron microscopy was used to evaluate microstructural behavior. Mechanical testing of the composite bars revealed no apparent change in modulus, strain to failure, or fracture strength after exposures. However, testing of only the epoxy matrix revealed changes in hardness, thermal properties, and FTIR results with increasing gamma irradiation. The results suggest the epoxy within the composite can be affected by exposure to gamma irradiation.

  5. MODULAR CAUSTIC SIDE SOLVENT EXTRACTION UNIT (MCU) GAMMA MONITORS SYSTEM FINAL REPORT

    SciTech Connect (OSTI)

    Casella, V

    2005-12-15

    The Department of Energy (DOE) selected Caustic-Side Solvent Extraction (CSSX) as the preferred technology for the removal of radioactive cesium from High-Level Waste (HLW) at the Savannah River Site (SRS). Before the full-scale Salt Waste Processing Facility (SWPF) becomes operational, the Closure Business Unit (CBU) plans to process a portion of dissolved saltcake waste through a Modular CSSX Unit (MCU). This work was derived from Technical Task Request SP-TTR-2004-00013, ''Gamma Monitor for MCU''. The deliverables for this task are the hardware and software for the gamma monitors and a report summarizing the testing and acceptance of this equipment for use in the MCU. Gamma-ray monitors are required to: (1) Measure the Cs-137 concentration in the decontaminated salt solution before entering the DSS (Decontaminated Salt Solution) Hold Tank, (2) Measure the Cs-137 concentration in the strip effluent before entering the Strip Effluent Hold Tank, (3) Verify proper operation of the solvent extraction system by verifying material balance within the process (The DSS Hold Tank Cs-137 concentration will be very low and the Cs-137 concentration in the Strip Effluent Hold Tank will be fifteen times higher than the Cs-137 concentration in the Feed Tank.) Sodium iodide monitors are used to measure the Cs-137 concentration in the piping before the DSS Hold tank, while GM monitors are used for Cs-137 measurements before the Strip Effluent Hold Tank. Tungsten shields were designed using Monte Carlo calculations and fabricated to reduce the process background radiation at the detector positions. These monitors were calibrated with NIST traceable standards that were specially made to be the same as the piping being monitored. Since this gamma ray monitoring system is unique, specially designed software was written and acceptance tested by Savannah River National Laboratory personnel. The software is a LabView-based application that serves as a unified interface for controlling the monitor hardware and communicating with the host Distributed Control System (DCS). In order to provide user friendly software for the process personnel, the software was broken down into just a few software modules. These software modules are the Application Window, Detector Selection, Detector Configuration Settings, Background Counting, and Routine Data Acquisition. Instructions for using the software have been included in a user's manual that is appended to this report. The work presented in this report meets all of the requirements set forth in the project task plan to design and implement gamma ray monitors for the MCU. Additional setup and testing of the system will be required when it implemented in the process.

  6. Background Radiation Measurements at High Power Research Reactors

    E-Print Network [OSTI]

    Ashenfelter, J; Baldenegro, C X; Band, H R; Barclay, G; Bass, C D; Berish, D; Bowden, N S; Bryan, C D; Cherwinka, J J; Chu, R; Classen, T; Davee, D; Dean, D; Deichert, G; Dolinski, M J; Dolph, J; Dwyer, D A; Fan, S; Gaison, J K; Galindo-Uribarri, A; Gilje, K; Glenn, A; Green, M; Han, K; Hans, S; Heeger, K M; Heffron, B; Jaffe, D E; Kettell, S; Langford, T J; Littlejohn, B R; Martinez, D; McKeown, R D; Morrell, S; Mueller, P E; Mumm, H P; Napolitano, J; Norcini, D; Pushin, D; Romero, E; Rosero, R; Saldana, L; Seilhan, B S; Sharma, R; Stemen, N T; Surukuchi, P T; Thompson, S J; Varner, R L; Wang, W; Watson, S M; White, B; White, C; Wilhelmi, J; Williams, C; Wise, T; Yao, H; Yeh, M; Yen, Y -R; Zhang, C; Zhang, X

    2015-01-01

    Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including $\\gamma$-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. The general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.

  7. Background Radiation Measurements at High Power Research Reactors

    E-Print Network [OSTI]

    J. Ashenfelter; B. Balantekin; C. X. Baldenegro; H. R. Band; G. Barclay; C. D. Bass; D. Berish; N. S. Bowden; C. D. Bryan; J. J. Cherwinka; R. Chu; T. Classen; D. Davee; D. Dean; G. Deichert; M. J. Dolinski; J. Dolph; D. A. Dwyer; S. Fan; J. K. Gaison; A. Galindo-Uribarri; K. Gilje; A. Glenn; M. Green; K. Han; S. Hans; K. M. Heeger; B. Heffron; D. E. Jaffe; S. Kettell; T. J. Langford; B. R. Littlejohn; D. Martinez; R. D. McKeown; S. Morrell; P. E. Mueller; H. P. Mumm; J. Napolitano; D. Norcini; D. Pushin; E. Romero; R. Rosero; L. Saldana; B. S. Seilhan; R. Sharma; N. T. Stemen; P. T. Surukuchi; S. J. Thompson; R. L. Varner; W. Wang; S. M. Watson; B. White; C. White; J. Wilhelmi; C. Williams; T. Wise; H. Yao; M. Yeh; Y. -R. Yen; C. Zhang; X. Zhang

    2015-06-11

    Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including $\\gamma$-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. The general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.

  8. Background Radiation Measurements at High Power Research Reactors

    E-Print Network [OSTI]

    J. Ashenfelter; B. Balantekin; C. X. Baldenegro; H. R. Band; G. Barclay; C. D. Bass; D. Berish; N. S. Bowden; C. D. Bryan; J. J. Cherwinka; R. Chu; T. Classen; D. Davee; D. Dean; G. Deichert; M. J. Dolinski; J. Dolph; D. A. Dwyer; S. Fan; J. K. Gaison; A. Galindo-Uribarri; K. Gilje; A. Glenn; M. Green; K. Han; S. Hans; K. M. Heeger; B. Heffron; D. E. Jaffe; S. Kettell; T. J. Langford; B. R. Littlejohn; D. Martinez; R. D. McKeown; S. Morrell; P. E. Mueller; H. P. Mumm; J. Napolitano; D. Norcini; D. Pushin; E. Romero; R. Rosero; L. Saldana; B. S. Seilhan; R. Sharma; N. T. Stemen; P. T. Surukuchi; S. J. Thompson; R. L. Varner; W. Wang; S. M. Watson; B. White; C. White; J. Wilhelmi; C. Williams; T. Wise; H. Yao; M. Yeh; Y. -R. Yen; C. Zhang; X. Zhang

    2015-11-11

    Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including $\\gamma$-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. The general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.

  9. Remote radiation dosimetry

    DOE Patents [OSTI]

    Braunlich, Peter F. (Pullman, WA); Tetzlaff, Wolfgang (Pullman, WA); Hegland, Joel E. (Pullman, WA); Jones, Scott C. (Pullman, WA)

    1991-01-01

    Disclosed are methods and apparatus for remotely measuring radiation levels. Such are particularly useful for measuring relatively high levels or dosages of radiation being administered in radiation therapy. They are also useful for more general radiation level measurements where remote sensing from the remaining portions of the apparatus is desirable. The apparatus uses a beam generator, such as a laser beam, to provide a stimulating beam. The stimulating beam is preferably of wavelengths shorter than 6 microns, or more advantageously less than 2 microns. The stimulating beam is used to stimulate a remote luminescent sensor mounted in a probe which emits stored luminescent energy resulting from exposure of the sensor to ionizing radiation. The stimulating beam is communicated to the remote luminescent sensor via transmissive fiber which also preferably serves to return the emission from the luminescent sensor. The stimulating beam is advantageously split by a beam splitter to create a detector beam which is measured for power during a reading period during which the luminescent phosphor is read. The detected power is preferably used to control the beam generator to thus produce desired beam power during the reading period. The luminescent emission from the remote sensor is communicated to a suitable emission detector, preferably after filtering or other selective treatment to better isolate the luminescent emission.

  10. Remote radiation dosimetry

    DOE Patents [OSTI]

    Braunlich, P.F.; Tetzlaff, W.; Hegland, J.E.; Jones, S.C.

    1991-03-12

    Disclosed are methods and apparatus for remotely measuring radiation levels. Such are particularly useful for measuring relatively high levels or dosages of radiation being administered in radiation therapy. They are also useful for more general radiation level measurements where remote sensing from the remaining portions of the apparatus is desirable. The apparatus uses a beam generator, such as a laser beam, to provide a stimulating beam. The stimulating beam is preferably of wavelengths shorter than 6 microns, or more advantageously less than 2 microns. The stimulating beam is used to stimulate a remote luminescent sensor mounted in a probe which emits stored luminescent energy resulting from exposure of the sensor to ionizing radiation. The stimulating beam is communicated to the remote luminescent sensor via a transmissive fiber which also preferably serves to return the emission from the luminescent sensor. The stimulating beam is advantageously split by a beam splitter to create a detector beam which is measured for power during a reading period during which the luminescent phosphor is read. The detected power is preferably used to control the beam generator to thus produce desired beam power during the reading period. The luminescent emission from the remote sensor is communicated to a suitable emission detector, preferably after filtering or other selective treatment to better isolate the luminescent emission. 8 figures.

  11. Ionizing radiation detector

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1990-01-01

    An ionizing radiation detector is provided which is based on the principle of analog electronic integration of radiation sensor currents in the sub-pico to nano ampere range between fixed voltage switching thresholds with automatic voltage reversal each time the appropriate threshold is reached. The thresholds are provided by a first NAND gate Schmitt trigger which is coupled with a second NAND gate Schmitt trigger operating in an alternate switching state from the first gate to turn either a visible or audible indicating device on and off in response to the gate switching rate which is indicative of the level of radiation being sensed. The detector can be configured as a small, personal radiation dosimeter which is simple to operate and responsive over a dynamic range of at least 0.01 to 1000 R/hr.

  12. Mon. Not. R. Astron. Soc. 401, 14651474 (2010) doi:10.1111/j.1365-2966.2009.15760.x Towards the properties of long gamma-ray burst progenitors

    E-Print Network [OSTI]

    Xu, Ren-Xin

    2010-01-01

    the properties of long gamma-ray burst progenitors with Swift data Xiao-Hong Cui,1 En-Wei Liang,2 Hou-Jun Lv,2 investigate the properties of both the prompt and X-ray afterglows of gamma-ray bursts (GRBs) in the burst . Key words: radiation mechanisms: non-thermal ­ gamma-rays: bursts. 1 INTRODUCTION One

  13. GeV Emission from Collisional Magnetized Gamma Ray Bursts

    E-Print Network [OSTI]

    P. Mészáros; M. J. Rees

    2011-04-26

    Magnetic fields may play a dominant role in gamma-ray bursts, and recent observations by the Fermi satellite indicate that GeV radiation, when detected, arrives delayed by seconds from the onset of the MeV component. Motivated by this, we discuss a magnetically dominated jet model where both magnetic dissipation and nuclear collisions are important. We show that, for parameters typical of the observed bursts, such a model involving a realistic jet structure can reproduce the general features of the MeV and a separate GeV radiation component, including the time delay between the two. The model also predicts a multi-GeV neutrino component.

  14. Search for the Decays B0 to e+e-gamma and B0 to mu+mu-gamma

    SciTech Connect (OSTI)

    Kim, H

    2007-06-22

    We present results of a search for the decays B{sup 0} {yields} {ell}{sup +}{ell}{sup -}{gamma} ({ell} = e, {mu}). The search is performed using 320x106 B{bar B} pairs collected at the {Gamma}(4S) resonance with the BABAR detector at the PEP-II B Factory at SLAC. We find no significant signal and set the following branching fraction upper limits at the 90% confidence level: {beta}(B{sup 0} {yields} e{sup +}e{sup -}{gamma}) < 1.2 x 10{sup -7} and {beta}(B{sup 0} {yields} {mu}{sup +}{mu}{sup -}{gamma}) < 1.5 x 10{sup -7}.

  15. Complete Two-Loop Corrections to H -> gamma gamma

    E-Print Network [OSTI]

    Giampiero Passarino; Christian Sturm; Sandro Uccirati

    2007-07-10

    In this paper the complete two-loop corrections to the Higgs-boson decay, H -> gamma gamma, are presented. The evaluations of both QCD and electroweak corrections are based on a numerical approach. The results cover all kinematical regions, including the WW normal-threshold, by introducing complex masses in the relevant (gauge-invariant) parts of the LO and NLO amplitudes.

  16. The effects of ionizing radiation on Reillex trademark HPQ, a new macroporous polyvinylpyridine resin, and on four conventional polystyrene anion exchange resins

    SciTech Connect (OSTI)

    Marsh, S.F.

    1990-11-01

    This study compares the effects of ionizing radiation on Reillex{trademark} HPQ, a recently available macroporous copolymer of 1-methyl-4-vinylpyridine/divinylbenzene, and on four conventional strong-base polystyrene anion exchange resins. The polystyrene resins investigated included one gel type, Dowex{trademark} 1 {times} 4, and three macroporous resins: Dow{trademark} MSA-1, Amberlite{trademark} IRA-900, and Lewatit{trademark} MP-500-FK. Each resin, in 7 M nitric acid, was subjected to seven different levels of {sup 60}Co gamma radiation ranging from 100 to 1000 megarads. Irradiated resins were measured for changes in dry weight, wet volume, chloride and Pu(IV) exchange capacities, and thermal stability. In separate experiments, each resin was subjected to approximately 340 megarads of in situ alpha particles from sorbed plutonium. Resin damage from alpha particles was less than half that caused by gamma rays, which may be a consequence of different production rates of radiolytic nitrite and nitro radicals in the two systems. Reillex{trademark} HPQ resin provided the greatest radiation stability, whereas Lewatit{trademark} MP-500-FK was the least stable of the resins tested. Thermogravimetric analyses of dry, nitrate-form resin revealed that dry Reillex{trademark} HPQ resin offered the best thermal stability for absorbed gamma doses to 370 megarads, but the worst thermal stability after exposures of 550 megarads or more. 25 refs., 11 figs., 13 tabs.

  17. Intrinsic radiation resistance in human chondrosarcoma cells

    SciTech Connect (OSTI)

    Moussavi-Harami, Farid [Departments of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA 52242 (United States); Mollano, Anthony [Departments of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA 52242 (United States); Martin, James A. [Departments of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA 52242 (United States); Ayoob, Andrew [Departments of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA 52242 (United States); Domann, Frederick E. [Department of Radiation Oncology, Iowa City, IA 52245 (United States); Gitelis, Steven [Department of Internal Medicine, Section of Medical Oncology, Chicago, IL 60612 (United States); Department of Orthopaedics Rush-Presbyterian St. Luke's Medical Center, Chicago, IL 60612 (United States); Buckwalter, Joseph A. [Departments of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA 52242 (United States)]. E-mail: joseph-buckwalter@uiowa.edu

    2006-07-28

    Human chondrosarcomas rarely respond to radiation treatment, limiting the options for eradication of these tumors. The basis of radiation resistance in chondrosarcomas remains obscure. In normal cells radiation induces DNA damage that leads to growth arrest or death. However, cells that lack cell cycle control mechanisms needed for these responses show intrinsic radiation resistance. In previous work, we identified immortalized human chondrosarcoma cell lines that lacked p16{sup ink4a}, one of the major tumor suppressor proteins that regulate the cell cycle. We hypothesized that the absence of p16{sup ink4a} contributes to the intrinsic radiation resistance of chondrosarcomas and that restoring p16{sup ink4a} expression would increase their radiation sensitivity. To test this we determined the effects of ectopic p16{sup ink4a} expression on chondrosarcoma cell resistance to low-dose {gamma}-irradiation (1-5 Gy). p16{sup ink4a} expression significantly increased radiation sensitivity in clonogenic assays. Apoptosis did not increase significantly with radiation and was unaffected by p16{sup ink4a} transduction of chondrosarcoma cells, indicating that mitotic catastrophe, rather than programmed cell death, was the predominant radiation effect. These results support the hypothesis that p16{sup ink4a} plays a role in the radiation resistance of chondrosarcoma cell lines and suggests that restoring p16 expression will improve the radiation sensitivity of human chondrosarcomas.

  18. New Applications of Gamma Spectroscopy: Characterization Tools for D&D Process Development, Inventory Reduction Planning & Shipping, Safety Analysis & Facility Management During the Heavy Element Facility Risk Reduction Program

    SciTech Connect (OSTI)

    Mitchell, M; Anderson, B; Gray, L; Vellinger, R; West, M; Gaylord, R; Larson, J; Jones, G; Shingleton, J; Harris, L; Harward, N

    2006-01-23

    Novel applications of gamma ray spectroscopy for D&D process development, inventory reduction, safety analysis and facility management are discussed in this paper. These applications of gamma spectroscopy were developed and implemented during the Risk Reduction Program (RPP) to successfully downgrade the Heavy Element Facility (B251) at Lawrence Livermore National Laboratory (LLNL) from a Category II Nuclear Facility to a Radiological Facility. Non-destructive assay in general, gamma spectroscopy in particular, were found to be important tools in project management, work planning, and work control (''Expect the unexpected and confirm the expected''), minimizing worker dose, and resulted in significant safety improvements and operational efficiencies. Inventory reduction activities utilized gamma spectroscopy to identify and confirm isotopics of legacy inventory, ingrowth of daughter products and the presence of process impurities; quantify inventory; prioritize work activities for project management; and to supply information to satisfy shipper/receiver documentation requirements. D&D activities utilize in-situ gamma spectroscopy to identify and confirm isotopics of legacy contamination; quantify contamination levels and monitor the progress of decontamination efforts; and determine the point of diminishing returns in decontaminating enclosures and glove boxes containing high specific activity isotopes such as {sup 244}Cm and {sup 238}Pu. In-situ gamma spectroscopy provided quantitative comparisons of several decontamination techniques (e.g. TLC-free Stripcoat{trademark}, Radiac{trademark} wash, acid wash, scrubbing) and was used as a part of an iterative process to determine the appropriate level of decontamination and optimal cost to benefit ratio. Facility management followed a formal, rigorous process utilizing an independent, state certified, peer-reviewed gamma spectroscopy program, in conjunction with other characterization techniques, process knowledge, and historical records, to provide information for work planning, work prioritization, work control, and safety analyses (e.g. development of hold points, stop work points); and resulted in B251 successfully achieving Radiological status on schedule. Gamma spectroscopy helped to define operational approaches to achieve radiation exposure ALARA, e.g. hold points, appropriate engineering controls, PPE, workstations, and time/distance/shielding in the development of ALARA plans. These applications of gamma spectroscopy can be used to improve similar activities at other facilities.

  19. Prompt TeV Emission from Cosmic Rays Accelerated by Gamma Ray Bursts Interacting with Surrounding Stellar Wind

    E-Print Network [OSTI]

    Soebur Razzaque; Olga Mena; Charles D. Dermer

    2008-11-24

    Protons accelerated in the internal shocks of a long duration gamma ray burst can escape the fireball as cosmic rays by converting to neutrons. Hadronic interactions of these neutrons inside a stellar wind bubble created by the progenitor star will produce TeV gamma rays via neutral meson decay and synchrotron radiation by charged pion-decay electrons in the wind magnetic field. Such gamma rays should be observable from nearby gamma ray bursts by currently running and upcoming ground-based detectors.

  20. RADIATION MONITORING

    E-Print Network [OSTI]

    Thomas, R.H.

    2010-01-01

    Radiation Exposure due to a Boiling Water Reactor Plume fromIN THE VICINITY OF A BOILING WATER REACTOR EXPOSURE RATE

  1. Innovative Gamma Ray Spectrometer Detection Systems for Conducting Scanning Surveys on Challenging Terrain - 13583

    SciTech Connect (OSTI)

    Palladino, Carl; Mason, Bryan; Engle, Matt; LeVangie, James [The Palladino Company, Inc., 720 Fillmore St., San Francisco, CA 94117 (United States)] [The Palladino Company, Inc., 720 Fillmore St., San Francisco, CA 94117 (United States); Dempsey, Gregg [United States Environmental Protection Agency, P.O. Box 98517, Las Vegas, NV 89193-8517 (United States)] [United States Environmental Protection Agency, P.O. Box 98517, Las Vegas, NV 89193-8517 (United States); Klemovich, Ron [HydroGeoLogic, Inc., 6340 Glenwood, Suite 200, Building No. 7, Overland Park, KS 66202 (United States)] [HydroGeoLogic, Inc., 6340 Glenwood, Suite 200, Building No. 7, Overland Park, KS 66202 (United States)

    2013-07-01

    The Santa Susana Field Laboratory located near Simi Valley, California was investigated to determine the nature and extent of gamma radiation anomalies. The primary objective was to conduct gamma scanning surveys over 100 percent of the approximately 1,906,000 square meters (471 acre) project site with the most sensitive detection system possible. The site had challenging topography that was not conducive to traditional gamma scanning detection systems. Terrain slope varied from horizontal to 48 degrees and the ground surface ranged from flat, grassy meadows to steep, rocky hillsides. In addition, the site was home to many protected endangered plant and animal species, and archaeologically significant sites that required minimal to no disturbance of the ground surface. Therefore, four innovative and unique gamma ray spectrometer detection systems were designed and constructed to successfully conduct gamma scanning surveys of approximately 1,076,000 square meters (266 acres) of the site. (authors)

  2. Improvement studies on neutron-gamma separation in HPGe detectors by using neural networks

    E-Print Network [OSTI]

    Serkan Akkoyun; Tuncay Bayram; S. Okan Kara

    2013-04-11

    The neutrons emitted in heavy-ion fusion-evaporation (HIFE) reactions together with the gamma-rays cause unwanted backgrounds in gamma-ray spectra. Especially in the nuclear reactions, where relativistic ion beams (RIBs) are used, these neutrons are serious problem. They have to be rejected in order to obtain clearer gamma-ray peaks. In this study, the radiation energy and three criteria which were previously determined for separation between neutron and gamma-rays in the HPGe detectors have been used in artificial neural network (ANN) for improving of the decomposition power. According to the preliminary results obtained from ANN method, the ratio of neutron rejection has been improved by a factor of 1.27 and the ratio of the lost in gamma-rays has been decreased by a factor of 0.50.

  3. Circumstellar discs in X/gamma-ray binaries: first results from the Echelle spectrograph

    E-Print Network [OSTI]

    Zamanov, R; Martí, J

    2015-01-01

    Here we report our first spectral observations of Be/X-ray and gamma-ray binaries obtained with the new Echelle spectrograph of the National Astronomical Observatory Rozhen. For four objects (LSI+61303, gamma Cas, MWC 148, 4U 2206+54), we report the parameters and estimate the sizes of their circumstellar discs using different emission lines (H-alpha, H-beta, H-gamma, HeI and FeII). For MWC 148, we find that the compact object goes deeply through the disc. The flank inflections of H-alpha can be connected with inner ring formed at the periastron passage or radiation transfer effects. We point out an intriguing similarity between the optical emission lines of the $\\gamma$-ray binary MWC 148 and the well known Be star $\\gamma$ Cas.

  4. Real time method and computer system for identifying radioactive materials from HPGe gamma-ray spectroscopy

    DOE Patents [OSTI]

    Rowland, Mark S. (Alamo, CA); Howard, Douglas E. (Livermore, CA); Wong, James L. (Dublin, CA); Jessup, James L. (Tracy, CA); Bianchini, Greg M. (Livermore, CA); Miller, Wayne O. (Livermore, CA)

    2007-10-23

    A real-time method and computer system for identifying radioactive materials which collects gamma count rates from a HPGe gamma-radiation detector to produce a high-resolution gamma-ray energy spectrum. A library of nuclear material definitions ("library definitions") is provided, with each uniquely associated with a nuclide or isotope material and each comprising at least one logic condition associated with a spectral parameter of a gamma-ray energy spectrum. The method determines whether the spectral parameters of said high-resolution gamma-ray energy spectrum satisfy all the logic conditions of any one of the library definitions, and subsequently uniquely identifies the material type as that nuclide or isotope material associated with the satisfied library definition. The method is iteratively repeated to update the spectrum and identification in real time.

  5. High Energy Gamma-Ray Emission from Gamma-Ray Bursts - Before GLAST

    SciTech Connect (OSTI)

    Fan, Yi-Zhong; Piran, Tsvi

    2011-11-29

    Gamma-ray bursts (GRBs) are short and intense emission of soft {gamma}-rays, which have fascinated astronomers and astrophysicists since their unexpected discovery in 1960s. The X-ray/optical/radio afterglow observations confirm the cosmological origin of GRBs, support the fireball model, and imply a long-activity of the central engine. The high-energy {gamma}-ray emission (> 20 MeV) from GRBs is particularly important because they shed some lights on the radiation mechanisms and can help us to constrain the physical processes giving rise to the early afterglows. In this work, we review observational and theoretical studies of the high-energy emission from GRBs. Special attention is given to the expected high-energy emission signatures accompanying the canonical early-time X-ray afterglow that was observed by the Swift X-ray Telescope. We also discuss the detection prospect of the upcoming GLAST satellite and the current ground-based Cerenkov detectors.

  6. M10.6.4: Design and manufacturing of AMC radiation dosimeter

    E-Print Network [OSTI]

    Makowski, D

    2010-01-01

    This report outlines progress in the development of radiation monitoring module designed according to the AMC standard. We have designed gamma and neutron radiation monitoring module dedicated for xTCA-based LLRF control system. The research shows that SRAM memory chip can be used as a neutron fluence detector. For gamma measurement RadFET detector was applied. Triple modular redundancy was involved to enhance the reliability of the module firmware to SEEs. The detector provides measured gamma and neutron dose rate as typical IPMI sensors. The measured radiation doses can be read via PCIe or Serial interfaces and archived in external database.

  7. Thermal, tensile and rheological properties of high density polyethylene (HDPE) processed and irradiated by gamma-ray in different atmospheres

    SciTech Connect (OSTI)

    Ferreto, H. F. R. E-mail: ana-feitoza@yahoo.com.br; Oliveira, A. C. F. E-mail: ana-feitoza@yahoo.com.br; Parra, D. F. E-mail: ablugao@ipen.br; Lugão, A. B. E-mail: ablugao@ipen.br; Gaia, R.

    2014-05-15

    The aim of this paper is to investigate structural changes of high density polyethylene (HDPE) modified by ionizing radiation (gamma rays) in different atmospheres. The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical-chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. This polymer was irradiated with gamma source of {sup 60}Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h. The changes in molecular structure of HDPE, after gamma irradiations were evaluated using thermogravimetric analysis (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere.

  8. Comparison of 2D and 3D gamma analyses

    SciTech Connect (OSTI)

    Pulliam, Kiley B.; Huang, Jessie Y.; Howell, Rebecca M.; Followill, David; Kry, Stephen F.; Bosca, Ryan; O’Daniel, Jennifer

    2014-02-15

    Purpose: As clinics begin to use 3D metrics for intensity-modulated radiation therapy (IMRT) quality assurance, it must be noted that these metrics will often produce results different from those produced by their 2D counterparts. 3D and 2D gamma analyses would be expected to produce different values, in part because of the different search space available. In the present investigation, the authors compared the results of 2D and 3D gamma analysis (where both datasets were generated in the same manner) for clinical treatment plans. Methods: Fifty IMRT plans were selected from the authors’ clinical database, and recalculated using Monte Carlo. Treatment planning system-calculated (“evaluated dose distributions”) and Monte Carlo-recalculated (“reference dose distributions”) dose distributions were compared using 2D and 3D gamma analysis. This analysis was performed using a variety of dose-difference (5%, 3%, 2%, and 1%) and distance-to-agreement (5, 3, 2, and 1 mm) acceptance criteria, low-dose thresholds (5%, 10%, and 15% of the prescription dose), and data grid sizes (1.0, 1.5, and 3.0 mm). Each comparison was evaluated to determine the average 2D and 3D gamma, lower 95th percentile gamma value, and percentage of pixels passing gamma. Results: The average gamma, lower 95th percentile gamma value, and percentage of passing pixels for each acceptance criterion demonstrated better agreement for 3D than for 2D analysis for every plan comparison. The average difference in the percentage of passing pixels between the 2D and 3D analyses with no low-dose threshold ranged from 0.9% to 2.1%. Similarly, using a low-dose threshold resulted in a difference between the mean 2D and 3D results, ranging from 0.8% to 1.5%. The authors observed no appreciable differences in gamma with changes in the data density (constant difference: 0.8% for 2D vs 3D). Conclusions: The authors found that 3D gamma analysis resulted in up to 2.9% more pixels passing than 2D analysis. It must be noted that clinical 2D versus 3D datasets may have additional differences—for example, if 2D measurements are made with a different dosimeter than 3D measurements. Factors such as inherent dosimeter differences may be an important additional consideration to the extra dimension of available data that was evaluated in this study.

  9. Sensitivity of the FERMI Detectors to Gamma-Ray Bursts from Evaporating Primordial Black Holes (PBHs)

    E-Print Network [OSTI]

    T. N. Ukwatta; Jane H. MacGibbon; W. C. Parke; K. S. Dhuga; S. Rhodes; A. Eskandarian; N. Gehrels; L. Maximon; D. C. Morris

    2010-03-23

    Primordial Black Holes (PBHs), which may have been created in the early Universe, are predicted to be detectable by their Hawking radiation. The Fermi Gamma-ray Space Telescope observatory offers increased sensitivity to the gamma-ray bursts produced by PBHs with an initial mass of $\\sim 5\\times 10^{14}$ g expiring today. PBHs are candidate progenitors of unidentified Gamma-Ray Bursts (GRBs) that lack X-ray afterglow. We propose spectral lag, which is the temporal delay between the high and low energy pulses, as an efficient method to identify PBH evaporation events with the Fermi Large Area Telescope (LAT).

  10. Cross Sections for the Electron Activation of Gamma-Ray Fluorescence

    E-Print Network [OSTI]

    Silviu Olariu; Agata Olariu; Yoshiaki Ito; Takeshi Mukoyama

    2000-06-26

    We report cross sections for the direct excitation of gamma-ray transitions up to 200 keV by the transient electromagnetic fields of electrons from a beam, for incident kinetic energies of 500 keV and 5 MeV. The cross sections for the electron activation of gamma-ray fluorescence are of the order of 300 nanobarns for an electron incident kinetic energy of 500 keV, and are of the order of 10 microbarns for an electron incident kinetic energy of 5 MeV. The electron excitation of nuclear transitions may lead to the development of pulsed sources of gamma radiation of narrowly defined energy.

  11. Recombining plasma in the gamma-ray-emitting mixed-morphology supernova remnant 3C 391

    SciTech Connect (OSTI)

    Ergin, T.; Sezer, A.; Saha, L.; Majumdar, P.; Chatterjee, A.; Bayirli, A.; Ercan, E. N.

    2014-07-20

    A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MCs) has been discovered to be strong GeV gamma-ray emitters by the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite have revealed that some of these interacting gamma-ray-emitting SNRs, such as IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+0.0) is another Galactic MM SNR interacting with MCs. It was observed in GeV gamma rays by Fermi-LAT as well as in the 0.3-10.0 keV X-ray band by Suzaku. In this work, 3C 391 was detected in GeV gamma rays with a significance of ?18? and we showed that the GeV emission is point-like in nature. The GeV gamma-ray spectrum was shown to be best explained by the decay of neutral pions assuming that the protons follow a broken power-law distribution. We revealed radiative recombination structures of silicon and sulfur from 3C 391 using Suzaku data. In this paper, we discuss the possible origin of this type of radiative plasma and hadronic gamma rays.

  12. Discovery of TeV Gamma-Ray Emission from the Cygnus Region of the Galaxy

    E-Print Network [OSTI]

    A. A. Abdo; B. Allen; D. Berley; E. Blaufuss; S. Casanova; C. Chen; D. G. Coyne; R. S. Delay; B. L. Dingus; R. W. Ellsworth; L. Fleysher; R. Fleysher; M. M. Gonzalez; J. A. Goodman; E. Hays; C. M. Hoffman; B. E. Kolterman; L. A. Kelley; C. P. Lansdell; J. T. Linnemann; J. E. McEnery; A. I. Mincer; I. V. Moskalenko; P. Nemethy; D. Noyes; J. M. Ryan; F. W. Samuelson; P. M. Saz Parkinson; M. Schneider; A. Shoup; G. Sinnis; A. J. Smith; A. W. Strong; G. W. Sullivan; V. Vasileiou; G. P. Walker; D. A. Williams; X. W. Xu; G. B. Yodh

    2006-11-21

    The diffuse gamma radiation arising from the interaction of cosmic ray particles with matter and radiation in the Galaxy is one of the few probes available to study the origin of the cosmic rays. Milagro is a water Cherenkov detector that continuously views the entire overhead sky. The large field-of-view combined with the long observation time makes Milagro the most sensitive instrument available for the study of large, low surface brightness sources such as the diffuse gamma radiation arising from interactions of cosmic radiation with interstellar matter. In this paper we present spatial and flux measurements of TeV gamma-ray emission from the Cygnus Region. The TeV image shows at least one new source MGRO J2019+37 as well as correlations with the matter density in the region as would be expected from cosmic-ray proton interactions. However, the TeV gamma-ray flux as measured at ~12 TeV from the Cygnus region (after excluding MGRO J2019+37) exceeds that predicted from a conventional model of cosmic ray production and propagation. This observation indicates the existence of either hard-spectrum cosmic-ray sources and/or other sources of TeV gamma rays in the region.

  13. Very Strong TeV Emission as Gamma-Ray Burst Afterglows

    E-Print Network [OSTI]

    Tomonori Totani

    1998-05-20

    Gamma-ray bursts (GRBs) and following afterglows are considered to be produced by dissipation of kinetic energy of a relativistic fireball and radiation process is widely believed as synchrotron radiation or inverse Compton scattering of electrons. We argue that the transfer of kinetic energy of ejecta into electrons may be inefficient process and hence the total energy released by a GRB event is much larger than that emitted in soft gamma-rays, by a factor of \\sim (m_p/m_e). We show that, in this case, very strong emission of TeV gamma-rays is possible due to synchrotron radiation of protons accelerated up to \\sim 10^{21} eV, which are trapped in the magnetic field of afterglow shock and radiate their energy on an observational time scale of \\sim day. This suggests a possibility that GRBs are most energetic in TeV range and such TeV gamma-rays may be detectable from GRBs even at cosmological distances, i.e., z \\sim 1, by currently working ground-based telescopes. Furthermore, this model gives a quantitative explanation for the famous long-duration GeV photons detected from GRB940217. If TeV gamma-ray emission which is much more energetic than GRB photons is detected, it provides a strong evidence for acceleration of protons up to \\sim 10^{21} eV.

  14. SciTech Connect: "gamma ray bursts"

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    gamma ray bursts" Find + Advanced Search Term Search Semantic Search Advanced Search All Fields: "gamma ray bursts" Semantic Semantic Term Title: Full Text: Bibliographic Data:...

  15. Gamma neutron assay method and apparatus

    DOE Patents [OSTI]

    Cole, J.D.; Aryaeinejad, R.; Greenwood, R.C.

    1995-01-03

    The gamma neutron assay technique is an alternative method to standard safeguards techniques for the identification and assaying of special nuclear materials in a field or laboratory environment, as a tool for dismantlement and destruction of nuclear weapons, and to determine the isotopic ratios for a blend-down program on uranium. It is capable of determining the isotopic ratios of fissionable material from the spontaneous or induced fission of a sample to within approximately 0.5%. This is based upon the prompt coincidence relationships that occur in the fission process and the proton conservation and quasi-conservation of nuclear mass (A) that exists between the two fission fragments. The system is used in both passive (without an external neutron source) and active (with an external neutron source) mode. The apparatus consists of an array of neutron and gamma-ray detectors electronically connected to determine coincident events. The method can also be used to assay radioactive waste which contains fissile material, even in the presence of a high background radiation field. 7 figures.

  16. Gamma neutron assay method and apparatus

    DOE Patents [OSTI]

    Cole, Jerald D. (Idaho Falls, ID); Aryaeinejad, Rahmat (Idaho Falls, ID); Greenwood, Reginald C. (Idaho Falls, ID)

    1995-01-01

    The gamma neutron assay technique is an alternative method to standard safeguards techniques for the identification and assaying of special nuclear materials in a field or laboratory environment, as a tool for dismantlement and destruction of nuclear weapons, and to determine the isotopic ratios for a blend-down program on uranium. It is capable of determining the isotopic ratios of fissionable material from the spontaneous or induced fission of a sample to within approximately 0.5%. This is based upon the prompt coincidence relationships that occur in the fission process and the proton conservation and quasi-conservation of nuclear mass (A) that exists between the two fission fragments. The system is used in both passive (without an external neutron source and active (with an external neutron source) mode. The apparatus consists of an array of neutron and gamma-ray detectors electronically connected to determine coincident events. The method can also be used to assay radioactive waste which contains fissile material, even in the presence of a high background radiation field.

  17. Radiation Dose-Response Model for Locally Advanced Rectal Cancer After Preoperative Chemoradiation Therapy

    SciTech Connect (OSTI)

    Appelt, Ane L., E-mail: ane.lindegaard.appelt@slb.regionsyddanmark.dk [Department of Oncology, Vejle Hospital, Vejle (Denmark); University of Southern Denmark, Odense (Denmark); Ploen, John [Department of Oncology, Vejle Hospital, Vejle (Denmark)] [Department of Oncology, Vejle Hospital, Vejle (Denmark); Vogelius, Ivan R. [Department of Radiation Oncology, Rigshospitalet, University of Copenhagen (Denmark)] [Department of Radiation Oncology, Rigshospitalet, University of Copenhagen (Denmark); Bentzen, Soren M. [Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin (United States)] [Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin (United States); Jakobsen, Anders [Department of Oncology, Vejle Hospital, Vejle (Denmark) [Department of Oncology, Vejle Hospital, Vejle (Denmark); University of Southern Denmark, Odense (Denmark)

    2013-01-01

    Purpose: Preoperative chemoradiation therapy (CRT) is part of the standard treatment of locally advanced rectal cancers. Tumor regression at the time of operation is desirable, but not much is known about the relationship between radiation dose and tumor regression. In the present study we estimated radiation dose-response curves for various grades of tumor regression after preoperative CRT. Methods and Materials: A total of 222 patients, treated with consistent chemotherapy and radiation therapy techniques, were considered for the analysis. Radiation therapy consisted of a combination of external-beam radiation therapy and brachytherapy. Response at the time of operation was evaluated from the histopathologic specimen and graded on a 5-point scale (TRG1-5). The probability of achieving complete, major, and partial response was analyzed by ordinal logistic regression, and the effect of including clinical parameters in the model was examined. The radiation dose-response relationship for a specific grade of histopathologic tumor regression was parameterized in terms of the dose required for 50% response, D{sub 50,i}, and the normalized dose-response gradient, {gamma}{sub 50,i}. Results: A highly significant dose-response relationship was found (P=.002). For complete response (TRG1), the dose-response parameters were D{sub 50,TRG1} = 92.0 Gy (95% confidence interval [CI] 79.3-144.9 Gy), {gamma}{sub 50,TRG1} = 0.982 (CI 0.533-1.429), and for major response (TRG1-2) D{sub 50,TRG1} and {sub 2} = 72.1 Gy (CI 65.3-94.0 Gy), {gamma}{sub 50,TRG1} and {sub 2} = 0.770 (CI 0.338-1.201). Tumor size and N category both had a significant effect on the dose-response relationships. Conclusions: This study demonstrated a significant dose-response relationship for tumor regression after preoperative CRT for locally advanced rectal cancer for tumor dose levels in the range of 50.4-70 Gy, which is higher than the dose range usually considered.

  18. NEW FERMI-LAT EVENT RECONSTRUCTION REVEALS MORE HIGH-ENERGY GAMMA RAYS FROM GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Atwood, W. B.; Baldini, L.; Bregeon, J.; Pesce-Rollins, M.; Sgro, C.; Tinivella, M.; Bruel, P.; Cohen-Tanugi, J.; Granot, J.; Longo, F.; Razzaque, S.; Zimmer, S. E-mail: nicola.omodei@stanford.edu

    2013-09-01

    Based on the experience gained during the four and a half years of the mission, the Fermi-LAT Collaboration has undertaken a comprehensive revision of the event-level analysis going under the name of Pass 8. Although it is not yet finalized, we can test the improvements in the new event reconstruction with the special case of the prompt phase of bright gamma-ray bursts (GRBs), where the signal-to-noise ratio is large enough that loose selection cuts are sufficient to identify gamma rays associated with the source. Using the new event reconstruction, we have re-analyzed 10 GRBs previously detected by the Large Area Telescope (LAT) for which an X-ray/optical follow-up was possible and found four new gamma rays with energies greater than 10 GeV in addition to the seven previously known. Among these four is a 27.4 GeV gamma ray from GRB 080916C, which has a redshift of 4.35, thus making it the gamma ray with the highest intrinsic energy ({approx}147 GeV) detected from a GRB. We present here the salient aspects of the new event reconstruction and discuss the scientific implications of these new high-energy gamma rays, such as constraining extragalactic background light models, Lorentz invariance violation tests, the prompt emission mechanism, and the bulk Lorentz factor of the emitting region.

  19. The HAWC Gamma-Ray Observatory: Design, Calibration, and Operation

    E-Print Network [OSTI]

    Abeysekara, A U; Alvarez, C; Álvarez, J D; Arceo, R; Arteaga-Velázquez, J C; Solares, H A Ayala; Barber, A S; Baughman, B M; Bautista-Elivar, N; Belmont, E; BenZvi, S Y; Berley, D; Rosales, M Bonilla; Braun, J; Caballero-Lopez, R A; Caballero-Mora, K S; Carramiñana, A; Castillo, M; Cotti, U; Cotzomi, J; de la Fuente, E; De León, C; DeYoung, T; Hernandez, R Diaz; Díaz-Vélez, J C; Dingus, B L; DuVernois, M A; Ellsworth, R W; Fernandez, A; Fiorino, D W; Fraija, N; Galindo, A; Garfias, F; González, L X; González, M M; Goodman, J A; Grabski, V; Gussert, M; Hampel-Arias, Z; Hui, C M; Hüntemeyer, P; Imran, A; Iriarte, A; Karn, P; Kieda, D; Kunde, G J; Lara, A; Lauer, R J; Lee, W H; Lennarz, D; Vargas, H León; Linares, E C; Linnemann, J T; Longo, M; Luna-GarcIa, R; Marinelli, A; Martinez, H; Martinez, O; Martínez-Castro, J; Matthews, J A J; Miranda-Romagnoli, P; Moreno, E; Mostafá, M; Nava, J; Nellen, L; Newbold, M; Noriega-Papaqui, R; Oceguera-Becerra, T; Patricelli, B; Pelayo, R; Pérez-Pérez, E G; Pretz, J; Rivière, C; Rosa-González, D; Salazar, H; Salesa, F; Sanchez, F E; Sandoval, A; Santos, E; Schneider, M; Silich, S; Sinnis, G; Smith, A J; Sparks, K; Springer, R W; Taboada, I; Toale, P A; Tollefson, K; Torres, I; Ukwatta, T N; Villaseñor, L; Weisgarber, T; Westerhoff, S; Wisher, I G; Wood, J; Yodh, G B; Younk, P W; Zaborov, D; Zepeda, A; Zhou, H

    2013-01-01

    The High-Altitude Water Cherenkov Gamma Ray Observatory (HAWC) is under construction 4100 meters above sea level at Sierra Negra, Mexico. We describe the design and cabling of the detector, the characterization of the photomultipliers, and the timing calibration system. We also outline a next-generation detector based on the water Cherenkov technique.

  20. Aging and Radiation Effects in Stockpile Electronics

    SciTech Connect (OSTI)

    Hartman, E.F.

    1999-03-25

    It is likely that aging is affecting the radiation hardness of stockpile electronics, and we have seen apparent examples of aging that affects the electronic radiation hardness. It is also possible that low-level intrinsic radiation that is inherent during stockpile life will damage or in a sense age electronic components. Both aging and low level radiation effects on radiation hardness and stockpile reliability need to be further investigated by using both test and modeling strategies that include appropriate testing of electronic components withdrawn from the stockpile.

  1. Towards an improved understanding of eta --> gamma^* gamma^*

    E-Print Network [OSTI]

    Xiao, C W; Hanhart, C; Kubis, B; Meißner, U -G; Wirzba, A

    2015-01-01

    We argue that high-quality data on the reaction $e^+e^-\\to \\pi^+\\pi^-\\eta$ will allow one to determine the double off-shell form factor $\\eta \\to \\gamma^*\\gamma^*$ in a model-independent way with controlled accuracy. This is an important step towards a reliable evaluation of the hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon. When analyzing the existing data for $e^+e^- \\to \\pi^+\\pi^-\\eta$ in the range of total energies $1\\text{GeV}^2off-shell form factor $F_{\\eta\\gamma^*\\gamma^*}(Q_1^2,Q_2^2)$ is consistent with the commonly employed factorization ansatz at least for $Q_1^2<1\\text{GeV}^2$, if the effect of the $a_2$ meson is taken into account. However, better data are needed to draw firm conclusions.

  2. GammaPod-A new device dedicated for stereotactic radiotherapy of breast cancer

    SciTech Connect (OSTI)

    Yu, Cedric X.; Shao Xinyu; Deng Jianchun; Duan Zhengcheng; Zhang Jin; Zheng, Mike; Yu, Ying S.; Regine, William

    2013-05-15

    Purpose: This paper introduces a new external beam radiotherapy device named GammaPod that is dedicated for stereotactic radiotherapy of breast cancer. Methods: The design goal of the GammaPod as a dedicated system for treating breast cancer is the ability to deliver ablative doses with sharp gradients under stereotactic image guidance. Stereotactic localization of the breast is achieved by a vacuum-assisted breast immobilization cup with built-in stereotactic frame. Highly focused radiation is achieved at the isocenter due to the cross-firing from 36 radiation arcs generated by rotating 36 individual Cobalt-60 beams. The dedicated treatment planning system optimizes an optimal path of the focal spot using an optimization algorithm borrowed from computational geometry such that the target can be covered by 90%-95% of the prescription dose and the doses to surrounding tissues are minimized. The treatment plan is intended to be delivered with continuous motion of the treatment couch. In this paper the authors described in detail the gamma radiation unit, stereotactic localization of the breast, and the treatment planning system of the GammaPod system. Results: A prototype GammaPod system was installed at University of Maryland Medical Center and has gone through a thorough functional, geometric, and dosimetric testing. The mechanical and functional performances of the system all meet the functional specifications. Conclusions: An image-guided breast stereotactic radiotherapy device, named GammaPod, has been developed to deliver highly focused and localized doses to a target in the breast under stereotactic image guidance. It is envisioned that the GammaPod technology has the potential to significantly shorten radiation treatments and even eliminate surgery by ablating the tumor and sterilizing the tumor bed simultaneously.

  3. Radiation dosimeter

    DOE Patents [OSTI]

    Fox, R.J.

    1981-09-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even through the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

  4. Radiation dosimeter

    DOE Patents [OSTI]

    Fox, Richard J. (Oak Ridge, TN)

    1983-01-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even though the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

  5. The 130 GeV gamma-ray line and generic dark matter model building constraints from continuum gamma rays, radio and antiproton data

    E-Print Network [OSTI]

    Masaki Asano; Torsten Bringmann; Gunter Sigl; Martin Vollmann

    2013-05-16

    An analysis of the Fermi gamma ray space telescope data has recently revealed a resolved gamma-ray feature close to the galactic center which is consistent with monochromatic photons at an energy of about 130 GeV. If interpreted in terms of dark matter (DM) annihilating into \\gamma\\gamma (\\gamma Z, \\gamma h), this would correspond to a DM particle mass of roughly 130 GeV (145 GeV, 155 GeV). The rate for these loop-suppressed processes, however, is larger than typically expected for thermally produced DM. Correspondingly, one would generically expect even larger tree level production rates of standard model fermions or gauge bosons. Here, we quantify this expectation in a rather model-independent way by relating the tree level and loop amplitudes with the help of the optical theorem. As an application, we consider bounds from continuum gamma rays, radio and antiproton data on the tree level amplitudes and translate them into constraints on the loop amplitudes. We find that, independently of the DM production mechanism, any DM model aiming at explaining the line signal in terms of charged standard model particles running in the loop is in rather strong tension with at least one of these constraints, with the exception of loops dominated by top quarks. We stress that attempts to explain the 130 GeV feature with internal bremsstrahlung do not suffer from such difficulties.

  6. Magnetic Structures in Gamma-Ray Burst Jets Probed by Gamma-Ray Polarization

    E-Print Network [OSTI]

    Daisuke Yonetoku; Toshio Murakami; Shuichi Gunji; Tatehiro Mihara; Kenji Toma; Yoshiyuki Morihara; Takuya Takahashi; Yudai Wakashima; Hajime Yonemochi; Tomonori Sakashita; Noriyuki Toukairin; Hirofumi Fujimoto; Yoshiki Kodama

    2012-08-27

    We report polarization measurements in two prompt emissions of gamma-ray bursts, GRB 110301A and GRB 110721A, observed with the Gamma-ray burst polarimeter (GAP) aboard IKAROS solar sail mission. We detected linear polarization signals from each burst with polarization degree of $\\Pi = 70 \\pm 22$% with statistical significance of $3.7 \\sigma$ for GRB 110301A, and $\\Pi = 84^{+16}_{-28}$% with $3.3 \\sigma$ confidence level for GRB 110721A. We did not detect any significant change of polarization angle. These two events had shorter durations and dimmer brightness compared with GRB 100826A, which showed a significant change of polarization angle, as reported in Yonetoku et al. (2011). Synchrotron emission model can be consistent with all the data of the three GRBs, while photospheric quasi-thermal emission model is not favorable. We suggest that magnetic field structures in the emission region are globally-ordered fields advected from the central engine.

  7. MAGNETIC STRUCTURES IN GAMMA-RAY BURST JETS PROBED BY GAMMA-RAY POLARIZATION

    SciTech Connect (OSTI)

    Yonetoku, Daisuke; Murakami, Toshio; Morihara, Yoshiyuki; Takahashi, Takuya; Wakashima, Yudai; Yonemochi, Hajime; Sakashita, Tomonori; Fujimoto, Hirofumi; Kodama, Yoshiki [College of Science and Engineering, School of Mathematics and Physics, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192 (Japan); Gunji, Shuichi; Toukairin, Noriyuki [Department of Physics, Faculty of Science, Yamagata University, 1-4-12, Koshirakawa, Yamagata, Yamagata 990-8560 (Japan); Mihara, Tatehiro [Cosmic Radiation Laboratory, RIKEN, 2-1, Hirosawa, Wako City, Saitama 351-0198 (Japan); Toma, Kenji, E-mail: yonetoku@astro.s.kanazawa-u.ac.jp [Department of Earth and Space Science, Osaka University, Toyonaka 560-0043 (Japan)

    2012-10-10

    We report polarization measurements in two prompt emissions of gamma-ray bursts, GRB 110301A and GRB 110721A, observed with the gamma-ray burst polarimeter (GAP) on borad the IKAROS solar sail mission. We detected linear polarization signals from each burst with polarization degree of {Pi} = 70 {+-} 22% with statistical significance of 3.7{sigma} for GRB 110301A, and {Pi} = 84{sup +16}{sub -28}% with 3.3{sigma} confidence level for GRB 110721A. We did not detect any significant change of polarization angle. These two events had shorter durations and dimmer brightness compared with GRB 100826A, which showed a significant change of polarization angle, as reported in Yonetoku et al. Synchrotron emission model can be consistent with the data of the three GRBs, while the photospheric quasi-thermal emission model is not favored. We suggest that magnetic field structures in the emission region are globally ordered fields advected from the central engine.

  8. Gamma and neutron detection modeling in the nuclear detection figure of merit (NDFOM) portal

    SciTech Connect (OSTI)

    Stroud, Phillip D [Los Alamos National Laboratory; Saeger, Kevin J [Los Alamos National Laboratory

    2009-01-01

    The Nuclear Detection Figure Of Merit (NDFOM) portal is a database of objects and algorithms for evaluating the performance of radiation detectors to detect nuclear material. This paper describes the algorithms used to model the physics and mathematics of radiation detection. As a first-principles end-to-end analysis system, it starts with the representation of the gamma and neutron spectral fluxes, which are computed with the particle and radiation transport code MCNPX. The gamma spectra emitted by uranium, plutonium, and several other materials of interest are described. The impact of shielding and other intervening material is computed by the method of build-up factors. The interaction of radiation with the detector material is computed by a detector response function approach. The construction of detector response function matrices based on MCNPX simulation runs is described in detail. Neutron fluxes are represented in a three group formulation to treat differences in detector sensitivities to thermal, epithermal, and fast neutrons.

  9. Inverse Gamma Distribution John D. Cook

    E-Print Network [OSTI]

    Cook, John D.

    Inverse Gamma Distribution John D. Cook October 3, 2008 Abstract These notes write up some basic facts regarding the inverse gamma distribution, also called the inverted gamma distribution. In a sense this distribution is unnecessary: it has the same distribution as the reciprocal of a gamma distribution. However

  10. Gamma-Ray Burst Lines

    E-Print Network [OSTI]

    Michael S. Briggs

    1999-10-20

    The evidence for spectral features in gamma-ray bursts is summarized. As a guide for evaluating the evidence, the properties of gamma-ray detectors and the methods of analyzing gamma-ray spectra are reviewed. In the 1980's, observations indicated that absorption features below 100 keV were present in a large fraction of bright gamma-ray bursts. There were also reports of emission features around 400 keV. During the 1990's the situation has become much less clear. A small fraction of bursts observed with BATSE have statistically significant low-energy features, but the reality of the features is suspect because in several cases the data of the BATSE detectors appear to be inconsistent. Furthermore, most of the possible features appear in emission rather than the expected absorption. Analysis of data from other instruments has either not been finalized or has not detected lines.

  11. An Interaction Region for Gamma-Gamma and Gamma-Electron Collisions at TESLA/SBLC

    E-Print Network [OSTI]

    R. Brinkmann; I. Ginzburg; N. Holtkamp; G. Jikia; O. Napoly; E. Saldin; E. Schneidmiller; V. Serbo; G. Silvestrov; V. Telnov; A. Undrus; M. Yurkov

    1997-07-08

    Linear colliders offer unique opportunities to study gamma-gamma (gg), gamma-electron (ge) interactions. Using the laser backscattering method one can obtain gg, ge colliding beams with an energy and luminosity comparable to that in e+e- collisions. This work is a part of the Conceptual Design of TESLA/SBLC linear colliders describing a second interaction region for gg, ge collisions. We consider here possible physics in high energy gg, ge collisions, e -> g conversion, requirements to lasers, collision schemes, attainable luminosities, backgrounds, possible lasers, optics at the interaction region and other associated problems.

  12. Gamma Ray Bursts and CETI

    E-Print Network [OSTI]

    Frank D. Smith Jr

    1993-02-10

    Gamma ray burst sources are isotropically distributed. They could be located at distances $\\sim 1000$ AU. (Katz \\cite{JK92}) GRB signals have many narrow peaks that are unresolved at the millisecond time resolution of existing observations. \\cite{JK87} CETI could use stars as gravitational lenses for interstellar gamma ray laser beam communication. Much better time resolution of GRB signals could rule out (or confirm?) the speculative hypothesis that GRB = CETI.

  13. Gamma-RayGamma-Ray Bursts: from SwiftBursts: from Swift

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Gamma-RayGamma-Ray Bursts: from SwiftBursts: from Swift to GLASTto GLAST Bing ZhangBing ZhangGehrels, et al), et al) #12;Gamma-ray bursts: the mostGamma-ray bursts: the most violent explosions fireball central photosphere internal external shocks engine (shocks) (reverse) (forward) gamma-ray UV

  14. Spectral Gamma-ray Signatures of Cosmological Dark Matter Annihilation

    E-Print Network [OSTI]

    Lars Bergstrom; Joakim Edsjo; Piero Ullio

    2001-12-13

    We propose a new signature for weakly interacting massive particle (WIMP) dark matter, a spectral feature in the diffuse extragalactic gamma-ray radiation. This feature, a sudden drop of the gamma-ray intensity at an energy corresponding to the WIMP mass, comes from the asymmetric distortion of the line due to WIMP annihilation into two gamma-rays caused by the cosmological redshift. Unlike other proposed searches for a line signal, this method is not very sensitive to the exact dark matter density distribution in halos and subhalos. The only requirement is that the mass distribution of substructure on small scales follows approximately the Press-Schechter law, and that smaller halos are on the average denser than large halos, which is a generic outcome of N-body simulations of Cold Dark Matter, and which has observational support. The upcoming Gamma-ray Large Area Space Telescope (GLAST) will be eminently suited to search for these spectral features. For numerical examples, we use rates computed for supersymmetric particle dark matter, where a detectable signal is possible.

  15. Wavelet Approach for Operational Gamma Spectral Peak Detection - Preliminary Assessment

    SciTech Connect (OSTI)

    ,

    2012-02-01

    Gamma spectroscopy for radionuclide identifications typically involves locating spectral peaks and matching the spectral peaks with known nuclides in the knowledge base or database. Wavelet analysis, due to its ability for fitting localized features, offers the potential for automatic detection of spectral peaks. Past studies of wavelet technologies for gamma spectra analysis essentially focused on direct fitting of raw gamma spectra. Although most of those studies demonstrated the potentials of peak detection using wavelets, they often failed to produce new benefits to operational adaptations for radiological surveys. This work presents a different approach with the operational objective being to detect only the nuclides that do not exist in the environment (anomalous nuclides). With this operational objective, the raw-count spectrum collected by a detector is first converted to a count-rate spectrum and is then followed by background subtraction prior to wavelet analysis. The experimental results suggest that this preprocess is independent of detector type and background radiation, and is capable of improving the peak detection rates using wavelets. This process broadens the doors for a practical adaptation of wavelet technologies for gamma spectral surveying devices.

  16. In situ radiation measurements at the former Soviet Nuclear Test Site

    SciTech Connect (OSTI)

    Tipton, W.J.

    1996-06-01

    A team from the Remote Sensing Laboratory conducted a series of in situ radiological measurements at the former Soviet Nuclear Test Site near Semipalatinsk, Kazakhstan, during the period of July 21-30, 1994. The survey team measured the terrestrial gamma radiation at selected areas on the site to determine the levels of natural and man-made radiation. The survey was part of a cooperative effort between the United States team and teams of radiation scientists from the National Nuclear Center of the Republic of Kazakhstan and the V.G. Khlopin Radium Institute in St. Petersburg, Russia. In addition to in situ radiation measurements made by the United States and Russian teams, soil samples were collected and analyzed by the Russian and Kazakhstani teams. All teams conducted their measurements at ten locations within the test site. The United States team also made a number of additional measurements to locate and verify the positions of three potential fallout plumes containing plutonium contamination from nonnuclear tests. In addition, the United States team made several measurements in Kurchatov City, the housing area used by personnel and their families who work(ed) at the test sites. Comparisons between the United States and Russian in situ measurements and the soil sample results are presented as well as comparisons with a Soviet aerial survey conducted in 1990-1991. The agreement between the different types of measurements made by all three countries was quite good.

  17. Contribution of GRB Emission to the GeV Extragalactic Diffuse Gamma-Ray Flux

    E-Print Network [OSTI]

    S. Casanova; B. L. Dingus; Bing Zhang

    2006-11-03

    TeV gamma rays emitted by GRBs are converted into electron-positron pairs via interactions with the extragalactic infrared radiation fields. In turn the pairs produced, whose trajectories are randomized by magnetic fields, will inverse Compton scatter off the cosmic microwave background photons. The beamed TeV gamma ray flux from GRBs is thus transformed into a GeV isotropic gamma ray flux, which contributes to the total extragalactic gamma-ray background emission. Assuming a model for the extragalactic radiation fields, for the GRB redshift distribution and for the GRB luminosity function, we evaluate the contribution of the GRB prompt and scattered emissions to the measured extragalactic gamma-ray flux. To estimate this contribution we optimistically require that the energy flux at TeV energies is about 10 times stronger than the energy flux at MeV energies. The resulting gamma-ray diffuse background is only a small fraction of what is observed, allowing blazars and other sources to give the dominant contribution.

  18. Measurements of B to V(Gamma) Decays

    SciTech Connect (OSTI)

    Yarritu, Aaron K.; ,

    2010-09-02

    The standard model has been highly successful at describing current experimental data. However, extensions of the standard model predict particles that have masses at energy scales that are above the electroweak scale. The flavor-changing neutral current processes of the B meson are sensitive to the influences of these new physics contributions. These processes proceed through loop diagrams, thus allowing new physics to enter at the same order as the standard model. New physics may contribute to the enhancement or suppression of rate asymmetries or the decay rates of these processes. The transition B {yields} V{gamma} (V = K*(892), {rho}(770), {omega}(782), {phi}(1020)) represents radiative decays of the B meson that proceed through penguin processes. Hadronic uncertainties limit the theoretical accuracy of the prediction of the branching fractions. However, uncertainties, both theoretical and experimental, are much reduced when considering quantities involving ratios of branching fractions, such as CP or isospin asymmetries. The most dominant exclusive radiative b {yields} s transition is B {yields} K*{gamma}. We present the best measurements of the branching fractions, direct CP, and isospin asymmetries of B {yields} K*{gamma}. The analogous b {yields} d transitions are B {yields} {rho}{gamma} and B {yields} {omega}{gamma}, which are suppressed by a factor of |V{sub td}/V{sub ts}|{sup 2} {approx} 0.04 relative to B {yields} K*{gamma}. A measurement of the branching fractions and isospin asymmetry of B{sup +} {yields} {rho}{sup +}{gamma} and B{sup 0} {yields} {rho}{sup 0}{gamma}, as well as a search for B {yields} {omega}{gamma}, are also given. These measurements are combined to calculate the ratio of CKM matrix elements |V{sub td}/V{sub ts}|, which corresponds to the length of one side of the unitary triangle. Finally, we present a search for the penguin annihilation process B {yields}{phi}{gamma}. We use a sample of 383 million B{bar B} events collected with the BABAR detector at the PEP-II asymmetric-energy B factory for the analysis of B {yields} K*{gamma}. We measure the branching fractions {Beta}(B{sup 0} {yields} K*{sup 0}{gamma}) = (4.47 {+-} 0.10 {+-} 0.16) x 10{sup -5} and {Beta}(B{sup +} {yields} K*{sup +}{gamma}) = (4.22 {+-} 0.14 {+-} 0.16) x 10{sup -5}. We measure the direct CP asymmetry to be -0.033 < {Alpha}{sub CP} (B {yields} K*{gamma}) < 0.028 and the isospin asymmetry to be 0.017 < {Delta}{sub 0-} < 0.116, where the limits are determined at the 90% C.L. and include both the statistical and systematic uncertainties. Using a sample of 347 million B{bar B} events, we measure the branching fractions {Beta}(B{sup +} {yields} {rho}{sup +}{gamma}) = (1.10{sub -0.33}{sup +0.37} {+-} 0.09) x 10{sup -6} and {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) = (0.79{sub -0.20}{sup +0.22} {+-} 0.06) x 10{sup -6}, the isospin asymmetry {Delta} = -0.35 {+-} 0.27, and set a 90% C.L. upper limit {Beta}(B {yields} {omega}{gamma}) < 0.78 x 10{sup -6}. We also measure the isospin-averaged branching fraction {Beta}(B {yields} ({rho}/{omega}){gamma}) = (1.25{sub -0.24}{sup +0.25} {+-} 0.09) x 10{sup -6}, from which we determine |V{sub td}/V{sub ts}|= 0.200{sub -0.020}{sup +0.021} {+-} 0.015, where the first uncertainty is experimental and the second theoretical. Finally, a sample of 124 million B{bar B} events is used to set an upper limit of {Beta}(B {yields} {phi}{gamma}) < 8.5 x 10{sup -7} at the 90% C.L.

  19. Ionizing Radiation Promotes Migration and Invasion of Cancer Cells Through Transforming Growth Factor-Beta-Mediated Epithelial-Mesenchymal Transition

    SciTech Connect (OSTI)

    Zhou Yongchun [Department of Radiation Oncology, Xijing Hospital Fourth Military Medical University, Xi'an (China); Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi'an (China); Liu Junye; Li Jing; Zhang Jie [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi'an (China); Xu Yuqiao [Department of Pathology, Xijing Hospital Fourth Military Medical University, Xi'an (China); Zhang Huawei; Qiu Lianbo; Ding Guirong [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi'an (China); Su Xiaoming [Department of Radiation Oncology, 306th Hospital of PLA, Beijing (China); Mei Shi [Department of Radiation Oncology, Xijing Hospital Fourth Military Medical University, Xi'an (China); Guo Guozhen, E-mail: guozhenguo@hotmail.com [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi'an (China)

    2011-12-01

    Purpose: To examine whether ionizing radiation enhances the migratory and invasive abilities of cancer cells through transforming growth factor (TGF-{beta})-mediated epithelial-mesenchymal transition (EMT). Methods and Materials: Six cancer cell lines originating from different human organs were irradiated by {sup 60}Co {gamma}-ray at a total dose of 2 Gy, and the changes associated with EMT, including morphology, EMT markers, migration and invasion, were observed by microscope, Western blot, immunofluorescence, scratch assay, and transwell chamber assay, respectively. Then the protein levels of TGF-{beta} in these cancer cells were detected by enzyme-linked immunosorbent assay, and the role of TGF-{beta} signaling pathway in the effect of ionizing radiation on EMT was investigate by using the specific inhibitor SB431542. Results: After irradiation with {gamma}-ray at a total dose of 2 Gy, cancer cells presented the mesenchymal phenotype, and compared with the sham-irradiation group the expression of epithelial markers was decreased and of mesenchymal markers was increased, the migratory and invasive capabilities were strengthened, and the protein levels of TGF-{beta} were enhanced. Furthermore, events associated with EMT induced by IR in A549 could be reversed through inhibition of TGF-{beta} signaling. Conclusions: These results suggest that EMT mediated by TGF-{beta} plays a critical role in IR-induced enhancing of migratory and invasive capabilities in cancer cells.

  20. And the remaining 22 photons: The development of gamma ray and gamma ray burst astronomy

    E-Print Network [OSTI]

    Trimble, V

    2005-01-01

    goblins and cosmic gamma ray bursts. Astrophysics and Spacelinear alignments of gamma-ray burst sources. Journal of theE.E. (eds. ), 1992. Gamma Ray Bursts. Cambridge, Cambridge

  1. Apparatus and method for identification of matrix materials in which transuranic elements are embedded using thermal neutron capture gamma-ray emission

    DOE Patents [OSTI]

    Close, D.A.; Franks, L.A.; Kocimski, S.M.

    1984-08-16

    An invention is described that enables the quantitative simultaneous identification of the matrix materials in which fertile and fissile nuclides are embedded to be made along with the quantitative assay of the fertile and fissile materials. The invention also enables corrections for any absorption of neutrons by the matrix materials and by the measurement apparatus by the measurement of the prompt and delayed neutron flux emerging from a sample after the sample is interrogated by simultaneously applied neutrons and gamma radiation. High energy electrons are directed at a first target to produce gamma radiation. A second target receives the resulting pulsed gamma radiation and produces neutrons from the interaction with the gamma radiation. These neutrons are slowed by a moderator surrounding the sample and bathe the sample uniformly, generating second gamma radiation in the interaction. The gamma radiation is then resolved and quantitatively detected, providing a spectroscopic signature of the constituent elements contained in the matrix and in the materials within the vicinity of the sample. (LEW)

  2. Status of the experiments on radiative branch of decay

    E-Print Network [OSTI]

    R. U. Khafizov; S. V. Tolokonnikov; V. A. Solovei; M. R. Kolhidashvili

    2009-03-09

    This report is dedicated to the investigation of radiative neutron decay. The theoretical spectrum of radiative gamma quanta, calculated within the framework of the standard electroweak interaction model, is compared with our experimental value of branching ratio (B.R.) for radiative neutron decay. It is noted that the study of radiative branches of elementary particle decay occupies a central place in the fundamental problem of searching for deviations from the standard electroweak model. Particular attention is paid to analyzing the results of the experiment conducted at the FRMII reactor of the Technical University of Munich in 2005.

  3. The emission of Gamma Ray Bursts as a test-bed for modified gravity

    E-Print Network [OSTI]

    Salvatore Capozziello; Gaetano Lambiase

    2015-04-15

    The extreme physical conditions of Gamma Ray Bursts can constitute a useful observational laboratory to test theories of gravity where very high curvature regimes are involved. Here we propose a sort of curvature engine capable, in principle, of explaining the huge energy emission of Gamma Ray Bursts. Specifically, we investigate the emission of radiation by charged particles non-minimally coupled to the gravitational background where higher order curvature invariants are present. The coupling gives rise to an additional force inducing a non-geodesics motion of particles. This fact allows a strong emission of radiation by gravitationally accelerated particles. As we will show with some specific model, the energy emission is of the same order of magnitude of that characterizing the Gamma Ray Burst physics. Alternatively, strong curvature regimes can be considered as a natural mechanism for the generation of highly energetic astrophysical events.

  4. The emission of Gamma Ray Bursts as a test-bed for modified gravity

    E-Print Network [OSTI]

    Salvatore Capozziello; Gaetano Lambiase

    2015-09-19

    The extreme physical conditions of Gamma Ray Bursts can constitute a useful observational laboratory to test theories of gravity where very high curvature regimes are involved. Here we propose a sort of curvature engine capable, in principle, of explaining the huge energy emission of Gamma Ray Bursts. Specifically, we investigate the emission of radiation by charged particles non-minimally coupled to the gravitational background where higher order curvature invariants are present. The coupling gives rise to an additional force inducing a non-geodesics motion of particles. This fact allows a strong emission of radiation by gravitationally accelerated particles. As we will show with some specific model, the energy emission is of the same order of magnitude of that characterizing the Gamma Ray Burst physics. Alternatively, strong curvature regimes can be considered as a natural mechanism for the generation of highly energetic astrophysical events. Possible applications to cosmology are discussed.

  5. The emission of Gamma Ray Bursts as a test-bed for modified gravity

    E-Print Network [OSTI]

    Capozziello, Salvatore

    2015-01-01

    The extreme physical conditions of Gamma Ray Bursts can constitute a useful observational laboratory to test theories of gravity where very high curvature regimes are involved. Here we propose a sort of curvature engine capable, in principle, of explaining the huge energy emission of Gamma Ray Bursts. Specifically, we investigate the emission of radiation by charged particles non-minimally coupled to the gravitational background where higher order curvature invariants are present. The coupling gives rise to an additional force inducing a non-geodesics motion of particles. This fact allows a strong emission of radiation by gravitationally accelerated particles. As we will show with some specific model, the energy emission is of the same order of magnitude of that characterizing the Gamma Ray Burst physics. Alternatively, strong curvature regimes can be considered as a natural mechanism for the generation of highly energetic astrophysical events.

  6. Gamma-Ray Bursts and the Earth: Exploration of Atmospheric, Biological, Climatic and Biogeochemical Effects

    E-Print Network [OSTI]

    Brian C. Thomas; Adrian L. Melott; Charles H. Jackman; Claude M. Laird; Mikhail V. Medvedev; Richard S. Stolarski; Neil Gehrels; John K. Cannizzo; Daniel P. Hogan; Larissa M. Ejzak

    2005-08-04

    Gamma-Ray Bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. We have used a two-dimensional atmospheric model to investigate the effects on the Earth's atmosphere of GRBs delivering a range of fluences, at various latitudes, at the equinoxes and solstices, and at different times of day. We have estimated DNA damage levels caused by increased solar UVB radiation, reduction in solar visible light due to $\\mathrm{NO_2}$ opacity, and deposition of nitrates through rainout of $\\mathrm{HNO_3}$. For the ``typical'' nearest burst in the last billion years, we find globally averaged ozone depletion up to 38%. Localized depletion reaches as much as 74%. Significant global depletion (at least 10%) persists up to about 7 years after the burst. Our results depend strongly on time of year and latitude over which the burst occurs. We find DNA damage of up to 16 times the normal annual global average, well above lethal levels for simple life forms such as phytoplankton. The greatest damage occurs at low to mid latitudes. We find reductions in visible sunlight of a few percent, primarily in the polar regions. Nitrate deposition similar to or slightly greater than that currently caused by lightning is also observed, lasting several years. We discuss how these results support the hypothesis that the Late Ordovician mass extinction may have been initiated by a GRB.

  7. Astrophysical S factor for C-13(p,gamma)N-14 and asymptotic normalization coefficients 

    E-Print Network [OSTI]

    Mukhamedzhanov, AM; Azhari, A.; Burjan, V.; Gagliardi, Carl A.; Kroha, V.; Sattarov, A.; Tang, X.; Trache, L.; Tribble, Robert E.

    2002-01-01

    We reanalyze the C-13(p,gamma)N-14 radiative capture reaction within the R-matrix approach. The low-energy astrophysical S factor has important contributions from both resonant and onresonant captures. The normalization of the nonresonant component...

  8. High spatial resolution X-ray and gamma ray imaging system using diffraction crystals

    DOE Patents [OSTI]

    Smither, Robert K. (Hinsdale, IL)

    2011-05-17

    A method and a device for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation are provided. The device comprises a plurality of arrays, with each array comprising a plurality of elements comprising a first collimator, a diffracting crystal, a second collimator, and a detector.

  9. Discovery of TeV Gamma-Ray Emission from the Cygnus Region of the Galaxy

    E-Print Network [OSTI]

    Abdo, A A; Berley, D; Blaufuss, E; Casanova, S; Chen, C; Coyne, D G; Delay, R S; Dingus, B L; Ellsworth, R W; Fleysher, L; Fleysher, R; González, M M; Goodman, J A; Hays, E; Hoffman, C M; Kolterman, B E; Kelley, L A; Lansdell, C P; Linnemann, J T; McEnery, J E; Mincer, A I; Moskalenko, I V; Némethy, P; Noyes, D; Ryan, J M; Samuelson, F W; Parkinson, P M S; Schneider, M; Shoup, A; Sinnis, G; Smith, A J; Strong, A W; Sullivan, G W; Vasileiou, V; Walker, G P; Williams, D A; Xu, X W; Yodh, G B

    2006-01-01

    The diffuse gamma radiation arising from the interaction of cosmic ray particles with matter and radiation in the Galaxy is one of the few probes available to study the origin of the cosmic rays. Milagro is a water Cherenkov detector that continuously views the entire overhead sky. The large field-of-view combined with the long observation time makes Milagro the most sensitive instrument available for the study of large, low surface brightness sources such as the diffuse gamma radiation arising from interactions of cosmic radiation with interstellar matter. In this paper we present spatial and flux measurements of TeV gamma-ray emission from the Cygnus Region. The TeV image shows at least one new source MGRO J2019+37 as well as correlations with the matter density in the region as would be expected from cosmic-ray proton interactions. However, the TeV gamma-ray flux as measured at ~12 TeV from the Cygnus region (after excluding MGRO J2019+37) exceeds that predicted from a conventional model of cosmic ray prod...

  10. Implications of final L3 measurement of {sigma}{sub tot}({gamma}{gamma}{yields}bb)

    SciTech Connect (OSTI)

    Chyla, Jiri

    2006-02-01

    The excess of data on the total cross section of bb production in {gamma}{gamma} collisions over QCD predictions, observed by L3, OPAL and DELPHI Collaborations at LEP2, has so far defied explanation. The recent final analysis of L3 data has brought important new information concerning the dependence of the observed excess on the {gamma}{gamma} collisions energy W{sub {gamma}}{sub {gamma}}. The implications of this dependence are discussed.

  11. Gamma-ray bursts, axion emission and string theory dilaton

    E-Print Network [OSTI]

    O. Bertolami

    1999-01-14

    The emission of axions from supernovae is an interesting possibility to account for the Gamma-Ray Bursts provided their energy can be effectively converted into electromagnetic energy elsewhere. The connection between supernova and gamma-ray bursts has been recently confirmed by the observed correlation between the burst of April 25, 1998 and the supernova SN1998bw. We argue that the axion convertion into photons can be more efficient if one considers the coupling between an intermediate scale axion and the string theory dilaton along with the inclusion of string loops. We also discuss the way dilaton dynamics may allow for a more effective energy exchange with electromagnetic radiation in the expansion process of fireballs.

  12. Radiation Monitoring Equipment Procedure: 7.513 Created: 10/30/2013 Version: 1.0 Revised

    E-Print Network [OSTI]

    Jia, Songtao

    equipment for performing radiation detection surveys. This ensures that the work environment is safe and can NaI: Sodium Iodide Counter D. Procedures 1. The lab is responsible for purchasing radiation detection equipment suitable to detect the type of radiation (i.e., alpha, beta, gamma or x ray) being used. Surveys

  13. Radiation receiver

    DOE Patents [OSTI]

    Hunt, A.J.

    1983-09-13

    The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles. 5 figs.

  14. Radiation receiver

    DOE Patents [OSTI]

    Hunt, Arlon J. (Oakland, CA)

    1983-01-01

    The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles.

  15. Automatic quenching of high energy gamma-ray sources by synchrotron photons

    E-Print Network [OSTI]

    L. Stawarz; J. G. Kirk

    2007-03-26

    We investigate a magnetized plasma in which injected high energy gamma-rays annihilate on a soft photon field, that is provided by the synchrotron radiation of the created pairs. For a very wide range of magnetic fields, this process involves gamma-rays between 0.3 GeV and 30 TeV. We derive a simple dynamical system for this process, analyze its stability to runaway production of soft photons and paris, and find conditions for it to automatically quench by reaching a steady state with an optical depth to photon-photon annihilation larger than unity. We discuss applications to broad-band gamma-ray emitters, in particular supermassive black holes. Automatic quenching limits the gamma-ray luminosity of these objects and predicts substantial pair loading of the jets of less active sources.

  16. AGATA - Advanced Gamma Tracking Array

    E-Print Network [OSTI]

    S. Akkoyun; A. Algora; B. Alikhani; F. Ameil; G. de Angelis; L. Arnold; A. Astier; A. Ataç; Y. Aubert; C. Aufranc; A. Austin; S. Aydin; F. Azaiez; S. Badoer; D. L. Balabanski; D. Barrientos; G. Baulieu; R. Baumann; D. Bazzacco; F. A. Beck; T. Beck; P. Bednarczyk; M. Bellato; M. A. Bentley; G. Benzoni; R. Berthier; L. Berti; R. Beunard; G. Lo Bianco; B. Birkenbach; P. G. Bizzeti; A. M. Bizzeti-Sona; F. Le Blanc; J. M. Blasco; N. Blasi; D. Bloor; C. Boiano; M. Borsato; D. Bortolato; A. J. Boston; H. C. Boston; P. Bourgault; P. Boutachkov; A. Bouty; A. Bracco; S. Brambilla; I. P. Brawn; A. Brondi; S. Broussard; B. Bruyneel; D. Bucurescu; I. Burrows; A. Bürger; S. Cabaret; B. Cahan; E. Calore; F. Camera; A. Capsoni; F. Carrió; G. Casati; M. Castoldi; B. Cederwall; J. -L. Cercus; V. Chambert; M. El Chambit; R. Chapman; L. Charles; J. Chavas; E. Clément; P. Cocconi; S. Coelli; P. J. Coleman-Smith; A. Colombo; S. Colosimo; C. Commeaux; D. Conventi; R. J. Cooper; A. Corsi; A. Cortesi; L. Costa; F. C. L. Crespi; J. R. Cresswell; D. M. Cullen; D. Curien; A. Czermak; D. Delbourg; R. Depalo; T. Descombes; P. Désesquelles; P. Detistov; C. Diarra; F. Didierjean; M. R. Dimmock; Q. T. Doan; C. Domingo-Pardo; M. Doncel; F. Dorangeville; N. Dosme; Y. Drouen; G. Duchêne; B. Dulny; J. Eberth; P. Edelbruck; J. Egea; T. Engert; M. N. Erduran; S. Ertürk; C. Fanin; S. Fantinel; E. Farnea; T. Faul; M. Filliger; F. Filmer; Ch. Finck; G. de France; A. Gadea; W. Gast; A. Geraci; J. Gerl; R. Gernhäuser; A. Giannatiempo; A. Giaz; L. Gibelin; A. Givechev; N. Goel; V. González; A. Gottardo; X. Grave; J. Gr?bosz; R. Griffiths; A. N. Grint; P. Gros; L. Guevara; M. Gulmini; A. Görgen; H. T. M. Ha; T. Habermann; L. J. Harkness; H. Harroch; K. Hauschild; C. He; A. Hernández-Prieto; B. Hervieu; H. Hess; T. Hüyük; E. Ince; R. Isocrate; G. Jaworski; A. Johnson; J. Jolie; P. Jones; B. Jonson; P. Joshi; D. S. Judson; A. Jungclaus; M. Kaci; N. Karkour; M. Karolak; A. Ka?ka?; M. Kebbiri; R. S. Kempley; A. Khaplanov; S. Klupp; M. Kogimtzis; I. Kojouharov; A. Korichi; W. Korten; Th. Kröll; R. Krücken; N. Kurz; B. Y. Ky; M. Labiche; X. Lafay; L. Lavergne; I. H. Lazarus; S. Leboutelier; F. Lefebvre; E. Legay; L. Legeard; F. Lelli; S. M. Lenzi; S. Leoni; A. Lermitage; D. Lersch; J. Leske; S. C. Letts; S. Lhenoret; R. M. Lieder; D. Linget; J. Ljungvall; A. Lopez-Martens; A. Lotodé; S. Lunardi; A. Maj; J. van der Marel; Y. Mariette; N. Marginean; R. Marginean; G. Maron; A. R. Mather; W. M?czy?ski; V. Mendéz; P. Medina; B. Melon; R. Menegazzo; D. Mengoni; E. Merchan; L. Mihailescu; C. Michelagnoli; J. Mierzejewski; L. Milechina; B. Million; K. Mitev; P. Molini; D. Montanari; S. Moon; F. Morbiducci; R. Moro; P. S. Morrall; O. Möller; A. Nannini; D. R. Napoli; L. Nelson; M. Nespolo; V. L. Ngo; M. Nicoletto; R. Nicolini; Y. Le Noa; P. J. Nolan; M. Norman; J. Nyberg; A. Obertelli; A. Olariu; R. Orlandi; D. C. Oxley; C. Özben; M. Ozille; C. Oziol; E. Pachoud; M. Palacz; J. Palin; J. Pancin; C. Parisel; P. Pariset; G. Pascovici; R. Peghin; L. Pellegri; A. Perego; S. Perrier; M. Petcu; P. Petkov; C. Petrache; E. Pierre; N. Pietralla; S. Pietri; M. Pignanelli; I. Piqueras; Z. Podolyak; P. Le Pouhalec; J. Pouthas; D. Pugnére; V. F. E. Pucknell; A. Pullia; B. Quintana; R. Raine; G. Rainovski; L. Ramina; G. Rampazzo; G. La Rana; M. Rebeschini; F. Recchia; N. Redon; M. Reese; P. Reiter; P. H. Regan; S. Riboldi; M. Richer; M. Rigato; S. Rigby; G. Ripamonti; A. P. Robinson; J. Robin; J. Roccaz; J. -A. Ropert; B. Rossé; C. Rossi Alvarez; D. Rosso; B. Rubio; D. Rudolph; F. Saillant; E. ?ahin; F. Salomon; M. -D. Salsac; J. Salt; G. Salvato; J. Sampson; E. Sanchis; C. Santos; H. Schaffner; M. Schlarb; D. P. Scraggs; D. Seddon; M. ?enyi?it; M. -H. Sigward; G. Simpson; J. Simpson; M. Slee; J. F. Smith; P. Sona; B. Sowicki; P. Spolaore; C. Stahl; T. Stanios; E. Stefanova; O. Stézowski; J. Strachan; G. Suliman; P. -A. Söderström; J. L. Tain; S. Tanguy; S. Tashenov; Ch. Theisen; J. Thornhill; F. Tomasi; N. Toniolo; R. Touzery; B. Travers; A. Triossi; M. Tripon; K. M. M. Tun-Lanoë; M. Turcato; C. Unsworth; C. A. Ur; J. J. Valiente-Dobon; V. Vandone; E. Vardaci; R. Venturelli; F. Veronese; Ch. Veyssiere; E. Viscione; R. Wadsworth; P. M. Walker; N. Warr; C. Weber; D. Weisshaar; D. Wells; O. Wieland; A. Wiens; G. Wittwer; H. J. Wollersheim; F. Zocca; N. V. Zamfir; M. Zi?bli?ski; A. Zucchiatti

    2012-09-17

    The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation gamma-ray spectrometer. AGATA is based on the technique of gamma-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a gamma ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realization of gamma-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly-segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterization of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximize its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer.

  17. Radiation Shielding Properties of Some Marbles in Turkey

    SciTech Connect (OSTI)

    Guenoglu, K.; Akkurt, I.

    2011-12-26

    Especially after development of technology, radiation started to be used in a large fields such as medicine, industry and energy. Using radiation in those fields bring hazardous effect of radiation into humancell. Thus radiation protection becomes important in physics. Although there are three ways for radiation protection, shielding of the radiation is the most commonly used method. Natural Stones such as marble is used as construction material especially in critical building and thus its radiation shielding capability should be determined.In this study, gamma ray shielding properties of some different types of marble mined in Turkey, have been measured using a NaI(Tl) scintillator detector. The measured results were also compared with the theoretical calculations XCOM.

  18. Crystal diffraction lens telescope for focusing nuclear gamma rays

    SciTech Connect (OSTI)

    Smither, R.K.; Fernandez, P.B.; Graber, T. [Argonne National Lab., IL (United States). Advanced Photon Source; Ballmoos, P. von; Naya, J.; Albernhe, F.; Vedrenne, G. [Centre d`Etude Spatiale des Rayonnements, Toulouse (France); Faiz, M. [KFUPM, Dhahran (Saudi Arabia). Physics Dept.

    1996-08-01

    A crystal diffraction lens was constructed at Argonne National Laboratory for use as a telescope to focus nuclear gamma rays. It consisted of 600 single crystals of germanium arranged in 8 concentric rings. The mounted angle of each crystal was adjusted to intercept and diffract the incoming gamma rays with an accuracy of a few arc sec. The performance of the lens was tested in two ways. In one case, the gamma rays were focused on a single medium size germanium detector. In the second case, the gamma rays were focused on the central germanium detector of a 3 x 3 matrix of small germanium detectors. The efficiency, image concentration and image quality, and shape were measured. The tests performed with the 3 x 3 matrix detector system were particularly interesting. The wanted radiation was concentrated in the central detector. The 8 other detectors were used to detect the Compton scattered radiation, and their energy was summed with coincident events in the central detector. This resulted in a detector with the efficiency of a large detector (all 9 elements) and the background of a small detector (only the central element). The use of the 3 x 3 detector matrix makes it possible to tell if the source is off axis and, if so, to tell in which direction. The crystal lens acts very much like a simple convex lens for visible light. Thus if the source is off to the left then the image will focus off to the right illuminating the detector on the right side: telling one in which direction to point the telescope. Possible applications of this type of crystal lens to balloon and satellite experiments will be discussed.

  19. Solids mass flow indication with radiation

    DOE Patents [OSTI]

    Macko, Joseph E. (Irwin, PA); Estriplet, Isnard (Irwin, PA)

    1985-06-04

    Method and apparatus for indicating mass flow of a solid particulate material through a rotary feeder. A radiation source and detector are positioned in a manner whereby radiation flux is directed through, and attenuated by, particulate material contained in rotating pockets. A Cesium-137 gamma source can be mounted within the shaft of the feeder, and one or more detectors can be mounted outside of the feeder housing. The detected signal is indicative of the mass of particulate material contained within a given pocket rotating within the feeder.

  20. Coaxial Mono-Energetic Gamma Generator for Active Interrogation

    E-Print Network [OSTI]

    Ludewigt, Bernhard A.

    2010-01-01

    Mono-Energetic Gamma Generator for Active Interrogation B.A.4. Coaxial gamma generator installed in the teststand. Thethe design of a gamma generator comparatively small and

  1. ON THE RECENTLY DISCOVERED CORRELATIONS BETWEEN GAMMA-RAY AND X-RAY PROPERTIES OF GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Dado, Shlomo; Dar, Arnon [Physics Department, Technion, Haifa 32000 (Israel)

    2013-09-20

    Recently, many correlations between the prompt {gamma}-ray emission properties and the X-ray afterglow properties of gamma-ray bursts (GRBs) have been inferred from a comprehensive analysis of the X-ray light curves of more than 650 GRBs measured with the Swift X-Ray Telescope (Swift/XRT) during the years 2004-2010. We show that these correlations are predicted by the cannonball (CB) model of GRBs. They result from the dependence of GRB observables on the bulk motion Lorentz factor and viewing angle of the jet of highly relativistic plasmoids (CBs) that produces the observed radiations by interaction with the medium through which it propagates. Moreover, despite their different physical origins, long GRBs (LGRBs) and short-hard bursts (SHBs) in the CB model share similar kinematic correlations, which can be combined into triple correlations satisfied by both LGRBs and SHBs.

  2. A search for optical counterparts of gamma-ray bursts. Final report

    SciTech Connect (OSTI)

    Park, Hye-Sook

    1995-03-09

    Gamma Ray Bursts (GRBS) are mysterious flashes of gamma rays lasting several tens to hundreds of seconds that occur approximately once per day. NASA launched the orbiting Compton Gamma Ray Observatory to study GRBs and other gamma ray phenomena. CGRO carries the Burst and Transient Experiment (BATSE) specifically to study GRBS. Although BATSE has collected data on over 600 GRBS, and confirmed that GRBs are localized, high intensity point sources of MeV gamma rays distributed isotropically in the sky, the nature and origin of GRBs remains a fundamental problem in astrophysics. BATSE`s 8 gamma ray sensors located on the comers of the box shaped CGRO can detect the onset of GRBs and record their intensity and energy spectra as a function of time. The position of the burst on the sky can be determined to < {plus_minus}10{degrees} from the BATSE data stream. This position resolution is not sufficient to point a large, optical telescope at the exact position of a GRB which would determine its origin by associating it with a star. Because of their brief duration it is not known if GRBs are accompanied by visible radiation. Their seemingly large energy output suggests thatthis should be. Simply scaling the ratio of visible to gamma ray intensities of the Crab Nebula to the GRB output suggests that GRBs ought to be accompanied by visible flashes of magnitude 10 or so. A few photographs of areas containing a burst location that were coincidentally taken during the burst yield lower limits on visible output of magnitude 4. The detection of visible light during the GRB would provide information on burst physics, provide improved pointing coordinates for precise examination of the field by large telescope and provide the justification for larger dedicated optical counterpart instruments. The purpose of this experiment is to detect or set lower limits on optical counterpart radiation simultaneously accompanying the gamma rays from

  3. Graphite Gamma Scan Results

    SciTech Connect (OSTI)

    Mark W. Drigert

    2014-04-01

    This report documents the measurement and data analysis of the radio isotopic content for a series of graphite specimens irradiated in the first Advanced Graphite Creep (AGC) experiment, AGC-1. This is the first of a series of six capsules planned as part of the AGC experiment to fully characterize the neutron irradiation effects and radiation creep behavior of current nuclear graphites. The AGC-1 capsule was irradiated in the Advanced Test Reactor (ATR) at INL at approximately 700 degrees C and to a peak dose of 7 dpa (displacements per atom). Details of the irradiation conditions and other characterization measurements performed on specimens in the AGC-1 capsule can be found in “AGC-1 Specimen Post Irradiation Data Report” ORNL/TM 2013/242. Two specimens from six different graphite types are analyzed here. Each specimen is 12.7 mm in diameter by 25.4 mm long. The isotope with the highest activity was 60Co. Graphite type NBG-18 had the highest content of 60Co with an activity of 142.89 µCi at a measurement distance of 47 cm.

  4. Thermal effects in radiation processing

    SciTech Connect (OSTI)

    Zagorski, Z.P.

    1984-10-21

    The balance of ionizing radiation energy incident on an object being processed is discussed in terms of energy losses, influencing the amount really absorbed. To obtain the amount of heat produced, the absorbed energy is corrected for the change in internal energy of the system and for the heat effect of secondary reactions developing after the initiation. The temperature of a processed object results from the heat evolved and from the specific heat of the material comprising the object. The specific heat of most materials is usually much lower than that of aqueous systems and therefore temperatures after irradiation are higher. The role of low specific heat in radiation processing at cryogenic conditions is stressed. Adiabatic conditions of accelerator irradiation are contrasted with the steady state thermal conditions prevailing in large gamma sources. Among specific questions discussed in the last part of the paper are: intermediate and final temperature of composite materials, measurement of real thermal effects in situ, neutralization of undesired warming experienced during radiation processing, processing at temperatures other than ambient and administration of very high doses of radiation.

  5. Beta-gamma discriminator circuit

    SciTech Connect (OSTI)

    Erkkila, B.H.; Wolf, M.A.; Eisen, Y.; Unruh, W.P.; Brake, R.J.

    1984-01-01

    The major difficulty encountered in the determination of beta-ray dose in field conditions is generally the presence of a relatively high gamma-ray component. Conventional dosimetry instruments use a shield on the detector to estimate the gamma-ray component in comparison with the beta-ray component. More accurate dosimetry information can be obtained from the measured beta spectrum itself. At Los Alamos, a detector and discriminator circuit suitable for use in a portable spectrometer have been developed. This instrument will discriminate between gammas and betas in a mixed field. The portable package includes a 256-channel MCA which can be programmed to give a variety of outputs, including a spectral display, and may be programmed to read dose directly.

  6. Monte Carlo determination of the neutron-gamma spectrum behind cadmium loaded polyethylene slabs irradiated by the Sandia Pulse Reactor III 

    E-Print Network [OSTI]

    Sartor, Raymond Francis

    1986-01-01

    reactor is to provide a neutron-gamma irradiation Fi e id for the testing of electronic components for radiation surviv- ability. Often ho~ever, there is a desire to test a component for resistance to damage From a neutron-gamma radiation field with a... cadmium I oaded pol yethyl ene shi el d conf i gurat i on. One of the reasons calcu let ional results of this type have not been done before i s that the gamma product ion cross sections for cadmium have not been ave i iabl e unt I I recently. A...

  7. Gravitational Wave Memory from Gamma Ray Bursts' Jets

    E-Print Network [OSTI]

    Ofek Birnholtz; Tsvi Piran

    2013-06-18

    While the possible roles of GRBs' progenitors as Gravitational Waves (GW) sources have been extensively studied, little attention has been given to the jet itself as a GW source. We expect the jet's acceleration to produce a GW Memory signal. While all relativistic jet models display anti-beaming of GW radiation away from the jet axis, thus radiating away from directions of GRBs' gamma radiation, this effect is not overwhelming. The decrease of the signal amplitude towards the cone of gamma-ray detectability is weak, and for some models and parameters the GW signal reaches a significant amplitude for much of the gamma-ray cone. Thus both signals may be jointly detected. We find different waveforms and fourier signatures for uniform jets and structured jet models - thus offering a method of using GW signatures to probe the internal structure and acceleration of GRB jets. The GW signal peaks just outside the jet (core) of a uniform (structuted) jet. Within the jet (core) the GW signal displays wiggles, due to a polarization effect; thus for a uniform jet, the peak amplitude accompanies a smoother signal than the peak of a structured jet. For the most probable detection angle and for typical GRB parameters, we expect frequencies < ~600Hz and amplitudes h~10^-25. Our estimates of the expected signals suggest that the signals are not strong enough for a single cluster of DECIGO nor for aLIGO's sensitivities. However, sensitivies of ~10^-25/sqrt(Hz) in the DECIGO band should suffice to detect typical long GRBs at 2Gpc and short GRBs at 200Mpc, implying a monthly event of a long GRB and a detection of a short GRB every decade. In addition, we expect much more frequent detection of GW from GRBs directed away from us, including orphan afterglows. The ultimate DECIGO sensitivy should increase the range and enable detecting these signals in all models even to high cosmological z.

  8. Gamma source for active interrogation

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Lou, Tak Pui; Barletta, William A.

    2012-10-02

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  9. Gamma source for active interrogation

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA); Lou, Tak Pui (Berkeley, CA); Barletta, William A. (Oakland, CA)

    2009-09-29

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  10. Gamma-ray Imaging Methods

    SciTech Connect (OSTI)

    Vetter, K; Mihailescu, L; Nelson, K; Valentine, J; Wright, D

    2006-10-05

    In this document we discuss specific implementations for gamma-ray imaging instruments including the principle of operation and describe systems which have been built and demonstrated as well as systems currently under development. There are several fundamentally different technologies each with specific operational requirements and performance trade offs. We provide an overview of the different gamma-ray imaging techniques and briefly discuss challenges and limitations associated with each modality (in the appendix we give detailed descriptions of specific implementations for many of these technologies). In Section 3 we summarize the performance and operational aspects in tabular form as an aid for comparing technologies and mapping technologies to potential applications.

  11. Radiation Protection Act (Pennsylvania)

    Broader source: Energy.gov [DOE]

    This Act combines the radiation safety provisions of The Atomic Energy Development and Radiation Control Act and the Environmental Radiation Protection Act, and empowers the Department of...

  12. DETECTORS FOR RADIATION DOSIMETRY

    E-Print Network [OSTI]

    Perez-Mendez, V.

    2010-01-01

    I. Applications of Radiation Detectors 1) X-Rays, Gammaof the Conference DETECTORS FOR RADIATION DOSIMETRY VictorT E D LBL9651 DETECTORS FOR RADIATION DOSIMETRY - DISCLAIM*

  13. Matter Wave Radiation Leading to Matter Teleportation

    E-Print Network [OSTI]

    Yong-Yi Huang

    2015-02-12

    The concept of matter wave radiation is put forward, and its equation is established for the first time. The formalism solution shows that the probability density is a function of displacement and time. A free particle and a two-level system are reinvestigated considering the effect of matter wave radiation. Three feasible experimental designs, especially a modified Stern-Gerlach setup, are proposed to verify the existence of matter wave radiation. Matter wave radiation effect in relativity has been formulated in only a raw formulae, which offers another explanation of Lamb shift. A possible mechanics of matter teleportation is predicted due to the effect of matter wave radiation.

  14. Late Ordovician geographic patterns of extinction compared with simulations of astrophysical ionizing radiation damage

    E-Print Network [OSTI]

    Adrian L. Melott; Brian C. Thomas

    2009-02-02

    Based on the intensity and rates of various kinds of intense ionizing radiation events such as supernovae and gamma-ray bursts, it is likely that the Earth has been subjected to one or extinction level events during the Phanerozoic. These induce changes in atmospheric chemistry so that the level of Solar ultraviolet-B radiation reaching the surface and near-surface waters may be doubled for up to a decade. This UVB level is known from experiment to be more than enough to kill off many kinds of organisms, particularly phytoplankton. It could easily induce a crash of the photosynthetic-based food chain in the oceans. Regularities in the latitudinal distribution of damage are apparent in simulations of the atmospheric changes. We previously proposed that the late Ordovician extinction is a plausible candidate for a contribution from an ionizing radiation event, based on environmental selectivity in trilobites. To test a null hypothesis based on this proposal, we confront latitudinal differential extinction rates predicted from the simulations with data from a published analysis of latitudinal gradients in the Ordovician extinction. The pattern of UVB damage always shows a strong maximum at some latitude, with substantially lower intensity to the north and south of this maximum. We find that the pattern of damage predicted from our simulations is consistent with the data assuming a burst approximately over the South Pole, and no further north than -75 degrees. We predict that any land mass (such as parts of north China, Laurentia, and New Guinea) which then lay north of the equator should be a refuge from UVB effects, and show a different pattern of extinction in the first strike of the end-Ordovician extinction, if induced by such a radiation event.

  15. GAMMA DETECTOR RESPONSE/SOIL CONCENTRATION CORRELATION STUDY AT THE AAR MANUFACTURING, INC. SITE, LIVONIA, MICHIGAN

    SciTech Connect (OSTI)

    ALTIC, NICK A

    2013-03-22

    At the NRC?s request, ORAU conducted surveys of the AAR Manufacturing site during the period of September 25 through September 27, 2012. The survey activities included walkover surveys and sampling activities. Once the survey team was onsite, the NRC personnel decided to forgo survey activities in the ?New Addition? and the pickling area. Areas of the planned study boundary were inaccessible due to overgrowth/large pieces of concrete covering the soil surface; therefore, the study boundary was redefined. Gamma walkover scans of the site boundary and ?front yard? identified multiple areas of elevated gamma radiation. As a result, two judgmental samples were collected. Sample results were above thorium background levels The answer to the PSQ relating to the relationship between thorium concentration in soil and NaI instrument response is ?Yes.? NaI instrument response can be used as a predictor of Th-232 concentration in the 0 to 1 m layer. An R2 value of 0.79 was determined for the surface soil relationship, thus satisfying the DQOs. Moreover, the regression was cross-checked by comparing the predicted Th-232 soil core concentration to the average Th-232 concentration (Section 5.3.2). Based on the cross-check, the regression equation provides a reasonable estimate for the Th-232 concentration at the judgmental locations. Consideration must be given when applying this equation to other soil areas of the site. If the contamination was heterogeneously distributed, and not distributed in a discrete layer as it was in the study area, then using the regression equation to predict Th-232 concentration would not be applicable.

  16. Tritium monitor with improved gamma-ray discrimination

    DOE Patents [OSTI]

    Cox, S.A.; Bennett, E.F.; Yule, T.J.

    1982-10-21

    Apparatus and method are presented for selective measurement of tritium oxide in an environment which may include other radioactive components and gamma radiation, the measurement including the selective separation of tritium oxide from a sample gas through a membrane into a counting gas, the generation of electrical pulses individually representative by rise times of tritium oxide and other radioactivity in the counting gas, separation of the pulses by rise times, and counting of those pulses representative of tritium oxide. The invention further includes the separate measurement of any tritium in the sample gas by oxidizing the tritium to tritium oxide and carrying out a second separation and analysis procedure as described above.

  17. Tritium monitor with improved gamma-ray discrimination

    DOE Patents [OSTI]

    Cox, Samson A. (Downers Grove, IL); Bennett, Edgar F. (Downers Grove, IL); Yule, Thomas J. (West Chicago, IL)

    1985-01-01

    Apparatus and method for selective measurement of tritium oxide in an environment which may include other radioactive components and gamma radiation, the measurement including the selective separation of tritium oxide from a sample gas through a membrane into a counting gas, the generation of electrical pulses individually representative by rise times of tritium oxide and other radioactivity in the counting gas, separation of the pulses by rise times, and counting of those pulses representative of tritium oxide. The invention further includes the separate measurement of any tritium in the sample gas by oxidizing the tritium to tritium oxide and carrying out a second separation and analysis procedure as described above.

  18. High Efficiency of Gamma-Ray Bursts Revisited

    E-Print Network [OSTI]

    Y. C. Zou; Z. G. Dai

    2007-03-07

    Using the conservation of energy and momentum during collisions of any two shells, we consider the efficiency of gamma-ray bursts by assuming that the ejecta from the central engine are equally massive and have the same Lorentz factors. We calculate the efficiency and the final Lorentz factor of the merged whole shell for different initial diversities of Lorentz factors and for different microscopic radiative efficiency. As a result, a common high efficiency in the range of 0.1 to 0.9 is considerable, and a very high value near 100% is also reachable if the diversity of the Lorentz factors is large enough.

  19. On an Improvement of the Planck radiation Energy Distribution

    E-Print Network [OSTI]

    Diego Saa

    2006-07-18

    The probability distribution function for thermodynamics and econophysics is obtained by solving an equilibrium equation. This approach is different from the common one of optimizing the entropy of the system or obtaining the state of maximum probability, which usually obtains as a result the Boltzmann distribution. The Gamma distribution is proposed as a better equation to describe the blackbody radiation in substitution of Planck's radiation equation. Also, a new form of entropy is proposed, that maintains the correct relation with the Clausius' formula.

  20. Gamma-Ray Burst Synthetic Spectra from Collisionless Shock PIC Simulations

    E-Print Network [OSTI]

    Christian Busk Hededal; Åke Nordlund

    2005-11-23

    The radiation from afterglows of gamma-ray bursts is generated in the collisionless plasma shock interface between a relativistic outflow and a quiescent circum-burst medium. The two main ingredients responsible for the radiation are high-energy, non-thermal electrons and a strong magnetic field. In this Letter we present, for the first time, synthetic spectra extracted directly from first principles particle-in-cell simulations of relativist collisionless plasma shocks. The spectra are generated by a numerical Fourier transformation of the electrical far-field from each of a large number of particles, sampled directly from the particle-in-cell simulations. Both the electromagnetic field and the non-thermal particle acceleration are self-consistent products of the Weibel two-stream instability. We find that the radiation spectrum from a $\\Gamma=15$ shock simulation show great resemblance with observed GRB spectra -- we compare specifically with that of GRB000301C.

  1. High energy Gamma-Ray Bursts as a result of the collapse and total annihilation of neutralino clumps

    E-Print Network [OSTI]

    R. S. Pasechnik; V. A. Beylin; V. I. Kuksa; G. M. Vereshkov

    2006-02-20

    Rare astrophysical events - cosmological gamma-ray bursts with energies over GeV - are considered as an origin of information about some SUSY parameters. The model of generation of the powerful gamma-ray bursts is proposed. According to this model the gamma-ray burst represents as a result of the collapse and the total annihilation of the neutralino clump. About 80 % of the clump mass radiates during about 100 second at the final stage of annihilation. The annihilation spectrum and its characteristic energies are calculated in the framework of Split Higgsino model.

  2. Atomistic simulations of radiation damage in amorphous metal alloys

    E-Print Network [OSTI]

    Baumer, Richard E. (Richard Edward)

    2013-01-01

    While numerous fundamental studies have characterized the atomic-level radiation response mechanisms in irradiated crystalline alloys, comparatively little is known regarding the mechanisms of radiation damage in amorphous ...

  3. Multiple gamma lines from semi-annihilation

    E-Print Network [OSTI]

    D'Eramo, Francesco

    Hints in the Fermi data for a 130 GeV gamma line from the galactic center have ignited interest in potential gamma line signatures of dark matter. Explanations of this line based on dark matter annihilation face a parametric ...

  4. Measurement of the ratio Gamma(K_L -> gamma gamma)/Gamma(K_L -> pi^0 pi^0 pi^0) with the KLOE detector

    E-Print Network [OSTI]

    Adinolfi, M; Ambrosino, F; Antonelli, A; Antonelli, M; Bacci, C; Bencivenni, G; Bertolucci, Sergio; Bini, C; Bloise, C; Bocci, V; Bossi, F; Branchini, P; Bulychjov, S A; Cabibbo, G; Caloi, R; Campana, P; Capon, G; Capussela, T; Carboni, G; Casarsa, M; Casavola, V; Cataldi, G; Ceradini, F; Cervelli, F; Cevenini, F; Chiefari, G; Ciambrone, P; Conetti, S; De Lucia, E; De Simone, P; De Zorzi, G; Dell'Agnello, S; Denig, A; Di Domenico, A; Di Donato, C; Di Falco, S; Di Micco, B; Doria, A; Dreucci, M; Erriquez, O; Farilla, A; Felici, G; Ferrari, A; Ferrer, M L; Finocchiaro, G; Forti, C; Franceschi, A; Franzini, P; Gatti, C; Gauzzi, P; Giannasi, A; Giovannella, S; Gorini, E; Graziani, E; Incagli, M; Kluge, W; Kulikov, V; Lacava, F; Lanfranchi, G; Lee-Franzini, Juliet; Leone, D; Lu, F; Martemyanov, M; Matsyuk, M; Mei, W; Merola, L; Messi, R; Miscetti, S; Moulson, M; Müller, S; Murtas, F; Napolitano, M; Nedosekin, A; Nguyen, F; Palomba, M; Pacciani, L; Palutan, M; Pasqualucci, E; Passalacqua, L; Passeri, A; Patera, V; Perfetto, F; Petrolo, E; Pirozzi, G; Pontecorvo, L; Primavera, M; Ruggieri, F; Santangelo, P; Santovetti, E; Saracino, G; Schamberger, R D; Sciascia, B; Sciubba, A; Scuri, F; Sfiligoi, I; Sibidanov, A L; Spadaro, T; Spiriti, E; Tabidze, M D; Tong, G L; Tortora, L; Valente, P; Valeriani, B; Venanzoni, G; Veneziano, Stefano; Ventura, A; Ventura, Sandro; Versaci, R

    2003-01-01

    We have measured the ratio R=Gamma(K_L -> gamma gamma)/ \\Gamma(K_L -> 3 pi^0) using the KLOE detector. From a sample of ~ 10^9 phi-mesons produced at DAFNE, the Frascati phi-factory, we select ~ 1.6 10^8 K_L-mesons tagged by observing K_S -> pi^+ pi^- following the reaction e^+ e^- -> phi -> K_L K_S. From this sample we select 27,375 K_L -> gamma gamma events and obtain R = (2.79 \\pm 0.02_{stat} \\pm 0.02_{syst}) \\times 10^{-3}. Using the world average value for BR(K_{L} -> 3 pi^0), we obtain BR(K_{L} -> gamma gamma) = (5.89 \\pm 0.07 \\pm 0.08) \\times 10^{-4} where the second error is due to the uncertainty on the 3 pi^0 branching fraction.

  5. The Diverse Environments of Gamma-Ray Bursts

    E-Print Network [OSTI]

    Perley, Daniel Alan

    2011-01-01

    of a Very Bright Gamma- Ray Burst in a Galactic Halo 3.1Galaxies of Dark Gamma-Ray Bursts: Observational Constraints1.3 Gamma-Ray Burst Classi?cation . . . . . . 1.4 Gamma-Ray

  6. FY2008 Report on GADRAS Radiation Transport Methods.

    SciTech Connect (OSTI)

    Mattingly, John K.; Mitchell, Dean James; Harding, Lee; Varley, Eric S.; Hilton, Nathan R.

    2008-10-01

    The primary function of the Gamma Detector Response and Analysis Software (GADRAS) is the solution of inverse radiation transport problems, by which the con-figuration of an unknown radiation source is inferred from one or more measured radia-tion signatures. GADRAS was originally developed for the analysis of gamma spec-trometry measurements. During fiscal years 2007 and 2008, GADRAS was augmented to implement the simultaneous analysis of neutron multiplicity measurements. This report describes the radiation transport methods developed to implement this new capability. This work was performed at the direction of the National Nuclear Security Administration's Office of Nonproliferation Research and Development. It was executed as an element of the Proliferation Detection Program's Simulation, Algorithm, and Modeling element. Acronyms BNL Brookhaven National Laboratory CSD Continuous Slowing-Down DU depleted uranium ENSDF Evaluated Nuclear Structure Data Files GADRAS Gamma Detector Response and Analysis Software HEU highly enriched uranium LANL Los Alamos National Laboratory LLNL Lawrence Livermore National Laboratory NA-22 Office of Nonproliferation Research and Development NNDC National Nuclear Data Center NNSA National Nuclear Security Administration ODE ordinary differential equation ONEDANT One-dimensional diffusion accelerated neutral particle transport ORNL Oak Ridge National Laboratory PARTISN Parallel time-dependent SN PDP Proliferation Detection Program RADSAT Radiation Scenario Analysis Toolkit RSICC Radiation Safety Information Computational Center SAM Simulation, Algorithms, and Modeling SNL Sandia National Laboratories SNM special nuclear material ToRI Table of Radioactive Isotopes URI uniform resource identifier XML Extensible Markup Language

  7. Light Curves of Swift Gamma Ray Bursts

    E-Print Network [OSTI]

    Paolo Cea

    2006-09-22

    Recent observations from the Swift gamma-ray burst mission indicate that a fraction of gamma ray bursts are characterized by a canonical behaviour of the X-ray afterglows. We present an effective theory which allows us to account for X-ray light curves of both (short - long) gamma ray bursts and X-ray rich flashes. We propose that gamma ray bursts originate from massive magnetic powered pulsars.

  8. Capture Gamma-Ray Libraries for Nuclear Applications

    SciTech Connect (OSTI)

    Sleaford, B.W.; Firestone, Richard B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M.; Basunia, S.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H.D.

    2010-05-01

    The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF has been used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90percent of all the decay energy an is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We use CASINO, a version of DICEBOX that is modified for this purpose. This can be used to simulate the neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modelling of unknown assemblies.

  9. Alpha Gamma Hot Cell Facility

    E-Print Network [OSTI]

    Kemner, Ken

    . These operations can result in elevated radiological risks to the facility and workers. ARG-US -- meaning and should be developed for and deployed in nuclear and radiological facilities to aid operation and reduceAlpha Gamma Hot Cell Facility Argonne National Laboratory is a U.S. Department of Energy laboratory

  10. The Universe Viewed in Gamma-Rays 1 Properties of Gamma-ray Bursts Localized by

    E-Print Network [OSTI]

    Enomoto, Ryoji

    The Universe Viewed in Gamma-Rays 1 Properties of Gamma-ray Bursts Localized by the HETE-2 and localize Gamma-ray bursts (GRBs) in wide field of view. HETE-2 have been localized about 20 GRBs per year hours after the burst. 1. The High Energy Transient Explorer 2 Gamma-ray burst (GRB) is the most

  11. General Relativistic Radiative Transfer

    E-Print Network [OSTI]

    S. Knop; P. H. Hauschildt; E. Baron

    2006-11-30

    We present a general method to calculate radiative transfer including scattering in the continuum as well as in lines in spherically symmetric systems that are influenced by the effects of general relativity (GR). We utilize a comoving wavelength ansatz that allows to resolve spectral lines throughout the atmosphere. The used numerical solution is an operator splitting (OS) technique that uses a characteristic formal solution. The bending of photon paths and the wavelength shifts due to the effects of GR are fully taken into account, as is the treatment of image generation in a curved spacetime. We describe the algorithm we use and demonstrate the effects of GR on the radiative transport of a two level atom line in a neutron star like atmosphere for various combinations of continuous and line scattering coefficients. In addition, we present grey continuum models and discuss the effects of different scattering albedos on the emergent spectra and the determination of effective temperatures and radii of neutron star atmospheres.

  12. An evolution of technologies and applications of gamma imagers in the nuclear cycle industry

    SciTech Connect (OSTI)

    Khalil, R. A. [AREVA/CANBERRA - Nuclear Measurements Business Unit (France); Carrel, F. [CEA, LIST, F-91191 Gif-sur-Yvette (France); Menaa, N.; De Toro, D. [AREVA/CANBERRA - Nuclear Measurements Business Unit (France); Schoepff, V.; Gmar, M. [CEA, LIST, F-91191 Gif-sur-Yvette (France); Varet, T. [AREVA/Nuclear Site Value Development Business Unit (France); Toubon, H. [AREVA/CANBERRA - Nuclear Measurements Business Unit (France)

    2011-07-01

    The tracking of radiation contamination and distribution has become a high priority in the nuclear cycle industry in order to respect the ALARA principle which is a main challenge during decontamination and dismantling activities. To support this need, AREVA/CANBERRA and CEA LIST have been actively carrying out research and development on a gamma-radiation imager. In this paper we will present the new generation of gamma camera, called GAMPIX. This system is based on the Timepix chip, hybridized with a CdTe substrate. A coded mask could be used in order to increase the sensitivity of the camera. Moreover, due to the USB connection with a standard computer, this gamma camera is immediately operational and user-friendly. The final system is a very compact gamma camera (global weight is less than 1 kg without any shielding) which could be used as a hand-held device for radioprotection purposes. In this article, we present the main characteristics of this new generation of gamma camera and we expose experimental results obtained during in situ measurements. Even though we present preliminary results the final product is under industrialization phase to address various applications specifications. (authors)

  13. Gamma-Rays from Large Scale Structure Formation and the Warm-Hot Intergalactic Medium: Cosmic Baryometry with Gamma-Rays

    E-Print Network [OSTI]

    Susumu Inoue; Masahiro Nagashima

    2005-02-17

    It is shown that inverse Compton gamma-rays from electrons accelerated in large scale structure formation shocks can be crucially affected by non-gravitational effects such as radiative cooling and galaxy formation, with corresponding uncertainties by an order of magnitude in either the gamma-ray source counts or the extragalactic background contribution. However, this also implies that such gamma-rays may in the near future provide us with valuable information about the fraction of cosmic baryons in different forms, particularly the warm-hot intergalactic medium where the majority of the baryons in the universe are believed to reside. We address this problem in a simple way through semi-analytic modeling of structure formation shocks which self-consistently treats merger and accretion shocks.

  14. A Study of Radiative Bottomonium Transitions using Converted Photons

    SciTech Connect (OSTI)

    Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; /INFN, Bari /Bari U.; Milanes, D.A.; /INFN, Bari; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum; Asgeirsson, D.J.; Hearty, C.; /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-08-15

    The authors use (111 {+-} 1) million {Upsilon}(3S) and (89 {+-} 1) million {Upsilon}(2S) events recorded by the BABAR detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions betwen bottomonium states using photons that have been converted to e{sup +}e{sup -} pairs by the detector material. They observe {Upsilon}(3S) {yields} {gamma}{chi}{sub b0,2}(1P) decay, make precise measurements of the branching fractions for {chi}{sub b1,2}(1P, 2P) {yields} {gamma}{Upsilon}(1S) and {chi}{sub b1,2}(2P) {yields} {gamma}{Upsilon}(2S) decays, and search for radiative decay to the {eta}{sub b}(1S) and {eta}{sub b}(2S) states.

  15. Thermonuclear Reaction Rate of 23Mg(p,gamma)24$Al

    E-Print Network [OSTI]

    H. Herndl; M. Fantini; C. Iliades; P. M. Endt; H. Oberhummer

    1998-06-05

    Updated stellar rates for the reaction 23Mg(p,gamma)24Al are calculated by using all available experimental information on 24Al excitation energies. Proton and gamma-ray partial widths for astrophysically important resonances are derived from shell model calculations. Correspondences of experimentally observed 24Al levels with shell model states are based on application of the isobaric multiplet mass equation. Our new rates suggest that the 23Mg(p,gamma)24Al reaction influences the nucleosynthesis in the mass A>20 region during thermonuclear runaways on massive white dwarfs.

  16. The Two-Point Correlation Function of Gamma-ray Bursts

    E-Print Network [OSTI]

    Li, Ming-Hua

    2015-01-01

    In this paper, we examine the spacial distribution of gamma-ray bursts (GRBs) using a sample of 373 objects. We subdivide the GRB data into two redshift intervals over the redshift range $0gamma}$ to the measured $\\xi(r)$ and obtain an amplitude and slope of $r_0= 1235.2 \\pm 342.6~h^{-1}$ Mpc and $\\gamma = 0.80\\pm 0.19 $ ($1\\sigma$ confidence level) over the scales $r=200$ to $10^4~h^{-1}$ Mpc. Our ...

  17. Observation of psi(3770)->gamma chi(c1)->gamma gamma J/psi

    E-Print Network [OSTI]

    Besson, David Zeke

    2006-05-01

    From e(+)e(-) collision data acquired with the CLEO detector at the Cornell Electron Storage Ring, we observe the non-D (D) over bar decay psi(3770)->gamma chi(c1) with a statistical significance of 6.6 standard deviations, ...

  18. Blueshifting may explain the gamma ray bursts

    E-Print Network [OSTI]

    Krasi?ski, Andrzej

    2015-01-01

    It is shown that the basic observed properties of the gamma-ray bursts (GRBs) are accounted for if one assumes that the GRBs arise by blueshifting the emission radiation of hydrogen and helium generated during the last scattering epoch. The blueshift generator for a single GRB is a Lema\\^{\\i}tre -- Tolman (L--T) region with a nonconstant bang-time function $t_B(r)$ matched into a Friedmann background. Blueshift visible to the observer arises \\textit{only on radial rays} that are emitted in the L--T region. The paper presents three L--T models with different Big Bang profiles, adapted for the highest and the lowest end of the GRB frequency range. The models account for: (1) The observed frequency range of the GRBs; (2) Their limited duration; (3) The afterglows; (4) Their hypothetical collimation into narrow jets; (5) The large distances to their sources; (6) The multitude of the observed GRBs. Properties (2), (3) and (6) are accounted for only qualitatively. With a small correction of the parameters of the mo...

  19. New Remote Method for Estimation of Contamination Levels of Reactor Equipment - 13175

    SciTech Connect (OSTI)

    Danilovich, Alexey; Ivanov, Oleg; Potapov, Victor; Semenov, Sergey; Semin, Ilya; Smirnov, Sergey; Stepanov, Vyacheslav; Volkovich, Anatoly

    2013-07-01

    Projects for decommissioning of shutdown reactors and reactor facilities carried out in several countries, including Russia. In the National Research Centre 'Kurchatov Institute' decontamination and decommissioning of the research reactor MR (Material Testing Reactor) has been initiated. The research reactor MR has a long history and consists of nine loop facilities for experiments with different kinds of fuel. During the operation of main and auxiliary equipment of reactors it was subjected to strong radioactive contamination. The character of this contamination requires individual strategies for the decontamination work. This requires information about the character of the distribution of radioactive contamination of equipment in the premises. A detailed radiation survey of these premises using standard dosimetric equipment is almost impossible because of high levels of radiation and high-density of the equipment that does not allow identifying the most active fragments using standard tools of measurement. The problem can be solved using the method of remote measurements of distribution of radioactivity with help of the collimated gamma-ray detectors. For radiation surveys of the premises of loop installations remotely operated spectrometric collimated system was used [1, 2, 3]. As a result of the work, maps of the distribution of activity and dose rate for surveyed premises were plotted and superimposed on its photo. The new results of measurements in different areas of the reactor and at its loop installations, with emphasis on the radioactive survey of highly-contaminated samples, are presented. (authors)

  20. Developing a Methodology for Characterizing the Effects of Building Materials’ Natural Radiation Background on a Radiation Portal Monitoring System 

    E-Print Network [OSTI]

    Fitzmaurice, Matthew Blake 1988-

    2012-11-06

    Naturally Occurring Radioactive Material ? Diameter ORNL Oak Ridge National Laboratory PMT Photomultiplier Tube PNNL Pacific Northwest National Laboratory PVT Polyvinyl Toluene RDD Radiological Dispersal Device vii RPM Radiation Portal Monitor... and Their Relation to Energy and Z5 ................................................................... 6 2 Detector Response Functions for HPGe, NaI, and PVT Spectrometers, Exposed to Cs-137 Gamma Rays6...

  1. Measurement of the gamma gamma* -> pi0 transition form factor

    SciTech Connect (OSTI)

    Aubert, B.

    2009-06-02

    We study the reaction e{sup +}e{sup -} {yields} e{sup +}e{sup -}{pi}{sup 0} in the single tag mode and measure the differential cross section d{sigma}/dQ{sup 2} and the {gamma}{gamma}* {yields} {pi}{sup 0} transition form factor in the mometum transfer range from 4 to 40 GeV{sup 2}. At Q{sup 2} > 10 GeV{sup 2} the measured form factor exceeds the asymptotic limit predicted by perturbative QCD. The analysis is based on 442 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.

  2. The Gamma Ray Burst Rate at High Photon Energies

    E-Print Network [OSTI]

    Karl Mannheim; Dieter Hartmann; Burkhardt Funk

    1996-05-17

    Some gamma-ray burst (GRB) spectra exhibit high energy tails with the highest photon energy detected at 18 GeV. The spectral slope of the high-energy tails is sufficiently flat in nu F_nu to consider the possibility of their detection at still higher energies. We calculate how many bursts can reasonably be expected above a given energy threshold for a cosmological distribution of bursts satisfying the observed apparent brightness distribution. The crucial point is that the gamma-ray absorption by pair production in the intergalactic diffuse radiation field eliminates bursts from beyond the gamma-ray horizon tau ~ 1, thus drastically reducing the number of bursts at high energies. Our results are consistent with the non-detection of bursts by current experiments in the 100 GeV to 100 TeV energy range. For the earth-bound detector array MILAGRO, we predict a maximal GRB rate of ~ 10 events per year. The Whipple Observatory can detect, under favorable conditions, ~1 event per year. The event rate for the HEGRA array is ~ 0.01 per year. Detection of significantly higher rates of bursts would severely challenge cosmological burst scenarios.

  3. A silicon photomultiplier readout for time of flight neutron spectroscopy with {gamma}-ray detectors

    SciTech Connect (OSTI)

    Pietropaolo, A.; Gorini, G.; Festa, G.; Andreani, C.; De Pascale, M. P.; Reali, E.; Grazzi, F.; Schooneveld, E. M.

    2009-09-15

    The silicon photomultiplier (SiPM) is a recently developed photosensor used in particle physics, e.g., for detection of minimum ionizing particles and/or Cherenkov radiation. Its performance is comparable to that of photomultiplier tubes, but with advantages in terms of reduced volume and magnetic field insensitivity. In the present study, the performance of a gamma ray detector made of an yttrium aluminum perovskite scintillation crystal and a SiPM-based readout is assessed for use in time of flight neutron spectroscopy. Measurements performed at the ISIS pulsed neutron source demonstrate the feasibility of {gamma}-detection based on the new device.

  4. Spectral Lags of Gamma-Ray Bursts from Primordial Black Hole (PBH) Evaporations

    E-Print Network [OSTI]

    T. N. Ukwatta; J. H. MacGibbon; W. C. Parke; K. S. Dhuga; A. Eskandarian; N. Gehrels; L. Maximon; D. C. Morris

    2009-08-14

    Primordial Black Holes (PBHs), which may have been created in the early Universe, are predicted to be detectable by their Hawking radiation. PBHs with an initial mass of 5.0 * 10^14 g should be expiring today with a burst of high energy particles. Evaporating PBHs in the solar neighborhood are candidate Gamma-Ray Bursts (GRBs) progenitors. We propose spectral lag, which is the temporal delay between the high energy photon pulse and the low energy photon pulse, as a possible method to detect PBH evaporation events with the Fermi Gamma-ray Space Telescope Observatory.

  5. Fiber optic thermal/fast neutron and gamma ray scintillation detector

    DOE Patents [OSTI]

    Neal, John S.; Mihalczo, John T.

    2006-11-28

    A detector system that combines a .sup.6Li loaded glass fiber scintillation thermal neutron detector with a fast scintillation detector in a single layered structure. Detection of thermal and fast neutrons and ionizing electromagnetic radiation is achieved in the unified detector structure. The fast scintillator replaces the polyethelene moderator layer adjacent the .sup.6Li loaded glass fiber panel of the neutron detector and acts as the moderator for the glass fibers. Fast neutrons, x-rays and gamma rays are detected in the fast scintillator. Thermal neutrons, x-rays and gamma rays are detected in the glass fiber scintillator.

  6. Short-term effects of Gamma Ray Bursts on oceanic photosynthesis

    E-Print Network [OSTI]

    Penate, Liuba; Cardenas, Rolando; Agusti, Susana

    2010-01-01

    We continue our previous work on the potential short-term influence of a gamma ray bursts on Earth's biosphere, focusing on the only important short-term effect on life: the ultraviolet flash which occurs as a result of the retransmission of the {\\gamma} radiation through the atmosphere. Thus, in this work we calculate the ultraviolet irradiances penetrating the first hundred meters of the water column, for Jerlov's ocean water types I, II and III. Then we estimate the UV flash potential for photosynthesis inhibition, showing that it can be important in a considerable part of the water column with light enough for photosynthesis to be done, the so called photic zone.

  7. Cellular response to low dose radiation: Role of phosphatidylinositol-3 kinase like kinases

    SciTech Connect (OSTI)

    Balajee, A.S.; Meador, J.A.; Su, Y.

    2011-03-24

    It is increasingly realized that human exposure either to an acute low dose or multiple chronic low doses of low LET radiation has the potential to cause different types of cancer. Therefore, the central theme of research for DOE and NASA is focused on understanding the molecular mechanisms and pathways responsible for the cellular response to low dose radiation which would not only improve the accuracy of estimating health risks but also help in the development of predictive assays for low dose radiation risks associated with tissue degeneration and cancer. The working hypothesis for this proposal is that the cellular mechanisms in terms of DNA damage signaling, repair and cell cycle checkpoint regulation are different for low and high doses of low LET radiation and that the mode of action of phosphatidylinositol-3 kinase like kinases (PIKK: ATM, ATR and DNA-PK) determines the dose dependent cellular responses. The hypothesis will be tested at two levels: (I) Evaluation of the role of ATM, ATR and DNA-PK in cellular response to low and high doses of low LET radiation in simple in vitro human cell systems and (II) Determination of radiation responses in complex cell microenvironments such as human EpiDerm tissue constructs. Cellular responses to low and high doses of low LET radiation will be assessed from the view points of DNA damage signaling, DNA double strand break repair and cell cycle checkpoint regulation by analyzing the activities (i.e. post-translational modifications and kinetics of protein-protein interactions) of the key target proteins for PI-3 kinase like kinases both at the intra-cellular and molecular levels. The proteins chosen for this proposal are placed under three categories: (I) sensors/initiators include ATM ser1981, ATR, 53BP1, gamma-H2AX, MDC1, MRE11, Rad50 and Nbs1; (II) signal transducers include Chk1, Chk2, FANCD2 and SMC1; and (III) effectors include p53, CDC25A and CDC25C. The primary goal of this proposal is to elucidate the differences in cellular defense mechanisms between low and high doses of low LET radiation and to define the radiation doses where the cellular DNA damage signaling and repair mechanisms tend to shift. This information is critically important to address and advance some of the low dose research program objectives of DOE. The results of this proposed study will lead to a better understanding of the mechanisms for the cellular responses to low and high doses of low LET radiation. Further, systematic analysis of the role of PIKK signaling pathways as a function of radiation dose in tissue microenvironment will provide useful mechanistic information for improving the accuracy of radiation risk assessment for low doses. Knowledge of radiation responses in tissue microenvironment is important for the accurate prediction of ionizing radiation risks associated with cancer and tissue degeneration in humans.

  8. Searches for Higgs boson pair production in the $hh\\to bb\\tau\\tau, \\gamma\\gamma WW*, \\gamma\\gamma bb, bbbb$ channels with the ATLAS detector

    E-Print Network [OSTI]

    Aad, Georges; Abdallah, Jalal; Abdinov, Ovsat; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agricola, Johannes; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; ?lvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Baca, Matthew John; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bieniek, Stephen Paul; Biesuz, Nicolo Vladi; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet

    2015-01-01

    Searches for both resonant and non-resonant Higgs boson pair production are performed in the $hh\\to bb\\tau\\tau, \\gamma\\gamma WW^*$ final states using 20.3 fb$^{-1}$ of $pp$ collision data at a center-of-mass energy of 8 TeV recorded with the ATLAS detector at the Large Hadron Collider. No evidence of their production is observed and 95% confidence level upper limits on the production cross sections are set. These results are then combined with the published results of the $hh\\to \\gamma\\gamma bb, bbbb$ analyses. An upper limit of 0.69 (0.47) pb on the non-resonant Standard Model like $hh$ production is observed (expected), corresponding to 70 (48) times of the SM $gg\\to hh$ cross section. For production via narrow resonances, cross section limits of $hh$ production from a heavy Higgs boson decay are set as a function of the heavy Higgs boson mass. The observed (expected) limits range from 2.1 (1.1) pb at 260 GeV to 0.011 (0.018) pb at 1000 GeV. These results are interpreted in the context of two simplified sce...

  9. Radiation Safety

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impacts on GlobalRachel Ruggirello RachelRadiation DrySafety Home

  10. Spatial and Spectral Modeling of the Gamma-ray Distribution in the Large Magellanic Cloud

    E-Print Network [OSTI]

    Foreman, Gary; Gruendl, Robert; Hughes, Annie; Fields, Brian; Ricker, Paul

    2015-01-01

    We perform spatial and spectral analyses of the Large Magellanic Cloud (LMC) gamma-ray emission collected over 66 months by the Fermi Gamma-ray Space Telescope. In our spatial analysis, we model the LMC cosmic-ray distribution and gamma-ray production using observed maps of the LMC interstellar medium, star formation history, interstellar radiation field, and synchrotron emission. We use bootstrapping of the data to quantify the robustness of spatial model performance. We model the LMC gamma-ray spectrum using fitting functions derived from the physics of $\\pi^0$ decay, bremsstrahlung, and inverse Compton scattering. We find the integrated gamma-ray flux of the LMC from 200 MeV to 20 GeV to be $1.38 \\pm 0.02 \\times 10^{-7}$ ph cm$^{-2}$ s$^{-1}$, of which we attribute about 10% to inverse Compton scattering and 40% to bremsstrahlung. From our work, we conclude that the spectral index of the LMC cosmic-ray proton population is 2.4$\\pm$0.2, and we find that cosmic-ray energy loss through gamma-ray production is...

  11. Adaptable radiation monitoring system and method

    DOE Patents [OSTI]

    Archer, Daniel E. (Livermore, CA); Beauchamp, Brock R. (San Ramon, CA); Mauger, G. Joseph (Livermore, CA); Nelson, Karl E. (Livermore, CA); Mercer, Michael B. (Manteca, CA); Pletcher, David C. (Sacramento, CA); Riot, Vincent J. (Berkeley, CA); Schek, James L. (Tracy, CA); Knapp, David A. (Livermore, CA)

    2006-06-20

    A portable radioactive-material detection system capable of detecting radioactive sources moving at high speeds. The system has at least one radiation detector capable of detecting gamma-radiation and coupled to an MCA capable of collecting spectral data in very small time bins of less than about 150 msec. A computer processor is connected to the MCA for determining from the spectral data if a triggering event has occurred. Spectral data is stored on a data storage device, and a power source supplies power to the detection system. Various configurations of the detection system may be adaptably arranged for various radiation detection scenarios. In a preferred embodiment, the computer processor operates as a server which receives spectral data from other networked detection systems, and communicates the collected data to a central data reporting system.

  12. Radiation tolerance of the FOXFET biasing scheme for AC-coupled Si microstrip detectors

    SciTech Connect (OSTI)

    Bacchetta, N.; Gotra, Yu. ); Bisello, D.; Da Ros, R.; Giraldo, A. Univ. di Padova . Dipt. di Fisica); Canali, C. Univ. di Modena . Facolta di Ingegneria); Fuochi, P.G. ); Fusaro, G. . Dept. di Elettronica e Informatica); Paccagnella, A. Univ. di Cagliari . Instituto di Elettrotecnica); Verzellesi, G. Univ. di Padova . Dept. di Elettronica e Informatica)

    1993-12-01

    The radiation response of FOXFETs has been studied for proton, gamma and neutron exposures. The punch-through behavior, which represents the normal FET operating conditions in Si microstrip detectors, has been found to be much less sensitive to radiation damage than threshold voltage. The device performance has been elucidated by means of two-dimensional simulations. The main radiation effects have been also taken into account in the numerical analysis and separately examined.

  13. Degradation of silicon ac-coupled microstrip detectors induced by radiation

    SciTech Connect (OSTI)

    Bacchetta, N.; Gotra, Yu.; Bisello, D.; Canali, C.; Fuochi, P.G.; Paccagnella, A.; Verzellesi, G.

    1993-12-01

    Results are presented showing the radiation response of ac-coupled FOXFET biased microstrip detectors and related test patterns to be used in the microvertex detector of the CDF experiment at Fermi National Laboratory. Radiation tolerance of detectors to gamma and proton irradiation has been tested and the radiation induced variations of the dc electrical parameters have been analyzed. Long term post-irradiation behavior of detector characteristics have been studied, and the relevant room temperature annealing phenomena have been discussed.

  14. Gamma Ray Bursts from Minijets

    E-Print Network [OSTI]

    Nir J. Shaviv; Arnon Dar

    1994-07-14

    Striking similarities exist between high energy gamma ray emission from active galactic nuclei (AGN) and gamma ray bursts (GRBs). They suggest that GRBs are generated by inverse Compton scattering from highly relativistic electrons in transient jets. Such jets may be produced along the axis of an accretion disk formed around stellar black holes (BH) or neutron stars (NS) in BH-NS and NS-NS mergers and in accretion induced collapse of magnetized white dwarfs (WD) or neutron stars in close binary systems. Such events may produce the cosmological GRBs. Transient jets formed by single old magnetized neutron stars in an extended Galactic halo may produce a local population of GRBs. Here we show that jet production of GRBs by inverse Compton scattering can explain quite simply the striking correlations that exist between various temporal features of GRBs, their duration histogram, the power spectrum of their complex multipeak light curves, their power-law high energy spectra and other features of GRBs. Some additional predictions are made including the expected polarization of gamma-rays in the bursts.

  15. Exposure to Ionizing Radiation Causes Long-Term Increase in Serum Estradiol and Activation of PI3K-Akt Signaling Pathway in Mouse Mammary Gland

    SciTech Connect (OSTI)

    Suman, Shubhankar; Johnson, Michael D.; Fornace, Albert J.; Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC ; Datta, Kamal

    2012-10-01

    Purpose: Exposure to ionizing radiation is an established risk factor for breast cancer. Radiation exposure during infancy, childhood, and adolescence confers the highest risk. Although radiation is a proven mammary carcinogen, it remains unclear where it acts in the complex multistage process of breast cancer development. In this study, we investigated the long-term pathophysiologic effects of ionizing radiation at a dose (2 Gy) relevant to fractionated radiotherapy. Methods and Materials: Adolescent (6-8 weeks old; n = 10) female C57BL/6J mice were exposed to 2 Gy total body {gamma}-radiation, the mammary glands were surgically removed, and serum and urine samples were collected 2 and 12 months after exposure. Molecular pathways involving estrogen receptor-{alpha} (ER{alpha}) and phosphatidylinositol-3-OH kinase (PI3K)-Akt signaling were investigated by immunohistochemistry and Western blot. Results: Serum estrogen and urinary levels of the oncogenic estrogen metabolite (16{alpha}OHE1) were significantly increased in irradiated animals. Immunostaining for the cellular proliferative marker Ki-67 and cyclin-D1 showed increased nuclear accumulation in sections of mammary glands from irradiated vs. control mice. Marked increase in p85{alpha}, a regulatory sub-unit of the PI3K was associated with increase in Akt, phospho-Akt, phospho-BAD, phospho-mTOR, and c-Myc in irradiated samples. Persistent increase in nuclear ER{alpha} in mammary tissues 2 and 12 months after radiation exposure was also observed. Conclusions: Taken together, our data not only support epidemiologic observations associating radiation and breast cancer but also, specify molecular events that could be involved in radiation-induced breast cancer.

  16. Diffusive Radiation in One-dimensional Langmuir Turbulence

    E-Print Network [OSTI]

    Fleishman, Gregory D

    2007-01-01

    We calculate spectra of radiation produced by a relativistic particle in the presence of one-dimensional Langmuir turbulence which might be generated by a streaming instability in the plasma, in particular, in the shock front or at the shock-shock interactions. The shape of the radiation spectra is shown to depend sensitively on the angle between the particle velocity and electric field direction. The radiation spectrum in the case of exactly transverse particle motion is degenerate and similar to that of spatially uniform Langmuir oscillations. In case of oblique propagation, the spectrum is more complex, it consists of a number of power-law regions and may contain a distinct high-frequency spectral peak. %at $\\omega=2\\omega\\pe \\gamma^2$. The emission process considered is relevant to various laboratory plasma settings and for astrophysical objects as gamma-ray bursts and collimated jets.

  17. Diffusive Radiation in One-dimensional Langmuir Turbulence

    E-Print Network [OSTI]

    Gregory D. Fleishman; Igor N. Toptygin

    2007-05-21

    We calculate spectra of radiation produced by a relativistic particle in the presence of one-dimensional Langmuir turbulence which might be generated by a streaming instability in the plasma, in particular, in the shock front or at the shock-shock interactions. The shape of the radiation spectra is shown to depend sensitively on the angle between the particle velocity and electric field direction. The radiation spectrum in the case of exactly transverse particle motion is degenerate and similar to that of spatially uniform Langmuir oscillations. In case of oblique propagation, the spectrum is more complex, it consists of a number of power-law regions and may contain a distinct high-frequency spectral peak. %at $\\omega=2\\omega\\pe \\gamma^2$. The emission process considered is relevant to various laboratory plasma settings and for astrophysical objects as gamma-ray bursts and collimated jets.

  18. Level density of $^{56}$Fe and low-energy enhancement of $?$-strength function

    E-Print Network [OSTI]

    A. V. Voinov; S. M. Grimes; U. Agvaanluvsan; E. Algin; T. Belgya; C. R. Brune; M. Guttormsen; M. J. Hornish; T. Massey; G. E. Mitchell; J. Rekstad; A. Schiller; S. Siem

    2006-04-06

    The $^{55}$Mn$(d,n)^{56}$Fe differential cross section is measured at $E_d=7$ MeV\\@. The $^{56}$Fe level density obtained from neutron evaporation spectra is compared to the level density extracted from the $^{57}$Fe$(^3$He,$\\alpha\\gamma)^{56}$Fe reaction by the Oslo-type technique. Good agreement is found between the level densities determined by the two methods. With the level density function obtained from the neutron evaporation spectra, the $^{56}$Fe $\\gamma$-strength function is also determined from the first-generation $\\gamma$ matrix of the Oslo experiment. The good agreement between the past and present results for the $\\gamma$-strength function supports the validity of both methods and is consistent with the low-energy enhancement of the $\\gamma$ strength below $\\sim 4$ MeV first discovered by the Oslo method in iron and molybdenum isotopes.

  19. Electron gas grid semiconductor radiation detectors

    DOE Patents [OSTI]

    Lee, Edwin Y. (Livermore, CA); James, Ralph B. (Livermore, CA)

    2002-01-01

    An electron gas grid semiconductor radiation detector (EGGSRAD) useful for gamma-ray and x-ray spectrometers and imaging systems is described. The radiation detector employs doping of the semiconductor and variation of the semiconductor detector material to form a two-dimensional electron gas, and to allow transistor action within the detector. This radiation detector provides superior energy resolution and radiation detection sensitivity over the conventional semiconductor radiation detector and the "electron-only" semiconductor radiation detectors which utilize a grid electrode near the anode. In a first embodiment, the EGGSRAD incorporates delta-doped layers adjacent the anode which produce an internal free electron grid well to which an external grid electrode can be attached. In a second embodiment, a quantum well is formed between two of the delta-doped layers, and the quantum well forms the internal free electron gas grid to which an external grid electrode can be attached. Two other embodiments which are similar to the first and second embodiment involve a graded bandgap formed by changing the composition of the semiconductor material near the first and last of the delta-doped layers to increase or decrease the conduction band energy adjacent to the delta-doped layers.

  20. Adaptors for radiation detectors

    DOE Patents [OSTI]

    Livesay, Ronald Jason

    2014-04-22

    Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

  1. Adaptors for radiation detectors

    DOE Patents [OSTI]

    Livesay, Ronald Jason

    2015-07-28

    Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

  2. Radiation dosimeters

    DOE Patents [OSTI]

    Hoelsher, James W. (Pullman, WA); Hegland, Joel E. (Pullman, WA); Braunlich, Peter F. (Pullman, WA); Tetzlaff, Wolfgang (Pullman, WA)

    1992-01-01

    Radiation dosimeters and dosimeter badges. The dosimeter badges include first and second parts which are connected to join using a securement to produce a sealed area in which at least one dosimeter is held and protected. The badge parts are separated to expose the dosimeters to a stimulating laser beam used to read dose exposure information therefrom. The badge is constructed to allow automated disassembly and reassembly in a uniquely fitting relationship. An electronic memory is included to provide calibration and identification information used during reading of the dosimeter. Dosimeter mounts which reduce thermal heating requirements are shown. Dosimeter constructions and production methods using thin substrates and phosphor binder-layers applied thereto are also taught.

  3. Alpha-beta radiation detector

    DOE Patents [OSTI]

    Fleming, Dale M. (Richland, WA); Simmons, Kevin L. (Kennewick, WA); Froelich, Thomas J. (West Richland, WA); Carter, Gregory L. (Richland, WA)

    1998-01-01

    The invention is based in part on the discovery that a plastic housing that is lightweight is surprisingly efficient inasmuch as background signals from any gamma radiation are significantly reduced by using a plastic housing instead of a metal housing. A further aspect of the present invention is the profile of the housing as a bi-linear approximation to a parabola resulting in full optical response from any location on the scintillation material to the photomultiplier tube. A yet further aspect of the present invention is that the survey probe is resistant to magnetic fields. A yet further aspect of the present invention is the use of a snap-fit retaining bracket that overcomes the need for multiple screws.

  4. Relative proton and gamma widths of astrophysically important states in 30S studied in the beta-decay of 31Ar

    E-Print Network [OSTI]

    G. T. Koldste; B. Blank; M. J. G. Borge; J. A. Briz; M. Carmona-Gallardo; L. M. Fraile; H. O. U. Fynbo; J. Giovinazzo; J. G. Johansen; A. Jokinen; B. Jonson; T. Kurturkian-Nieto; J. H. Kusk; T. Nilsson; A. Perea; V. Pesudo; E. Picado; K. Riisager; A. Saastamoinen; O. Tengblad; J. -C. Thomas; J. Van de Walle

    2013-05-20

    Resonances just above the proton threshold in 30S affect the 29P(p,gamma)30S reaction under astrophysical conditions. The (p,gamma)-reaction rate is currently determined indirectly and depends on the properties of the relevant resonances. We present here a method for finding the ratio between the proton and gamma partial widths of resonances in 30S. The widths are determined from the beta-2p and beta-p-gamma decay of 31Ar, which is produced at the ISOLDE facility at the European research organization CERN. Experimental limits on the ratio between the proton and gamma partial widths for astrophysical relevant levels in 30S have been found for the first time. A level at 4688(5) keV is identified in the gamma spectrum, and an upper limit on the proton to gamma width of 0.26 (95 % C.L.) is found. In the two-proton spectrum two levels at 5227(3) keV and 5847(4) keV are identified. These levels are previously seen to gamma decay and upper limits on the gamma to proton width of 0.5 and 9, respectively, (95 % C.L.) are found, where the latter differs from previous calculations.

  5. Low-energy enhancement in the \\gamma-ray strength functions of $^{73,74}$Ge

    E-Print Network [OSTI]

    Renstrøm, T; Utsumoniya, H; Schwengner, R; Goriely, S; Larsen, A C; Filipescu, D M; Gheorghe, I; Bernstein, L A; Bleuel, D L; Glodariu, T; Görgen, A; Guttormsen, M; Hagen, T W; Kheswa, B V; Lui, Y -W; Negi, D; Ruud, I E; Shima, T; Siem, S; Takahisa, K; Tesileanu, O; Tornyi, T G; Tveten, G M; Wiedeking, M

    2015-01-01

    The $\\gamma$-ray strength functions and level densities of $^{73,74}$Ge have been extracted up to the neutron separation energy S$_n$ from particle-$\\gamma$ coincidence data using the Oslo method. Moreover, the $\\gamma$-ray strength function of $^{74}$Ge above S$_n$ has been determined from photo-neutron measurements, hence these two experiments cover the range of E$_\\gamma \\approx$ 1-13 MeV for $^{74}$Ge. The obtained data show that both $^{73,74}$Ge display an increase in strength at low $\\gamma$ energies. The experimental $\\gamma$-ray strength functions are compared with $M1$ strength functions deduced from average $B(M1)$ values calculated within the shell model for a large number of transitions. The observed low-energy enhancements in $^{73,74}$Ge are adopted in the calculations of the $^{72,73}$Ge(n,$\\gamma$) cross sections, where there are no direct experimental data. Calculated reaction rates for more neutron-rich germanium isotopes are shown to be strongly dependent on the presence of the low-energy ...

  6. GAMMA-RAY POLARIZATION INDUCED BY COLD ELECTRONS VIA COMPTON PROCESSES

    SciTech Connect (OSTI)

    Chang Zhe; Jiang Yunguo; Lin Hainan, E-mail: changz@ihep.ac.cn, E-mail: jiangyg@ihep.ac.cn, E-mail: linhn@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, 100049 Beijing (China)

    2013-05-20

    The polarization measurement is an important tool to probe the prompt emission mechanism in gamma-ray bursts (GRBs). The synchrotron photons can be scattered by cold electrons in the outflow via Compton scattering (CS) processes. The observed polarization depends on both the photon energy and the viewing angle. With the typical bulk Lorentz factor {Gamma} {approx} 200, photons with energy E > 10 MeV tend to have smaller polarization than photons with energy E < 1 MeV. At the right viewing angle, i.e., {theta} {approx} {Gamma}{sup -1}, the polarization achieves its maximal value, and the polarization angle changes 90 Degree-Sign relative to the initial polarization direction. Thus, the synchrotron radiation plus CS model can naturally explain the 90 Degree-Sign change of the polarization angle in GRB 100826A.

  7. Physiological and molecular characterization of the enhanced salt tolerance induced by low-dose gamma irradiation in Arabidopsis seedlings

    SciTech Connect (OSTI)

    Qi, Wencai; Zhang, Liang; Xu, Hangbo; Wang, Lin; Jiao, Zhen

    2014-07-25

    Highlights: • 50-Gy gamma irradiation markedly promotes the seedling growth under salt stress in Arabidopsis. • The contents of H{sub 2}O{sub 2} and MDA are obviously reduced by low-dose gamma irradiation under salt stress. • Low-dose gamma irradiation stimulates the activities of antioxidant enzymes under salt stress. • Proline accumulation is required for the low-gamma-ray-induced salt tolerance. • Low gamma rays differentially regulate the expression of genes related to salt stress. - Abstract: It has been established that gamma rays at low doses stimulate the tolerance to salt stress in plants. However, our knowledge regarding the molecular mechanism underlying the enhanced salt tolerance remains limited. In this study, we found that 50-Gy gamma irradiation presented maximal beneficial effects on germination index and root length in response to salt stress in Arabidopsis seedlings. The contents of H{sub 2}O{sub 2} and MDA in irradiated seedlings under salt stress were significantly lower than those of controls. The activities of antioxidant enzymes and proline levels in the irradiated seedlings were markedly increased compared with the controls. Furthermore, transcriptional expression analysis of selected genes revealed that some components of salt stress signaling pathways were stimulated by low-dose gamma irradiation under salt stress. Our results suggest that gamma irradiation at low doses alleviates the salt stress probably by modulating the physiological responses as well as stimulating the stress signal transduction in Arabidopsis seedlings.

  8. DOE Occupational Radiation Exposure, 2001 report

    SciTech Connect (OSTI)

    None, None

    2001-12-31

    The goal of the U.S. Department of Energy (DOE) is to conduct its operations, including radiological, to ensure the safety and health of all DOE employees, contractors, and subcontractors. The DOE strives to maintain radiation exposures to its workers below administrative control levels and DOE limits and to further reduce these exposures to levels that are “As Low As Reasonably Achievable” (ALARA). The 2001 DOE Occupational Radiation Exposure Report provides a summary and analysis of the occupational radiation exposure received by individuals associated with DOE activities. The DOE mission includes stewardship of the nuclear weapons stockpile and the associated facilities, environmental restoration of DOE, and energy research.

  9. Study of Radiative Decays of Psi(2S) Mesons

    E-Print Network [OSTI]

    Kaiyan Gao

    2009-09-16

    We studied the decay psi(2S) to gamma eta_c(2S) with 25.9 million psi(2S) events collected with the CLEO-c detector. No psi(2S) to gamma eta_c(2S) decays were observed in any of the eleven exclusive eta_c(2S) decay modes studied. The product branching fraction upper limits were determined for all modes. The 90% confidence level upper limit of branching fraction of psi(2S) to gamma eta_c (2S) was obtained.

  10. Radiation chemistry in solvent etxraction: FY2011 research

    SciTech Connect (OSTI)

    Bruce J. Mincher; Stephen P. Mezyk; Leigh R. Martin

    2011-09-01

    This report summarizes work accomplished under the Fuel Cycle Research and Development (FCR&D) program in the area of radiation chemistry during FY 2011. The tasks assigned during FY 2011 included: (1) Continue measurements free radical reaction kinetics in the organic phase; (2) Continue development of an alpha-radiolysis program and compare alpha and gamma radiolysis for CMPO; (3) Initiate an effort to understand dose rate effects in radiation chemistry; and (4) Continued work to characterize TALSPEAK radiation chemistry, including the examination of metal complexed ligand kinetics. Progress made on each of these tasks is reported here. Briefly, the method developed to measure the kinetics of the reactions of the NO3 radical with solvent extraction ligands in organic solution during FY10 was extended here to a number of compounds to better understand the differences between radical reactions in the organic versus aqueous phases. The alpha-radiolysis program in FY11 included irradiations of CMPO solutions with 244Cm, 211At and the He ion beam, for comparison to gamma irradiations, and a comparison of the gamma irradiation results for CMPO at three different gamma dose rates. Finally, recent results for TALSPEAK radiolysis are reported, summarizing the latest in an effort to understand how metal complexation to ligands affects their reaction kinetics with free radicals.

  11. Operation Greenhouse. Scientific Director's report of atomic weapon tests at Eniwetok, 1951. Annex 1. 1. Prompt-gamma-ray measurements. Part 2. Prompt-gamma-ray intensity as a function of time

    SciTech Connect (OSTI)

    Hall, W.C.

    1985-09-01

    This report describes the procedure followed and the results obtained in measuring, as a function of time, the prompt gamma radiation emitted within 1,000 seconds after the explosion of the atomic weapons studies in Operation Greenhouse. The design of the experiment and a description of the equipment are given. The fast coaxial scintillation detectors for the Greenhouse test were used without collimators at a distance of several mean free paths from the source. Numerous factors complicated the interpretation of the data obtained, thus reducing the accuracy that may be ascribed to the results. The probable peak gamma-ray intensity, the time of occurrence of the peak, and the prompt-gamma decay curves as a function of time were obtained for each shot. A composite decay curve fitting all the shots was obtained, and from this, a scaling factor was deduced which related the shot energy to the gamma-ray intensity.

  12. Gamma Ray Burst as Sources of Exotic Particles

    E-Print Network [OSTI]

    Morgan, Ian; De Pree, Erin; Tennyson, Kevin

    2015-01-01

    We consider the possible production of stable lightest first level KK particle (LKP) in baryonic gamma ray bursts (GRB) out flows. We numerically computed the energy-dependent cross-sections of Kaluza-Klein (KK) excitations for the Standard Model gauge bosons, photon and Z. Next, we determined the feasibility of producing these KK excitations in gamma-ray emitting regions of GRBs. We found that a GRB fireball that accelerates baryons to energies greater than 10^14 eV could produce KK excitations out to approximately 10^12 cm from the central engine, indicating that GRBs may be a significant source of the LKP. Finally, we explore the potential observational consequences of our results.

  13. SIRAD e Personal radiation detectors Hani Alnawaf c

    E-Print Network [OSTI]

    Yu, Peter K.N.

    , Australia c Illawarra Health and Medical Research Institute, Centre for Medical Radiation Physics qualitative measurement of exposure to radiation for mid range dose exposure. This is performed using;Cheung et al., 2002, 2004, 2006a, b). When measuring low-level personal radiation, devices

  14. Positron and gamma-photon production and nuclear reactions in cascade processes initiated by a sub-terawatt femtosecond laser

    E-Print Network [OSTI]

    Kaplan, Alexander

    Positron and gamma-photon production and nuclear reactions in cascade processes initiated by a sub, through specially arranged cascade processes in optimal targets, substantial amounts of nuclear radiation-6951 97 02350-4 Numerous proposals to induce nuclear transformations by intense lasers see, e.g., Ref. 1

  15. Black Stars and Gamma Ray Bursts

    E-Print Network [OSTI]

    Tanmay Vachaspati

    2007-06-08

    Stars that are collapsing toward forming a black hole but are frozen near the Schwarzschild horizon are termed ``black stars''. Collisions of black stars, in contrast to black hole collisions, may be sources of gamma ray bursts, whose basic parameters are estimated quite simply and are found to be consistent with observed gamma ray bursts. Black star gamma ray bursts should be preceded by gravitational wave emission similar to that from the coalescence of black holes.

  16. TESLA*HERA Based gamma-p and gamma-A Colliders

    E-Print Network [OSTI]

    A. K. Ciftci; S. Sultansoy; O. Yavas

    2000-07-05

    Main parameters and physics search potential of gamma-p and gamma-A colliders, which will be available due to constructing the TESLA linear electron-positron collider tangentially to the HERA proton ring, are discussed.

  17. Hydrodynamic properties of gamma-ray bursts outflows deduced from thermal component

    E-Print Network [OSTI]

    Pe'er, Asaf; O'Mahony, Shane; Margutti, Raffaella; Ryde, Felix; Larsson, Josefin; Lazzatti, Davide; Livio, Mario

    2015-01-01

    We study the properties of a significant thermal emission component that was identified in 47 GRBs observed by different instruments. Within the framework of the "fireball" model, we deduce the values of the Lorentz factor Gamma, and the acceleration radius, r_0, for these bursts. We find that all the values of Gamma in our sample are in the range 10^2 = 310. We find a very weak dependence of Gamma on the acceleration radius r_0, Gamma ~ r_0^alpha with alpha = -0.10 +- 0.09 at sigma = 2.1 confidence level. The values of r_0 span a wide range, 10^7 ~10^{8.5} cm. This is higher than the gravitational radius of a 10 M_sun black hole by a factor ~100. We argue that this result provides indirect evidence for jet propagation inside a massive star, and suggests the existence of recollimation shocks that take place close to this radius.

  18. DETECTORS FOR RADIATION DOSIMETRY

    E-Print Network [OSTI]

    Perez-Mendez, V.

    2010-01-01

    J. Price, "Nuclear Radiation Detection" (2nd ed. , New York:4) G. F. Knoll, "Radiation Detection and Measurement" (NewSons, Inc. from "Radiation Detection and Measurement," G. F.

  19. Gamma-ray irradiated polymer optical waveguides

    SciTech Connect (OSTI)

    Lai, C.-C.; Wei, T.-Y.; Chang, C.-Y.; Wang, W.-S.; Wei, Y.-Y.

    2008-01-14

    Optical waveguides fabricated by gamma-ray irradiation on polymer through a gold mask are presented. The gamma-ray induced index change is found almost linearly dependent on the dose of the irradiation. And the measured propagation losses are low enough for practical application. Due to the high penetrability of gamma ray, uniform refractive index change in depth can be easily achieved. Moreover, due to large-area printing, the uniformity of waveguide made by gamma-ray irradiation is much better than that by e-beam direct writing.

  20. Radiation Characterization Summary: ACRR Central Cavity Free-Field Environment with the 32-Inch Pedestal at the Core Centerline (ACRR-FF-CC-32-cl).

    SciTech Connect (OSTI)

    Vega, Richard Manuel; Parma, Edward J.; Naranjo, Gerald E.; Lippert, Lance L.; Vehar, David W.; Griffin, Patrick J.

    2015-08-01

    This document presents the facilit y - recommended characteri zation o f the neutron, prompt gamma - ray, and delayed gamma - ray radiation fields in the Annular Core Research Reactor ( ACRR ) for the cen tral cavity free - field environment with the 32 - inch pedestal at the core centerline. The designation for this environmen t is ACRR - FF - CC - 32 - cl. The neutron, prompt gamma - ray , and delayed gamma - ray energy spectra , uncertainties, and covariance matrices are presented as well as radial and axial neutron and gamma - ray fluence profiles within the experiment area of the cavity . Recommended constants are given to facilitate the conversion of various dosimetry readings into radiation metrics desired by experimenters. Representative pulse operations are presented with conversion examples . Acknowledgements The authors wish to th ank the Annular Core Research Reactor staff and the Radiation Metrology Laboratory staff for their support of this work . Also thanks to David Ames for his assistance in running MCNP on the Sandia parallel machines.

  1. ME 361F Radiation and Radiation Protection Laboratory ABET EC2000 syllabus

    E-Print Network [OSTI]

    Ben-Yakar, Adela

    8. Reactor Health Physics Practices Class/Laboratory Schedule (Type, number and duration of sessions-Ray Attenuation · Low-Level Gamma Ray Spectrometry · Reactor Health Physics · Neutron Shielding · Sodium Iodide. Apply principles of engineering, basic science, and mathematics (including multivariate calculus

  2. Gamma Ray Burst Central Engines

    E-Print Network [OSTI]

    Todd A. Thompson

    2008-07-04

    I review aspects of the theory of long-duration gamma-ray burst (GRB) central engines. I focus on the requirements of any model; these include the angular momentum of the progenitor, the power, Lorentz factor, asymmetry, and duration of the flow, and both the association and the non-association with bright supernovae. I compare and contrast the collapsar and millisecond proto-magnetar models in light of these requirements. The ability of the latter model to produce a flow with Lorentz factor ~100 while simultaneously maintaining a kinetic luminosity of ~10^50 ergs/s for a timescale of ~10-100 s is emphasized.

  3. Gamma-ray novae as probes of relativistic particle acceleration at non-relativistic shocks

    E-Print Network [OSTI]

    Metzger, Brian D; Vurm, Indrek; Hascoet, Romain; Beloborodov, Andrei M; Chomiuk, Laura

    2015-01-01

    The Fermi LAT discovery that classical novae produce >100 MeV gamma-rays establishes that shocks and relativistic particle acceleration are key features of these events. These shocks are likely to be radiative due to the high densities of the nova ejecta at early times coincident with the gamma-ray emission. Thermal X-rays radiated behind the shock are absorbed by neutral gas and reprocessed into optical emission, similar to Type IIn (interacting) supernovae. The ratio of gamma-ray and optical luminosities, L_gam/L_opt, thus sets a lower limit on the fraction of the shock power used to accelerate relativistic particles, e_nth. The measured values of L_gam/L_opt for two classical novae, V1324 Sco and V339 Del, constrains e_nth > 1e-2 and > 1e-3, respectively. Inverse Compton models for the gamma-ray emission are disfavored given the low electron acceleration efficiency, e_nth ~ 1e-4-1e-3, inferred from observations of Galactic cosmic rays and particle-in-cell (PIC) numerical simulations. Recent hybrid PIC simu...

  4. Gamma-Ray Polarimetry of Two X-Class Solar Flares

    E-Print Network [OSTI]

    Steven E. Boggs; W. Coburn; E. Kalemci

    2005-10-19

    We have performed the first polarimetry of solar flare emission at gamma-ray energies (0.2-1 MeV). These observations were performed with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) for two large flares: the GOES X4.8-class solar flare of 2002 July 23, and the X17-class flare of 2003 October 28. We have marginal polarization detections in both flares, at levels of 21% +/- 9% and -11% +/- 5% respectively. These measurements significantly constrain the levels and directions of solar flare gamma-ray polarization, and begin to probe the underlying electron distributions.

  5. Gravitational Waves versus X and Gamma Ray Emission in a Short Gamma-Ray Burst

    E-Print Network [OSTI]

    F. G. Oliveira; Jorge A. Rueda; Remo Ruffini

    2014-03-28

    The recent progress in the understanding the physical nature of neutron star equilibrium configurations and the first observational evidence of a genuinely short gamma-ray burst, GRB 090227B, allows to give an estimate of the gravitational waves versus the X and Gamma-ray emission in a short gamma-ray burst.

  6. Radiation Control (Virginia)

    Broader source: Energy.gov [DOE]

    The Department of Health is responsible for regulating radiation and radioactive materials in the Commonwealth of Virginia. Although the Department's Radiation Control Program primarily focuses on...

  7. RADIATIVE AND PASSIVE COOLING

    E-Print Network [OSTI]

    Martin, M.

    2011-01-01

    Ext. 6782 Radiative and Passive Cooling Marlo Martin andof the Second Nation- al Passive Solar Conference (owned rights. ,I I RADIATIVE AND PASSIVE COOLING* LAIVRENCE

  8. "We will die and become science" : the production of invisibility and public knowledge about Chernobyl radiation effects in Belarus

    E-Print Network [OSTI]

    Kuchinskaya, Olga

    2007-01-01

    maps of contamination and levels of background radiation. Byto be measuring radiation everywhere. There was a map ofmaps of radioactive contamination of the district that used to be displayed in the radiation

  9. Proton and gamma irradiation of Fabry-Perot quantum cascade lasers for space qualification

    SciTech Connect (OSTI)

    Myers, Tanya L.; Cannon, Bret D.; Brauer, Carolyn S.; Hansen, Stewart; Crowther, Blake

    2015-01-01

    Fabry-Perot quantum cascade lasers (QCLs) were characterized following irradiation by high energy (64 MeV) protons and Cobalt-60 gamma rays. Seven QCLs were exposed to radiation dosages that are typical for a space mission in which the total accumulated dosages from both radiation sources varied from 20 krad(Si) to 46.3 krad(Si). The QCLs did not show any measurable changes in threshold current or slope efficiency suggesting the suitability of QCLs for use in space-based missions.

  10. Proton and gamma irradiation of Fabry-Perot quantum cascade lasers for space qualification

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Myers, Tanya L.; Cannon, Bret D.; Brauer, Carolyn S.; Hansen, Stewart; Crowther, Blake

    2015-01-20

    Fabry-Perot quantum cascade lasers (QCLs) were characterized following irradiation by high energy (64 MeV) protons and Cobalt-60 gamma rays. Seven QCLs were exposed to radiation dosages that are typical for a space mission in which the total accumulated dosages from both radiation sources varied from 20 krad(Si) to 46.3 krad(Si). The QCLs did not show any measurable changes in threshold current or slope efficiency suggesting the suitability of QCLs for use in space-based missions.

  11. Temporal variations in space-time and progenitors of gamma ray burst and millisecond pulsars

    E-Print Network [OSTI]

    Preston Jones

    2007-08-31

    A time varying space-time metric is shown to be a source of electromagnetic radiation. The post-Newtonian approximation is used as a realistic model of the connection between the space-time metric and a time varying gravitational potential. Large temporal variations in the metric from the coalescence of colliding black holes and neutron stars are shown to be possible progenitors of gamma ray burst and millisecond pulsars.

  12. Delayed Fission Gamma-ray Characteristics of Th-232 U-233 U-235 U-238 and Pu-239

    SciTech Connect (OSTI)

    Lane, Taylor; Parma, Edward J.

    2015-08-01

    Delayed fission gamma-rays play an important role in determining the time dependent ioniz- ing dose for experiments in the central irradiation cavity of the Annular Core Research Reactor (ACRR). Delayed gamma-rays are produced from both fission product decay and from acti- vation of materials in the core, such as cladding and support structures. Knowing both the delayed gamma-ray emission rate and the time-dependent gamma-ray energy spectrum is nec- essary in order to properly determine the dose contributions from delayed fission gamma-rays. This information is especially important when attempting to deconvolute the time-dependent neutron, prompt gamma-ray, and delayed gamma-ray contribution to the response of a diamond photo-conducting diode (PCD) or fission chamber in time frames of milliseconds to seconds following a reactor pulse. This work focused on investigating delayed gamma-ray character- istics produced from fission products from thermal, fast, and high energy fission of Th-232, U-233, U-235, U-238, and Pu-239. This work uses a modified version of CINDER2008, a transmutation code developed at Los Alamos National Laboratory, to model time and energy dependent photon characteristics due to fission. This modified code adds the capability to track photon-induced transmutations, photo-fission, and the subsequent radiation caused by fission products due to photo-fission. The data is compared against previous work done with SNL- modified CINDER2008 [ 1 ] and experimental data [ 2 , 3 ] and other published literature, includ- ing ENDF/B-VII.1 [ 4 ]. The ability to produce a high-fidelity (7,428 group) energy-dependent photon fluence at various times post-fission can improve the delayed photon characterization for radiation effects tests at research reactors, as well as other applications.

  13. CONSTRAINTS ON VERY HIGH ENERGY GAMMA-RAY EMISSION FROM GAMMA-RAY BURSTS R. Atkins,1,2

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    CONSTRAINTS ON VERY HIGH ENERGY GAMMA-RAY EMISSION FROM GAMMA-RAY BURSTS R. Atkins,1,2 W. Benbow,3 emission from gamma-ray bursts (GRBs) during the prompt emission phase. Detection of >100 GeV counterparts on potential GRB models. Subject headinggs: gamma rays: bursts -- gamma rays: observations 1. INTRODUCTION

  14. Investigation into Nanostructured Lanthanum Halides and CeBr{sub 3} for Nuclear Radiation Detection

    SciTech Connect (OSTI)

    Guss, P., Guise, R., Mukhopadhyay, S., Yuan, D.

    2011-06-22

    This slide-show presents work on radiation detection with nanostructured lanthanum halides and CeBr{sub 3}. The goal is to extend the gamma energy response on both low and high-energy regimes by demonstrating the ability to detect low-energy x-rays and relatively high-energy activation prompt gamma rays simultaneously using the nano-structured lanthanum bromide, lanthanum fluoride, cerium bromide, or other nanocrystal material. Homogeneous and nano structure cases are compared.

  15. Gamma-ray imaging system. Innovative technology summary report

    SciTech Connect (OSTI)

    NONE

    1998-11-01

    The RadScan 600 gamma-ray imaging system is designed to survey large surface areas for radiological contamination with accuracy and efficiency. The resulting survey data are clear, concise, and precise in describing how much contamination is present at exact locations. Data can be permanently stored electronically and on video tape, making storage and retrieval economical and efficient. This technology can perform accurate measurements in high radiation contamination areas while minimizing worker exposure. The RadScan 600 system is a safe and effective alternative to hand-held radiation detection devices. Performance data of the demonstrated survey area of the RadScan 600 system versus the baseline, which is the hand-held radiation detection devices (RO-2 and RO-7) for a given survey, production rate is 72% of the baseline. It should be noted that the innovative technology provides 100% coverage at a unit cost of $8.64/m{sup 2} versus a static measurement of a unit cost of $1.61/m{sup 2} for the baseline.

  16. Vacuum fluctuations and radiation reaction in radiative processes of entangled states

    E-Print Network [OSTI]

    Menezes, G

    2015-01-01

    We investigate radiative processes of inertial two-level atoms in an entangled state interacting with a quantum electromagnetic field. We assume a dipole interaction between the atoms. The main intention is to identify and to analyze quantitatively the distinct contributions of vacuum fluctuations and radiation reaction to the decay rate of the entangled state.

  17. Radiation Protection and Licensing FNAL Radiation Physics Team

    E-Print Network [OSTI]

    McDonald, Kirk

    (ALARA). January 13, 2012 Radiation Protection and Licensing #12;4 Shielding for Prompt Radiation Protect

  18. New experiment on the neutron radiative decay

    E-Print Network [OSTI]

    Khafizov R. U.; Kolesnikov I. A.; Tolokonnikov S. V.; Torokhov V. D.; Solovei V. A.; Kolhidashvili M. R.; Konorov I. A

    2009-10-05

    The report is dedicated to the preparation of the new experiment on the neutron radiative decay what is conducted for the last years. We started the experimental research of this neutron decay branch with the experiment conducted at ILL in 2002 and continued in another experiment at the second and third cycles at the FRMII reactor of the Technical University of Munich in 2005. In the first experiment we succeeded in measuring only the upper limit on the relative intensity (B.R.) of the radiative neutron decay and in the second we succeeded in discovering events of radiative neutron decay and measure its B.R.=(3.2+-1.6)10-3 (with C.L.=99.7% and gamma quanta energy over 35 keV). The obtained average B.R. value was approximately twice the theoretical value calculated earlier within the framework of the standard electroweak model. However, due to significant experimental error it would be preliminary to deduce that based on this finding a deviation from the standard model has been observed. To prove or disprove the existence of a deviation it is necessary to conduct a new experiment that would allow to measure the radiative peak in timing spectra with precision in the order of 1%. By the present time we have prepared a new experiment the main result of which would be the measurement of B.R. for the radiative branch of neutron decay with this precision.

  19. GRB 090727 AND GAMMA-RAY BURSTS WITH EARLY-TIME OPTICAL EMISSION

    SciTech Connect (OSTI)

    Kopac, D.; Gomboc, A.; Japelj, J. [Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000 Ljubljana (Slovenia); Kobayashi, S.; Mundell, C. G.; Bersier, D.; Cano, Z.; Smith, R. J.; Steele, I. A.; Virgili, F. J. [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead, CH41 1LD (United Kingdom); Guidorzi, C. [Physics Departments, University of Ferrara, via Saragat 1, I-44122, Ferrara (Italy); Melandri, A., E-mail: drejc.kopac@fmf.uni-lj.si [INAF-Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate (Italy)

    2013-07-20

    We present a multi-wavelength analysis of Swift gamma-ray burst GRB 090727, for which optical emission was detected during the prompt gamma-ray emission by the 2 m autonomous robotic Liverpool Telescope and subsequently monitored for a further two days with the Liverpool and Faulkes Telescopes. Within the context of the standard fireball model, we rule out a reverse shock origin for the early-time optical emission in GRB 090727 and instead conclude that the early-time optical flash likely corresponds to emission from an internal dissipation process. Putting GRB 090727 into a broader observational and theoretical context, we build a sample of 36 gamma-ray bursts (GRBs) with contemporaneous early-time optical and gamma-ray detections. From these GRBs, we extract a sub-sample of 18 GRBs, which show optical peaks during prompt gamma-ray emission, and perform detailed temporal and spectral analysis in gamma-ray, X-ray, and optical bands. We find that in most cases early-time optical emission shows sharp and steep behavior, and notice a rich diversity of spectral properties. Using a simple internal shock dissipation model, we show that the emission during prompt GRB phase can occur at very different frequencies via synchrotron radiation. Based on the results obtained from observations and simulation, we conclude that the standard external shock interpretation for early-time optical emission is disfavored in most cases due to sharp peaks ({Delta}t/t < 1) and steep rise/decay indices, and that internal dissipation can explain the properties of GRBs with optical peaks during gamma-ray emission.

  20. A LINGERING NON-THERMAL COMPONENT IN THE GAMMA-RAY BURST PROMPT EMISSION: PREDICTING GeV EMISSION FROM THE MeV SPECTRUM

    SciTech Connect (OSTI)

    Basak, Rupal; Rao, A. R., E-mail: rupalb@tifr.res.in, E-mail: arrao@tifr.res.in [Tata Institute of Fundamental Research, Mumbai 400005 (India)

    2013-09-20

    The high-energy GeV emission of gamma-ray bursts (GRBs) detected by Fermi/LAT has a significantly different morphology compared to the lower energy MeV emission detected by Fermi/GBM. Though the late-time GeV emission is believed to be synchrotron radiation produced via an external shock, this emission as early as the prompt phase is puzzling. A meaningful connection between these two emissions can be drawn only by an accurate description of the prompt MeV spectrum. We perform a time-resolved spectroscopy of the Gamma-ray Burst Monitor (GBM) data of long GRBs with significant GeV emission, using a model consisting of two blackbodies and a power law. We examine in detail the evolution of the spectral components and find that GRBs with high GeV emission (GRB 090902B and GRB 090926A) have a delayed onset of the power-law component in the GBM spectrum, which lingers at the later part of the prompt emission. This behavior mimics the flux evolution in the Large Area Telescope (LAT). In contrast, bright GBM GRBs with an order of magnitude lower GeV emission (GRB 100724B and GRB 091003) show a coupled variability of the total and the power-law flux. Further, by analyzing the data for a set of 17 GRBs, we find a strong correlation between the power-law fluence in the MeV and the LAT fluence (Pearson correlation: r = 0.88 and Spearman correlation: ? = 0.81). We demonstrate that this correlation is not influenced by the correlation between the total and the power-law fluences at a confidence level of 2.3?. We speculate the possible radiation mechanisms responsible for the correlation.

  1. A history of gamma ray bursts and other astronomical conundrums

    E-Print Network [OSTI]

    Trimble, V; Trimble, V

    2006-01-01

    V. Trimble, in “Gamma Ray Bursts: 30 Years of Discovery,”V. Trimble, in “Gamma Ray Bursts,” Ed. C. Ho et al. ,A History of Gamma Ray Bursts and Other Astronomical

  2. Observations of Gamma-Ray Bursts at Extreme Energies

    E-Print Network [OSTI]

    Aune, Taylor

    2012-01-01

    of Gamma-Ray Bursts . . . . . . . . . . . . . Redshift-Ancient Unvierse with Gamma-Ray Bursts, pages 330–333. AIP,A. Olson. Observations of Gamma-Ray Bursts of Cosmic Origin.

  3. The Astrophysical S-factor of the 12C(\\alpha,\\gamma)16O Reaction at Solar Energies

    E-Print Network [OSTI]

    Sadeghi, H; Khalili, H

    2013-01-01

    The astrophysical S-factor of the 4He-12C radiative capture is calculated in the potential model at the energy range 0.1-2.0 MeV. Radiative capture 12C(\\alpha,\\gamma)16O is extremely relevant for the fate of massive stars and determines if the remnant of a supernova explosion becomes a black hole or a neutron star. Because this reaction occurs at low-energies the experimental measurements is very difficult and perhaps impossible. In this paper, radiative capture of the 12C(\\alpha,\\gamma)16O reaction at very low-energies is taken as a case study. In comparison with other theoretical methods and available experimental data, excellent agreement is achieved for the astrophysical S-factor of this process.

  4. Reaction Rate Sensitivity of the gamma-Process Path

    E-Print Network [OSTI]

    T. Rauscher

    2004-07-16

    The location of the (gamma,p)/(gamma,n) and (gamma,alpha)/(gamma,n) line at gamma-process temperatures is discussed, using recently published reaction rates based on global Hauser-Feshbach calculations. The results can directly be compared to previously published, classic gamma-process discussions. The nuclei exhibiting the largest sensitivity to uncertainties in nuclear structure and reaction parameters are specified.

  5. Neutron monitoring systems including gamma thermometers and methods of calibrating nuclear instruments using gamma thermometers

    DOE Patents [OSTI]

    Moen, Stephan Craig; Meyers, Craig Glenn; Petzen, John Alexander; Foard, Adam Muhling

    2012-08-07

    A method of calibrating a nuclear instrument using a gamma thermometer may include: measuring, in the instrument, local neutron flux; generating, from the instrument, a first signal proportional to the neutron flux; measuring, in the gamma thermometer, local gamma flux; generating, from the gamma thermometer, a second signal proportional to the gamma flux; compensating the second signal; and calibrating a gain of the instrument based on the compensated second signal. Compensating the second signal may include: calculating selected yield fractions for specific groups of delayed gamma sources; calculating time constants for the specific groups; calculating a third signal that corresponds to delayed local gamma flux based on the selected yield fractions and time constants; and calculating the compensated second signal by subtracting the third signal from the second signal. The specific groups may have decay time constants greater than 5.times.10.sup.-1 seconds and less than 5.times.10.sup.5 seconds.

  6. Thermal neutron capture gamma-rays

    SciTech Connect (OSTI)

    Tuli, J.K.

    1983-01-01

    The energy and intensity of gamma rays as seen in thermal neutron capture are presented. Only those (n,..cap alpha..), E = thermal, reactions for which the residual nucleus mass number is greater than or equal to 45 are included. These correspond to evaluations published in Nuclear Data Sheets. The publication source data are contained in the Evaluated Nuclear Structure Data File (ENSDF). The data presented here do not involve any additional evaluation. Appendix I lists all the residual nuclides for which the data are included here. Appendix II gives a cumulated index to A-chain evaluations including the year of publication. The capture gamma ray data are given in two tables - the Table 1 is the list of all gamma rays seen in (n,..gamma..) reaction given in the order of increasing energy; the Table II lists the gamma rays according to the nuclide.

  7. DETECTORS FOR RADIATION DOSIMETRY

    E-Print Network [OSTI]

    Perez-Mendez, V.

    2010-01-01

    RPL) The interaction of radiation with matter in crystallineradiation. Some interactions with crystalline matter are

  8. Exploring Broadband GRB Behavior During gamma-ray Emission

    E-Print Network [OSTI]

    S. A. Yost; H. F. Swan; E. S. Rykoff; F. Aharonian; C. W. Akerlof; A. Alday; M. C. B. Ashley; S. Barthelmy; D. Burrows; D. L. Depoy; R. J. Dufour; J. D. Eastman; R. D. Forgey; N. Gehrels; E. Gö?ü?; T. Güver; J. P. Halpern; L. C. Hardin; D. Horns; U. K?z?lo?lu; H. A. Krimm; S. Lepine; E. P. Liang; J. L. Marshall; T. A. McKay; T. Mineo; N. Mirabal; M. Özel; A. Phillips; J. L. Prieto; R. M. Quimby; P. Romano; G. Rowell; W. Rujopakarn; B. E. Schaefer; J. M. Silverman; R. Siverd; M. Skinner; D. A. Smith; I. A. Smith; S. Tonnesen; E. Troja; W. T. Vestrand; J. C. Wheeler; J. Wren; F. Yuan; B. Zhang

    2006-11-14

    The robotic ROTSE-III telescope network detected prompt optical emission contemporaneous with the gamma-ray emission of Swift events GRB051109A and GRB051111. Both datasets have continuous coverage at high signal-to-noise levels from the prompt phase onwards, thus the early observations are readily compared to the Swift XRT and BAT high energy detections. In both cases, the optical afterglow is established, declining steadily during the prompt emission. For GRB051111, there is evidence of an excess optical component during the prompt emission. The component is consistent with the flux spectrally extrapolated from the gamma-rays, using the gamma-ray spectral index. A compilation of spectral information from previous prompt detections shows that such a component is unusual. The existence of two prompt optical components - one connected to the high-energy emission, the other to separate afterglow flux, as indicated in GRB051111 - is not compatible with a simple ``external-external'' shock model for the GRB and its afterglow.

  9. Exploring Broadband GRB Behavior During gamma-ray Emission

    E-Print Network [OSTI]

    Yost, S A; Rykoff, E S; Aharonian, F; Akerlof, C W; Alday, A; Ashley, M C B; Barthelmy, S; Burrows, D; Depoy, D L; Dufour, R J; Eastman, J D; Forgey, R D; Gehrels, N; G"uver, T; Halpern, J P; Hardin, L C; Horns, D; Krimm, H A; Lepine, S; Liang, E P; Marshall, J L; McKay, T A; Mineo, T; Mirabal, N; Phillips, A; Prieto, J L; Quimby, R M; Romano, P; Rowell, G; Rujopakarn, W; Schaefer, B E; Silverman, J M; Siverd, R; Skinner, M; Smith, D A; Smith, I A; Tonnesen, S; Troja, E; Vestrand, W T; Wheeler, J C; Wren, J; Yuan, F; Zhang, B

    2006-01-01

    The robotic ROTSE-III telescope network detected prompt optical emission contemporaneous with the gamma-ray emission of Swift events GRB051109A and GRB051111. Both datasets have continuous coverage at high signal-to-noise levels from the prompt phase onwards, thus the early observations are readily compared to the Swift XRT and BAT high energy detections. In both cases, the optical afterglow is established, declining steadily during the prompt emission. For GRB051111, there is evidence of an excess optical component during the prompt emission. The component is consistent with the flux spectrally extrapolated from the gamma-rays, using the gamma-ray spectral index. A compilation of spectral information from previous prompt detections shows that such a component is unusual. The existence of two prompt optical components - one connected to the high-energy emission, the other to separate afterglow flux, as indicated in GRB051111 - is not compatible with a simple ``external-external'' shock model for the GRB and i...

  10. Nickel-based superalloy operating temperature determination via analysis of gamma/gamma' microstructure and coating/base material interdiffusion

    E-Print Network [OSTI]

    Ham, Wendy D. (Wendy Decker)

    2005-01-01

    The average operating temperature of RENÉ N5® high pressure turbine blades was evaluated via [gamma]/[gamma]' microstructure and coating/base metal interdiffusion methods. The [gamma]' volume fraction was measured by point ...

  11. Neutron and gamma-ray emission from palladium deuteride under supercritical conditions

    SciTech Connect (OSTI)

    Jorne, J. )

    1991-03-01

    This paper reports on palladium which is exposed to pressurized deuterium gas at 60 atm and 198 K and the temperature is cycled up to 593 K, beyond the critical point for palladium deuteride. Two neutron and gamma-ray counters, located near the pressurized vessel, show evidence of excess neutrons and gamma rays beyond the background level. Similar experiments with an empty cell or with a hydrogen-palladium cell show no excess in neutrons and gamma rays beyond the background levels. If the excess in neutrons is due to fusion, a corresponding fusion rate of 10{sup 21} fusion/d-d {center dot} s can be estimated, which is comparable to the rate of 10{sup 23} for electrochemically induced fusion.

  12. THRESHOLD RADIOACTIVITY FOR BULK FOOD SAMPLES BY GAMMA SPECTROSCOPY...

    Office of Scientific and Technical Information (OSTI)

    THRESHOLD RADIOACTIVITY FOR BULK FOOD SAMPLES BY GAMMA SPECTROSCOPY Citation Details In-Document Search Title: THRESHOLD RADIOACTIVITY FOR BULK FOOD SAMPLES BY GAMMA SPECTROSCOPY...

  13. CONTRIBUTION OF GAMMA-RAY-LOUD RADIO GALAXIES' CORE EMISSIONS...

    Office of Scientific and Technical Information (OSTI)

    The Fermi gamma-ray satellite has recently detected gamma-ray emissions from radio galaxy cores. From these samples, we first examine the correlation between the luminosities...

  14. Properties of the gamma function 

    E-Print Network [OSTI]

    Smith, William Boyce

    1960-01-01

    ( ) + Qr} converges if snd only if rsl Loci(&+g ) converges. r=l Oc& r=l formly over the set S if for each 6 + 0, there is sn in- teger Ng such that if 'n, v & gll ~ II, j. i+ u, te] ? Ogive', f, t]) & a, for sll z in S. l. lr. tn-teat). 1TL I...~~ (iiy. i Let ~&)= h~ %(&N}i Thus Euler's A(k} function gives s n~~ factorial when x is an integer, but does it give s factorial when x is not sn integer' ? To answer this we shall show the relation between Euler ~a snd the Gamma function. To do...

  15. Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

    DOE Patents [OSTI]

    Boatner, Lynn A. (Oak Ridge, TN); Sales, Brian C. (Oak Ridge, TN)

    1989-01-01

    Lead-iron phosphate glasses containing a high level of Fe.sub.2 O.sub.3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90.degree. C., with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10.sup.2 to 10.sup.3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe.sub.2 O.sub.3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800.degree. C., since they exhibit very low melt viscosities in the 800.degree. to 1050.degree. C. temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550.degree. C. and are not adversely affected by large doses of gamma radiation in H.sub.2 O at 135.degree. C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms.

  16. Gamma Spectrum from Neutron Capture on Tungsten Isotopes

    SciTech Connect (OSTI)

    Hurst, Aaron; Summers, Neil; Sleaford, Brad; Firestone, Richard B; Belgya, T.; Revay, Z.S.

    2010-04-29

    An evaluation of thermal neutron capture on the stable tungsten isotopes is presented, with preliminary results for the compound systems 183;184;185;187W. The evaluation procedure compares the g-ray cross-section data collected at the Budapest reactor, with Monte Carlo simulations of g-ray emission following the thermal neutron-capture process. The statistical-decay code DICEBOX was used for the Monte Carlo simulations. The evaluation yields new gamma rays in 185W and the confirmation of spins in 187W, raising the number of levels below which the level schemes are considered complete, thus increasing the number of levels that can be used in neutron data libraries.

  17. The Prompt and High Energy Emission of Gamma Ray Bursts

    SciTech Connect (OSTI)

    Meszaros, P.

    2009-05-25

    I discuss some recent developments concerning the prompt emission of gamma-ray bursts, in particular the jet properties and radiation mechanisms, as exemplified by the naked-eye burst GRB 080319b, and the prompt X-ray emission of XRB080109/SN2008d, where the progenitor has, for the first time, been shown to contribute to the prompt emission. I discuss then some recent theoretical calculations of the GeV/TeV spectrum of GRB in the context of both leptonic SSC models and hadronic models. The recent observations by the Fermi satellite of GRB 080916C are then reviewed, and their implications for such models are discussed, together with its interesting determination of a bulk Lorentz factor, and the highest lower limit on the quantum gravity energy scale so far.

  18. Gamma-Ray Bursts - a Primer For Relativists

    E-Print Network [OSTI]

    Tsvi Piran

    2002-05-12

    Gamma-Ray Bursts (GRBs) - short bursts of 100-1MeV photons arriving from random directions in the sky are probably the most relativistic objects discovered so far. Still, somehow they did not attract the attention of the relativistic community. In this short review I discuss briefly GRB observations and show that they lead us to the fireball model - GRBs involve macroscopic relativistic motion with Lorentz factors of a few hundred or more. I show that GRB sources involve, most likely, new born black holes, and their progenitors are Supernovae or neutron star mergers. I show that both GRB progenitors and the process of GRB itself produce gravitational radiation and I consider the possibility of detecting this emission. Finally I show that GRBs could serve as cosmological indicators that could teach us about the high redshift ($z \\approx 5-15$) dark ages of the universe.

  19. Calorimetry of gamma-ray bursts: echos in gravitational waves

    E-Print Network [OSTI]

    Maurice H. P. M. van Putten; Amir Levinson

    2001-05-24

    Black holes surrounded by a disk or torus may drive the enigmatic cosmological gamma-ray bursts (GRBs). Equivalence in poloidal topology to pulsar magnetospheres shows a high incidence of the black hole-luminosity $L_H$ into the surrounding magnetized matter. We argue that this emission is re-radiated into gravitational waves at $L_{GW}\\simeq L_H/3$ in frequencies of order 1kHz, winds and, potentially, MeV neutrinos. The total energy budget and input to the GRB from baryon poor jets are expected to be standard in this scenario, consistent with recent analysis of afterglow data. Collimation of these outflows by baryon rich disk or torus winds may account for the observed spread in opening angles up to about $35^o$. This model may be tested by future LIGO/VIRGO observations.

  20. Properties of Low Luminosity Afterglow Gamma-ray Bursts

    E-Print Network [OSTI]

    Dereli, H; Gendre, B; Amati, L; Dichiara, S

    2015-01-01

    Aims: We characterize a sample of Gamma-Ray Bursts with low luminosity X-ray afterglows (LLA GRBs), and study their properties. Method: We select a sample consisting of the 12\\% faintest X-ray afterglows from the total population of long GRBs (lGRBs) with known redshift. We study their intrinsic properties (spectral index, decay index, distance, luminosity, isotropic radiated energy and peak energy) to assess whether they belong to the same population than the brighter afterglow events. Results: We present strong evidences that these events belong to a population of nearby events, different from that of the general population of lGRBs. These events are faint during their prompt phase, and include the few possible outliers of the Amati relation. Out of 14 GRB-SN associations, 9 are in LLA GRB sample, prompting for caution when using SN templates in observational and theoretical models for the general lGRBs population.