National Library of Energy BETA

Sample records for gamma radiation levels

  1. Radiation Levels in Real Time?

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

    Gamma radiation levels in the southern Nevada area will soon be accessible around the world at the touch of a finger. Makers of the cell phone application EcoData: Radiation are ...

  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.

    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.

    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. Radiation Levels in Real Time?

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

    Levels in Real Time? There's an App for That! Gamma radiation levels in the southern Nevada area will soon be accessible around the world at the touch of a finger. Makers of the cell phone application EcoData: Radiation are expanding their global network of radiation monitoring stations to include up-to-date readings from the Community Environmental Monitoring Program (CEMP) based out of southern Nevada. The CEMP was established in 1981 to monitor manmade and natural radiation levels surrounding

  7. Gamma Radiation & X-Rays

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

    Gamma Radiation and X-Rays 1. Gamma radiation and X-rays are electromagnetic radiation like visible light, radio waves, and ultraviolet light. These electromagnetic radiations differ only in the amount of energy they have. Gamma rays and X-rays are the most energetic of these. 2. Gamma radiation is able to travel many meters in air and many centimeters in human tissue. It readily penetrates most materials and is sometimes called "penetrating radiation." 3. X-rays are like gamma rays.

  8. Tensile Testing of Aged TR-55 Silicone Rubber (Gamma Radiation...

    Office of Scientific and Technical Information (OSTI)

    Tensile Testing of Aged TR-55 Silicone Rubber (Gamma Radiation Under Tensile Strain): ... Title: Tensile Testing of Aged TR-55 Silicone Rubber (Gamma Radiation Under Tensile ...

  9. Apparatus and method for detecting gamma radiation

    DOE Patents [OSTI]

    Sigg, Raymond A.

    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.

  10. 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.

  11. 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.

  12. Composition and apparatus for detecting gamma radiation

    DOE Patents [OSTI]

    Hofstetter, Kenneth J.

    1994-01-01

    A gamma radiation detector and a radioluminiscent composition for use therein. The detector includes a radioluminscent 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.

  13. 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 DHSs 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 Electrons 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

  14. 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

  15. GAMMA RADIATION DOSAGE-MEASURING GLASSES AND METHOD OF USING

    DOE Patents [OSTI]

    Bishay, A.M.

    1963-05-14

    A dosimeter glass for gamma radiation characterized by a borate base, a substantial amount of bismuth trioxide and a minor amount of either arsenic or antimony trioxides is presented. (AEC)

  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. Radiation resistance testing of high-density polyethylene. [Gamma rays

    SciTech Connect (OSTI)

    Dougherty, D.R.; Adams, J.W.

    1983-01-01

    Mechanical tests following gamma inrradiation and creep tests during irradiation have been conducted on high-density polyethylene (HDPE) to assess the adequacy of this material for use in high-integrity containers (HICs). These tests were motivated by experience in nuclear power plants in which polyethylene electrical insulation detoriorated more rapidly than expected due to radiation-induced oxidation. This suggested that HDPE HICs used for radwaste disposal might degrade more rapidly than would be expected in the absence of the radiation field. Two types of HDPE, a highly cross-linked rotationally molded material and a non-cross-linked blow molded material, were used in these tests. Gamma-ray irradiations were performed at several dose rates in environments of air, Barnwell and Hanford backfill soils, and ion-exchange resins. The results of tensile and bend testing on these materials following irradiation will be presented along with preliminary results on creep during irradiation.

  18. Current Trends in Gamma Radiation Detection for Radiological Emergency Response

    SciTech Connect (OSTI)

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

    2011-09-01

    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. In recent years, since the establishment of the Domestic Nuclear Detection Office by the Department of Homeland Security, a tremendous amount of progress has been made in detection materials (scintillators, semiconductors), imaging techniques (Compton imaging, use of active masking and hybrid imaging), data acquisition systems with digital signal processing, field programmable gate arrays and embedded isotopic analysis software (viz. gamma detector response and analysis software [GADRAS]1), fast template matching, and data fusion (merging radiological data with geo-referenced maps, digital imagery to provide better situational awareness). In this stride to progress, a significant amount of interdisciplinary research and development has taken placetechniques and spin-offs from medical science (such as x-ray radiography and tomography), materials engineering (systematic planned studies on scintillators to optimize several qualities of a good scintillator, nanoparticle applications, quantum dots, and photonic crystals, just to name a few). No trend analysis of radiation detection systems would be complete without mentioning the unprecedented strategic position taken by the National Nuclear Security Administration (NNSA) to deter, detect, and interdict illicit trafficking in nuclear and other radioactive materials across international borders and through the global maritime transportationthe so-called second line of defense.

  19. Probing the Cosmic X-ray and MeV Gamma-ray Background Radiation...

    Office of Scientific and Technical Information (OSTI)

    Probing the Cosmic X-ray and MeV Gamma-ray Background Radiation through the Anisotropy Citation Details In-Document Search Title: Probing the Cosmic X-ray and MeV Gamma-ray ...

  20. 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.

  1. Gamma thermometer based reactor core liquid level detector

    DOE Patents [OSTI]

    Burns, Thomas J.

    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.

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

    DOE Patents [OSTI]

    Hondorp, Hugh L.

    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.

  3. Health effects of low-level radiation in shipyard workers. Final report: [Draft

    SciTech Connect (OSTI)

    Matanoski, G.M.

    1991-06-01

    The Nuclear Shipyard Workers Study (NSWS) was designed to determine whether there is an excess risk of leukemia or other cancers associated with exposure to low levels of gamma radiation. The study compares the mortality experience of shipyard workers who qualified to work in radiation areas to the mortality of similar workers who hold the same types of jobs but who are not authorized to work in radiation areas. The population consists of workers from six government and two private shipyards.

  4. Operating Experience Level 3, DOE Occupational Radiation Exposures...

    Energy Savers [EERE]

    DOE Occupational Radiation Exposures for 2013 Operating Experience Level 3, DOE Occupational Radiation Exposures for 2013 January 29, 2015 OE-3 2015-01: DOE Occupational Radiation...

  5. Population doses from environmental gamma radiation in Iraq

    SciTech Connect (OSTI)

    Marouf, B.A.; Mohamad, A.S.; Taha, J.S.; al-Haddad, I.K. )

    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.

  6. 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%.

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

    Energy Savers [EERE]

    Low-Level Radiation Research Letter on Low-Level Radiation Research The Secretary of Energy Advisory Board (SEAB) transmitted a letter to the Department regarding its perspective ...

  8. Background compensation for a radiation level monitor

    DOE Patents [OSTI]

    Keefe, D.J.

    1975-12-01

    Background compensation in a device such as a hand and foot monitor is provided by digital means using a scaler. With no radiation level test initiated, a scaler is down-counted from zero according to the background measured. With a radiation level test initiated, the scaler is up-counted from the previous down-count position according to the radiation emitted from the monitored object and an alarm is generated if, with the scaler having crossed zero in the positive going direction, a particular number is exceeded in a specific time period after initiation of the test. If the test is initiated while the scale is down-counting, the background count from the previous down- count stored in a memory is used as the initial starting point for the up-count.

  9. Probing Radiation Damage at the Molecular Level

    SciTech Connect (OSTI)

    Mason, N. J.; Smialek, M. A.; Moore, S. A.; Folkard, M.; Hoffmann, S. V.

    2006-12-01

    Radiation damage of DNA and other cellular components has traditionally been attributed to ionisation via direct impact of high-energy quanta or by complex radical chemistry. However recent research has shown that strand breaks in DNA may be initiated by secondary electrons and is strongly dependent upon the target DNA base identity. Such research provides the fascinating perspective that it is possible that radiation damage may be described and understood at an individual molecular level introducing new possibilites for therapy and perhaps providing an insight into the origins of life.

  10. Measurement of the asymmetry parameter in the hyperon radiative decay. Sigma. sup + r arrow p. gamma

    SciTech Connect (OSTI)

    Foucher, M.; Albuquerque, I.F.; Bondar, N.F.; Carrigan, R. Jr.; Chen, D.; Li Chengze; Cooper, P.S.; Denisov, A.S.; Dobrovolsky, A.V.; Dubbs, T.; Endler, A.M.F.; Escobar, C.O.; Tang Fukun; Golovtsov, V.L.; Goritchev, P.A.; Gottschalk, H.; Gouffon, P.; Grachev, V.T.; Shi Huanzhang; Yan Jie; Khanzadeev, A.V.; Kubantsev, M.A.; Kuropatkin, N.P.; Lach, J.; Luksys, M.; Lebedenko, V.N.; Dai Lisheng; Mahon, J.R.P.; McCliment, E.; Morelos, A.; Newsom, C.; Lang Pengfei; Pommot Maia, M.C.; Samsonov, V.M.; Zheng Shuchen; Smith, V.J.; Terentyev, N.K.; Timm, S.; Tkatch, I.I.; Uvarov, L.N.; Vorobyov, A.A.; Zhao Wenheng; Zhong Yuanyuan; Li Yunshan Institute of High Energy Physics, Beijing St. Petersburg Nuclear Physics Institute, Gatchina Institute of Theoretical and Experimental Physics, Moscow University of Iowa, Iowa City, Iowa 52242 Universidade de Sao Paulo, Sao Paulo

    1992-05-18

    We have measured the asymmetry parameter ({alpha}{sub {gamma}}) in the hyperon radiative decay {Sigma}{sup +}{r arrow}{ital p}{gamma} with a sample of 34 754{plus minus}212 events obtained in a polarized charged hyperon beam experiment at Fermilab. We find {alpha}{sub {gamma}}={minus}0.720{plus minus}0.086{plus minus}0.045, where the quoted errors are statistical and systematic, respectively.

  11. Experimental search for the radiative capture reaction d + d {yields} {sup 4}He + {gamma} from the dd{mu} muonic molecule state J = 1

    SciTech Connect (OSTI)

    Baluev, V. V.; Bogdanova, L. N.; Bom, V. R.; Demin, D. L.; Eijk, C. W. E. van; Filchenkov, V. V.; Grafov, N. N.; Grishechkin, S. K.; Gritsaj, K. I.; Konin, A. D.; Mikhailyukov, K. L.; Rudenko, A. I.; Vinogradov, Yu. I.; Volnykh, V. P.; Yukhimchuk, A. A.; Yukhimchuk, S. A.

    2011-07-15

    A search for the muon-catalyzed fusion reaction d + d {yields} {sup 4}He + {gamma} in the dd{mu} muonic molecule was performed using the experimental installation TRITON with BGO detectors for {gamma}-quanta. A high-pressure target filled with deuterium was exposed to the negative muon beam of the JINR Phasotron to detect {gamma}-quanta with the energy 23.8 MeV. An experimental estimation for the yield of radiative deuteron capture from the dd{mu} state J = 1 was obtained at the level of {eta}{sub {gamma}} {<=} 8 Multiplication-Sign 10{sup -7} per fusion.

  12. 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.

  13. 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.

  14. 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}|.

  15. METHOD AND APPARATUS FOR PRODUCING AND ANALYZING POLARIZED GAMMA RADIATION

    DOE Patents [OSTI]

    Hamermesh, M.; Hanna, S.S.; Perlow, G.J.

    1964-04-21

    A method of polarizing and resolving the plane of polarization of gamma rays is described. Polarization is produced by positioning a thin disc of ferromagnetic metal, cortaining /sup 57/Co, in a magnetic field. Resolution is accomplished by rotating a thin disc of iron enriched in /sup 57/Fe relative to a second magnetic field and noting the change of gamma absorption at each rotational position. (AEC)

  16. GAMMA RADIATION INTERACTS WITH MELANIN TO ALTER ITS OXIDATION-REDUCTION POTENTIAL AND RESULTS IN ELECTRIC CURRENT PRODUCTION

    SciTech Connect (OSTI)

    Turick, C.; Ekechukwu, A.; Milliken, C.

    2011-05-17

    The presence of melanin pigments in organisms is implicated in radioprotection and in some cases, enhanced growth in the presence of high levels of ionizing radiation. An understanding of this phenomenon will be useful in the design of radioprotective materials. However, the protective mechanism of microbial melanin in ionizing radiation fields has not yet been elucidated. Here we demonstrate through the electrochemical techniques of chronoamperometry, chronopotentiometry and cyclic voltammetry that microbial melanin is continuously oxidized in the presence of gamma radiation. Our findings establish that ionizing radiation interacts with melanin to alter its oxidation-reduction potential. Sustained oxidation resulted in electric current production and was most pronounced in the presence of a reductant, which extended the redox cycling capacity of melanin. This work is the first to establish that gamma radiation alters the oxidation-reduction behavior of melanin, resulting in electric current production. The significance of the work is that it provides the first step in understanding the initial interactions between melanin and ionizing radiation taking place and offers some insight for production of biomimetic radioprotective materials.

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

    DOE Patents [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.

  18. Radiation detection system for portable gamma-ray spectroscopy

    DOE Patents [OSTI]

    Rowland, Mark S.; Howard, Douglas E.; Wong, James L.; Jessup, James L.; Bianchini, Greg M.; Miller, Wayne O.

    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.

  19. 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.

  20. Revisit the radiative decays of J/{psi} and {psi}{sup '}{yields}{gamma}{eta}{sub c}({gamma}{eta}{sub c}{sup '})

    SciTech Connect (OSTI)

    Li Gang; Zhao Qiang

    2011-10-01

    With the new measurements of J/{psi} and {psi}{sup '}{yields}{gamma}{eta}{sub c}({gamma}{eta}{sub c}{sup '}) from the CLEO and BES-III collaboration, we reinvestigate the intermediate meson loop (IML) contributions to these radiative decays in association with the quark model M1 transitions in an effective Lagrangian approach. It shows that the ''unquenched'' effects due to the intermediate hadron loops can be better quantified by the new data for J/{psi}{yields}{gamma}{eta}{sub c}. Although the IML contributions are relatively small in J/{psi}{yields}{gamma}{eta}{sub c}, they play a crucial role in {psi}{sup '}{yields}{gamma}{eta}{sub c}({gamma}{eta}{sub c}{sup '}). A prediction for the IML contributions to {psi}(3770){yields}{gamma}{eta}{sub c}({gamma}{eta}{sub c}{sup '}) is made. Such unquenched effects allow us to reach a coherent description of those three radiative transitions, and gain some insights into the underlying dynamics.

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

    DOE Patents [OSTI]

    Chiles, Marion M.; Mihalczo, John T.; Blakeman, Edward D.

    1989-02-07

    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.

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

    DOE Patents [OSTI]

    Chiles, Marion M.; Mihalczo, John T.; Blakeman, Edward D.

    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.

  3. 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.

  4. Characterization of commercial proton exchange membrane materials after exposure to beta and gamma radiation

    SciTech Connect (OSTI)

    Thomson, S.N.; Carson, R.; Muirhead, C.; Li, H.; Castillo, I.; Boniface, H.; Suppiah, S.; Ratnayake, A.; Robinson, J.

    2015-03-15

    Proton Exchange Membrane (PEM) type electrolysis cells have a potential use for tritium removal and heavy water upgrading. AECL is currently exposing various commercial PEM materials to both gamma (Cobalt-60 source) and beta (tritiated water) radiation to study the effects of radiation on these materials. This paper summarizes the testing methods and results that have been collected to date. The PEM materials that are or have been exposed to radiation are: Nafion 112, 212, 117 and 1110. Membrane characterization pre- and post- exposure consists of non-destructive inspection (FTIR, SEM/XPS), mechanical (tensile strength, percentage elongation, and modulus), electrical (resistance), or chemical (ion-exchange capacity - IEC). It has appeared that the best characterization techniques to compare exposed versus unexposed membranes were IEC, ultimate tensile strength and percent elongation. These testing techniques are easy and cheap to perform. The non-destructive tests, such as SEM and FTIR did not provide particularly useful information on radiation-induced degradation. Where changes in material properties were measured after radiation exposure, they would be expected to result in poorer cell performance. However, for modest ?-radiation exposure, all membranes showed a slight decrease in cell voltage (better performance). In contrast, the one ?-radiation exposed membrane did show the expected increase in cell voltage. The counterintuitive trend for ?-radiation exposed membranes is not yet understood. Based on these preliminary results, it appears that ?- and ?-radiation exposures have different effects.

  5. 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.

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

    DOE Patents [OSTI]

    Condreva, Kenneth J.

    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.

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

    SciTech Connect (OSTI)

    Lazzati, Davide; Morsony, Brian J.; Margutti, Raffaella; Begelman, Mitchell C.

    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.

  8. Radiation levels on empty cylinders containing heel material

    SciTech Connect (OSTI)

    Shockley, C.W.

    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.

  9. Analysis of electret ion chamber radon detector response to {sup 222}Rn and interference from background gamma radiation

    SciTech Connect (OSTI)

    Usman, S.; Spitz, H.; Lee, S.

    1999-01-01

    Environmental radon ({sup 222}Rn) monitors that incorporate electret detectors are confounded by background gamma radiation, which may cause the electret to discharge by as much as 7.5 volts per mR. Although background gamma corrections were formerly made by multiplying the known background gamma exposure rate with a constant conversion factor, this research demonstrates that doing so introduces an error ranging up to about 20%, especially in high gamma background areas. A new, more accurate method of background gamma correction has been developed that uses an average, voltage-dependent discharge factor, D{sub {gamma}} (V Kg C{sup {minus}1}). This factor and its coefficients were experimentally determined by separately exposing groups of electret radon detectors to photons from {sup 60}Co and {sup 137}Cs. Statistical analysis shows that D{sub {gamma}} is independent of the orientation of the electret during irradiation but that some dependency on dose rate or energy of the irradiating photons may be expected. The discharge of the electret due only to gamma irradiation, V{sub {gamma}}, is determined by multiplying the total integrated gamma exposure by D{sub {gamma}}. The discharge of the electret during a radon measurement can then be corrected for background gamma radiation by subtracting V{sub {gamma}} from the total discharge of the electret resulting in a net discharge due solely to radon. A new equation has also been developed in this study for the radon discharge factor, D{sub Rn} (V m{sup 3}Bq{sup {minus}1} s{sup {minus}1}), that is entirely consistent with the gamma discharge radon detectors to known concentrations of radon.

  10. Operating Experience Level 3, DOE Occupational Radiation Exposures for 2013

    Broader source: Energy.gov [DOE]

    This Operating Experience Level 3 (OE-3) document provides an overview summary of radiation doses from occupational exposures at the Department of Energy (DOE), including the National Nuclear Security Administration for the year 2013.

  11. 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.

  12. 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

  13. Dynamical dipole gamma radiation in heavy-ion collisions on the basis of a quantum molecular dynamics model

    SciTech Connect (OSTI)

    Wu, H. L.; Tian, W. D.; Ma, Y. G.; Cai, X. Z.; Chen, J. G.; Fang, D. Q.; Guo, W.; Wang, H. W.

    2010-04-15

    Dynamical dipole gamma-ray emission in heavy-ion collisions is explored in the framework of the quantum molecular dynamics model. The studies are focused on systems of {sup 40}Ca bombarding {sup 48}Ca and its isotopes at different incident energies and impact parameters. Yields of gamma rays are calculated and the centroid energy and dynamical dipole emission width of the gamma spectra are extracted to investigate the properties of gamma emission. In addition, sensitivities of dynamical dipole gamma-ray emission to the isospin and the symmetry energy coefficient of the equation of state are studied. The results show that detailed study of dynamical dipole gamma radiation can provide information on the equation of state and the symmetry energy around the normal nuclear density.

  14. Features of the action of low-energy gamma radiation on the hydrogen permeability of certain materials

    SciTech Connect (OSTI)

    Tazhibaeva, I.L.; Bekman, I.N.; Rudenko, N.V.; Shestakov, V.P.

    1985-07-01

    This paper determines the diffusion coefficients, the constants of permeability, and solubility of hydrogen in palladium, nickel, and Armco iron under the action of low-energy gamma radiation. It was established that without radiation all of the kinetic diffusion curves of hydrogen in palladium and nickel straighten well in a functional scale. In armco iron, some deviations are observed.

  15. A broadband gamma-ray spectrometry using novel unfolding algorithms for characterization of laser wakefield-generated betatron radiation

    SciTech Connect (OSTI)

    Jeon, Jong Ho Nakajima, Kazuhisa Pathak, Vishwa Bandhu; Cho, Myung Hoon; Yoo, Byung Ju; Shin, Kang Woo; Kim, Hyung Taek; Sung, Jae Hee; Lee, Seung Ku; Choi, Il Woo; Rhee, Yong Joo; Shin, Jung Hun; Jo, Sung Ha; Hojbota, Calin; Cho, Byeoung Ick; Nam, Chang Hee

    2015-12-15

    We present a high-flux, broadband gamma-ray spectrometry capable of characterizing the betatron radiation spectrum over the photon energy range from 10 keV to 20 MeV with respect to the peak photon energy, spectral bandwidth, and unique discrimination from background radiations, using a differential filtering spectrometer and the unfolding procedure based on the Monte Carlo code GEANT4. These properties are experimentally verified by measuring betatron radiation from a cm-scale laser wakefield accelerator (LWFA) driven by a 1-PW laser, using a differential filtering spectrometer consisting of a 15-filter and image plate stack. The gamma-ray spectra were derived by unfolding the photostimulated luminescence (PSL) values recorded on the image plates, using the spectrometer response matrix modeled with the Monte Carlo code GEANT4. The accuracy of unfolded betatron radiation spectra was assessed by unfolding the test PSL data simulated with GEANT4, showing an ambiguity of less than 20% and clear discrimination from the background radiation with less than 10%. The spectral analysis of betatron radiation from laser wakefield-accelerated electron beams with energies up to 3 GeV revealed radiation spectra characterized by synchrotron radiation with the critical photon energy up to 7 MeV. The gamma-ray spectrometer and unfolding method presented here facilitate an in-depth understanding of betatron radiation from LWFA process and a novel radiation source of high-quality photon beams in the MeV regime.

  16. 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.

  17. 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.

  18. 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.

  19. 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)

  20. 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.

  1. Measuring the activity of a {sup 51}Cr neutrino source based on the gamma-radiation spectrum

    SciTech Connect (OSTI)

    Gorbachev, V. V. Gavrin, V. N.; Ibragimova, T. V.; Kalikhov, A. V.; Malyshkin, Yu. M.; Shikhin, A. A.

    2015-12-15

    A technique for the measurement of activities of intense β sources by measuring the continuous gamma-radiation (internal bremsstrahlung) spectra is developed. A method for reconstructing the spectrum recorded by a germanium semiconductor detector is described. A method for the absolute measurement of the internal bremsstrahlung spectrum of {sup 51}Cr is presented.

  2. Weak radiative decay [Lambda][r arrow][ital n][gamma] and the radiative capture reaction [ital K][sup [minus

    SciTech Connect (OSTI)

    Larson, K.D.; Noble, A.J.; Bassalleck, B.; Burkhardt, H.; Fickinger, W.J.; Hall, J.R.; Hallin, A.L.; Hasinoff, M.D.; Horvath, D.; Jones, P.G.; Lowe, J.; McIntyre, E.K.; Measday, D.F.; Miller, J.P.; Roberts, B.L.; Robinson, D.K.; Sakitt, M.; Salomon, M.; Stanislaus, S.; Waltham, C.E.; Warner, T.M.; Whitehouse, D.A.; Wolfe, D.M. Boston University, Boston, Massachusetts 02215 University of British Columbia, Vancouver, British Columbia, V6T 1Z1 Brookhaven National Laboratory, Upton, New York 11973 Case Western Reserve University, Cleveland, Ohio 44106 Central Research Institute for Physics, H-1525 Budapest Los Alamos Meson Physics Facility, Los Alamos, New Mexico 87545 University of New Mexico, Albuquerque, New Mexico 87131 University of Nottingham, Nottingham, NG7 2RD Princeton University, Princeton, New Jersey

    1993-02-01

    The branching ratio for the [Lambda] weak radiative decay [Lambda][r arrow][ital n][gamma] has been measured. Three statistically independent results from the same experiment (Brookhaven E811) are reported here. They are combined with a previously published measurement, also from Brookhaven E811, to yield a result of ([Lambda][r arrow][ital n][gamma])/([Lambda][r arrow]anything)=(1.75[plus minus]0.15)[times]10[sup [minus]3], based on 1800 events after background subtraction. This represents a factor of 75 increase in statistics over the previous world total. A comparison with recent theoretical papers shows that no existing model provides a completely satisfactory description of all data on weak radiative decays. A search is also reported for the radiative capture process [ital K][sup [minus

  3. 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.

  4. 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.

  5. 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.

  6. Gamma Radiation Aging Study of a Dow Corning SE 1700 Porous Structure Made by Direct Ink Writing

    SciTech Connect (OSTI)

    Small, Ward; Alviso, Cindy T.; Metz, Tom R.

    2015-11-13

    Dow Corning SE 1700 (reinforced polydimethylsiloxane) porous structures were made by direct ink writing (DIW). The specimens (~50% porosity) were subjected to a compressive strain of ~25% while exposed to a gamma radiation dose of 1, 5, or 10 Mrad under vacuum. Compression set and load retention of the aged specimens were measured after a ~24 h relaxation period. Compression set (relative to deflection) increased with radiation dose: 11, 35, and 51% after 1, 5, and 10 Mrad, respectively. Load retention was 96-97% for the doses tested. The SE 1700 compared favorably to M9763 cellular silicone tested under the same conditions.

  7. High performance gamma measurements of equipment retrieved from Hanford high-level nuclear waste tanks

    SciTech Connect (OSTI)

    Troyer, G.L.

    1997-03-17

    The cleanup of high level defense nuclear waste at the Hanford site presents several progressive challenges. Among these is the removal and disposal of various components from buried active waste tanks to allow new equipment insertion or hazards mitigation. A unique automated retrieval system at the tank provides for retrieval, high pressure washing, inventory measurement, and containment for disposal. Key to the inventory measurement is a three detector HPGe high performance gamma spectroscopy system capable of recovering data at up to 90% saturation (200,000 counts per second). Data recovery is based on a unique embedded electronic pulser and specialized software to report the inventory. Each of the detectors have different shielding specified through Monte Carlo simulation with the MCNP program. This shielding provides performance over a dynamic range of eight orders of magnitude. System description, calibration issues and operational experiences are discussed.

  8. GROUND LEVEL INVESTIGATION OF ANOMALOUS RADIATION LEVELS IN NIAGARA FALLS, NEW YORK

    Office of Legacy Management (LM)

    GROUND LEVEL INVESTIGATION OF ANOMALOUS RADIATION LEVELS IN NIAGARA FALLS, NEW YORK W. D. Cottrell, D. J. Christian, and F. F. Haywood ,d ;v ~ !;);;J;$ '9;) -i, - 'L." ; i--j -7,) ;3 i, Work performed by Health and Safety Research Division Oak Ridge National Laboratory Oak Ridge, Tennessee 37630 O&J. 2,7 +, / 7&y' March 1979 \ operated by UNION CARBIDE CORPORATIOII for the DEPARTMENT OF ENERGY as part of the Formerly Utilized Sites- Remedial Action Program

  9. P ORNiiTM-7004 Results of Ground Level Radiation

    Office of Legacy Management (LM)

    from a program initiated in 1974 by the Atomic Energy CoNnissiOn (AEC) for ... GAMMA-RAY EXPOSURE RATES (pRhr.) Fig. 5. On-site locations and mean external exposure ...

  10. Radioactive waste isolation in salt: geochemistry of brine in rock salt in temperature gradients and gamma-radiation fields - a selective annotated bibliography

    SciTech Connect (OSTI)

    Hull, A.B.; Williams, L.B.

    1985-07-01

    Evaluation of the extensive research concerning brine geochemistry and transport is critically important to successful exploitation of a salt formation for isolating high-level radioactive waste. This annotated bibliography has been compiled from documents considered to provide classic background material on the interactions between brine and rock salt, as well as the most important results from more recent research. Each summary elucidates the information or data most pertinent to situations encountered in siting, constructing, and operating a mined repository in salt for high-level radioactive waste. The research topics covered include the basic geology, depositional environment, mineralogy, and structure of evaporite and domal salts, as well as fluid inclusions, brine chemistry, thermal and gamma-radiation effects, radionuclide migration, and thermodynamic properties of salts and brines. 4 figs., 6 tabs.

  11. Impact of Millimeter-Level Margins on Peripheral Normal Brain Sparing for Gamma Knife Radiosurgery

    SciTech Connect (OSTI)

    Ma, Lijun; Sahgal, Arjun; Larson, David A.; Pinnaduwage, Dilini; Fogh, Shannon; Barani, Igor; Nakamura, Jean; McDermott, Michael; Sneed, Penny

    2014-05-01

    Purpose: To investigate how millimeter-level margins beyond the gross tumor volume (GTV) impact peripheral normal brain tissue sparing for Gamma Knife radiosurgery. Methods and Materials: A mathematical formula was derived to predict the peripheral isodose volume, such as the 12-Gy isodose volume, with increasing margins by millimeters. The empirical parameters of the formula were derived from a cohort of brain tumor and surgical tumor resection cavity cases (n=15) treated with the Gamma Knife Perfexion. This was done by first adding margins from 0.5 to 3.0 mm to each individual target and then creating for each expanded target a series of treatment plans of nearly identical quality as the original plan. Finally, the formula was integrated with a published logistic regression model to estimate the treatment-induced complication rate for stereotactic radiosurgery when millimeter-level margins are added. Results: Confirmatory correlation between the nominal target radius (ie, R{sub T}) and commonly used maximum target size was found for the studied cases, except for a few outliers. The peripheral isodose volume such as the 12-Gy volume was found to increase exponentially with increasing Δ/R{sub T}, where Δ is the margin size. Such a curve fitted the data (logarithmic regression, R{sup 2} >0.99), and the 12-Gy isodose volume was shown to increase steeply with a 0.5- to 3.0-mm margin applied to a target. For example, a 2-mm margin on average resulted in an increase of 55% ± 16% in the 12-Gy volume; this corresponded to an increase in the symptomatic necrosis rate of 6% to 25%, depending on the Δ/R{sub T} values for the target. Conclusions: Millimeter-level margins beyond the GTV significantly impact peripheral normal brain sparing and should be applied with caution. Our model provides a rapid estimate of such an effect, particularly for large and/or irregularly shaped targets.

  12. 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; Offenhusser, 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 (110{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.

  13. 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)

  14. 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...

  15. 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.

  16. Enrichment of magnetic alignment stimulated by {gamma}-radiation in core-shell type nanoparticle Mn-Zn ferrite

    SciTech Connect (OSTI)

    Naik, P. P.; Tangsali, R. B.; Sonaye, B.; Sugur, S.

    2013-02-05

    Core shell type nanoparticle Mn{sub x}Zn{sub 1-x}Fe{sub 2}O{sub 4} systems with x=0.55, 0.65 and 0.75 were prepared using autocombustion method. The systems were characterized using tools like XRD and IR for structure confirmation. Magnetic parameter measurements like Saturation magnetization and coercivity were obtained from hysteresis loop which exhibited a symmetry shift due to core shell nature of the nanoparticles. Nanoparticles of particle size between 21.2nm to 25.7nm were found to show 20 percent shrinkage after being radiated by the {gamma}-radiation. This is due to variation in the cation distribution which also affects the cell volume of the cubic cell. Lattice constant reduction observed is reflected in the magnetic properties of the samples. A considerable hike in the saturation magnetization of the samples was observed due to enrichment of magnetic alignment in the magnetic core of the particles. Samples under investigation were irradiated with gamma radiation from Co{sup 60} source for different time intervals.

  17. Semiconductor Radiation Detectors with Frisch Collars and Collimators for Gamma Ray Spectroscopy and Imaging

    SciTech Connect (OSTI)

    Douglas McGregor; Alireza Kargar; Mark Harrison; Adam Brooks; Walter McNei; Rans Lowell; Adam Graebner

    2006-12-04

    To study CdZnTe as a high energy resolution gamma ray detector with a novel new design, and to build a detector array from the new detector design

  18. 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...

  19. Determination of low-level radioactivity in environmental samples by gamma spectroscopy at Argonne National Laboratory

    SciTech Connect (OSTI)

    Streets, W.E.; Heinrich, R.R.; Lamoureux, L.L.

    1988-01-01

    We currently have six Ge/Ge(Li) detectors that are being used for gamma counting of environmental samples (three with horizontal geometry, three with vertical geometry). The detectors were calibrated for close-geometry efficiency by counting standards in a set configuration (a height of 6.4 cm in a 4-oz. wide-mouthed Naglene bottle) immediately adjacent to the cryostat face. This configuration was chosen so that the standards would be symmetrical to the centers of both the horizontal and vertical detectors. Two solid standards were prepared by adding a known amount of Standard Reference Material NBL No. 6-A (Pitchblende) and NBL No. 7-A (Monazite Sand) to a blanked soil and mixing. Homogeneity of the standards was checked by counting each standard at each quadrant (on a horizontal detector). The final mixtures showed less than 1% deviation between the high and low quadrant counts. Two liquid secondary standards were prepared from stock solutions of /sup 137/Cs, /sup 131/I, and /sup 110m/Ag, which has been characterized as point sources using several detector efficiency curves. These efficiencies were determined using point source standards from the National Bureau of Standards (NBS) and International Atomic Energy Agency (IAEA). All standards had activity levels that allowed less than 1% counting statistics to be obtained on the major peaks (i.e., those with stronger branching ratio) within two hours. Analysis of the resulting data yield smooth efficiency curves for each of the six detectors. Although the standard compositions varied, solid and liquid, the densities were all approx. =1.0 g/cm/sup 3/. 3 refs.

  20. THE RADIATIVE X-RAY AND GAMMA-RAY EFFICIENCIES OF ROTATION-POWERED PULSARS

    SciTech Connect (OSTI)

    Vink, Jacco; Bamba, Aya; Yamazaki, Ryo

    2011-02-01

    We present a statistical analysis of the X-ray luminosity of rotation-powered pulsars and their surrounding nebulae using the sample of Kargaltsev and Pavlov, and we complement this with an analysis of the {gamma}-ray emission of Fermi-detected pulsars. We report a strong trend in the efficiency with which spin-down power is converted to X-ray and {gamma}-ray emission with characteristic age: young pulsars and their surrounding nebulae are efficient X-ray emitters, whereas in contrast old pulsars are efficient {gamma}-ray emitters. We divided the X-ray sample in a young ({tau}{sub c} < 1.7 x 10{sup 4} yr) and old sample and used linear regression to search for correlations between the logarithm of the X-ray and {gamma}-ray luminosities and the logarithms of the periods and period derivatives. The X-ray emission from young pulsars and their nebulae are both consistent with L{sub X}{proportional_to} P-dot{sup 3}/P{sup 6}. For old pulsars and their nebulae the X-ray luminosity is consistent with a more or less constant efficiency {eta}{identical_to}L{sub X}/ E-dot{sub rot}{approx}8x10{sup -5}. For the {gamma}-ray luminosity we confirm that L{sub {gamma}} {proportional_to} {radical}E-dot{sub rot}. We discuss these findings in the context of pair production inside pulsar magnetospheres and the striped wind model. We suggest that the striped wind model may explain the similarity between the X-ray properties of the pulsar wind nebulae and the pulsars themselves, which according to the striped wind model may both find their origin outside the light cylinder, in the pulsar wind zone.

  1. An apparatus for the study of high temperature water radiolysis in a nuclear reactor: Calibration of dose in a mixed neutron/gamma radiation field

    SciTech Connect (OSTI)

    Edwards, Eric J.; Wilson, Paul P. H.; Anderson, Mark H.; Mezyk, Stephen P.; Pimblott, Simon M.; Bartels, David M.

    2007-12-15

    The cooling water of nuclear reactors undergoes radiolytic decomposition induced by gamma, fast electron, and neutron radiation in the core. To model the process, recombination reaction rates and radiolytic yields for the water radical fragments need to be measured at high temperature and pressure. Yields for the action of neutron radiation are particularly hard to determine independently because of the beta/gamma field also present in any reactor. In this paper we report the design of an apparatus intended to measure neutron radiolysis yields as a function of temperature and pressure. A new methodology for separation of neutron and beta/gamma radiolysis yields in a mixed radiation field is proposed and demonstrated.

  2. 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.

  3. 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.

  4. Definition of Radiation

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

    Gamma Radiation and X-Rays Beta Radiation Alpha Radiation Irradiation Radioactive Contamination Definitions Detection Measurement Safety Around Radiation Sources Types of ...

  5. Near-Core and In-Core Neutron Radiation Monitors for Real Time Neutron Flux Monitoring and Reactor Power Level Measurements

    SciTech Connect (OSTI)

    Douglas S. McGregor; Marvin L. Adams; Igor Carron; Paul Nelson

    2006-06-12

    MPFDs are a new class of detectors that utilize properties from existing radiation detector designs. A majority of these characteristics come from fission chamber designs. These include radiation hardness, gamma-ray background insensitivity, and large signal output.

  6. Structure and solid-state reactivity of Sc, Y, and lanthanide complexes of propiolic and tetrolic acid. [gamma radiation

    SciTech Connect (OSTI)

    Brodkin, J.S.

    1990-01-01

    The structure/reactivity relationships for several metal complexes of propynoic and 2-butynoic acid (propiolic and tetrolic acids, referred to as prop and tetr) were studied. Single-crystal X-ray structure determinations were carried out for Sc(prop){sub 3}, Lat(tetr){sub 3}{center dot}2H{sub 2}O, and two pseudo-polymorphs of La propiolate, La(prop){sub 3}{center dot}3H{sub 2}O and La(prop){sub 3}{center dot}3CH{sub 3}OH. The structures were analyzed for the presence of short (< 4.2 {angstrom}) contacts between {alpha} and {beta}{prime} carbon atoms of neighboring acetylenic functional groups. The existence of a continuous series of such contacts in the structure indicates that the compound has potential to undergo a 1,2-addition reaction leading to the formation of a polymeric product. All of the compounds studied were found to be potentially reactive. The propiolate and tetrolate complexes react in the solid state upon exposure to {gamma}-radiation. The radiation-induced reaction products of both La propiolate derivatives were shown by NMR spectral analysis to be branched polymers. The product resulting from the {gamma}-irradiation of Sc(prop){sub 3} was shown to be polymeric also, however, in this case, not branched. When La(tetr){sub 3}{center dot}2H{sub 2}O was exposed to {gamma}-radiation, the resultant product was not polymeric. The relative orientation of the reactive groups was believed to be a factor in determining whether or not branched polymers would be produced. Thermal analysis of the propiolate complexes indicated that solid state polymerization of these compounds can also occur by thermal induction. However, La(tetr){sub 3}{center dot}2H{sub 2}O is more likely to undergo decomposition than solid-state polymerization when heated. This result is probably associated with the presence of a terminal methyl group on the triple bond.

  7. 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.

  8. 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;...

  9. 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.

  10. A search for. mu. yields e. gamma. at the level of 10 sup minus 13

    SciTech Connect (OSTI)

    Amann, J.F.; Black, K.; Bolton, R.D.; Carius, S.; Cooper, M.D.; Foreman, W.; Hansen, C.; Harrison, R.; Hart, G.; Hart, V.; Hoffman, C.M.; Hoffman, N.; Hunter, T.; Hogan, G.E.; June, N.; Kercher, D.; Little, J.; Kozlowski, T.; Mischke, R.E.; Naivar, F.J.; Novak, J.; Oothoudt, M.A.; Pillai, C.; Schilling, S.; Smith, W.; Stanislaus, S.; Sturrock, J.; Szymanski, J.; Van Dyke, J.; Werbeck, R.D.; Whitehouse, D.; Wilkinson, C. (Los A

    1990-01-01

    The status of the MEGA experiment is described. It is a search for the decay {mu} {r arrow} e{gamma} with a branching ratio sensitivity of approximately 10{sup {minus}13}. The observation of this decay would indicate the existence of physics outside the standard model of electroweak interactions. The experiment employs highly modular, fast detectors, state-of-the-art electronics, and a staged trigger with on-line filters. The detectors are contained in a 1.5 T solenoidal field produced by a superconducting magnet. Positrons are confined to the central region and are measured by a set of thin MWPCs. Photons are measured by one of four layers of pair spectrometers in the outer region. Most aspects of the detector design have been validated in engineering runs; data taking will begin in 1990 with most of the electron arm and one pair spectrometer layer installed. 5 refs., 4 figs.

  11. Directional gamma detector

    DOE Patents [OSTI]

    LeVert, Francis E.; Cox, Samson A.

    1981-01-01

    An improved directional gamma radiation detector has a collector sandwiched etween two layers of insulation of varying thicknesses. The collector and insulation layers are contained within an evacuated casing, or emitter, which releases electrons upon exposure to gamma radiation. Delayed electrons and electrons entering the collector at oblique angles are attenuated as they pass through the insulation layers on route to the collector.

  12. 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.

  13. Alpha Radiation

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

    Basics of Radiation Gamma Radiation and X-Rays Beta Radiation Alpha Radiation Irradiation Radioactive Contamination Definitions Detection Measurement Safety Around Radiation Sources Types of Radiation Exposure Managing Radiation Emergencies Basics of Radiation Characteristics of Alpha Radiation 1. Alpha radiation is not able to penetrate skin. 2. Alpha-emitting materials can be harmful to humans if the materials are inhaled, swallowed, or absorbed through open wounds. 3. A variety of instruments

  14. A Simple and Efficient Methodology To Improve Geometric Accuracy in Gamma Knife Radiation Surgery: Implementation in Multiple Brain Metastases

    SciTech Connect (OSTI)

    Karaiskos, Pantelis; Moutsatsos, Argyris; Pappas, Eleftherios; Georgiou, Evangelos; Roussakis, Arkadios; Torrens, Michael; Seimenis, Ioannis

    2014-12-01

    Purpose: To propose, verify, and implement a simple and efficient methodology for the improvement of total geometric accuracy in multiple brain metastases gamma knife (GK) radiation surgery. Methods and Materials: The proposed methodology exploits the directional dependence of magnetic resonance imaging (MRI)-related spatial distortions stemming from background field inhomogeneities, also known as sequence-dependent distortions, with respect to the read-gradient polarity during MRI acquisition. First, an extra MRI pulse sequence is acquired with the same imaging parameters as those used for routine patient imaging, aside from a reversal in the read-gradient polarity. Then, “average” image data are compounded from data acquired from the 2 MRI sequences and are used for treatment planning purposes. The method was applied and verified in a polymer gel phantom irradiated with multiple shots in an extended region of the GK stereotactic space. Its clinical impact in dose delivery accuracy was assessed in 15 patients with a total of 96 relatively small (<2 cm) metastases treated with GK radiation surgery. Results: Phantom study results showed that use of average MR images eliminates the effect of sequence-dependent distortions, leading to a total spatial uncertainty of less than 0.3 mm, attributed mainly to gradient nonlinearities. In brain metastases patients, non-eliminated sequence-dependent distortions lead to target localization uncertainties of up to 1.3 mm (mean: 0.51 ± 0.37 mm) with respect to the corresponding target locations in the “average” MRI series. Due to these uncertainties, a considerable underdosage (5%-32% of the prescription dose) was found in 33% of the studied targets. Conclusions: The proposed methodology is simple and straightforward in its implementation. Regarding multiple brain metastases applications, the suggested approach may substantially improve total GK dose delivery accuracy in smaller, outlying targets.

  15. 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.

  16. Measurement of the branching ratio and asymmetry parameter for the {Sigma}{sup +}{r_arrow}{ital p}{gamma} radiative decay

    SciTech Connect (OSTI)

    Timm, S.; Albuquerque, I.F.; Bondar, N.F.; Carrigan, R. Jr.; Chen, D.; Cooper, P.S.; Lisheng, D.; Denisov, A.S.; Dobrovolsky, A.V.; Dubbs, T.; Endler, A.M.F.; Escobar, C.O.; Foucher, M.; Golovtsov, V.L.; Gottschalk, H.; Gouffon, P.; Grachev, V.T.; Khanzadeev, A.V.; Kubantsev, M.A.; Kuropatkin, N.P.; Lach, J.; Lang Pengfei; Langland, J.; Li Chengze; Li Yunshan; Luksys, M.; Mahon, J.R.P.; McCliment, E.; Morelos, A.; Newsom, C.; Pommot Maia, M.C.; Samsonov, V.M.; Schegelsky, V.A.; Shi Huanzhang; Smith, V.J.; Tang Fukun; Terentyev, N.K.; Tkatch, I.I.; Uvarov, L.N.; Vorobyov, A.A.; Yan Jie; Wenheng, Z.; Zheng Shuchen; Zhong Yuanyuan

    1995-05-01

    We have measured the branching ratio for the hyperon radiative decay {Sigma}{sup +}{r_arrow}{ital p}{gamma} using the Fermilab polarized charged hyperon beam. This measurement and our previously published result on the asymmetry parameter in the same decay are part of Fermilab experiment E761. We find {ital B}({Sigma}{sup +}{r_arrow}{ital p}{gamma})/{ital B}({Sigma}{sup +}{r_arrow}{ital p}{pi}{sup 0}) to be [2.32{plus_minus}0.11(stat){plus_minus}0.10(syst)]{times}10{sup {minus}3} with a sample of 31 901 events. The higher statistics and careful attention to systematic uncertainties make these significant improvements over previous measurements. We describe how our measurements were performed and briefly review the theoretical implications of these results.

  17. Testing and Performance Validation of a Sensitive Gamma Ray Camera Designed for Radiation Detection and Decommissioning Measurements in Nuclear Facilities-13044

    SciTech Connect (OSTI)

    Mason, John A.; Looman, Marc R.; Poundall, Adam J.; Towner, Antony C.N.; Creed, Richard; Pancake, Daniel

    2013-07-01

    This paper describes the measurements, testing and performance validation of a sensitive gamma ray camera designed for radiation detection and quantification in the environment and decommissioning and hold-up measurements in nuclear facilities. The instrument, which is known as RadSearch, combines a sensitive and highly collimated LaBr{sub 3} scintillation detector with an optical (video) camera with controllable zoom and focus and a laser range finder in one detector head. The LaBr{sub 3} detector has a typical energy resolution of between 2.5% and 3% at the 662 keV energy of Cs-137 compared to that of NaI detectors with a resolution of typically 7% to 8% at the same energy. At this energy the tungsten shielding of the detector provides a shielding ratio of greater than 900:1 in the forward direction and 100:1 on the sides and from the rear. The detector head is mounted on a pan/tile mechanism with a range of motion of ±180 degrees (pan) and ±90 degrees (tilt) equivalent to 4 π steradians. The detector head with pan/tilt is normally mounted on a tripod or wheeled cart. It can also be mounted on vehicles or a mobile robot for access to high dose-rate areas and areas with high levels of contamination. Ethernet connects RadSearch to a ruggedized notebook computer from which it is operated and controlled. Power can be supplied either as 24-volts DC from a battery or as 50 volts DC supplied by a small mains (110 or 230 VAC) power supply unit that is co-located with the controlling notebook computer. In this latter case both power and Ethernet are supplied through a single cable that can be up to 80 metres in length. If a local battery supplies power, the unit can be controlled through wireless Ethernet. Both manual operation and automatic scanning of surfaces and objects is available through the software interface on the notebook computer. For each scan element making up a part of an overall scanned area, the unit measures a gamma ray spectrum. Multiple

  18. Radiation coloration resistant glass

    DOE Patents [OSTI]

    Tomozawa, M.; Watson, E.B.; Acocella, J.

    1986-11-04

    A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10[sup 7] rad, the coloration resistant glass does not lose transparency. 3 figs.

  19. Radiation coloration resistant glass

    DOE Patents [OSTI]

    Tomozawa, Minoru; Watson, E. Bruce; Acocella, John

    1986-01-01

    A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10.sup.7 rad, the coloration resistant glass does not lose transparency.

  20. Measurement of the W Gamma --> mu nu gamma Cross-Section, Limits on Anomalous Trilinear Vector Boson Couplings, and the Radiation Amplitude Zero in p anti-p Collisions at s**(1/2) = 1.96 TeV

    SciTech Connect (OSTI)

    Askew, Andrew Warren

    2004-11-01

    This thesis details the measurement of the p{bar p} {yields} W{gamma} + X {yields} {mu}{nu}{gamma} + X cross section at {radical}s = 1.96 TeV using the D0 detector at Fermilab, in 134.5 pb{sup -1} of integrated luminosity. From the photon E{sub T} spectrum limits on anomalous couplings of the photon to the W are obtained. At 95% confidence level, limits of -1.05 < {Delta}{kappa} < 1.04 for {lambda} = 0 and -0.28 < {lambda} < 0.27 for {Delta}{kappa} = 0 are obtained on the anomalous coupling parameters. The charge signed rapidity difference from the data is displayed, and its significance discussed.

  1. 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.

  2. 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.

  3. Measurement of the solar ultraviolet radiation at ground level in Bangi, Malaysia

    SciTech Connect (OSTI)

    Aljawi, Ohoud; Gopir, Geri; Duay, Abdul Basit

    2015-04-24

    Understanding the amount of ultraviolet (UV) radiation received by human, plant, and animal organisms near the earth’s surface is important to a wide range of fields such as cancer research, agriculture and forestry. The solar ultraviolet spectral irradiance at ground level was measured using the Avantes spectrometer for the period of January to March 2014 at Bangi (2°55´N, 101°46´E, 50 m above sea level) in Malaysia. These data were used to estimate the diurnal variation of UV irradiance (300 – 400 nm). The maximum irradiance of UV radiation was 45 W m{sup −2} on horizontal surface. The maximum irradiance of UV received in the local noon time, and the minimum values of UV irradiance was received in the local morning time. It is found a bigger value of UV radiation was observed on clear sky in January. The estimation of daily flux average of UV irradiance was (921± 91) kJ m{sup −2}.

  4. 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.

  5. Non-radiative carrier recombination enhanced by two-level process: A first-principles study

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

    Yang, Ji -Hui; Shi, Lin; Wang, Lin -Wang; Wei, Su -Huai

    2016-02-16

    In this study, non-radiative recombination plays an important role in the performance of optoelectronic semiconductor devices such as solar cells and light-emitting diodes. Most textbook examples assume that the recombination process occurs through a single defect level, where one electron and one hole are captured and recombined. Based on this simple picture, conventional wisdom is that only defect levels near the center of the bandgap can be effective recombination centers. Here, we present a new two-level recombination mechanism: first, one type of carrier is captured through a defect level forming a metastable state; then the local defect configuration rapidly changesmore » to a stable state, where the other type of carrier is captured and recombined through another defect level. This novel mechanism is applied to the recombination center Te2+cd in CdTe. We show that this two-level process can significantly increase the recombination rate (by three orders of magnitude) in agreement with experiments. We expect that this two-level recombination process can exist in a wide range of semiconductors, so its effect should be carefully examined in characterizing optoelectronic materials.« less

  6. SYNTH - Gamma Ray Spectrum Synthesizer

    Energy Science and Technology Software Center (OSTI)

    2009-05-18

    SYNTH was designed to synthesize the results of typical gamma-ray spectroscopy experiments. The code allows a user to specify the physical characteristics of a gamma-ray source, the quantity of radionuclides emitting gamma radiation, the source-to-detector distance and the presence and type of any intervening absorbers, the size and type of the gamma-ray detector, and the electronic set-up used to gather the data.

  7. 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

  8. Environmental radiation monitoring of low-level wastes by the State of Washington

    SciTech Connect (OSTI)

    Conklin, A.W.; Mooney, R.R.; Erickson, J.L.

    1989-11-01

    The Washington State Department of Health, as the state`s regulatory agency for radiation, monitors several forms of low-level radioactive wastes. The monitoring is done to assess the potential impact on the environment and on public health. The emphasis of the monitoring program is placed on the solid and liquid wastes from defense activities on the Hanford Reservation, commercial wastes at the site located on leased land at Hanford and uranium mill tailings in Northeastern Washington. Although not classified as low-level waste, monitoring is also periodically conducted at selected landfills and sewage treatment facilities and other licensees, where radioactive wastes are known or suspected to be present. Environmental pathways associated with waste disposal are monitored independently, and/or in conjunction with the waste site operators to verify their results and evaluate their programs. The Department also participates in many site investigations conducted by site operators and other agencies, and conducts it`s own special investigations when deemed necessary. Past investigations and special projects have included allegations of adverse environmental impact of I-129, uranium in ground water, impacts of wastes on the agricultural industry, radioactivity in seeps into the Columbia River from waste sites, identifying lost waste sites at Hanford, differentiating groundwater contamination from defense versus commercial sources, and radioactivity in municipal landfills and sewers. The state`s environmental radiation monitoring program has identified and verified a number of environmental problems associated with radioactive waste disposal, but has, to date, identified no adverse offsite impacts to public health.

  9. Miniaturized radiation chirper

    DOE Patents [OSTI]

    Umbarger, C. John; Wolf, Michael A.

    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.

  10. 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.

  11. Simultaneous beta and gamma spectroscopy

    DOE Patents [OSTI]

    Farsoni, Abdollah T.; Hamby, David M.

    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.

  12. 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

  13. 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.

  14. MULTIPLE THICKNESS TIMES DENSITY GAMMA GAGE

    DOE Patents [OSTI]

    Cherry, N.H.

    1962-07-24

    A device was developed for measuring simultaneously the thicknesses of two dissimilar materials superimposed on each other, such as coating of one material on another. The apparatus utilizes a double gamma radiation source producing radiation in two narrow band energy levels. The different materials attenuate the two bands of energy unequally with the result that a composite signal is received which can be analyzed to separate out the components due to the differing materials and indicate the thickness or densities of the two layers. (AEC)

  15. Defense-in-Depth, How Department of Energy Implements Radiation Protection in Low Level Waste Disposal

    Broader source: Energy.gov [DOE]

    Defense-in-Depth, How Department of Energy Implements Radiation Protection in Low Level Waste Disposal Linda Suttora*, U.S. Department of Energy ; Andrew Wallo, U.S. Department of Energy Abstract: The United States Department of Energy (DOE) has adopted an integrated protection system for the safety of radioactive waste disposal similar to the concept of a safety case that is used internationally. This approach has evolved and been continuously improved as a result of many years of experience managing low-level waste (LLW) and mixed LLW from on-going operations, decommissioning and environmental restoration activities at 29 sites around the United States. The integrated protection system is implemented using a defense-in-depth approach taking into account the combination of natural and engineered barriers, performance objectives, long-term risk assessments, maintenance of those assessments based on the most recent information to ascertain continued compliance, site-specific waste acceptance criteria based on the risk assessment and a commitment to continuous improvement. There is also a strong component of stakeholder involvement. The integrated protection system approach will be discussed to demonstrate the commitment to safety for US DOE disposal.

  16. 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.

  17. Gamma and X-ray Dosimetric Method

    DOE Patents [OSTI]

    Taplin, G.V.; Douglas, C.H.

    1954-06-29

    This patent application concerns a highly stable two-phase liquid system for use in a colorimetric dosimeter for measuring X-ray and gamma radiation.

  18. Astrophysical S factor for the radiative-capture reaction p{sup 6}Li {yields} {sup 7}Be{gamma}

    SciTech Connect (OSTI)

    Dubovichenko, S. B.; Burtebaev, N. Zazulin, D. M.; Kerimkulov, Zh. K.; Amar, A. S. A.

    2011-07-15

    A new measurement of differential cross sections for elastic p{sup 6}Li scattering in the energy range 0.35-1.2 MeV was performed. A partial-wave analysis of the data obtained in this way was carried out, and potentials simulating the p{sup 6}Li interaction were constructed. Various experiments devoted to studying elastic p{sup 6}Li scattering over the broad energy range of 0.5-50 MeV were analyzed on the basis of the optical model. By using the potentials obtained from the partial-wave analysis, the possibility of describing the astrophysical S factor for radiative proton capture on {sup 6}Li at low energies was considered within the potential cluster model involving forbidden states.

  19. Radiation chemical effects in experiments to study the reaction of glass in an environment of gamma-irradiated air, groundwater, and tuff

    SciTech Connect (OSTI)

    Van Konynenburg, R.A.

    1986-05-02

    The results of experiments performed by John K. Bates et al. on the reaction of nuclear waste glass with a gamma-irradiated 90{sup 0}C aqueous solution were analyzed using theory developed from past research in radiation chemistry. The aqueous solution they used is similar to what would be expected in a water-saturated environment in a nuclear waste repository in tuff. The purpose of our study was to develop an understanding of the radiation-chemical processes that occurred in the Bates et al. experiments so the results could be applied to the design and performance analysis of a proposed repository in unsaturated tuff in Nevada. For the Bates et al. experiments at the highest dose (269 Mrad), which originally contained about 16 ml of "equilibrated" water taken from Nevada Test Site Well J-13 and 5.4 ml of air, we predicted that water decomposition to H{sub 2} and O{sub 2} would produce a pressure increase of at least 1.0 MPa at 20{sup 0}C. We also predicted that nitrogen fixation from the air would occur, producing an increase of 1.6 x 10{sup -4} M in total fixed nitrogen concentration in solution. In addition, an equimolar production of H{sup +} would occur, which would be buffered by the HCO{sub 3}{sup -} in the water. The fixed nitrogen in solution was predicted to be present as NO{sub 2}{sup -} and NO{sub 3}{sup -} with the ratio influenced by the presence of materials catalytic to the decomposition of H{sub 2}O{sub 2}. We found reasonable agreement between our predictions and the observations of Bates et al., where comparisons were possible. We apply the results to the proposed Nevada repository to the degree possible, given the different expected conditions.

  20. Gamma ray camera

    DOE Patents [OSTI]

    Perez-Mendez, Victor

    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.

  1. 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.

  2. 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.

  3. CGRaBS: An All-Sky Survey of Gamma-Ray Blazar Candidates (Journal...

    Office of Scientific and Technical Information (OSTI)

    Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 79 ASTRONOMY AND ASTROPHYSICS; COSMIC GAMMA SOURCES; GAMMA RADIATION; ASTROPHYSICS ...

  4. 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).

  5. Portable compton gamma-ray detection system

    DOE Patents [OSTI]

    Rowland, Mark S.; Oldaker, Mark E.

    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.

  6. 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.

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

    DOE Patents [OSTI]

    Kimbrough, Joseph Robert; Colella, Nicholas John

    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.

  8. 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 ¹³⁷Cs 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

  9. Resonant electronic transport through a triple quantum-dot with Λ-type level structure under dual radiation fields

    SciTech Connect (OSTI)

    Guan, Chun; Xing, Yunhui; Zhang, Chao; Ma, Zhongshui

    2014-08-14

    Due to quantum interference, light can transmit through dense atomic media, a phenomenon known as electromagnetically induced transparency (EIT). We propose that EIT is not limited to light transmission and there is an electronic analog where resonant transparency in charge transport in an opaque structure can be induced by electromagnetic radiation. A triple-quantum-dots system with Λ-type level structure is generally opaque due to the level in the center dot being significantly higher and therefore hopping from the left dot to the center dot is almost forbidden. We demonstrate that an electromagnetically induced electron transparency (EIET) in charge of transport can indeed occur in the Λ-type system. The direct evidence of EIET is that an electron can travel from the left dot to the right dot, while the center dot apparently becomes invisible. We analyze EIET and the related shot noise in both the zero and strong Coulomb blockade regimes. It is found that the EIET (position, height, and symmetry) can be tuned by several controllable parameters of the radiation fields, such as the Rabi frequencies and detuning frequencies. The result offers a transparency/opaque tuning technique in charge transport using interfering radiation fields.

  10. GAMMA PROPORTIONAL COUNTER CONTAINING HIGH Z GAS AND LOW Z MODERATOR

    DOE Patents [OSTI]

    Fox, R.

    1963-07-23

    A gamma radiation counter employing a gas proportional counter is described. The radiation counter comprises a cylindrical gas proportional counter which contains a high atomic number gas and is surrounded by a low atomic number gamma radiation moderator material. At least one slit is provided in the moderator to allow accident gamma radiation to enter the moderator in the most favorable manner for moderation, and also to allow low energy gamma radiation to enter the counter without the necessity of passing through the moderator. This radiation counter is capable of detecting and measuring gamma radiation in the energy range of 0.5-5 Mev. (AEC)

  11. CONTRIBUTION OF GAMMA-RAY-LOUD RADIO GALAXIES' CORE EMISSIONS...

    Office of Scientific and Technical Information (OSTI)

    CORE EMISSIONS TO THE COSMIC MeV AND GeV GAMMA-RAY BACKGROUND RADIATION Citation Details In-Document Search Title: CONTRIBUTION OF GAMMA-RAY-LOUD RADIO GALAXIES' CORE ...

  12. 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.

  13. Baseline measurements of terrestrial gamma radioactivity at the CEBAF site

    SciTech Connect (OSTI)

    Wollenberg, H.A.; Smith, A.R.

    1991-10-01

    A survey of the gamma radiation background from terrestrial sources was conducted at the CEBAF site, Newport News, Virginia, on November 12--16, 1990, to provide a gamma radiation baseline for the site prior to the startup of the accelerator. The concentrations and distributions of the natural radioelements in exposed soil were measured, and the results of the measurements were converted into gamma-ray exposure rates. Concurrently, samples were collected for laboratory gamma spectral analyses.

  14. U235: a gamma ray analysis code for uranium isotopic determination...

    Office of Scientific and Technical Information (OSTI)

    Subject: 44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; 99 MATHEMATICS, COMPUTERS, INFORMATION SCIENCE, MANAGEMENT, LAW, MISCELLANEOUS; GAMMA RADIATION; URANIUM 235; ...

  15. Plutonium radiation surrogate

    DOE Patents [OSTI]

    Frank, Michael I.

    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.

  16. Automatic Energy Calibration of Gamma-Ray Spectrometers

    Energy Science and Technology Software Center (OSTI)

    2011-09-19

    The software provides automatic method for calibrating the energy scale of high-purity germanium (HPGe) and scintillation gamma-ray spectrometers, using natural background radiation as the source of calibration gamma rays. In field gamma-ray spectroscopy, radioactive check sources may not be available; temperature changes can shift detector electronic gain and scintillator light output; and a user’s experience and training may not include gamma-ray energy calibration. Hence, an automated method of calibrating the spectrometer using natural background wouldmore » simplify its operation, especially by technician-level users, and by enhancing spectroscopic data quality, it would reduce false detections. Following a typically one-minute count of background gamma-rays, the measured spectrum is searched for gamma-ray peaks, producing a list of peak centroids, in channels1. Next, the ratio algorithm attempts to match the peak centroids found in the search to a user-supplied list of calibration gamma-ray energies. Finally, if three or more calibration energies have been matched to peaks, the energy equation parameters are determined by a least-squares fit2, and the spectrum has been energy-calibrated. The ratio algorithm rests on the repeatable but irregular spacing of the background gammaray energies—together they form a unique set of ratios, when normalized to the highest energy calibration gamma ray; so too, the corresponding peak centroids in the spectrum. The algorithm matches energy ratios to peak centroid ratios, to determine which peak matches a given calibration energy.« less

  17. 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...

  18. Working with SRNL - Our Facilities- Gamma Irradiation Facility

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

    for irradiating solid and liquid samples, allowing a wide range of tests to determine the effects of radiation on materials. Typically, the Gamma Irradiation Facility is used to...

  19. Observations of gamma radiation between 0. 4 MeV and 7 MeV at balloon altitudes using a Compton telescope

    SciTech Connect (OSTI)

    Lockwood, J.A.; Webber, W.R.; Friling, L.A.; Macri, J.; Hsieh, L.

    1981-09-15

    Results are presented from a balloon flight at Palestine, Texas, in 1978 to measure the atmospheric and diffuse ..gamma..-ray flux in the energy range 0.4--7.0 MeV. The observations were made with a Compton telescope which included pulse-shape discrimination of the first scattering detector and a time-of-flight system between the first and second detector elements. The total downward ..gamma..-ray flux at 3.7 g cm/sup -2/ is given by the spectrum 3.1 x 10/sup -2/ x E/sup -1.74/ (photons cm/sup -2/ s/sup -1/ MeV/sup -1/ sr/sup -1/) for 0.5gamma..-ray flux to the atmospheric ..gamma..-rays indicate that 0.2 MeV

  20. 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.

  1. Underwater radiation detector

    DOE Patents [OSTI]

    Kruse, Lyle W.; McKnight, Richard P.

    1986-01-01

    A detector apparatus for differentiating between gamma and neutron radiation is provided. The detector includes a pair of differentially shielded Geiger-Mueller tubes. The first tube is wrapped in silver foil and the second tube is wrapped in lead foil. Both the silver and lead foils allow the passage of gamma rays at a constant rate in a gamma ray only field. When neutrons are present, however, the silver activates and emits beta radiation that is also detected by the silver wrapped Geiger-Mueller tube while the radiation detected by the lead wrapped Geiger-Mueller tube remains constant. The amount of radiation impinging on the separate Geiger-Mueller tubes is then correlated in order to distinguish between the neutron and gamma radiations.

  2. Ion-induced gammas for photofission interrogation of HEU.

    SciTech Connect (OSTI)

    Doyle, Barney Lee (Sandia National Laboratories, Albuquerque, NM); Antolak, Arlyn J.; Morse, Daniel H.; Provencio, Paula Polyak (Sandia National Laboratories, Albuquerque, NM)

    2006-03-01

    High-energy photons and neutrons can be used to actively interrogate for heavily shielded special nuclear material (SNM), such as HEU (highly enriched uranium), by detecting prompt and/or delayed induced fission signatures. In this work, we explore the underlying physics for a new type of photon source that generates high fluxes of mono-energetic gamma-rays from low-energy (<500 keV) proton-induced nuclear reactions. The characteristic energies (4- to 18-MeV) of the gamma-rays coincide with the peak of the photonuclear cross section. The source could be designed to produce gamma-rays of certain selected energies, thereby improving the probability of detecting shielded HEU or providing a capability to determine enrichment inside sealed containers. The fundamental physics of such an interrogation source were studied in this LDRD through scaled ion accelerator experiments and radiation transport modeling. The data were used to assess gamma and neutron yields, background, and photofission-induced signal levels from several (p,{gamma}) target materials under consideration.

  3. Composition for radiation shielding

    DOE Patents [OSTI]

    Kronberg, James W.

    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.

  4. 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.

  5. Development of autonomous gamma dose logger for environmental monitoring

    SciTech Connect (OSTI)

    Jisha, N. V.; Krishnakumar, D. N.; Surya Prakash, G.; Kumari, Anju; Baskaran, R.; Venkatraman, B.

    2012-03-15

    Continuous monitoring and archiving of background radiation levels in and around the nuclear installation is essential and the data would be of immense use during analysis of any untoward incidents. A portable Geiger Muller detector based autonomous gamma dose logger (AGDL) for environmental monitoring is indigenously designed and developed. The system operations are controlled by microcontroller (AT89S52) and the main features of the system are software data acquisition, real time LCD display of radiation level, data archiving at removable compact flash card. The complete system operates on 12 V battery backed up by solar panel and hence the system is totally portable and ideal for field use. The system has been calibrated with Co-60 source (8.1 MBq) at various source-detector distances. The system is field tested and performance evaluation is carried out. This paper covers the design considerations of the hardware, software architecture of the system along with details of the front-end operation of the autonomous gamma dose logger and the data file formats. The data gathered during field testing and inter comparison with GammaTRACER are also presented in the paper. AGDL has shown excellent correlation with energy fluence monitor tuned to identify {sup 41}Ar, proving its utility for real-time plume tracking and source term estimation.

  6. 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.

  7. 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.

  8. 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.

  9. Radiation detector

    DOE Patents [OSTI]

    Fultz, Brent T.

    1983-01-01

    Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer 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.

  10. 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

  11. BETA-GAMMA PERSONNEL DOSIMETER

    DOE Patents [OSTI]

    Davis, D.M.; Gupton, E.D.; Hart, J.C.; Hull, A.P.

    1961-01-17

    A personnel dosimeter is offered which is sensitive to both gamma and soft beta radiations from all directions within a hemisphere. The device is in the shape of a small pill box which is worn on a worker-s wrist. The top and sides of the device are provided with 50 per cent void areas to give 50 per cent response to the beta rays and complete response to the gamma rays. The device is so constructed as to have a response which will approximate the dose received by the basal layer of the human epidermis.

  12. 66 Neutron, 22 Gamma-Ray Group Cross Sections for Radiation Transport for Neutron Energies Up to 400 MeV.

    Energy Science and Technology Software Center (OSTI)

    1995-12-12

    Version 00 For a variety of applications (accelerator shielding, the use of neutrons in radiotherapy, radiation damage studies, etc.) It is necessary to carry out transport calculations involving medium-energy neutrons. HILO86R multigroup cross sections are in the form needed for the CCC-254/ANISN-ORNL and CCC-543/TORT-DORT discrete ordinates codes and in the CCC-474/MORSE-CGA Monte Carlo code.

  13. Neutron, gamma ray and post-irradiation thermal annealing effects on power semiconductor switches

    SciTech Connect (OSTI)

    Schwarze, G.E.; Frasca, A.J.

    1994-09-01

    The effects of neutrons and gamma rays on the electrical and switching characteristics of power semiconductor switches must be known and understood by the designer of the power conditioning, control, and transmission subsystem of space nuclear power systems. The SP-100 radiation requirements at 25 m from the nuclear source are a neutron fluence of 10{sup 13} n/cm {sup 2} and a gamma dose of 0.5 Mrads. Experimental data showing the effects of neutrons and gamma rays on the performance characteristics of power-type NPN Bipolar Junction Transistors (BJTs), Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs), and Static Induction Transistors (SITs) are given in this paper. These three types of devices were tested at radiation levels which met or exceeded the SP-100 requirements. For the SP-100 radiation requirements, the BJTs were found to be most sensitive to neutrons, the MOSFETs were most sensitive to gamma rays, and the SITs were only slightly sensitive to neutrons. Post-irradiation thermal anneals at 300 K and up to 425 K were done on these devices and the effectiveness of these anneals are also discussed.

  14. Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

    SciTech Connect (OSTI)

    Buhl, T.E.; Hansen, W.R.

    1984-05-01

    Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables.

  15. 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. ); Gotchy, R.L. )

    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.

  16. Pulsed pyroelectric crystal-powered gamma source

    SciTech Connect (OSTI)

    Chen, A. X.; Antolak, A. J.; Leung, K.-N.; Raber, T. N.; Morse, D. H.

    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.

  17. High resistivity aluminum antimonide radiation detector

    DOE Patents [OSTI]

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

    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.

  18. 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.

  19. 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.

  20. Astrophysical S-factor for the radiative-capture reaction p{sup 13}C {yields} {sup 14}N{gamma}

    SciTech Connect (OSTI)

    Dubovichenko, S. B.

    2012-02-15

    The possibility of describing experimental data on the astrophysical S factor for radiative proton capture on a {sup 13}C nucleus at energies in the range 0.03-0.8 MeV is considered within the potential cluster model involving forbidden states. It is shown that the energy dependence of this astrophysical S factor can be reasonably explained on the basis of the E1 transition to the {sup 3}P{sub 1}-wave bound state of the {sup 14}N nucleus in the p{sup 13}C channel from the {sup 3}S{sub 1} wave of p{sup 13}C scattering in the resonance energy region around 0.55 MeV in the laboratory frame.

  1. Combination neutron-gamma ray detector

    DOE Patents [OSTI]

    Stuart, Travis P.; Tipton, Wilbur J.

    1976-10-26

    A radiation detection system capable of detecting neutron and gamma events and distinguishing therebetween. The system includes a detector for a photomultiplier which utilizes a combination of two phosphor materials, the first of which is in the form of small glass beads which scintillate primarily in response to neutrons and the second of which is a plastic matrix which scintillates in response to gammas. A combination of pulse shape and pulse height discrimination techniques is utilized to provide an essentially complete separation of the neutron and gamma events.

  2. 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.

  3. 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 ¹³⁷Cs 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.

  4. Method and Apparatus for Measuring Radiation Quantities

    DOE Patents [OSTI]

    Roberts, N.O.

    1955-01-25

    This patent application describes a compact dosimeter for measuring X-ray and gamma radiation by the use of solutions which undergo a visible color change upon exposure to a predetermined quantity of radiation.

  5. Energy levels and radiative rates for transitions in B-like to F-like Kr ions (Kr XXXII-XXVIII)

    SciTech Connect (OSTI)

    Aggarwal, K.M. Keenan, F.P.; Lawson, K.D.

    2008-05-15

    Energy levels, radiative rates, oscillator strengths, line strengths, and lifetimes have been calculated for transitions in B-like to F-like Kr ions, Kr XXXIII-XXVIII. For the calculations, the fully relativistic GRASP code has been adopted, and results are reported for all electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) transitions among the lowest 125, 236, 272, 226, and 113 levels of Kr XXXII, Kr XXXI, Kr XXX, Kr XXIX, and Kr XXVIII, respectively, belonging to the n {<=} 3 configurations. Comparisons are made with earlier available theoretical and experimental results, and some discrepancies have been noted and explained.

  6. KGK-2-type detector of gamma-radiation power for diagnosis of nuclear reactor radiation fields within the range from 1 µGy/s to 100 Gy/s

    SciTech Connect (OSTI)

    Koshelev, A. S. Dovbysh, L. Ye.; Khoruzhy, V. Kh.; Chuklyaev, S. V.

    2015-12-15

    The construction of the KGK-2-type detector of γ-radiation power is briefly described. The diagnostic possibilities of the detector are shown by the example of results of the dose rate measurement in the energy start-ups of the BR-K1 and BR-1M reactors implemented in the mode of generating fission pulses on delayed neutrons. The possibilities of using the KGK-2 detector for postpulse γ diagnostics are demonstrated by the example of results of measurements in the fission pulse on prompt neutrons of the BR-1M reactor.

  7. 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

  8. On the level of the cosmic ray sea flux

    SciTech Connect (OSTI)

    Casanova, S.; Aharonian, F. A.; Gabici, S.; Torii, K.; Fukui, Y.; Onishi, T.; Yamamoto, H.; Kawamura, A.

    2009-04-08

    The study of Galactic diffuse {gamma} radiation combined with the knowledge of the distribution of the molecular hydrogen in the Galaxy offers a unique tool to probe the cosmic ray flux in the Galaxy. A methodology to study the level of the cosmic ray 'sea' and to unveil target-accelerator systems in the Galaxy, which makes use of the data from the high resolution survey of the Galactic molecular clouds performed with the NANTEN telescope and of the data from {gamma}-ray instruments, has been developed. Some predictions concerning the level of the cosmic ray 'sea' and the {gamma}-ray emission close to cosmic ray sources for instruments such as Fermi and Cherenkov Telescope Array are presented.

  9. 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.

  10. Cosmic-ray physics with the milagro gamma-ray observatory (Journal...

    Office of Scientific and Technical Information (OSTI)

    The Milagro gamma-ray observatory is a water Cherenkov detector with an energy response ... COUNTERS; COSMIC RADIATION; EMISSION; ENERGY; MODULATION; PHYSICS; TIME DEPENDENCE; WATER

  11. 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.

  12. 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. Much of the historical mechanical performance data of irradiated concrete does not accurately reflect typical radiation conditions in NPPs or conditions out to 60 or 80 years of radiation exposure. 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.

  13. 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.

  14. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, William J.; Lessing, Paul A.

    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.

  15. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, William J.; Lessing, Paul A.

    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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Gamma beam system at ELI-NP

    SciTech Connect (OSTI)

    Ur, Calin Alexandru

    2015-02-24

    The Gamma Beam System of ELI-NP will produce brilliant, quasi-monochromatic gamma-ray beams via Inverse Compton Scattering of short laser pulses on relativistic electron beam pulses. The scattered radiation is Doppler upshifted by more than 1,000,000 times and is forward focused in a narrow, polarized, tunable, laser-like beam. The gamma-ray beam at ELI-NP will be characterized by large spectral density of about 10{sup 4} photons/s/eV, narrow bandwidth (< 0.5%) and tunable energy from 200 keV up to about 20 MeV. The Gamma Beam System is a state-of-the-art equipment employing techniques and technologies at the limits of the present-day's knowledge.

  1. Disturbance of DKK1 level is partly involved in survival of lung cancer cells via regulation of ROMO1 and γ-radiation sensitivity

    SciTech Connect (OSTI)

    Kim, In Gyu; Kim, Seo Yoen; Biomedical Translational Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 ; Kim, Hyun A; Kim, Jeong Yul; Lee, Jae Ha; Choi, Soo Im; Department of Radiation Biotechnology and Applied Radioisotope, University of Science and Technology , 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 ; Han, Jeong Ran; Kim, Kug Chan; Cho, Eun Wie

    2014-01-03

    Highlights: •DKK1 was expressed differently among non-small-cell lung cancer cell lines. •DKK1 negatively regulated ROMO1 gene expression. •Disturbance of DKK1 level induced the imbalance of cellular ROS. •DKK1/ROMO1-induced ROS imbalance is involved in cell survival in NSCLC. -- Abstract: Dickkopf1 (DKK1), a secreted protein involved in embryonic development, is a potent inhibitor of the Wnt signaling pathway and has been postulated to be a tumor suppressor or tumor promoter depending on the tumor type. In this study, we showed that DKK1 was expressed differently among non-small-cell lung cancer cell lines. The DKK1 expression level was much higher in A549 cells than in H460 cells. We revealed that blockage of DKK1 expression by silencing RNA in A549 cells caused up-regulation of intracellular reactive oxygen species (ROS) modulator (ROMO1) protein, followed by partial cell death, cell growth inhibition, and loss of epithelial–mesenchymal transition property caused by ROS, and it also increased γ-radiation sensitivity. DKK1 overexpression in H460 significantly inhibited cell survival with the decrease of ROMO1 level, which induced the decrease of cellular ROS. Thereafter, exogenous N-acetylcysteine, an antioxidant, or hydrogen peroxide, a pro-oxidant, partially rescued cells from death and growth inhibition. In each cell line, both overexpression and blockage of DKK1 not only elevated p-RB activation, which led to cell growth arrest, but also inactivated AKT/NF-kB, which increased radiation sensitivity and inhibited cell growth. This study is the first to demonstrate that strict modulation of DKK1 expression in different cell types partially maintains cell survival via tight regulation of the ROS-producing ROMO1 and radiation resistance.

  2. Analytical study of the effects of the Low-Level Jet on moisture convergence and vertical motion fields at the Southern Great Plains Cloud and Radiation Testbed site

    SciTech Connect (OSTI)

    Bian, X.; Zhong, S.; Whiteman, C.D.; Stage, S.A.

    1996-04-01

    The Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) is located in a region that is strongly affected by a prominent meteorological phenomenon--the Great Plains Low-Level Jet (LLJ). Observations have shown that the LLJ plays a vital role in spring and summertime cloud formation and precipitation over the Great Plains. An improved understanding of the LLJ characteristics and its impact on the environment is necessary for addressing the fundamental issue of development and testing of radiational transfer and cloud parameterization schemes for the general circulation models (GCMs) using data from the SGP CART site. A climatological analysis of the summertime LLJ over the SGP has been carried out using hourly observations from the National Oceanic and Atmospheric Administration (NOAA) Wind Profiler Demonstration Network and from the ARM June 1993 Intensive Observation Period (IOP). The hourly data provide an enhanced temporal and spatial resolution relative to earlier studies which used 6- and 12-hourly rawinsonde observations at fewer stations.

  3. 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}.

  4. Gamma ray detector shield

    DOE Patents [OSTI]

    Ohlinger, R.D.; Humphrey, H.W.

    1985-08-26

    A gamma ray detector shield comprised of a rigid, lead, cylindrical-shaped vessel having upper and lower portions with an pneumatically driven, sliding top assembly. Disposed inside the lead shield is a gamma ray scintillation crystal detector. Access to the gamma detector is through the sliding top assembly.

  5. 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.

  6. 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.

  7. Process for gamma ray induced degradation of polychlorinated biphenyls

    DOE Patents [OSTI]

    Meikrantz, David H.; Mincher, Bruce J.; Arbon, Rodney E.

    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.

  8. Energy levels, oscillator strengths, and radiative rates for Si-like Zn XVII, Ga XVIII, Ge XIX, and As XX

    SciTech Connect (OSTI)

    Abou El-Maaref, A.; Allam, S.H.; El-Sherbini, Th.M.

    2014-01-15

    The energy levels, oscillator strengths, line strengths, and transition probabilities for transitions among the terms belonging to the 3s{sup 2}3p{sup 2}, 3s3p{sup 3}, 3s{sup 2}3p3d, 3s{sup 2}3p4s, 3s{sup 2}3p4p and 3s{sup 2}3p4d configurations of silicon-like ions (Zn XVII, Ga XVIII, Ge XIX, and As XX) have been calculated using the configuration-interaction code CIV3. The calculations have been carried out in the intermediate coupling scheme using the BreitPauli Hamiltonian. The present calculations have been compared with the available experimental data and other theoretical calculations. Most of our calculations of energy levels and oscillator strengths (in length form) show good agreement with both experimental and theoretical data. Lifetimes of the excited levels have also been calculated. -- Highlights: We have calculated the fine-structure energy levels of Si-like Zn, Ga, Ge and As. The calculations are performed using the configuration interaction method (CIV3). We have calculated the oscillator strengths, line strengths and transition rates. The wavelengths of the transitions are listed in this article. We also have made comparisons between our data and other calculations.

  9. 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

  10. 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.

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

    DOE Patents [OSTI]

    Hailey, C.J.; Ziock, K.P.

    1992-06-02

    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. 6 figs.

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

    DOE Patents [OSTI]

    Hailey, Charles J.; Ziock, Klaus-Peter

    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.

  13. 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.

  14. 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.

  15. 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)

  16. 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.

  17. 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 = 2.36.1). Median K{sub AR} = 581 mGy (374876). Median P{sub KA} = 3908 uGym{sup 2} (24895865) DRL = 5865 uGym{sup 2}. 947 patients were included in the PCI group where median FT was 11.2 min (7.717.4). Median K{sub AR} = 1501 mGy (9282224). Median P{sub KA} = 8736 uGym{sup 2} (544912,900) DRL = 12,900 uGym{sup 2}. This study established a benchmark for radiation dose for diagnostic and interventional coronary angiography in Queensland public facilities.

  18. 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.

  19. 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, Grgory; 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

  20. Radiation Impact of Very Low Level Radioactive Steel Reused in Building Industry with Emphasis on External Exposure Pathway - 12569

    SciTech Connect (OSTI)

    Panik, Michal; Hrncir, Tomas; Necas, Vladimir

    2012-07-01

    Considerable quantities of various materials are accumulated during the decommissioning process of nuclear installations. Some of arising materials are activated or contaminated. However, many of them continue to have an economic value and exist in a form that can be recycled or reused for special purposes. Furthermore much of the material generated during decommissioning process will contain only small amounts of radionuclides. For these materials there exist environmental and economic incentives to maximize the use of the concept of clearance from further regulatory control. This impact analysis is devoted to mentioned incentives. The aim is to conditionally clear maximum amount of the scrap steel and consequently recycle and reuse it in form of reinforcing components in tunnel and bridge building scenarios. Recent calculations relevant for external exposure pathway indicate that concept of conditional clearance represent a feasible option for the management of radioactive materials. Even in chosen specific industrial applications it is possible to justify new, approximately one order of magnitude higher, clearance levels. However analysis of other possible exposure pathways relevant for particular scenario of reuse of conditionally cleared materials has to be performed in order to confirm indications from partially obtained results. Basically, the concept of conditional clearance can bring two basic benefits. Firstly it is saving of considerable funds, which would be otherwise used for treatment, conditioning and disposal of materials at appropriate radioactive waste repository. Moreover materials with intrinsic value (particularly metals) can be recycled and reused in industrial applications instead of investing resources on mining and production process in order to obtain new, 'fresh' materials. (authors)

  1. Radiative Decays Involving Light Scalar Mesons

    SciTech Connect (OSTI)

    Deirdre Black; Masayasu Harada; Joseph Schechter

    2002-09-01

    We present a vector dominance model to describe radiative decays involving the light scalar mesons. Assuming that the light scalar mesons form a nonet this model gives relations among various decay amplitudes of the form S--> gamma gamma, V-->Sgamma and S--> Vgamma, where S and V denote scalar and vector mesons. By comparing with experimental radiative decay rates, including those recently measured for phi--> PP'gamma, we obtain various predictions. We discuss briefly ongoing extensions of the present work in an attempt to describe the radiative phi decay measurements in detail.

  2. UTILIZATION OF PHOSWICH DETECTORS FOR SIMULTANEOUS, MULTIPLE RADIATION DETECTION

    SciTech Connect (OSTI)

    William H. Miller; Manuel Diaz de Leon

    2003-04-15

    A phoswich radiation detector is comprised of a phosphor sandwich in which several different phosphors are viewed by a common photomultiplier. By selecting the appropriate phosphors, this system can be used to simultaneously measure multiple radiation types (alpha, beta, gamma and/or neutron) with a single detector. Differentiation between the signals from the different phosphors is accomplished using digital pulse shape discrimination techniques. This method has been shown to result in accurate discrimination with highly reliable and versatile digital systems. This system also requires minimal component count (i.e. only the detector and a computer for signal processing). A variety of detectors of this type have been built and tested including: (1) a triple phoswich system for alpha/beta/gamma swipe counting, (2) two well-type detectors for measuring low levels of low energy photons in the presence of a high energy background, (3) a large area detector for measuring beta contamination in the presence of a photon background, (4) another large area detector for measuring low energy photons from radioactive elements such as uranium in the presence of a photon background. An annular geometry, triple phoswich system optimized for measuring alpha/beta/gamma radiation in liquid waste processing streams is currently being designed.

  3. RADIATION COUNTER

    DOE Patents [OSTI]

    Goldsworthy, W.W.

    1958-02-01

    This patent relates to a radiation counter, and more particularly, to a scintillation counter having high uniform sensitivity over a wide area and capable of measuring alpha, beta, and gamma contamination over wide energy ranges, for use in quickly checking the contami-nation of personnel. Several photomultiplier tubes are disposed in parallel relationship with a light tight housing behind a wall of scintillation material. Mounted within the housing with the photomultipliers are circuit means for producing an audible sound for each pulse detected, and a range selector developing a voltage proportional to the repetition rate of the detected pulses and automatically altering its time constant when the voltage reaches a predetermined value, so that manual range adjustment of associated metering means is not required.

  4. Optical gamma thermometer

    SciTech Connect (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.

  5. 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.

  6. 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

  7. Thermoluminescence and dielectric response of gamma irradiated muscovite mica

    SciTech Connect (OSTI)

    Kaur, Sukhnandan Singh, Surinder Singh, Lakhwant; Lochab, S. P.

    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.

  8. ORNL/RASA-84/LJ3 Health and Safety Research Division RESULTS...

    Office of Legacy Management (LM)

    Systematic and Biased Soil Samples. ...... 2 Gamma Radiation Levels. . .. .. . . ... of elevated gamma radiation levels at 59 Trudy Drive. ...... . . . . . . . . . . . ...

  9. JOINT EPA/DOE STATEMENT: Radiation Monitors Confirm That No Radiation...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    JOINT EPADOE STATEMENT: Radiation Monitors Confirm That No Radiation Levels of Concern Have Reached the United States JOINT EPADOE STATEMENT: Radiation Monitors Confirm That No ...

  10. 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.

  11. 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.

  12. Gamma Detector Response and Analysis Software (GADRAS) v. 16.0

    Energy Science and Technology Software Center (OSTI)

    2009-12-24

    GADRAS is a general purpose application for the modeling and analysis of radiation detector responses, primarily gamma spectroscopic instruments and neutron detectors based on proportional counters. It employs radiation source and detector response models to predict the response of user-defined detectors to user-defined sources. It implements methods to identify radiation sources from their measured signatures, primarily the measured gamma spectrum and neutron count rate. Radiation source emissions are calculated using analytical and numerical radiation transportmore » models. Detector responses are calculated using point models of the detector material, dimensions, collimation, and scattering environment. Analytical methods are implemented using linear and nonlinear regression techniques.« less

  13. Radiation attenuation gauge with magnetically coupled source

    DOE Patents [OSTI]

    Wallace, Steven A.

    1978-01-01

    A radiaton attenuation gauge for measuring thickness and density of a material comprises, in combination, a source of gamma radiation contained within a housing comprising magnetic or ferromagnetic material, and a means for measuring the intensity of gamma radiation. The measuring means has an aperture and magnetic means disposed adjacent to the aperture for attracting and holding the housed source in position before the aperture. The material to be measured is disposed between the source and the measuring means.

  14. Transition undulator radiation as bright infrared sources

    SciTech Connect (OSTI)

    Kim, K.J.

    1995-02-01

    Undulator radiation contains, in addition to the usual component with narrow spectral features, a broad-band component in the low frequency region emitted in the near forward direction, peaked at an angle 1/{gamma}, where {gamma} is the relativistic factor. This component is referred to as the transition undulator radiation, as it is caused by the sudden change in the electron`s longitudinal velocity as it enters and leaves the undulator. The characteristic of the transition undulator radiation are analyzed and compared with the infrared radiation from the usual undulator harmonics and from bending magnets.

  15. Gamma-irradiated bacterial preparation having anti-tumor activity

    DOE Patents [OSTI]

    Vass, Arpad A.; Tyndall, Richard L.; Terzaghi-Howe, Peggy

    1999-01-01

    A bacterial preparation from Pseudomonas species isolated #15 ATCC 55638 that has been exposed to gamma radiation exhibits cytotoxicity that is specific for neoplastic carcinoma cells. A method for obtaining a bacterial preparation having antitumor activity consists of suspending a bacterial isolate in media and exposing the suspension to gamma radiation. A bacterial preparation of an aged culture of an amoeba-associated bacteria exhibits anti-reverse transcriptase activity. A method for obtaining a bacterial preparation having anti-reverse transcriptase activity from an amoeba-associated bacterial isolate grown to stationary phase is disclosed.

  16. Gamma Detector Response and Analysis Software%u2013Detector Response Function

    Energy Science and Technology Software Center (OSTI)

    2015-04-01

    Version 00 GADRAS-DRF contains a suite of capabilities related to radiation detection. Its primary function is the simulation of gamma-ray and neutron detector signals to radiation sources. It also contains limited analysis functionality. GADRAS-DRF is the public version of the full version of GADRAS with capabilities such as radiation transport and advanced analyses removed.

  17. 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.

  18. 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.

  19. RADIATION SHIELDING DEVICE

    DOE Patents [OSTI]

    Wigner, E.P.; Young, G.J.

    1958-09-23

    ABS>A radiation shield that is suitable for the protection of personnel from both gamma rays and nentrons is described. The shield is comprised of a hollow wall and an aggregate consisting of iron and water in approximately equal amounts by volume substantially filling the wall. A means is provided to circulate the water through the wall to cool the shield when in use.

  20. 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.

  1. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, Robert A.; Perez-Mendez, Victor; Kaplan, Selig N.

    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.

  2. Precision Measurement of {eta} --> {gamma} {gamma} Decay Width via the Primakoff Effect

    SciTech Connect (OSTI)

    Gan, Liping Gin

    2013-08-01

    A precision measurement of the {eta} --> {gamma} {gamma} decay width via the Primakoff effect is underway in Hall D at Jefferson Lab. The decay width will be extracted from measured differential cross sections at forward angles on two light targets, liquid hydrogen and 4He, using a 11.5 GeV tagged photon beam. Results of this experiment will not only potentially resolve a long standing discrepancy between the Primakoff and the collider measurements, but will also reduce the experimental uncertainty by a factor of two on the average value of previous experimental results listed by the Particle Data Group(PDG). It will directly improve all other eta partial decay widths which rely on the accuracy of the eta radiative decay width. The projected 3% precision on the {Gamma}({eta} --> {gamma} {gamma} ) measurement will have a significant impact on the experimental determination of the fundamental parameters in QCD, such as the ratio of light quark masses (m{sub u},m{sub d},m{sub s}) and the {eta} - {eta}' mixing angle. It will be a sensitive probe for understanding QCD symmetries and the origin and the dynamics of QCD symmetry breaking.

  3. Search for the decay K+ to pi+ gamma gamma in the pi+ momentum region P > 213 MeV/c

    SciTech Connect (OSTI)

    Artamonov, A.V.; Bassalleck, B.; Bhuyan, B.; Blackmore, E.W.; Bryman, D.A.; Chen, S.; Chiang, I.-H.; Christidi, I.-A.; Cooper, P.S.; Diwan, M.V.; Frank, J.S.; Fujiwara,T.; Hu, J.; Jaffe, D.E.; Kabe, S.; Kettell, S.H.; Khabibullin, M.M.; Khotjantsev, A.N.; Kitching, P.; Kobayashi, M.; Komatsubara, T.K.; ,

    2005-05-01

    We have searched for the K{sup +} {yields} {pi}{sup +}{gamma}{gamma} decay in the kinematic region with {pi}{sup +} momentum close to the end point. No events were observed, and the 90% confidence-level upper limit on the partial branching ratio was obtained, B(K{sup +} {yields} {pi}{sup +}{gamma}{gamma}, P > 213 MeV/c) < 8.3 x 10{sup -9} under the assumption of chiral perturbation theory including next-to-leading order ''unitarity'' corrections. The same data were used to determine an upper limit on the K{sup +} {yields} {pi}{sup +}{gamma} branching ratio of 2.3 x 10{sup -9} at the 90% confidence level.

  4. Delayed gamma technique for fissile material assay

    SciTech Connect (OSTI)

    Mozin, Vladimir; Tobin, Stephen; Vujie, Jasmina; Hunt, Alan

    2010-01-01

    Research sponsored by the Next Generation Safeguards Initiative are investigating several non-destructive assay techniques for the quantification of fissile plutonium mass in spent nuclear fuel assemblies. AppHcation of the delayed gamma signatures is investigated in this context. The objective of the research is to assess whether the delayed gamma assay instrument can provide sufficient sensitivity, isotope specificity and accuracy as required in nuclear material safeguards. This effort includes theoretical and experimental components for the optimal combination of interrogation parameters. A new modeling algorithm offering a high level of detail was developed specifically for this purpose and was validated in series of benchmark experiments. Preliminary modeling of the delayed gamma response from spent fuel assemblies was accomplished offering a future direction for the design process.

  5. Neutron-driven gamma-ray laser

    DOE Patents [OSTI]

    Bowman, Charles D.

    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.

  6. 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.

  7. Optomechanical design of a prompt gamma reaction history diagnostic

    SciTech Connect (OSTI)

    Hermann, Hans W; Kaufman, Morris I; Malone, Robert M; Frogget, Brent C; Tunnell, Thomas W; Cox, Brian; Frayer, Daniel K; Ali, Zaheer; Stoeffl, Wolfgang

    2009-01-01

    The National Ignition Facility and the Omega Laser Facility both have a need for measuring prompt gamma radiation as part of a nuclear diagnostic program. A new gamma-detection diagnostic using off-axis-parabolic mirrors has been built. Some new techniques were used in the design, construction, and tolerancing of this gamma ray diagnostic. Because of the wavelength requirement (250-700 nm), the optical element surface finishes were a key design consideration. The optical enclosure had to satisfy pressure safety concerns and shielding against electromagnetic interference induced by gammas and neutrons. Structural finite element analysis was needed to meet rigorous optical and safety requirements. The optomechanical design is presented. Alignment issues are also discussed.

  8. 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.

  9. A comparison of the alpha and gamma radiolysis of CMPO

    SciTech Connect (OSTI)

    Bruce J. Mincher; Stephen P. Mezyk; Gary Groenewold; Gracy Elias

    2011-06-01

    The radiation chemistry of CMPO has been investigated using a combination of irradiation and analytical techniques. The {alpha}-, and {gamma}-irradiation of CMPO resulted in identical degradation rates (G-value, in {mu}mol Gy{sup -1}) for both radiation types, despite the difference in their linear energy transfer (LET). Similarly, variations in {gamma}-ray dose rates did not affect the degradation rate of CMPO. The solvent extraction behavior was different for the two radiation types, however. Gamma-irradiation resulted in steadily increasing distribution ratios for both forward and stripping extractions, with respect to increasing absorbed radiation dose. This was true for samples irradiated as a neat organic solution, or irradiated in contact with the acidic aqueous phase. In contrast, {alpha}-irradiated samples showed a rapid drop in distribution ratios for forward and stripping extractions, followed by essentially constant distribution ratios at higher absorbed doses. These differences in extraction behavior are reconciled by mass spectrometric examination of CMPO decomposition products under the different irradiation sources. Irradiation by {gamma}-rays resulted in the rupture of phosphoryl-methylene bonds with the production of phosphinic acid products. These species are expected to be complexing agents for americium that would result in higher distribution ratios. Irradiation by {alpha}-sources appeared to favor rupture of carbamoyl-methylene bonds with the production of less deleterious acetamide products.

  10. 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.

  11. WASH-

    Office of Legacy Management (LM)

    Measurement of External Gamma and Beta-Gamma Radiation Levels . . . . . . . . . . . . ... of Water and Mud Samples External Gamma Radiation Levels (in pRhr) at 1 Meter above ...

  12. {phi}{yields}{pi}{sup 0}{eta}{gamma} and {phi}{yields}{pi}{sup 0}{pi}{sup 0}{gamma} decays and mixing between low and high mass scalar mesons

    SciTech Connect (OSTI)

    Teshima, T.; Kitamura, I.; Morisita, N.

    2007-09-01

    Radiative decays {phi}{yields}{eta}{pi}{sup 0}{gamma} and {phi}{yields}{pi}{sup 0}{pi}{sup 0}{gamma} are studied assuming that these decays are caused through the intermediate a{sub 0}(980){gamma} and f{sub 0}(980){gamma} states, respectively. Fitting the experimental data of the {eta}{pi}{sup 0} and {pi}{sup 0}{pi}{sup 0} invariant mass spectrum in the decays {phi}{yields}{eta}{pi}{sup 0}{gamma} and {pi}{sup 0}{pi}{sup 0}{gamma}, it is shown that the processes {phi}{yields}a{sub 0}{gamma} and {phi}{yields}f{sub 0}{gamma} are dominated by the K{sup +}K{sup -} loop interaction rather than the pointlike {phi}a{sub 0}(f{sub 0}){gamma} one both for the nonderivative and derivative SPP coupling. The experimental data of {gamma}[{phi}{yields}f{sub 0}{gamma}]/{gamma}[{phi}{yields}a{sub 0}{gamma}] predicts that g{sub f{sub 0}}{sub KK}/g{sub a{sub 0}}{sub KK}{approx}2. Considering the effects of the mixing between low mass scalar qqqq states and high mass scalar qq states to these coupling constants g{sub f{sub 0}}{sub KK} and g{sub a{sub 0}}{sub KK}, one suggests that this mixing is rather large.

  13. JOINT EPA/DOE STATEMENT: Radiation Monitors Confirm That No Radiation

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Levels of Concern Have Reached the United States | Department of Energy JOINT EPA/DOE STATEMENT: Radiation Monitors Confirm That No Radiation Levels of Concern Have Reached the United States JOINT EPA/DOE STATEMENT: Radiation Monitors Confirm That No Radiation Levels of Concern Have Reached the United States March 18, 2011 - 12:00am Addthis WASHINGTON - The United States Government has an extensive network of radiation monitors around the country and no radiation levels of concern have been

  14. RADIATION WAVE DETECTOR

    DOE Patents [OSTI]

    Wouters, L.F.

    1958-10-28

    The detection of the shape and amplitude of a radiation wave is discussed, particularly an apparatus for automatically indicating at spaced lntervals of time the radiation intensity at a flxed point as a measure of a radiation wave passing the point. The apparatus utilizes a number of photomultiplier tubes surrounding a scintillation type detector, For obtainlng time spaced signals proportional to radiation at predetermined intervals the photolnultiplier tubes are actuated ln sequence following detector incidence of a predetermined radiation level by electronic means. The time spaced signals so produced are then separately amplified and relayed to recording means.

  15. 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.

  16. 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.

  17. Experimental and theoretical study of organometallic radiation-protective materials adapted to radiation sources with a complex isotopic composition

    SciTech Connect (OSTI)

    Russkikh, I. M.; Seleznev, E. N.; Tashlykov, O. L. Shcheklein, S. E.

    2015-12-15

    The significance of optimizing the content of components of a radiation-protective material, which is determined by the isotopic composition of radioactive contamination, depending on the reactor type, operating time, and other factors is demonstrated. The results of computational and experimental investigation of the gamma-radiation attenuation capacity of homogenous radiation-protective materials with different fillers are reported.

  18. Unidentified Gamma-Ray Sources: Hunting Gamma-Ray Blazars

    SciTech Connect (OSTI)

    Massaro, F.; D'Abrusco, R.; Tosti, G.; Ajello, M.; Gasparrini, A.Paggi.D.

    2012-04-02

    One of the main scientific objectives of the ongoing Fermi mission is unveiling the nature of the unidentified {gamma}-ray sources (UGSs). Despite the large improvements of Fermi in the localization of {gamma}-ray sources with respect to the past {gamma}-ray missions, about one third of the Fermi-detected objects are still not associated to low energy counterparts. Recently, using the Wide-field Infrared Survey Explorer (WISE) survey, we discovered that blazars, the rarest class of Active Galactic Nuclei and the largest population of {gamma}-ray sources, can be recognized and separated from other extragalactic sources on the basis of their infrared (IR) colors. Based on this result, we designed an association method for the {gamma}-ray sources to recognize if there is a blazar candidate within the positional uncertainty region of a generic {gamma}-ray source. With this new IR diagnostic tool, we searched for {gamma}-ray blazar candidates associated to the UGS sample of the second Fermi {gamma}-ray catalog (2FGL). We found that our method associates at least one {gamma}-ray blazar candidate as a counterpart each of 156 out of 313 UGSs analyzed. These new low-energy candidates have the same IR properties as the blazars associated to {gamma}-ray sources in the 2FGL catalog.

  19. Gamma Ray Spectrum Catalogs from Idaho National Laboratory (INL)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Heath, R. L.

    Gamma-ray spectrometry is widely applied as a tool for the assay of radioactive source material to identify the isotopes present and characterize radiation fields. Beginning with the startup of the world's first high-flux beam reactor, Materials Test Reactor (MTR), INL has pioneered the development of x-ray spectrometry for use in basic nuclear research and a variety of disciplines using radioisotopes and other radiation sources. Beginning in the early 1950s, a program was instituted to make the technique a precise laboratory tool. Standards were established for detectors and nuclear electronics to promote the production of commercial laboratory spectrometers. It was also necessary to produce a comprehensive collection of standard detector response functions for individual radio nuclides to permit the use of gamma-ray spectrometers for identification of radioisotopes present in radiation sources. This led to the publication of standard measurement methodology and a set of Gamma-Ray Spectrum Catalogues. These publications, which established standards for detector systems, experimental methods and reference spectra for both NaI (Tl) scintillation detectors and Ge(Li) - Si( Li) semiconductor devices, became standard reference works, distributed worldwide. Over 40,000 copies have been distributed by the Office of Science and Technical Information (OSTI). Unfortunately, although they are still very much in demand, they are all out of print at this time. The INL is converting this large volume of data to a format which is consistent with current information technology and meets the needs of the scientific community. Three are available online with the longest being more than 800 pages in length. Plotted spectra and decay data have been converted to digital formats and updated, including decay scheme graphics. These online catalogs are: • Ge(Li)-Si(Li) Gamma Spectrum Catalog (Published 3-29-1999) • NaI(Tl) Gamma Spectrum Catalog (Published 4-1-1997) • Gamma

  20. Inclusive radiative J/{psi} decays

    SciTech Connect (OSTI)

    Besson, D.; Pedlar, T. K.; Cronin-Hennessy, D.; Gao, K. Y.; Hietala, J.; Kubota, Y.; Klein, T.; Lang, B. W.; Poling, R.; Scott, A. W.; Zweber, P.; Dobbs, S.; Metreveli, Z.; Seth, K. K.; Tomaradze, A.; Libby, J.; Powell, A.; Wilkinson, G.; Ecklund, K. M.; Love, W.

    2008-08-01

    Using data taken with the CLEO-c detector at the Cornell Electron Storage Ring, we have investigated the direct-photon momentum spectrum in the decay J/{psi}(1S){yields}{gamma}gg, via the ''tagged'' process: e{sup +}e{sup -}{yields}{psi}(2S); {psi}(2S){yields}J/{psi}{pi}{sup +}{pi}{sup -}; J/{psi}{yields}{gamma}+X. Including contributions from two-body radiative decay processes, we find the ratio of the inclusive direct-photon branching fraction to that of the dominant three-gluon branching fraction [R{sub {gamma}}=B(gg{gamma})/B(ggg)] to be R{sub {gamma}}=0.137{+-}0.001{+-}0.016{+-}0.004, where the errors shown are statistical, systematic, and the model-dependent uncertainty related to the extrapolation to zero photon energy. The shape of the scaled photon energy spectrum in J/{psi}{yields}gg{gamma} is observed to be very similar to that of {upsilon}{yields}gg{gamma}. The R{sub {gamma}} value obtained is roughly consistent with that expected by a simple quark-charge scaling [R{sub {gamma}}{approx}(q{sub c}/q{sub b}){sup 2}] of the value determined at the {upsilon}(1S), but somewhat higher than the value expected from the running of the strong coupling constant.

  1. U and Pu Gamma-Ray Measurements of Spent Fuel Using a Gamma-Ray Mirror Band-Pass Filter

    SciTech Connect (OSTI)

    Ziock, Klaus-Peter; Alameda, J.B.; Brejnholt, N.F.; Decker, T.A.; Descalle, M.A.; Fernandez-Perea, M.; Hill, R.M.; Kisner, R.A.; Melin, A.M.; Patton, B.W.; Ruz, J.; Soufli, R.; Pivovaroff, M.J.

    2014-01-01

    Abstract. We report on the use of grazing incidence gamma-ray mirrors to serve as a narrow band-pass filter for advanced non-destructive analysis (NDA) of spent nuclear fuel. The purpose of the mirrors is to limit the radiation reaching a HPGe detector to narrow spectral bands around characteristic emission lines from fissile isotopes in the fuel. This overcomes the normal rate issues when performing gamma-ray NDA measurements. In a proof-of-concept experiment, a set of simple flat gamma-ray mirrors were used to directly observe the atomic florescence lines from U and Pu from spent fuel pins with the detector located in a shirt-sleeve environment. The mirrors, consisting of highly polished silicon substrates deposited with WC/SiC multilayer coatings, successfully deflected the lines of interest while the intense primary radiation beam from the fuel was blocked by a lead beam stop. The gamma-ray multilayer coatings that make the mirrors work at the gamma-ray energies used here (~ 100 keV) have been experimentally tested at energies as high as 645 keV, indicating that direct observation of nuclear emission lines from 239Pu should be possible with an appropriately designed optic and shielding configuration.

  2. Delayed Gamma-Ray Spectroscopy for Spent Nuclear Fuel Assay

    SciTech Connect (OSTI)

    Campbell, Luke W.; Hunt, Alan W.; Ludewigt, Bernhard A.; Mozin, Vladimir V.

    2012-04-01

    High-energy, beta-delayed gamma-ray spectroscopy is investigated as a non-destructive assay technique for the determination of plutonium mass in spent nuclear fuel. This approach exploits the unique isotope-specific signatures contained in the delayed gamma-ray emission spectra detected following active interrogation with an external neutron source. A high fidelity modeling approach is described that couples radiation transport, analytical decay/depletion, and a newly developed gamma-ray emission source reconstruction code. Initially simulated and analyzed was a “one-pass” delayed gamma-ray assay that focused on the long-lived signatures. Also presented are the results of an independent study that investigated “pulsed mode” measurements, to capture the more isotope-specific, short-lived signatures. Initial modeling results outlined in this paper suggest that delayed gamma-ray assay of spent nuclear fuel assemblies can be accomplished with a neutron generator of sufficient strength and currently available gamma-ray detectors.

  3. Gamma Detector Response and Analysis Software - Light

    Energy Science and Technology Software Center (OSTI)

    2004-06-14

    GADRAS is used to analyze gamma-ray spectra, which may be augmented by neutron count rate information. The fundamental capabilities of GADRAS are imparted by physics-based detector response functions for a variety of gamma ray and neufron detectors. The software has provisions for characterizing detector response parameters so that specta can be computed accurately over the range 30keV key to II MeV. Associated neutron detector count rates can also be computed for characterized detectors. GADRAS incorporatesmore » a variety of analysis algorithms that utilize the computed spectra. The full version of GADRAS incorporates support for computation of radiation leakages from complex source models, but this capability is not supported by GADRAS-LT. GADRAS has been and will continue to be disseminated free of charge to government agencies and National Laboratories as OUO software. GADRAS-LT is a limited software version that was prepared for exclusive use of our Technology Transfer parnter Thermo Electron (TE). TE will use the software to characterize and test radiation detectors that are fabricated under the terms of our partnership. The development of these sensors has been defined as a National Security priority by our sponsor, NNSA/NA-20, by DHS/S&T, and by SNL president Paul Robinson. Although GADRAS-LT is OUO, features that are not essential to the detector development have been removed. TE will not be licensed to commercialize GADRAS-LT or to distribute it to third parties.« less

  4. The natural radioactivity measurements in coastal sediment samples along the East Coast of Tamilnadu using gamma spectrometry technique

    SciTech Connect (OSTI)

    Chandramohan, J.; Tholkappian, M.; Harikrishnan, N.; Ravisankar, R.

    2015-08-28

    The natural radioactivity concentration in beach sediment samples collected from Pattipulam to Devanampattinam of East Coast of Tamilnadu have been determined by NaI (TI) gamma ray spectrometer. The specific activity concentrations range from ≤ 2.21 (BDL) to 37.02 Bq kg{sup −1} with a mean of 3.79 Bqkg{sup −1} for {sup 238}U, ≤ 2.11 (BDL) to 643.77 Bqkg{sup −1} with a mean of 49.60 Bqkg{sup −1} for {sup 232}Th and 300.34 Bqkg{sup −1} to 449.08 Bqkg{sup −1} with a mean of 360.23 Bqkg{sup −1} for {sup 40}K. The potential radiological hazards due to natural radionuclides content such as Radium Equivalent activity (Ra{sub eq}), Representative level index (RLI), External hazard index (H{sub ex}), absorbed gamma does rate (D{sub R}), and Annual effective dose rate (AEDR) are estimated to assess the radiation hazard associated with the sediments. The obtained data are compared with the recommended safety limits and international approved values. All the values are well below the recommended safety limits indicating that radiation levels do not poses any significant health hazard to the public in the area as a result of the natural radioactivity of beach sediments. This study may help the baseline data for more extensive works in the same subjects of future studies.

  5. 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}.

  6. 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 Earths 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.

  7. 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.

  8. Medical gamma ray imaging

    DOE Patents [OSTI]

    Osborne, Louis S.; Lanza, Richard C.

    1984-01-01

    A method and apparatus for determining the distribution of a position-emitting radioisotope into an object, the apparatus consisting of a wire mesh radiation converter, an ionizable gas for propagating ionization events caused by electrodes released by the converter, a drift field, a spatial position detector and signal processing circuitry for correlating near-simultaneous ionization events and determining their time differences, whereby the position sources of back-to-back collinear radiation can be located and a distribution image constructed.

  9. RADIATION SHIELDING COMPOSITION

    DOE Patents [OSTI]

    Dunegan, H.L.

    1963-01-29

    A light weight radiation shielding composition is described whose mechanical and radiological properties can be varied within wide limits. The composition of this shielding material consists of four basic ingredients: powder of either Pb or W, a plastic resin, a resin plasticizer, and a polymerization catalyst to promote an interaction of the plasticizer with the plastic resin. Air may be mixed into the above ingredients in order to control the density of the final composition. For equivalent gamma attenuation, the shielding composition weighs one-third to one-half as much as conventional Pb shielding. (AEC)

  10. Radiation-resistant microorganism

    DOE Patents [OSTI]

    Fliermans, Carl B.

    2007-01-09

    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.