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Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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1

Assessment of radon concentration and external gamma radiation level in the environs of Narwapahar uranium mine, India and its radiological significance  

Science Journals Connector (OSTI)

In the environs of uranium mining, milling and processing facilities and in the uranium mineralized terrain, a little higher ambient radon concentration and gamma radiation level may be expected in comparison ...

B. K. Rana; R. M. Tripathi; J. S. Meena…

2011-11-01T23:59:59.000Z

2

Gamma radiation field intensity meter  

DOE Patents [OSTI]

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.

Thacker, L.H.

1995-10-17T23:59:59.000Z

3

Gamma radiation field intensity meter  

DOE Patents [OSTI]

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.

Thacker, L.H.

1994-08-16T23:59:59.000Z

4

Gamma radiation field intensity meter  

DOE Patents [OSTI]

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.

Thacker, Louis H. (Knoxville, TN)

1995-01-01T23:59:59.000Z

5

Gamma radiation field intensity meter  

DOE Patents [OSTI]

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.

Thacker, Louis H. (Knoxville, TN)

1994-01-01T23:59:59.000Z

6

Apparatus and method for detecting gamma radiation  

DOE Patents [OSTI]

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.

Sigg, R.A.

1994-12-13T23:59:59.000Z

7

A method for calculation of radiation quantities at all points in gamma radiation calibration fields  

Science Journals Connector (OSTI)

......Chi-square test in a gamma radiation calibration field was...dimensions) in a gamma radiation calibration field can...be used in dosimetry software of gamma radiation calibration fields...2000) Vienna: IAEA. Safety Reports Series, No......

S. M. Hosseini-Pooya; M. Khoshnoodi; A. Ansarinejad; F. Torkzadeh; M. Jafarizadeh

2008-03-01T23:59:59.000Z

8

A Device for Search of Gamma-Radiation Intensive Sources at the Radiation Accident Condition  

SciTech Connect (OSTI)

The procedure designed for measuring angular distributions of gamma radiation and for search of gamma radiation intensive sources is described. It is based on application of the original multidetector device ShD-1, for measuring an angular distribution in a complete solid angle (4 pi). The calibration results and data on the angular distributions of intensity of gamma radiation at the roof of Chornobyl NPP ''Shelter'' are presented.

Batiy, Valeriy; Klyuchnykov, A; Kochnev, N; Rudko, Vladimir; shcherbin, vladimir; Yegorov, V; Schmieman, Eric A.

2005-08-08T23:59:59.000Z

9

Recoilless Nuclear Resonance Absorption of Gamma Radiation  

Science Journals Connector (OSTI)

...GAMMA-RAYS, ARKIV FOR FYSIK 6 : 49 ( 1953...OF GAMMA-RAYS - THEORY AND PRELIMINARY EXPERIMENTS...energy loss. The basic feature of this method...prediction of the theory was that the recoilless...formulation of the theory that the mo-mentum...Malmfors, Arkiv Fysik 6, 49 (1953...

Rudolf L. Mössbauer

1962-09-07T23:59:59.000Z

10

Inactivation of aflatoxin B1 by using the synergistic effect of hydrogen peroxide and gamma radiation.  

Science Journals Connector (OSTI)

...peroxide. A 100-krad dose of gamma radiation was sufficient to inactivate...peroxide. A 100-krad dose of gamma radiation was sufficient to inactivate...inhibitors pharmacology radiation effects Animals Dose-Response Relationship...

U D Patel; P Govindarajan; P J Dave

1989-02-01T23:59:59.000Z

11

LATTICE DYNAMICS NUCLEAR RESONANCE ABSORPTION OF GAMMA-RADIATION  

E-Print Network [OSTI]

crystalline domains are taken. Absorption studies of the dynamics of atomic motions in condensed matterLATTICE DYNAMICS NUCLEAR RESONANCE ABSORPTION OF GAMMA-RADIATION AND COHERENT DECAY MODES Institut Max von Laue-Paul Langevin, Grenoble, France R6sumb. -La section efficace pour l'absorption nucleaire

Paris-Sud XI, Université de

12

Attenuation of VHE Gamma Rays by the Milky Way Interstellar Radiation Field  

SciTech Connect (OSTI)

The attenuation of very high energy gamma rays by pair production on the Galactic interstellar radiation field has long been thought of as negligible. However, a new calculation of the interstellar radiation field consistent with multi-wavelength observations by DIRBE and FIRAS indicates that the energy density of the Galactic interstellar radiation field is higher, particularly in the Galactic center, than previously thought. We have made a calculation of the attenuation of very high energy gamma rays in the Galaxy using this new interstellar radiation field which takes into account its nonuniform spatial and angular distributions. We find that the maximum attenuation occurs around 100 TeV at the level of about 25% for sources located at the Galactic center, and is important for both Galactic and extragalactic sources.

Moskalenko, Igor V.; /Stanford U., HEPL; Porter, Troy A.; /Louisiana State U.; Strong, Andrew W.; /Garching, Max Planck Inst., MPE

2006-04-19T23:59:59.000Z

13

E-Print Network 3.0 - acute gamma radiation Sample Search Results  

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

expressions for the spectral evolution of the early afterglow radiation from gamma-ray bursts... this transition, the radiative efficiency will steadily decrease as ffl ...

14

E-Print Network 3.0 - aux radiations gamma Sample Search Results  

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

expressions for the spectral evolution of the early afterglow radiation from gamma-ray bursts... this transition, the radiative efficiency will steadily decrease as ffl ...

15

Calicivirus Inactivation by Nonionizing (253.7-Nanometer-Wavelength [UV]) and Ionizing (Gamma) Radiation  

Science Journals Connector (OSTI)

...7-nm-wavelength [UV]) radiation, inactivation by ionizing (gamma) radiation was studied as a process...constituents on inactivation by radiation. MATERIALS AND METHODS Viruses...Shoji Corporation, Tokyo, Japan) was propagated in MDCK...

Ana Maria de Roda Husman; Paul Bijkerk; Willemijn Lodder; Harold van den Berg; Walter Pribil; Alexander Cabaj; Peter Gehringer; Regina Sommer; Erwin Duizer

2004-09-01T23:59:59.000Z

16

Radiation protection in inhomogeneous beta–gamma fields and modelling of hand phantoms with MCNPX  

Science Journals Connector (OSTI)

......performed using the MCNPX software. In order to investigate...recommendations regarding radiation protection measures...Karlsruhe GmbH, Central Safety Department, KES...Simulation Gamma Rays Hand radiation effects Humans Models...radiation effects Software...

Ch. Blunck; F. Becker; L. Hegenbart; B. Heide; J. Schimmelpfeng; M. Urban

2009-02-01T23:59:59.000Z

17

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

SciTech Connect (OSTI)

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.

Matanoski, G.M.

1991-06-01T23:59:59.000Z

18

E-Print Network 3.0 - attenuates gamma radiation Sample Search...  

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

Astrophysics Research Group Collection: Physics 60 MilagroA TeV Observatory for Gamma Ray Bursts Summary: to gamma rays is likely to complement synchrotron radiation and produce...

19

Gravitational radiation from long gamma-ray bursts  

E-Print Network [OSTI]

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

Maurice H. P. M. van Putten

2001-02-11T23:59:59.000Z

20

Effects of gamma radiation on Serratia marcescens; a comparison of effects of two different exposure rates  

E-Print Network [OSTI]

'Donovan, Effect of gamma radiation on Serratia marcescens: Comparison of the radiosensi- tivity of pigmented and nonpigmented cells. Radiation Res, 48, 40-52 (1971). 18. Alison P. Casarett, Radiation ~Biolo . p. 159. Prentice-Hall, Inc. , Englewood Cliffs... EFFECTS OF GAMMA RADIATION ON SL'RNATIA MARCESCENS A COMPARISON OF EFFECTS OF TWO DIFFERENT EXPOSURE RATES A Thesis by CHRISTY ANNETTE MOORE Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirements...

Moore, Christy Annette

1972-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Population doses from environmental gamma radiation in Iraq  

SciTech Connect (OSTI)

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.

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

1992-05-01T23:59:59.000Z

22

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

E-Print Network [OSTI]

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

Zhang, Bing

23

MEASUREMENT OF THE HIGH GAMMA RADIATION DOSE USING THE MEMS BASED DOSIMETER AND RADIOLISYS EFFECT  

E-Print Network [OSTI]

radiation dose. If we consider, that the average time of exploitation is estimated to be 40 years and veryMEASUREMENT OF THE HIGH GAMMA RADIATION DOSE USING THE MEMS BASED DOSIMETER AND RADIOLISYS EFFECT M of high and very high doses of ionizing radiation is crucial for the monitoring of the existing Nuclear

Boyer, Edmond

24

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

E-Print Network [OSTI]

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

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

1998-05-01T23:59:59.000Z

25

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

SciTech Connect (OSTI)

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.

Radyushkin, Anatoly V. [ODU, JLAB

2014-07-01T23:59:59.000Z

26

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

E-Print Network [OSTI]

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

Florida, University of

27

APPLICATION OF JITTER RADIATION: GAMMA-RAY BURST PROMPT POLARIZATION  

SciTech Connect (OSTI)

A high degree of polarization of gamma-ray burst (GRB) prompt emission has been confirmed in recent years. In this paper, we apply jitter radiation to study the polarization feature of GRB prompt emission. In our framework, relativistic electrons are accelerated by turbulent acceleration. Random and small-scale magnetic fields are generated by turbulence. We further determine that the polarization property of GRB prompt emission is governed by the configuration of the random and small-scale magnetic fields. A two-dimensional compressed slab, which contains a stochastic magnetic field, is applied in our model. If the jitter condition is satisfied, the electron deflection angle in the magnetic field is very small and the electron trajectory can be treated as a straight line. A high degree of polarization can be achieved when the angle between the line of sight and the slab plane is small. Moreover, micro-emitters with mini-jet structures are considered to be within a bulk GRB jet. The jet 'off-axis' effect is intensely sensitive to the observed polarization degree. We discuss the depolarization effect on GRB prompt emission and afterglow. We also speculate that the rapid variability of GRB prompt polarization may be correlated with the stochastic variability of the turbulent dynamo or the magnetic reconnection of plasmas.

Mao, Jirong [Astrophysical Big Bang Lab, RIKEN, Saitama 351-0198 (Japan); Wang, Jiancheng, E-mail: jirong.mao@riken.jp [Yunnan Observatory, Chinese Academy of Sciences, 650011 Kunming, Yunnan Province (China)

2013-10-10T23:59:59.000Z

28

E-Print Network 3.0 - activity gamma radiation Sample Search...  

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

no. (will be inserted by hand later) Summary: as a function of time. Key words: Gamma ray : bursts -- Shock waves -- ISM : jets and outflous -- Radiation... .10.1; 02.18.5...

29

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

DOE Patents [OSTI]

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.

Dioszegi, Istvan; Salwen, Cynthia; Vanier, Peter

2014-12-30T23:59:59.000Z

30

Estimation of external gamma radiation dose in the area of Bory Stobrawskie forests (PL)  

Science Journals Connector (OSTI)

Rather poor relationship between E I and H...was found. The correlation coefficient value was 0.46, supposing existence of other important sources of gamma radiation in environment that were not i...

Agnieszka Do?ha?czuk-?ródka

2012-09-01T23:59:59.000Z

31

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

E-Print Network [OSTI]

had larger air cells with thicker cell walls. The cakes were also tougher and had more resistance to compression. CHAPTER I II EFFECT OF GAMMA RADIATION ON SELECTED PHYSICAL PROPERTIES OF LIqUID EGG WHITE Intr oduct ion As indi. cated in Chapter... EFFECT OF GAMMA RADIATION ON SELECTED FUNCTIONAL AND PHYSICAL PROPERTIES OF LIQUID EGG WHITE A Thesis By Hershell Ray Ball, Jr. Approved as to style and content by) (Chairman of Committee) ead of Department) (Me mba (Member) ( ber) ~Ja...

Ball, Hershell Ray

1966-01-01T23:59:59.000Z

32

Gamma Radiation Effects on Physical, Optical, and Structural Properties of Binary As-S glasses  

SciTech Connect (OSTI)

Gamma radiation induces changes in physical, optical, and structural properties in chalcogenide glasses., Previous research has focused on As{sub 2}S{sub 3} and families of glasses containing Ge. For the first time, we present composition and dose dependent data on the As-S binary glass series. Binary As{sub x}S{sub 100-x} (x = 30, 33, 36, 40, and 42) glasses were irradiated with gamma radiation using a {sup 60}Co source at 2.8 Gy/s to accumulated doses of 1, 2, 3, and 4 MGy. The irradiated samples were characterized at each dose level for density, refractive index, x-ray diffraction, and Raman spectrum. These results are compared to those of as-made and 1 year aged samples. We report an initial increase in density followed by a decrease as a function of dose that contradicts the expected compositional dependence of molar volume of these glasses. This unusual behavior is explained based on microvoid formation and nanoscale phase-separation induced by the irradiation in these glasses. XRD, Raman, and EPR data provide supporting evidence, underscoring the importance of optimally- or overly-constrained structures for stability under aging or irradiation.

Sundaram, S. K.; McCloy, John S.; Riley, Brian J.; Murphy, Mark K.; Qiao, Hong (Amy) [Amy; Windisch, Charles F.; Walter, Eric D.; Crum, Jarrod V.; Golovchak, Roman; Shpotyuk, O.

2012-03-01T23:59:59.000Z

33

Neutron and gamma radiation effects in proton exchanged optical waveguides  

Science Journals Connector (OSTI)

The effect of neutron and gamma ray irradiations on the optical properties of proton exchanged Z-cut lithium niobate optical planar waveguides were investigated. The damage thresholds...

Passaro, Vittorio; Armenise, Mario

2002-01-01T23:59:59.000Z

34

Low Level Gamma Spectroscopy Measurements of Radium and Cesium in Lucerne (Medicago Sativa)  

SciTech Connect (OSTI)

Nineteen years after Chernobyl nuclear accident, activity concentration of 137Cs still could be detected in food and soil samples in Central and Eastern Europe. In this paper radiation levels of radium and cesium in Lucerne will be presented. It is a perennial plant with a deep root system and it is widely grown throughout the world as forage for cattle. The samples of Lucerne were taken from twelve different locations in Vojvodina in the summer period July-September 2004. The samples were specially dried on the air and after that ground, powdered and mineralized by method of dry burning on the temperature of 450 deg. C. Gamma spectrometry measurements of the ash were performed by means of actively shielded germanium detector with maximal background reduction. For cesium 137Cs 10 mBq/kg order of magnitude detection limits were achieved.

Fokapic, S.; Bikit, I.; Mrda, D.; Veskovic, M.; Slivka, J. [Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 4, 21 000 Novi Sad (Serbia); Mihaljev, Z. [Scientific Veterinary Institute, Rumenacki put 20, 21 000 Novi Sad (Serbia); Cupic, Z. [Research Institute for Reproduction, A.I. and Embryo Transfer Temerin, 21235 Temerin, Industrijska zona bb. (Serbia)

2007-04-23T23:59:59.000Z

35

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

SciTech Connect (OSTI)

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.

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

2011-05-17T23:59:59.000Z

36

Indoor and Outdoor in Situ High-Resolution Gamma Radiation Measurements in Urban Areas of Cyprus  

E-Print Network [OSTI]

In situ, high-resolution, gamma-ray spectrometry of a total number of 70 outdoor and 20 indoor representative measurements were performed in preselected, common locations of the main urban areas of Cyprus. Specific activities and gamma absorbed dose rates in air due to the naturally occurring radionuclides of Th-232 and U-238 series, and K-40 are determined and discussed. Effective dose rate to the Cyprus population due to terrestrial gamma radiation is derived directly from this work. The results obtained outdoors match very well with those derived previously by high-resolution gamma spectrometry of soil samples, which were collected from the main island bedrock surface. This implies that the construction and building materials in urban areas do not affect the external gamma dose rate; thus they are mostly of local origin. Finally, the indoor/outdoor gamma dose ratio was found to be 1.4 +- 0.5.

E. Svoukis; H. Tsertos

2006-10-02T23:59:59.000Z

37

Automotive Component Measurements forAutomotive Component Measurements for Determining VehicleDetermining Vehicle--Level RadiatedLevel Radiated  

E-Print Network [OSTI]

1 Automotive Component Measurements forAutomotive Component Measurements for Determining VehicleDetermining Vehicle--Level RadiatedLevel Radiated Automotive Component Measurements forAutomotive ComponentEmissionsEmissionsEmissions Todd Hubing Mi h li P f f V hi l El t iMichelin Professor of Vehicular Electronics Clemson University

Stuart, Steven J.

38

What is the radiative process of the prompt phase of Gamma Ray Bursts?  

SciTech Connect (OSTI)

Despite the dramatic improvement of our knowledge of the phenomenology of Gamma Ray Bursts, we still do not know several fundamental aspects of their physics. One of the puzzles concerns the nature of the radiative process originating the prompt phase radiation. Although the synchrotron process qualifies itself as a natural candidate, it faces severe problems, and many efforts have been done looking for alternatives. These, however, suffer from other problems, and there is no general consensus yet on a specific radiation mechanism.

Ghisellini, G. [INAF-Osservatorio Astronomico di Brera, Via Bianchi 46 I-23807 Merate (Italy)

2010-07-15T23:59:59.000Z

39

Influence of relaxation transitions on radiation-initiated cationic graft polymerization. [Gamma radiation  

SciTech Connect (OSTI)

Radiation grafting of vinyl n-butyl ether (VBE) to polyvinyl chloride (PVC) over a broad temperature range was investigated. The relaxation transitions in the PVC/VBE system were also determined. Grafting of vinyl alkyl ethers proceeds entirely by a cationic mechanism in a reaction medium that has been dried to a water concentration no greater than 0.1-1.0 ppm. In this connection, the diffusion properties of water in the temperature region were studied. Commercial films of unplasticized PVC (thickness 200 M); were subjected to swelling in two systems: in a 50% solution of VBE in benzene at 25/sup 0/C, and in the pure monomer at 40/sup 0/C. The reaction mixtures were first dried over metallic sodium in a deaerated atmosphere. The specimens were irradiated in a Co gamma-radiation unit to a dose of 10 kGy at a dose rate of 3 Gy/sec. The first reaction mixture was investigated over a range of temperatures from -60/sup 0/ to +70/sup 0/C, and the second from -15/sup 0/ to +50/sup 0/C. The degree of grafting was determined from the increase in weight of the original ungrafted film. The temperature was held to within +/-1/sup 0/C. The relaxation transitions in the swollen polymer systems were determined by two methods, thermostimulated current (TSC) and thermomechanics (TM). It was found that in the region of the glass transition of a swollen PVC-VBE system, radiation-initiated cationic graft polymerization proceeds at a maximal rate, and there are changes in state of the water molecules (the agents of breaking the ion reaction chain) and in their diffusion properties within the matrix.

Kudryavtsev, V.N.; Kabanov, V.Ya.; Chalykh, A.E.; Spitsyn, V.I.

1982-05-01T23:59:59.000Z

40

Cancer incidence in areas with elevated levels of natural radiation  

Science Journals Connector (OSTI)

It has been reported that on reaching a certain level of cell damage the production of repair enzymes is triggered which decreases the chromosome aberrations. If this happens, prolonged exposure to high levels of natural radiation in areas with elevated levels of background radiation could decrease the frequency of chromosome aberrations. Recent epidemiological studies indicated that there is an increased risk of cancer in healthy individuals with high levels of chromosomal aberrations. Studies performed in Nordic countries as well as Italy, showed that increased levels of chromosome aberrations in lymphocytes can be used to predict cancer risk in humans. One may conclude that a dose of ionising radiation sufficient to produce a certain level of cell damage increases production of antioxidants and repair enzymes that decrease either the frequency of chromosome aberrations or the cancer risk. People in some areas of Ramsar, a city in northern Iran, receive an annual radiation dose from background radiation that is more than five times higher than the 20 mSv. Yr-1 that is permitted for radiation workers. Inhabitants of Ramsar have lived for many generations in these high background areas. If an annual radiation dose of a few hundred mSv is detrimental to health, causing genetic abnormalities or an increased risk of cancer, it should be evident in these people. The absorbed dose rate in some high background radiation areas of Ramsar is approximately 55-200 times higher than that of the average global dose rate. It has been reported that 3â??8% of all cancers are caused by current levels of ionising radiation. If this estimation were true, all the inhabitants of such an area with extraordinary elevated levels of natural radiation would have died of cancer. Our cytogenetic studies show no significant differences between people in the high background area compared to people in normal background areas. As there was no increased level of chromosome aberrations, it may be predicted that the cancer incidence is not higher than in the neighbouring areas with a normal background radiation level. Although there is not yet solid epidemiological information, most local physicians in Ramsar report anecdotally that there is no increase in the incidence rates of cancer or leukemia in their area. There are no data to indicate a significant increase of cancer incidence in other high background radiation areas (HBRAs). Furthermore, several studies show a significant decrease of cancer death rates in areas with high backgrounds. It can be concluded that prolonged exposure to high levels of natural radiation possibly triggers processes such as the production of antioxidants and repair enzymes, which decreases the frequency of chromosome aberrations and the cancer incidence rate.

S.M.J. Mortazavi; M. Ghiassi-Nejad; P.A. Karam; T. Ikushima; A. Niroomand-Rad; J.R. Cameron

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Radiation levels on empty cylinders containing heel material  

SciTech Connect (OSTI)

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.

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

1991-12-31T23:59:59.000Z

42

Gamma radiation induced degradation in PE-PP block copolymer  

SciTech Connect (OSTI)

In the present investigation, effect of gamma irradiation on the PP-PE block copolymer has been studied. The polymer has been subjected to gamma irradiation from 100 to 500 Mrad dosages. Characterization of the polymer using XRD and FTIR was done both before irradiation and after irradiation in each step. Effect of irradiation on the electrical properties of the material has also been studied. FTIR study shows that the sample loses C - C stretching mode of vibration but gains C=C stretching mode of vibration after irradiation. Present investigation clearly indicates that though the electrical conductivity increases in the material, it undergoes degradation and shows brittleness due to irradiation.

Ravi, H. R.; Sreepad, H. R.; Ahmed, Khaleel; Govindaiah, T. N. [P.G. Department of Physics, Government College (Autonomous), Mandya - 571401, Karnataka State (India)

2012-06-05T23:59:59.000Z

43

Effects of low levels of radiation on humans  

SciTech Connect (OSTI)

The state of knowledge on effects of low-level ionizing radiations on humans is reviewed. Several problems relating to dose thresholds or lack of thresholds for several types of cancer and high LET radiations and the effects of fractionation and dose protection are discussed. (ACR)

Auxier, J.A.

1981-01-01T23:59:59.000Z

44

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

E-Print Network [OSTI]

a region of current filamentation, and show that the jitter radiation may be used as a radiative diagnostic to determine features of the magnetic field distribution within this region. For gamma-ray bursts, this instability may play a significant...

Reynolds, Sarah J

2012-05-31T23:59:59.000Z

45

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.

46

Radiative energy shifts of an accelerated two-level system  

Science Journals Connector (OSTI)

We consider the influence of acceleration on the radiative energy shifts of atoms in Minkowski space. We study a two-level atom coupled to a scalar quantum field. Using a Heisenberg picture approach, we are able to separate the contributions of vacuum fluctuations and radiation reaction to the Lamb shift of the two-level atom. The resulting energy shifts for the special case of a uniformly accelerated atom are then compared with those of an atom at rest.

Jürgen Audretsch and Rainer Müller

1995-07-01T23:59:59.000Z

47

Radiation detection system for portable gamma-ray spectroscopy  

DOE Patents [OSTI]

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.

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

2006-06-20T23:59:59.000Z

48

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

E-Print Network [OSTI]

This study was undertaken to gain a greater understanding of the effects of gamma radiation and storage at 2'C on the microbiological, sensorial and chemical quality of pico de gallo. Samples of pico de gallo were exposed to cobalt'o at a dose of I...

Miller, Gerald Howard

1994-01-01T23:59:59.000Z

49

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

SciTech Connect (OSTI)

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.

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)

2012-08-10T23:59:59.000Z

50

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

SciTech Connect (OSTI)

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.

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

2013-03-10T23:59:59.000Z

51

Gamma ray bursts may be blueshifted bundles of the relic radiation  

E-Print Network [OSTI]

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

Krasi?ski, Andrzej

2015-01-01T23:59:59.000Z

52

Gamma ray bursts may be blueshifted bundles of the relic radiation  

E-Print Network [OSTI]

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

Andrzej Krasi?ski

2015-02-02T23:59:59.000Z

53

Reduction of Quark Mass Scheme Dependence in B bar -> Xs gamma at the NNLL Level  

SciTech Connect (OSTI)

The uncertainty of the theoretical prediction of the B {yields} X{sub s}{gamma} branching ratio at NLL level is dominated by the charm mass renormalization scheme ambiguity. In this paper we calculate those NNLL terms which are related to the renormalization of m{sub c}, in order to get an estimate of the corresponding uncertainty at the NNLL level. We find that these terms significantly reduce (by typically a factor of two) the error on BR(B {yields} X{sub s}{gamma}) induced by the definition of m{sub c}. Taking into account the experimental accuracy of around 10% and the future prospects of the B factories, we conclude that a NNLL calculation would increase the sensitivity of the observable B {yields} X{sub s}{gamma} to possible new degrees of freedom beyond the SM significantly.

Asatrian, H.M.; /Yerevan Phys. Inst.; Greub, C.; /Bern U.; Hovhannisyan, A.; /Yerevan Phys. Inst.; Hurth, T.; /CERN /SLAC; Poghosyan, V.; /Yerevan Phys. Inst.

2005-06-20T23:59:59.000Z

54

Results of calculations of external gamma radiation exposure rates from fallout and related radionuclide compositions. Operation Teapot, 1955  

SciTech Connect (OSTI)

This report presents data on calculated gamma radiation exposure rates and ground deposition of related radionuclides resulting from events that deposited detectable radioactivity outside the Nevada Test Site complex.

Hicks, H.G.

1981-07-01T23:59:59.000Z

55

P ORNiiTM-7004 Results of Ground Level Radiation  

Office of Legacy Management (LM)

ORNiiTM-7004 ORNiiTM-7004 Results of Ground Level Radiation Measurements in Support of the 1978 Aerial Survey of the Lake Ontario Ordnance W o rks, Lewiston, New York _ ict~~.. By A, grven _, ,_~ ~.~ _,. :::;(' ~. . ' -- .- ,. R. W . Doane F. F. Haywood W . H. Shinpaugh ORNL/TM-7004 Dist. Category UC-41 Contract No. W-7405eng-26 RESULTS OF GROUND LEVEL RADIATION MEASUREMENTS IN SUPPORT OF THE 1978 AERIAL SURVEY OF THE LAKE ONTARIO ORDNANCE WORKS, LEWISTON, NEW YORK B. A. Berven F. F. Haywood R. W. Doane W. H. Shinpaugh Work performed by Health and Safety Research Division Date Published: September 1979 Oak Ridge National Laboratory Oak Ridge, Tennessee 37830 operated by UNION CARBIDE CORPORATION for the DEPARTMENT OF ENERGY as part of the Formerly Utilized Sites -

56

Operation of {sup 3}He Proportional Chambers in High Gamma Radiation Fields  

SciTech Connect (OSTI)

Operation of {sup 3}He proportional chambers with irradiated fissile materials is limited because of the sensitivity of these chambers to gamma ray events. The optimum performance of these chambers is achieved with proper selection of an additive gas to the chambers and with proper choice of preamplifier and linear amplifier time constants. The counting efficiency of a 4-atm, {sup 3}He-CO2 chamber is improved from 35% to 43% in a 200 R/hr gamma radiation field by decreasing the linear amplifier time constant. Likewise, the counting efficiency of a 1-atm, {sup 3}He-CF4 is improved from 11% to 14% in a 200 R/hr gamma radiation field by decreasing the linear amplifier time constant. The 4-atm, {sup 3}He-CO2 1-in.-OD chamber has a higher efficiency than the 1-atm, {sup 3}He-CF4 1-in.-OD chamber although the energy resolution of the 3 He-CF4 chamber is better than that for the {sup 3}He-CO2 chamber.

Hill, N.W.; Miller, V.C.; Valentine, T.E.; Williams, J.A.

1999-09-01T23:59:59.000Z

57

Gamma spectroscopic measurements using the PID350 pixelated CdTe radiation detector  

E-Print Network [OSTI]

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

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

2010-01-01T23:59:59.000Z

58

Determination of the natural radioactivity levels in north west of Dukhan, Qatar using high-resolution gamma-ray spectrometry  

Science Journals Connector (OSTI)

This study is aimed at the determination of the activity concentrations of naturally occuring and technologically enhanced levels of radiation in 34 representative soil samples that have been collected from an inshore oil field area which was found to have, in a previous study, the highest observed value of 226Ra concentration among 129 soil samples. The activity concentrations of 238U and 226Ra have been inferred from gamma-ray transitions associated with their decay progenies and measured using a hyper-pure germanium detector. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented, together with the values of the activity concentrations associated with the naturally occuring radionuclide chains for all the samples collected from NW Dukhan. Discrete-line, gamma-ray energy transitions from spectral lines ranging in energy from ?100 keV up to 2.6 MeV have been associated with characteristic decays of the various decay products within the 235.8U and 232Th radioactive decay chains. These data have been analyzed, under the assumption of secular equilibrium for the U and Th decay chains. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented. The weighted mean value of the activity concentrations of 226Ra in one of the samples was found to be around a factor of 2 higher than the values obtained in the previous study and approximately a factor of 10 higher than the accepted worldwide average value of 35 Bq/kg. The weighted mean values of the activity concentrations of 232Th and 40K were also deduced and found to be within the worldwide average values of 30 and 400 Bq/kg, respectively. Our previous study reported a value of 201.9±1.5Stat.±13Syst. Bq/kg for 226Ra in one sample and further investigation in the current work determined a measured value for 226Ra of 342.00±1.9Stat.±25Syst. Bq/kg in a sample taken from the same locality. This is significantly higher than all the other investigated soil samples in the current and previous works. Notably, the Th levels in the same sample are within the worldwide average expectations, implying that the increased 226Ra concentration arises from TENORM processes.

Huda Al-Sulaiti; Tabassum Nasir; K.S. Al Mugren; N. Alkhomashi; N. Al-Dahan; M. Al-Dosari; D.A. Bradley; S. Bukhari; M. Matthews; P.H. Regan; T. Santawamaitre; D. Malain; A. Habib

2012-01-01T23:59:59.000Z

59

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

SciTech Connect (OSTI)

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.

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

1981-11-01T23:59:59.000Z

60

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

E-Print Network [OSTI]

embrittlement by decreasing overall corrosion and/or by decreasing the amount of hydrogen ingress for a givenCold neutron prompt gamma activation analysis, a non-destructive technique for hydrogen level to quantitatively assess hydrogen concentration in zirconium alloys. The technique, called Cold Neutron Prompt Gamma

Motta, Arthur T.

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Design and Testing of a Novel Wide Range - Segmented Gamma Scanner Incorporating Tomographic Gamma Scanning for Measuring Both Low and Intermediate Level Waste in Drums - 13470  

SciTech Connect (OSTI)

This paper describes the design and testing of a novel automated Wide Range Segmented Gamma ray Scanning (WR-SGS) assay instrument that also incorporates Tomographic Gamma Scanning (TGS). The instrument is designed for the measurement of both Low and Intermediate Level Waste (LLW and ILW) in 200 litre drums and other waste containers covering a wide range of density. Like earlier ANTECH WR-SGS instruments, the system employs a single shielded and collimated high purity germanium (HPGe) detector to quantify the radionuclide content of the waste and like conventional SGS instruments it is suitable for the measurement of relatively homogeneous waste matrices. Also, like earlier WR-SGS systems the instrument incorporates an automated variable aperture collimator, which allows the vertical segment height to be adjusted in order to measure both high dose-rate and very low activity drums. The instrument employs both conventional discrete SGS vertical segment measurements as well as vertical segment measurement by continuous helical-scanning of the drum as it rotates. This latter method reduces measurement times for SGS measurements. In order to determine the density corrections for both low and high-density drums, a high activity Eu-152 transmission source is employed. When not in use, and in place of a conventional shutter mechanism, the shielded transmission source is moved to a shielded storage position to eliminate background radiation from the source. Due to its novel features, the WR-SGS is applicable to the measurement of both very low and very high activity waste drums as well as waste drums with a wide range of density. If located in a low background position and with the effective shielding of the strong transmission source, the instrument can be used to measure very low level or exempt waste. In order to extend the range of applicability to the measurement of heterogeneous drums, TGS measurement capability has been included in the basic WR-SGS design. This is achieved by adding horizontal motion to the waste drum rotation platform and incorporating TGS collimation into the variable aperture collimator, as well as a filter to reduce the detector signal when straight-through measurements are made using the strong transmission source. Test measurements are presented of the system operating in both SGS and TGS modes using different drum densities and source strengths. The test measurement results are compared with benchmarked MCNP Monte Carlo calculations. The Wide Range SGS - TGS instrument extends the range of both activity and density that can be measured in 200 and 340 litre drums. (authors)

Mason, John A.; Looman, Marc R.; Odell, Lawrence V.; Poundall, Adam J.; Towner, Antony C.N. [ANTECH, A. N. Technology Ltd., Unit 6, Thames Park, Wallingford, Oxfordshire, OX10 9TA (United Kingdom)] [ANTECH, A. N. Technology Ltd., Unit 6, Thames Park, Wallingford, Oxfordshire, OX10 9TA (United Kingdom); Hong, Dae-Seok; Jang, Won-Hyuk; Kwak, Kyung-Kil [Korea Atomic Energy Research Institute, 111, Daedoek-daero 989 beon-gil, Yuseong-gu, Daejeon (Korea, Republic of)] [Korea Atomic Energy Research Institute, 111, Daedoek-daero 989 beon-gil, Yuseong-gu, Daejeon (Korea, Republic of); Seo, Seung-Min [Young In Scientific Co. Ltd, 22, Apgujeong-ro 28 gil, Gangnam-gu, Seoul (Korea, Republic of)] [Young In Scientific Co. Ltd, 22, Apgujeong-ro 28 gil, Gangnam-gu, Seoul (Korea, Republic of); Piotrowski, Matt [ANTECH Corporation, 9050 Marshall Court, Westminster, CO, 80031 (United States)] [ANTECH Corporation, 9050 Marshall Court, Westminster, CO, 80031 (United States)

2013-07-01T23:59:59.000Z

62

Polyaniline/poly acid acrylic thin film composites: a new gamma radiation detector  

SciTech Connect (OSTI)

In this paper, we present a new and straightforward route to prepare polyaniline/poly acid acrylic (PAA) thin film composites in large areas and on almost any surface. This method was developed to improve the mechanical and adherence properties of polyaniline devices used as ionization radiation sensors. The route consists of the combination of the metal oxidant with polymer acid to form a highly homogeneous and viscous paste, which can be easily spread over any surface. In the second step, an aniline acid solution is brought in contact with the dried paste where polymerization occurs, yielding a high homogeneous and conducting polymer composite. The UV-visible absorption and infrared analysis confirm that a polyaniline/PAA complex is obtained. The four-point conductivity measurements show that the composite conductivity {rho} is the order of 5 {omega}{sup -1} cm{sup -1}. Preliminary gamma radiation interaction with the composite shows that the doped composite exhibits a linear response that can be used in the development of real-time radiation sensors for the dose range from 0 to 5000 Gy.

Lima Pacheco, Ana P.; Araujo, Elmo S.; Azevedo, Walter M. de

2003-03-15T23:59:59.000Z

63

Performance of e/$\\gamma$-based Triggers at the CMS High Level Trigger  

E-Print Network [OSTI]

The CMS experiment has been designed with a two-level trigger system: the Level 1 (L1) Trigger, implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS reconstruction and analysis software running on a computer farm. In order to achieve a good rate reduction with as little as possible impact on the physics efficiency, the algorithms used at HLT are designed to follow as closely as possible the ones used in the offline reconstruction. Here, we will present the algorithms used for the online reconstruction of electrons and photons (e/$\\gamma$), both at L1 and HLT, and their performance and the planned improvements of these HLT objects.

Demiragli, Zeynep

2014-01-01T23:59:59.000Z

64

Very High Energy Gamma Rays from Supernova Remnants and Constraints on the Galactic Interstellar Radiation Field  

SciTech Connect (OSTI)

The large-scale Galactic interstellar radiation field (ISRF) is the result of stellar emission and dust re-processing of starlight. Where the energy density of the ISRF is high (e.g., the Galactic Centre), the dominant {gamma}-ray emission in individual supernova remnants (SNRs), such as G0.9+0.1, may come from inverse Compton (IC) scattering of the ISRF. Several models of the ISRF exist. The most recent one, which has been calculated by us, predicts a significantly higher ISRF than the well used model of Mathis, Mezger, and Panagia [1]. However, comparison with data is limited to local observations. Based on our current estimate of the ISRF we predict the gamma-ray emission in the SNRs G0.9+0.1 and RXJ1713, and pair-production absorption features above 20 TeV in the spectra of G0.9+0.1, J1713-381, and J1634-472. We discuss how GLAST, along with current and future very high energy instruments, may be able to provide upper bounds on the large-scale ISRF.

Porter, T.A.; Moskalenko, I.V.; Strong, A.W.

2007-04-30T23:59:59.000Z

65

Very High Energy Gamma Rays from Supernova Remnants and Constraints on the Galactic Interstellar Radiation Field  

E-Print Network [OSTI]

The large-scale Galactic interstellar radiation field (ISRF) is the result of stellar emission and dust re-processing of starlight. Where the energy density of the ISRF is high (e.g., the Galactic Centre), the dominant gamma-ray emission in individual supernova remnants (SNRs), such as G0.9+0.1, may come from inverse Compton (IC) scattering of the ISRF. Several models of the ISRF exist. The most recent one, which has been calculated by us, predicts a significantly higher ISRF than the well-used model of Mathis, Mezger, and Panagia. However,comparison with data is limited to local observations. Based on our current estimate of the ISRF we predict the gamma-ray emission in the SNRs G0.9+0.1 and RXJ1713, and pair-production absorption features above 20 TeV in the spectra of G0.9+0.1, J1713-381, and J1634-472. We discuss how GLAST, along with current and future very high energy instruments, may be able to provide upper bounds on the large-scale ISRF.

Porter, T A; Strong, A W

2007-01-01T23:59:59.000Z

66

Very High Energy Gamma Rays from Supernova Remnants and Constraints on the Galactic Interstellar Radiation Field  

E-Print Network [OSTI]

The large-scale Galactic interstellar radiation field (ISRF) is the result of stellar emission and dust re-processing of starlight. Where the energy density of the ISRF is high (e.g., the Galactic Centre), the dominant gamma-ray emission in individual supernova remnants (SNRs), such as G0.9+0.1, may come from inverse Compton (IC) scattering of the ISRF. Several models of the ISRF exist. The most recent one, which has been calculated by us, predicts a significantly higher ISRF than the well-used model of Mathis, Mezger, and Panagia. However,comparison with data is limited to local observations. Based on our current estimate of the ISRF we predict the gamma-ray emission in the SNRs G0.9+0.1 and RXJ1713, and pair-production absorption features above 20 TeV in the spectra of G0.9+0.1, J1713-381, and J1634-472. We discuss how GLAST, along with current and future very high energy instruments, may be able to provide upper bounds on the large-scale ISRF.

T. A. Porter; I. V. Moskalenko; A. W. Strong

2007-04-13T23:59:59.000Z

67

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

SciTech Connect (OSTI)

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

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

2007-01-01T23:59:59.000Z

68

GRABGAM: A Gamma Analysis Code for Ultra-Low-Level HPGe SPECTRA  

SciTech Connect (OSTI)

The GRABGAM code has been developed for analysis of ultra-low-level HPGe gamma spectra. The code employs three different size filters for the peak search, where the largest filter provides best sensitivity for identifying low-level peaks and the smallest filter has the best resolution for distinguishing peaks within a multiplet. GRABGAM basically generates an integral probability F-function for each singlet or multiplet peak analysis, bypassing the usual peak fitting analysis for a differential f-function probability model. Because F is defined by the peak data, statistical limitations for peak fitting are avoided; however, the F-function does provide generic values for peak centroid, full width at half maximum, and tail that are consistent with a Gaussian formalism. GRABGAM has successfully analyzed over 10,000 customer samples, and it interfaces with a variety of supplementary codes for deriving detector efficiencies, backgrounds, and quality checks.

Winn, W.G.

1999-07-28T23:59:59.000Z

69

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

E-Print Network [OSTI]

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

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

2012-05-01T23:59:59.000Z

70

Comparative investigations of sodium arsenite, arsenic trioxide and cadmium sulphate in combination with gamma-radiation on apoptosis, micronuclei induction and DNA damage in a human lymphoblastoid cell line  

Science Journals Connector (OSTI)

In the field of radiation protection the combined exposure to radiation and other toxic agents is recognised as an important research area. To elucidate the basic mechanisms of simultaneous exposure, the interaction of the carcinogens and environmental toxicants cadmium and two arsenic compounds, arsenite and arsenic trioxide, in combination with gamma-radiation in human lymphoblastoid cells (TK6) were investigated. Gamma-radiation induced significant genotoxic effects such as micronuclei formation, DNA damage and apoptosis, whereas arsenic and cadmium had no significant effect on these indicators of cellular damage at non-toxic concentrations. However, in combination with gamma-radiation arsenic trioxide induced a more than additive apoptotic rate compared to the sum of the single effects. Here, the level of apoptotic cells was increased, in a dose-dependent way, up to two-fold compared to the irradiated control cells. Arsenite did not induce a significant additive effect at any of the concentrations or radiation doses tested. On the other hand, arsenic trioxide was less effective than arsenite in the induction of DNA protein cross-links. These data indicate that the two arsenic compounds interact through different pathways in the cell. Cadmium sulphate, like arsenite, had no significant effect on apoptosis in combination with gamma-radiation at low concentrations and, at high concentrations, even reduced the radiation-induced apoptosis. An additive effect on micronuclei induction was observed with 1 ?M cadmium sulphate with an increase of up to 80% compared to the irradiated control cells. Toxic concentrations of cadmium and arsenic trioxide seemed to reduce micronuclei induction. The results presented here indicate that relatively low concentrations of arsenic and cadmium, close to those occuring in nature, may interfere with radiation effects. Differences in action of the two arsenic compounds were identified.

Sabine Hornhardt; Maria Gomolka; Linda Walsh; Thomas Jung

2006-01-01T23:59:59.000Z

71

Sandia National Laboratories: Research: Facilities: Gamma Irradiation  

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

Gamma Irradiation Facility Gamma Irradiation Facility Photo of Gamma Irradiation Facility The Gamma Irradiation Facility (GIF) provides high-fidelity simulation of nuclear radiation environments for materials and component testing. The low-dose irradiation facility also offers an environment for long-duration testing of materials and electronic components. Such testing may take place over a number of months or even years. Research and other activities The single-structure GIF can house a wide variety of gamma irradiation experiments with various test configurations and at different dose and dose rate levels. Radiation fields at the GIF are produced by high-intensity gamma-ray sources. To induce ionizing radiation effects and damage in test objects, the objects are subjected to high-energy photons from gamma-source

72

The influence of {gamma}-ray radiation on electrical properties of CuGaSe{sub 2}  

SciTech Connect (OSTI)

The effect of {gamma}-ray radiation on the conductivity of low-resistivity (10{sup 2}2-10{sup 4} {Omega} cm) and high-resistivity (10{sup 5}-10{sup 7} {Omega} cm) CuGaSe{sub 2} single crystals has been studied in the temperature range 77-330 K. It is found that the resistivity of low-resistivity samples increases as the dose of {gamma}-ray radiation is increased, while the resistivity of high-resistivity samples is practically independent of the radiation dose. It is assumed that a decrease in the conductivity of the low-resistivity samples occurs owing to scattering of free charge carriers at defects (charged centers) formed as a result of irradiation with {gamma}-ray photons. It is found that the dose of the {gamma}-ray irradiation does not affect the temperature dependence of resistivity in the low- and high-resistivity samples in the temperature range 77-300 K.

Kasumoglu, I.; Kerimova, T. G., E-mail: ktaira@physics.ab.az; Mamedova, I. A. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan)

2011-01-15T23:59:59.000Z

73

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

SciTech Connect (OSTI)

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.

Shokair, Isaac R.

2011-09-01T23:59:59.000Z

74

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

SciTech Connect (OSTI)

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.

Troyer, G.L.

1997-03-17T23:59:59.000Z

75

E-Print Network 3.0 - area gamma radiation Sample Search Results  

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

POWER LAW SPECTRA OF GAMMARAY BURSTS Summary: SMOOTHLY BROKEN POWER LAW SPECTRA OF GAMMA-RAY BURSTS F. Ryde Stockholm Observatory, SE-133 36... . It is used to fit Gamma-Ray Burst...

76

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

DOE Patents [OSTI]

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.

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

2012-09-04T23:59:59.000Z

77

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)

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.

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

1985-07-01T23:59:59.000Z

78

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

E-Print Network [OSTI]

Abstract-- We have recently completed a large-area, coded- aperture, gamma-ray imager for use. The in- strument uses a rank-19, one-dimensional coded aperture to cast shadow patterns onto a 0.57 m2 Na sufficient radiation can reach a large gamma-ray detec- tor from a small source to make detection possible

Horn, Berthold K.P.

79

Radioactivity level in soil of a palaeo beach in the south-eastern part of Bangladesh and evaluation of radiation hazard  

Science Journals Connector (OSTI)

......outdoor and indoor radiation hazard indices...annual effective dose rates. MATERIALS...Denundation of the Bay of Bengal extending along...kg). Gamma radiation hazard indices...based on the estimation that 1 Bq kg...gamma radiation dose rates. The index......

Ashna Islam; Mahfuza Sharifa Sultana; Aleya Begum; Selina Yeasmin

2013-12-01T23:59:59.000Z

80

Solid low-level radioactive waste radiation stability studies  

E-Print Network [OSTI]

properties and condition; on the other, on the specific features of thermal and radiation influences on it (Spitsyn et al. 1983). For the average composition of the fission products going to wastes repositories, the mean energy of irradiation may vary from... to the container determines, in part, the life of the container. Cormsion studies of containers by solidified wastes has indicated no problem areas in limited measurements to date; however very long-term effects have not been evaluated. The useful life...

Williams, Arnold Andre?

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

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

SciTech Connect (OSTI)

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)

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

2008-05-15T23:59:59.000Z

82

Gamma radiation and dose rate investigations on the Adriatic islands of magmatic origin  

Science Journals Connector (OSTI)

......Gamma ray spectrometry in seawater The underwater measuring system...electronics for data acquisition, storage and transmission. The power...direct gamma ray spectrometry in seawater, the obtained spectrum from...spectrometric measurement in the seawater. Isotope Energy (keV) Net......

Branko Petrinec; Zdenko Franic; Nenad Leder; Christos Tsabaris; Tomislav Bituh; Gordana Marovic

2010-06-01T23:59:59.000Z

83

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

SciTech Connect (OSTI)

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

Li, Jing; Vitusevich, Svetlana; Pud, Sergii; Sydoruk, Viktor; Offenhäusser, Andreas [Peter Grünberg Institute, Forschungszentrum Jülich (Germany); Petrychuk, Mykhailo [Taras Shevchenko National University, Kiev (Ukraine); Danilchenko, Boris [Institute of Physics, NASU, Kiev (Ukraine)

2013-12-04T23:59:59.000Z

84

Core-level photoemission of the Si(1 1 1) surface using synchrotron radiation  

E-Print Network [OSTI]

-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan c Synchrotron Radiation Laboratory, The Institute of Solid StateCore-level photoemission of the Si(1 1 1)± 21 p � 21 p -Ag surface using synchrotron radiation, Wako-shi, Saitama 351-0198, Japan b Department of Physics, School of Science, University of Tokyo, 7

Hasegawa, Shuji

85

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

SciTech Connect (OSTI)

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.

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.

1989-06-01T23:59:59.000Z

86

Study of the radiative decay J/psi. -->. gamma. eta. pi. /sup +/. pi. /sup -/  

SciTech Connect (OSTI)

The Mark III collaboration has performed a high statistics study of the reaction J/psi ..-->.. ..gamma..eta..pi../sup +/..pi../sup -/, with two different final states of the eta, eta ..-->.. ..gamma gamma.. and eta ..-->.. ..pi../sup 0/..pi../sup +/..pi../sup -/. Both modes have a broad structure from 1.2 to 1.9 GeV/c/sup 2/ and two structures, which decay via delta/sup + -/..pi../sup - +/, delta/sup + -/ ..-->.. eta..pi../sup + -/, are identified at 1.28 and 1.39 GeV/c/sup 2/. No signal is observed in the iota(1440) signal region.

Becker, J.J.; Blaylock, G.T.; Bolton, T.; Brown, J.S.; Bunnell, K.O.; Burnett, T.H.; Cassell, R.E.; Coffman, D.; Cook, V.; Coward, D.H.

1987-02-01T23:59:59.000Z

87

E-Print Network 3.0 - accompanying gamma radiation Sample Search...  

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

in which they deliver... emission. This is often, but not always, accompanied by gamma ray emission. There are a few excited states... -9117 (734) 763-4540 fax kearfott@umich.edu...

88

Determining the Impact of Concrete Roadways on Gamma Ray Background Readings for Radiation Portal Monitoring Systems  

E-Print Network [OSTI]

locations have reported abnormally high gamma background count rates. The higher background data has been attributed, in part, to the concrete surrounding the portal monitors. Higher background can ultimately lead to more material passing through the RPMs...

Ryan, Christopher Michael

2012-07-16T23:59:59.000Z

89

Extending the response of the sum coincidence spectrometer to multiple gamma radiation cascades  

E-Print Network [OSTI]

). crystal of sodium iodide with the sample placed inside of it is used. For larger crystals there is less probability of part of the gamma-ray energy escaping. This method gives a high detection efficiency; however, the resolution of large crystals can... be limited by light collection problems. For precision gamma-ray spectroscopy, high resolution out-weighs the disadvantage of low detection efficiency. The three-crystal scintillation spectrometer, developed by Maieschein' and Bair5, gives higher counting...

Helton, Victor Dean

1964-01-01T23:59:59.000Z

90

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

E-Print Network [OSTI]

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

Martin Pohl; Reinhard Schlickeiser

1999-11-24T23:59:59.000Z

91

GammaSense: Infrastructureless Positioning Using Background Radioactivity  

Science Journals Connector (OSTI)

We introduce the harvesting of natural background radioactivity for positioning. Using a standard Geiger-Müller counter as sensor, we fingerprint the natural levels of gamma radiation with the aim of then roughly pinpointing the position of a client ...

Doina Bucur; Mikkel Baun Kjærgaard

2008-10-01T23:59:59.000Z

92

Enhancement of natural background gamma-radiation dose around uranium microparticles in the human body  

Science Journals Connector (OSTI)

...photoelectrons. For most ionizing radiations, a large proportion...the absorbed dose is deposited...having a shorter range and being more strongly ionizing close to the...in high local doses, causing damage...enhancement of the radiation dose in volumes...

2010-01-01T23:59:59.000Z

93

FY08 Annual Report: Amorphous Semiconductors for Gamma Radiation Detection (ASGRAD)  

SciTech Connect (OSTI)

This is the annual report for an old project funded by NA22. The purpose of the project was to develop amorphous semiconductors for use as radiation detectors. The annual report contains information about the progress made in synthesizing, characterizing, and radiation response testing of these new materials.

Johnson, Bradley R.; Riley, Brian J.; Crum, Jarrod V.; Ryan, Joseph V.; Sundaram, S. K.; McCloy, John S.; Rockett, Angus

2009-02-01T23:59:59.000Z

94

Red shift in spectra of galaxies as a consequence of gravitational radiation of the same level as electromagnetic  

E-Print Network [OSTI]

In elaboration of the results presented earlier the red shift is also regarded in this investigation as a widening of electromagnetic radiation spectra, determined by the existence of gravitational radiation of a banded spectrum of the same level as electromagnetic.

S. I. Fisenko; I. S. Fisenko

2010-01-07T23:59:59.000Z

95

OBSERVATIONAL SIGNATURES OF SUB-PHOTOSPHERIC RADIATION-MEDIATED SHOCKS IN THE PROMPT PHASE OF GAMMA-RAY BURSTS  

SciTech Connect (OSTI)

A shock that forms below the photosphere of a gamma-ray burst (GRB) outflow is mediated by Compton scattering of radiation advected into the shock by the upstream fluid. The characteristic scale of such a shock, a few Thomson depths, is larger than any kinetic scale involved by several orders of magnitude. Hence, unlike collisionless shocks, radiation-mediated shocks cannot accelerate particles to nonthermal energies. The spectrum emitted by a shock that emerges from the photosphere of a GRB jet reflects the temperature profile downstream of the shock, with a possible contribution at the highest energies from the shock transition layer itself. We study the properties of radiation-mediated shocks that form during the prompt phase of GRBs and compute the time-integrated spectrum emitted by the shocked fluid following shock breakout. We show that the time-integrated emission from a single shock exhibits a prominent thermal peak, with the location of the peak depending on the shock velocity profile. We also point out that multiple shock emission can produce a spectrum that mimics a Band spectrum.

Levinson, Amir, E-mail: Levinson@wise.tau.ac.il [School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); JILA, University of Colorado and National Institute of Standards and Technology, 440 UCB, Boulder, CO 80309-0440 (United States)

2012-09-10T23:59:59.000Z

96

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

E-Print Network [OSTI]

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

S. Bonazzola; E. Gourgoulhon

1998-01-16T23:59:59.000Z

97

Estimation of the committed radiation dose resulting from gamma radionuclides ingested with food  

Science Journals Connector (OSTI)

The objective of the study was to estimate the value of the radiation dose absorbed in consequence of consumption of popular food products for individual age groups. Potatoes, corn and sugar beet were selected...

Piotr Gody?; Agnieszka Do?ha?czuk-?ródka…

2014-03-01T23:59:59.000Z

98

An evaluation of commercial IBM PC software for the analysis of low-level environmental gamma-ray spectra  

SciTech Connect (OSTI)

A comparative evaluation of seven commercial gamma-ray analysis software packages, written for the IBM PC, was performed. Four software packages were supplied by US nuclear instrument manufacturers. A fifth package was supplied by a French nuclear instrument manufacturer. Two additional packages were supplied by software companies in the United States and Finland. For this evaluation emphasis was given to accuracy, peak detection, noise and phantom peak rejection for low level environmental sample analysis. System requirements, nuclide identification, ease of operation and other optional utilities were also considered. Of the seven software packages evaluated, two contained the most desirable features required for environmental applications. 9 tabs.

Sanderson, C.G. (International Atomic Energy Agency (Monaco))

1988-01-01T23:59:59.000Z

99

Photon Activation Analysis Of Light Elements Using 'Non-Gamma' Radiation Spectroscopy - The Instrumental Determination Of Phosphorus  

SciTech Connect (OSTI)

Unlike metal determinations the analysis of light elements (e.g., carbon, oxygen, phosphorus) is frequently problematic, in particular if analysed instrumentally. In photon activation analysis (PAA) the respective activation products do not emit gamma radiation in the most cases. Usually, annihilation quanta counting and subsequent decay curve analysis have been used for determinations of C, N, O, and F. However, radiochemical separation of the respective radioisotopes mostly is indispensable. For several reasons, some of the light elements cannot be analysed following this procedure, e.g. phosphorus. In this contribution the instrumental PAA of phosphorus in organic matrix by activation with bremsstrahlung of an electron linear accelerator and subsequent beta spectroscopy is described. The accuracy of the results was excellent as obtained by analysis of a BCR Reference Material.

Segebade, Christian [Idaho Accelerator Centre (IAC), Idaho State University, 1500 Alvin Ricken Drive, Pocatello, ID 83201 (United States); Goerner, Wolf [Bundesanstalt fuer Materialforschung und -pruefung, unter den Eichen 86, 12205 Berlin (Germany)

2011-06-01T23:59:59.000Z

100

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

SciTech Connect (OSTI)

The fundamental nature of mass is one of the greatest mysteries in physics. The Higgs mechanism is a theoretically appealing way to account for the different masses of elementary particles and implies the existence of a new, yet unseen particle, the Higgs boson. We search for evidence of a light scalar (e.g. a Higgs boson) in the radiative decays of the narrow {Upsilon}(3S) resonance: {Upsilon}(3S) {yields} {gamma}A{sup 0}, A{sup 0} {yields} {mu}{sup +}{mu}{sup -}. Such an object appears in extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. 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 product {Beta}({Upsilon}(3S) {yields} {gamma}A{sup 0}) x {Beta}(A{sup 0} {yields} {mu}{sup +}{mu}{sup -}) at (0.25 - 5.2) x 10{sup -6} in the mass range 0.212 {<=} m{sub A{sup 0}} {<=} 9.3 GeV. We also set a limit on the dimuon branching fraction of the {eta}{sub b} meson {Beta}({eta}{sub b} {yields} {mu}{sup +}{mu}{sup -}) < 0.8% at 90% C.L. The results are preliminary.

Aubert, B

2009-06-02T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

CONTRIBUTION OF GAMMA-RAY-LOUD RADIO GALAXIES' CORE EMISSIONS TO THE COSMIC MeV AND GeV GAMMA-RAY BACKGROUND RADIATION  

SciTech Connect (OSTI)

The Fermi gamma-ray satellite has recently detected gamma-ray emissions from radio galaxy cores. From these samples, we first examine the correlation between the luminosities at 5 GHz, L{sub 5GHz}, and at 0.1-10 GeV, L{sub {gamma}}, of gamma-ray-loud radio galaxies. We find that the correlation is significant with L{sub {gamma}}{proportional_to}L{sup 1.16}{sub 5GHz} based on a partial correlation analysis. Using this correlation and the radio luminosity function (RLF) of radio galaxies, we explore the contribution of gamma-ray-loud radio galaxies to the unresolved extragalactic gamma-ray background (EGRB). The gamma-ray luminosity function is obtained by normalizing the RLF to reproduce the source-count distribution of the Fermi gamma-ray-loud radio galaxies. We find that gamma-ray-loud radio galaxies can explain {approx}25% of the unresolved Fermi EGRB flux above 100 MeV and will also make a significant contribution to the EGRB in the 1-30 MeV energy band. Since blazars explain 22% of the EGRB above 100 MeV, radio-loud active galactic nucleus populations explain {approx}47% of the unresolved EGRB. We further make an interpretation on the origin of the EGRB. The observed EGRB spectrum at 0.2-100 GeV does not show an absorption signature by the extragalactic background light. Thus, the dominant population of the origin of EGRB at very high energy (>30 GeV) might be either nearby gamma-ray-emitting sources or sources with very hard gamma-ray spectra.

Inoue, Yoshiyuki, E-mail: yinoue@kusastro.kyoto-u.ac.jp [Department of Astronomy, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)

2011-05-20T23:59:59.000Z

102

Radiative heating of the ISCCP upper level cloud regimes and its impact on the large-scale tropical circulation  

E-Print Network [OSTI]

Radiative heating of the ISCCP upper level cloud regimes and its impact on the large-scale tropical 2012; accepted 14 December 2012; published 31 January 2013. [1] Radiative heating profiles. The resulting radiative heating profiles have maxima of approximately 1 K/day near 12 km, with equal heating

103

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

E-Print Network [OSTI]

. Male Sprague-Dawley rats (15-weeks old, n=32) were randomized to receive an adequate (45 mg Fe/kg diet) or high (650 mg Fe/kg diet) Fe diet for 4 weeks and either 3 Gy (8 fractions, 0.375 Gy each) of 137Cs radiation (?RAD) or sham exposure every other...

Yuen, Evelyn P

2013-04-19T23:59:59.000Z

104

Luffa fibers and gamma radiation as improvement tools of polymer Gonzalo Martnez-Barrera a,  

E-Print Network [OSTI]

, 4200-465 Porto, Portugal c Institute of Mechanical Engineering and Industrial Management (INEGI. The highest bending deformation is obtained with 0.9 wt% of fibers and 100 kGy of radiation dose. Ã? 2013, silica fume, silica sand; the last one the most used due to size distribution, ranging from 0.6 to 4.0 mm

North Texas, University of

105

Radiation Probabilities, Auger Effect and Energy Level Widths for Au(79)  

Science Journals Connector (OSTI)

The theory of energy level widths developed by Weisskopf and Wigner and by Wentzel is applied to the calculation of the energy level widths of Au(79). Radiation and Auger transition probabilities are determined separately with the aid of numerically integrated nonrelativistic eigenfunctions, the latter being calculated for electrons moving in the Fermi-Thomas field of Tl(81)++. Sources of error are considered, the major one being the nonrelativistic treatment. The band width due to the interaction of electrons in different atoms in the crystal lattice does not add materially to the level width of the OI and lower states. Except for the K state, the Auger contribution to the width exceeds that of the radiation transitions. Where the majority of the significant Auger effects have been calculated (LI,MI,NI) the total calculated width is found to be appreciably in excess of the observed width, but of the same order. The results confirm the view that the contributions of radiation transitions and Auger effects to the level widths of the initial and final states of the atom suffice to explain the magnitude of the widths of the x-ray lines emitted by the heavy elements.

E. G. Ramberg and F. K. Richtmyer

1937-06-01T23:59:59.000Z

106

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

E-Print Network [OSTI]

. Hassanein Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University in the Earth's atmosphere, at sea level, and underground [3]. Many of the studies have been focused on nuclear for analyzing time correlations, mean values, dispersion and multivariate distribu- tions, although some work

Harilal, S. S.

107

Effects of Mn and Fe Levels on Bacillus subtilis Spore Resistance and Effects of Mn2+, Other Divalent Cations, Orthophosphate, and Dipicolinic Acid on Protein Resistance to Ionizing Radiation  

Science Journals Connector (OSTI)

...exposed to ionizing radiation in vitro display...response to dose, with increasing...doses of gamma radiation increase...within a narrow range of Mn concentrations...from gamma ray doses (15 kGy...resistance to ionizing radiation, desiccation...

Amanda C. Granger; Elena K. Gaidamakova; Vera Y. Matrosova; Michael J. Daly; Peter Setlow

2010-11-05T23:59:59.000Z

108

Effect of {gamma}-ray radiation on electrical properties of heat-treated Tb{sub x}Sn{sub 1-x}Se single crystals  

SciTech Connect (OSTI)

The effect of {gamma}-ray radiation on the electrical properties of heat-treated Tb{sub 0.01}Sn{sub 0.99}Se (sample 1) and Tb{sub 0.05}Sn{sub 0.95}Se (sample 2) samples is studied. It is found that, as a result of irradiation with {gamma}-ray 1.25-MeV photons, the charge-carrier concentration decreases in the temperature range T = 77-200 K by 17 and 6.3% for samples 1 and 2, respectively. It is assumed that, in the course of irradiation with {gamma}-ray photons, terbium impurity atoms are located between sites of the crystal lattice; in addition, Frenkel defects are formed.

Huseynov, J. I., E-mail: cih_58@mail.ru; Jafarov, T. A. [Azerbaijan State Pedagogical University (Azerbaijan)

2012-04-15T23:59:59.000Z

109

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

E-Print Network [OSTI]

the Ihaaua Ma?hey. Ie belonged te tha ~ grump unposed to ?antrum Nldiatiamy de%turn?ad fram ~ po ge lggmarmn aeu?e? at a desa level st N. R milli?up/hr, f'em 34 hours evemy fourth day over a three-year period (total dossi 608 rsp. ), During th? three...

Leidy, Ross Bennett

2012-06-07T23:59:59.000Z

110

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

E-Print Network [OSTI]

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

Michael A. Ivanov

2007-01-10T23:59:59.000Z

111

Directional gamma detector  

DOE Patents [OSTI]

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.

LeVert, Francis E. (Downers Grove, Knoxville, TN); Cox, Samson A. (Downers Grove, IL)

1981-01-01T23:59:59.000Z

112

Measurement of natural radioactivity and dose rate assessment of terrestrial gamma radiation in the soil of southern Punjab, Pakistan  

Science Journals Connector (OSTI)

......terrestrial background radiation mainly due to these...assess the population radiation doses(4-9). However...data are available on naturally occuring and artificial radionulides...order to assess the radiation doses for the general......

I. Fatima; J. H. Zaidi; M. Arif; M. Daud; S. A. Ahmad; S. N. A. Tahir

2008-01-01T23:59:59.000Z

113

Alpha Radiation  

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

Basics of Radiation 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 have been designed to measure alpha radiation. Special training in use of these instruments is essential for making accurate measurements. 4. A civil defense instrument (CD V-700) cannot detect the presence of radioactive materials that produce alpha radiation unless the radioactive materials also produce beta and/or gamma radiation.

114

Report to the DOE nuclear data committee. [EV RANGE 10-100; CROSS SECTIONS; PHOTONEUTRONS; NEUTRONS; GAMMA RADIATION; COUPLED CHANNEL THEORY; DIFFERENTIAL CROSS SECTIONS; MEV RANGE 01-10; ; CAPTURE; GAMMA SPECTRA; THERMAL NEUTRONS; COMPUTER CALCULATIONS; DECAY; FISSION PRODUCTS; FISSION YIELD; SHELL MODELS; NUCLEAR DATA COLLECTIONS  

SciTech Connect (OSTI)

Topics covered include: studies of (n, charged particle) reactions with 14 to 15 MeV neutrons; photoneutron cross sections for /sup 15/N; neutron radiative capture; Lane-model analysis of (p,p) and (n,n) scattering on the even tin isotopes; neutron scattering cross sections for /sup 181/Ta, /sup 197/Au, /sup 209/Bi, /sup 232/Th, and /sup 238/U inferred from proton scattering and charge exchange cross sections; neutron-induced fission cross sections of /sup 245/Cm and /sup 242/Am; fission neutron multiplicities for /sup 245/Cm and /sup 242/Am; the transport of 14 MeV neutrons through heavy materials 150 < A < 208; /sup 249/Cm energy levels from measurement of thermal neutron capture gamma rays; /sup 231/Th energy levels from neutron capture gamma ray and conversion electron spectroscopy; new measurements of conversion electron binding energies in berkelium and californium; nuclear level densities; relative importance of statistical vs. valence neutron capture in the mass-90 region; determination of properties of short-lived fission products; fission yield of /sup 87/Br and /sup 137/I from 15 nuclei ranging from /sup 232/Th to /sup 249/Cf; evaluation of charged particle data for the ECPL library; evaluation of secondary charged-particle energy and angular distributions for ENDL; and evaluated nuclear structure libraries derived from the table of isotopes. (GHT)

Struble, G.L.; Haight, R.C.

1981-03-01T23:59:59.000Z

115

A preliminary report on the determination of natural radioactivity levels of the State of Qatar using high-resolution gamma-ray spectrometry  

Science Journals Connector (OSTI)

This study is aimed at the determination of the activity concentrations of naturally occuring and technically enhanced levels of radiation in soil samples collected across the landscape of Qatar. Representative soil samples from various locations across the Qatarian peninsula have been collected and analyzed in order to establish activity concentrations associated with the 235,8U and 232Th natural decay chains and also the long-lived naturally occurring radionuclide 40K. The activity concentrations have been measured using a hyper-pure germanium detector. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented, together with the preliminary values of the activity concentrations associated with the naturally occuring radionuclide chains for six soil samples collected from the Qatarian peninsula. Sample 228, which has been collected from an inshore oil-field area, was observed to have the highest observed value of 226Ra concentration among the six samples. The weighted mean values of the activity concentrations of the radionuclides 238U, 232Th and 40K in one particular sample (sample 228) were, respectively, found to be 213.9±1.4, 4.55±0.11 and 111.4±3.6 Bq/kg, which compare with the worldwide weighted mean values in soil samples, 33, 45 and 420 Bq/kg, respectively. The deduced activity concentration of 238U in sample 228 in the current work was found to be significantly higher than the worldwide average value and was also significantly higher than the values determined for the five other initial samples discussed here. The mean values of the activity concentration of the 232Th series, 40K and 137Cs in Bq/kg from the six investigated soil samples were found to be 9.4±1.3, 204±22 and 5.8±5.6, respectively, with the quoted uncertainty referring to the standard deviation among these measurements.

H. Al-Sulaiti; P.H. Regan; D.A. Bradley; D. Malain; T. Santawamaitre; A. Habib; M. Matthews; S. Bukhari; M. Al-Dosari

2010-01-01T23:59:59.000Z

116

Improving the Fermilab Booster Notching Efficiency, Beam Losses and Radiation Levels  

SciTech Connect (OSTI)

A fast vertical 1.08-m long kicker (notcher) located in the Fermilab Booster Long-05 straight section is currently used to remove 3 out of 84 circulating bunches after injection to generate an abort gap. With the maximum magnetic field of 72.5 Gauss, it removes only 87% of the 3-bunch intensity at 400 MeV, with 75% loss on pole tips of the focusing Booster magnets, 11% on the Long-06 collimators, and 1% in the rest of the ring. We propose to improve the notching efficiency and reduce beam loss in the Booster by using three horizontal kickers in the Long-12 section. STRUCT calculations show that using horizontal notchers, one can remove up to 96% of the 3-bunch intensity at 400-700 MeV, directing 95% of it to a new beam dump at the Long-13 section. This fully decouples notching and collimation. The beam dump absorbs most of the impinging proton energy in its jaws. The latter are encapsulated into an appropriate radiation shielding that reduces impact on the machine components, personnel and environment to the tolerable levels. MARS simulations show that corresponding prompt and residual radiation levels can be reduced ten times compared to the current ones.

Rakhno, I.L.; Drozhdin, A.I.; Mokhov, N.V.; Sidorov, V.I.; Tropin, I.S.; /Fermilab

2012-05-14T23:59:59.000Z

117

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

SciTech Connect (OSTI)

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 ? 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 radionuclides may be selected by the operator and will be identified if present. In scanning operation the unit scans a designated region and superimposes over a video image the distribution of measured radioactivity. For the total scanned area or object RadSearch determines the total activity of operator selected radionuclides present and the gamma dose-rate measured at the detector head. Results of hold-up measurements made in a nuclear facility are presented, as are test measurements of point sources distributed arbitrarily on surfaces. These latter results are compared with the results of benchmarked MCNP Monte Carlo calculations. The use of the device for hold-up and decommissioning measurements is validated. (authors)

Mason, John A.; Looman, Marc R.; Poundall, Adam J.; Towner, Antony C.N. [ANTECH, A. N. Technology Ltd., Unit 6, Thames Park, Wallingford, Oxfordshire, OX10 9TA (United Kingdom)] [ANTECH, A. N. Technology Ltd., Unit 6, Thames Park, Wallingford, Oxfordshire, OX10 9TA (United Kingdom); Creed, Richard; Pancake, Daniel [Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States)] [Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States)

2013-07-01T23:59:59.000Z

118

The similar effects of low-dose ionizing radiation and non-ionizing radiation from background environmental levels of exposure  

Science Journals Connector (OSTI)

The meltdown and release of radioactivity (ionizing radiation) from four damaged nuclear reactors at the Fukushima Nuclear Facility in Japan in March 2011 continues to contaminate air and ocean water even 1 year ...

Cindy Sage

2012-06-01T23:59:59.000Z

119

Source level model for propeller blade rate radiation for the world’s merchant fleet  

Science Journals Connector (OSTI)

A model is developed for the acoustic source strength of blade rate line energy produced by single?screw merchant vessels. These source strengths are based on observed cavitation time histories on merchant vessels and on limitations imposed by considerations of propeller design procedures and ship vibration criteria. Relationships are presented for the expected value of the blade rate source strength for ships of different lengths expressed both as a monopole source strength located at a known depth below a free surface and as a dipole source strength that describes the pressure radiated to the farfield. These relationships are based on a small sample of merchant shipcharacteristics and are exercised for the estimated population of ships at sea. This calculation yields a statistical description of the distribution of source level and frequency of propeller blade rate acoustic energy for the fleet of single?screw merchant vessels.

Leslie M. Gray; David S. Greeley

1980-01-01T23:59:59.000Z

120

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

SciTech Connect (OSTI)

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

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

2013-01-31T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
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121

Essay on the gamma ray laser  

E-Print Network [OSTI]

This work discusses the possibility of inducing the emission of gamma radiation from nuclear isomers by two-photon transitions, in the more general context of the problem of the amplification of gamma radiation.

Silviu Olariu

1999-07-18T23:59:59.000Z

122

Radiation protection: Natural radiation risks  

Science Journals Connector (OSTI)

... radiation to which humans are exposed consists of four components - cosmic, gamma, internal, radon. The relative contribution that each makes to the sum is shown in the chart. ... but exposure of the whole body to terrestrial gamma rays and of the lungs to radon daughters are influenced by the nature and location of housing. Gamma rays are emitted ...

M. C. O'Riordan

1983-11-17T23:59:59.000Z

123

Gamma activity and radiation dose in concrete building blocks used for construction of dwellings in Jos, Nigeria  

Science Journals Connector (OSTI)

......IAEA-RGU-1. The detection efficiency calibration of the detector was performed using a reference soil sample prepared by Rocketdyne Laboratories, CA, which is traceable to a mixed standard gamma source (No. 48772-356, from Analytic Inc., Atlanta......

J. A. Ademola; I. P. Farai

2006-12-01T23:59:59.000Z

124

Miniaturized radiation chirper  

DOE Patents [OSTI]

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.

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

1980-01-01T23:59:59.000Z

125

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.

126

Design and Operation of a tunable MeV-level Compton-scattering-based (gamma-ray) source  

SciTech Connect (OSTI)

A mono-energetic gamma-ray (MEGa-ray) source based on Compton-scattering, targeting nuclear physics applications such as nuclear resonance fluorescence, has been constructed and commissioned at Lawrence Livermore National Laboratory. In this paper, the overall architecture of the system, as well as some of the critical design decisions made in the development of the source, are discussed. The performances of the two laser systems (one for electron production, one for scattering), the electron photoinjector, and the linear accelerator are also detailed, and initial {gamma}-ray results are presented.

Gibson, D J; Albert, F; Anderson, S G; Betts, S M; Messerly, M J; Phan, H H; Semenov, V A; Shverdin, M Y; Tremaine, A M; Hartemann, F V; Siders, C W; McNabb, D P; Barty, C P

2009-07-07T23:59:59.000Z

127

Neutron radiation can activate K-ras via a point mutation in codon 146 and induces a different spectrum of ras mutations than does gamma radiation.  

Science Journals Connector (OSTI)

research-article Research Article Neutron radiation can activate K-ras via a point...School of Medicine, New York 10016. Neutron radiation is known to produce tumors in...RF/J mice by a single acute dose of neutron irradiation. Activated ras genes were...

S R Sloan; E W Newcomb; A Pellicer

1990-01-01T23:59:59.000Z

128

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

SciTech Connect (OSTI)

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.

Zhang Jin; Lu Ye; Zhang Shuangnan [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Liang Enwei; Sun Xiaona [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning 530004 (China); Zhang Bing, E-mail: lew@gxu.edu.cn [Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154 (United States)

2013-09-01T23:59:59.000Z

129

Blazar Duty-Cycle at gamma-ray Frequecies: Constraints from Extragalactic Background Radiation and Prospects for AGILE and GLAST  

E-Print Network [OSTI]

We take into account the constraints from the observed extragalactic gamma-ray background to estimate the maximum duty cycle allowed for a selected sample of WMAP Blazars, in order to be detectable by AGILE and GLAST gamma-ray experiments. For the nominal sensitivity values of both instruments, we identify a subset of sources which can in principle be detectable also in a steady state without over-predicting the extragalactic background. This work is based on the results of a recently derived Blazar radio LogN-LogS obtained by combining several multi-frequency surveys.

Pittori, Carlotta; Colafrancesco, Sergio; Giommi, Paolo

2007-01-01T23:59:59.000Z

130

Blazar Duty-Cycle at gamma-ray Frequecies: Constraints from Extragalactic Background Radiation and Prospects for AGILE and GLAST  

E-Print Network [OSTI]

We take into account the constraints from the observed extragalactic gamma-ray background to estimate the maximum duty cycle allowed for a selected sample of WMAP Blazars, in order to be detectable by AGILE and GLAST gamma-ray experiments. For the nominal sensitivity values of both instruments, we identify a subset of sources which can in principle be detectable also in a steady state without over-predicting the extragalactic background. This work is based on the results of a recently derived Blazar radio LogN-LogS obtained by combining several multi-frequency surveys.

Carlotta Pittori; Elisabetta Cavazzuti; Sergio Colafrancesco; Paolo Giommi

2007-05-04T23:59:59.000Z

131

Energy levels, radiative rates and lifetimes for transitions in Br-like ions with 38 $\\le$ Z $\\le$ 42  

E-Print Network [OSTI]

Energy levels and radiative rates for transitions in five Br-like ions (Sr IV, Y V, Zr VI, Nb VII and Mo VIII) are calculated with the general-purpose relativistic atomic structure package ({\\sc grasp}). Extensive configuration interaction has been included and results are presented among the lowest 31 levels of the 4s$^2$4p$^5$, 4s$^2$4p$^4$4d and 4s4p$^6$ configurations. Lifetimes for these levels have also been determined, although unfortunately no measurements are available with which to compare. However, recently theoretical results have been reported by Singh {\\em et al} [Phys. Scr. {\\bf 88} (2013) 035301] using the same {\\sc grasp} code. But their reported data for radiative rates and lifetimes cannot be reproduced and show discrepancies of up to five orders of magnitude with the present calculations.

Aggarwal, K M

2014-01-01T23:59:59.000Z

132

Presented at the 2004 Applied Superconductivity Conference at Jacksonville, Florida, USA, Oct 3-8, 2004. Abstract--Extremely high radiation, levels with accumulated  

E-Print Network [OSTI]

these radiation doses. We plan to use stainless steel tape, that being a metal, is a robust radiation resistant-8, 2004. Abstract--Extremely high radiation, levels with accumulated doses comparable to those in nuclear). Removing large heat loads, protecting the superconducting coils against quenching, the long term

Gupta, Ramesh

133

Calculation of gamma radiation dose rate and radon concentration due to granites used as building materials in Iran  

Science Journals Connector (OSTI)

......G. Magusa, North Cyprus, via Mersin 10, Turkey Natural radioactivity concentrations...equivalent from all natural sources of radiation...health(4). Radon gas is a radionuclide present...to determining the natural radioactivity concentration......

A. Abbasi

2013-07-01T23:59:59.000Z

134

High-energy radiation visualizer (HERV): A new system for imaging in x-ray and gamma-ray emission regions  

SciTech Connect (OSTI)

The authors present a description and results of the operation for {gamma}-ray and X-ray objects for the compact visualization system high-energy radiation visualizer (HERV). The imaging in this system is based on use of a conical collimator, scintillator plate, and image intensifier as a detector and CCD matrix as a readout device. The use of HERV as a two-dimensional X-ray image visualizer for the Compton scatter inspection system was considered and first results are discussed. The possibility of using different hexagonal-coded apertures imaging for HERV is discussed and results of Monte Carlo simulation and experiments with optical analog of coded aperture are presented.

Sudarkin, A.N.; Ivanov, O.P.; Stepanov, V.E.; Volkovich, A.G.; Turin, A.S.; Danilovich, A.S.; Rybakov, D.D.; Urutskoev, L.I. [RECOM Ltd., Moscow (Russian Federation)] [RECOM Ltd., Moscow (Russian Federation)

1996-08-01T23:59:59.000Z

135

Childhood exposures to Rn-222 and background gamma radiation in the uranium provinces of south Kazakhstan and northern Kyrgyzstan  

Science Journals Connector (OSTI)

The project was undertaken in southern Kazakhstan and Kyrgyzstan. It was speculated that the radiation doses in these areas would be sufficiently high and dispersed to facilitate a case–control study where the radiation doses to leukaemia subjects/their siblings could be compared with those received by control children. As a precursor a pilot project was undertaken to confirm radiation exposures in the region. This was undertaken in association with regional childhood cancer treatment centres. Children from families affected by childhood leukaemia were monitored for 1 month for external ?-radiation dose and for exposure to radon gas. 28 children from families in Kazakhstan and from 31 families in Kyrgyzstan were monitored. The median measured radon in air concentration recorded in Kazakhstan was 123 Bq m?3 and in Kyrgyzstan was 177 Bq m?3. These represent 24-h average indoor/outdoor values. In the case of the ?-doses the mean annual dose was 1.2 mGy for Kazakhstan and 2.1 mGy for Kyrgyzstan. Overall, the results suggest that the populations studied receive similar annual radiation doses to those received by populations living in other areas with enhanced natural radioactivity and that further study of Kazakh and Kyrgyz populations would not facilitate a successful case–control study for childhood leukaemia.

N.D. Priest; D. Hoel; B. Uralbekov; D.O. Baizakova; M. Burkitbayev

2013-01-01T23:59:59.000Z

136

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

E-Print Network [OSTI]

We search for a light scalar particle produced in single-photon decays of the Upsilon(3S) resonance through the process Upsilon(3S) -> gamma A0, A0 -> 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 A0 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*10^6 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 B(Upsilon(3S) -> gamma A0)*B(A0 -> invisible) at (0.7-31)*10^{-6} in the mass range m(A0)<=7.8 GeV. The results are preliminary.

The BaBar Collaboration; B. Aubert

2008-07-31T23:59:59.000Z

137

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

SciTech Connect (OSTI)

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.

Aubert, B

2008-11-05T23:59:59.000Z

138

The Estimation of Molecular and Cytogenetic Effects in Mice Exposed to Chronic Low Dose-Rate Gamma-Radiation  

Science Journals Connector (OSTI)

Molecular and cytogenetic parameters were estimated in male CBA/lac mice exposed to chronic low dose-rate ?-radiation (62 cGy/year) for 40, 80, 120, 210, and 365 days. After 40 days of exposure (6.7 cGy), sple...

A. N. Osipov; A. L. Elakov; P. V. Puchkov…

2002-10-01T23:59:59.000Z

139

Gamma ray bursts ROBERT S MACKAY  

E-Print Network [OSTI]

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

Rourke, Colin

140

The Polarization Dependence of Gamma-Gamma Absorption - Implications for Gamma-Ray Bursts and Blazars  

E-Print Network [OSTI]

This paper presents an analysis of the dependence of the opacity for high-energy gamma-rays to gamma-gamma absorption by low-energy photons, on the polarization of the gamma-ray and target photons. This process has so far only been considered using the polarization-averaged gamma-gamma absorption cross section. It is demonstrated that in the case of polarized gamma-ray emission, subject to source-intrinsic gamma-gamma absorption by polarized target photons, this may lead to a slight over-estimation of the gamma-gamma opacity by up to ~ 10 % in the case of a perfectly ordered magnetic field. Thus, for realistic astrophysical scenarios with partially ordered magnetic fields, the use of the polarization-averaged gamma-gamma cross section is justified for practical purposes, such as estimates of minimum Doppler factors inferred for gamma-ray bursts and blazars, based on gamma-gamma transparency arguments, and this paper quantifies the small error incurred by the unpolarized-radiation approximation. Furthermore, i...

Boettcher, Markus

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Effects of an acute dose of gamma radiation exposure on stem diameter growth, carbon gain, and biomass partitioning in Helianthus annuus  

SciTech Connect (OSTI)

Nineteen-day-old dwarf sunflower plants (Helianthus annuus, variety NK894) received a variable dose (0-40 Gy) from a cobalt-60 gamma source. A very sensitive stem monitoring device, developed at Battelle's Pacific Northwest Laboratories, Richland, Washington was used to measure real-time changes in stem diameter. Exposure of plants caused a significant reduction in stem growth and root biomass. Doses as low as 5 Gy resulted in a significant increase in leaf density, suggesting that nonreversible morphological growth changes could be induced by very low doses of radiation. Carbohydrate analysis of 40-Gy irradiated plants demonstrated significantly more starch content in leaves and significantly less starch content in stems 18 days after exposure than did control plants. In contrast, the carbohydrate content in roots of 40-Gy irradiated plants were not significantly different from unirradiated plants 18 days after exposure. These results indicate that radiation either decreased phloem transport or reduced the availability of sugar reducing enzymes in irradiated plants. 44 refs., 12 figs.

Thiede, M.E.

1988-05-25T23:59:59.000Z

142

Influence of gamma radiation on the activities of some carbohydrate metabolic enzymes in the cotyledons and the leaves of fenugreek (Trigonella foenum-graecum L. ) bean seedlings  

SciTech Connect (OSTI)

Studies indicated that 21-day old cotyledons from gamma irradiated seeds of fenugreek beans were heavier and had more starch and sugar than their non-irradiated controls. To test whether these effects occurred in the leaves and to seek a possible biochemical explanation for these results, the activities of five enzymes involved in carbohydrate metabolism were studied. Three groups of fenugreek bean seeds were irradiated (100-300 Gy) and then allowed to grow for 21 days. On harvest, wet and dry weights of both cotyledons and leaves were determined. Starch and sugar contents in cotyledons and leaves were measured. The five enzymes ..cap alpha..-amylase, ..beta..-amylase, starch phosphorylase, ADPG-pyrophosphorylase and ribulose-1,5-diphosphate carboxylase were extracted from cotyledons and leaves, respectively. The protein contents and activities of the enzyme extracts were determined. The results suggest an increase in carbohydrate metabolism in cotyldeons and a decrease in leaves due to the radiation treatment of the seeds before germination. Thus, increased amounts of starch and sugars are observed in the cotyledons, and decreased amounts in the leaves. Radiation damage to the translocatory system of the plant may retard the movement of sugars from the cotyledons to the other parts of the plant. This may cause accumulation of sugars and starch in the cotyledons, leading to an increase in their size and weight.

Ahanotu, P.A.

1985-01-01T23:59:59.000Z

143

Vertical structure and turbulent saturation level in fully radiative protoplanetary disc models  

Science Journals Connector (OSTI)

......Unlike, for example, the solar butterfly diagram, the field reversals shown in Fig. 2...OUTLOOK We have performed 3D radiative MHD simulations of MRI-turbulent protoplanetary...sufficient to justify the assumption of ideal MHD. The logical next step will be to include......

M. Flaig; W. Kley; R. Kissmann

2010-12-21T23:59:59.000Z

144

Effects of combined radiofrequency radiation exposure on levels of reactive oxygen species in neuronal cells  

Science Journals Connector (OSTI)

......typical CDMA signal of 837 MHz and a WCDMA signal of 1950 MHz were applied to the RTL...incubator with a humidified atmosphere of 5% CO2. Analysis...exposure to UMTS 1950 MHz radiation and co-exposure...reaction of menadione with plasma thiols: enhancement......

Kyoung Ah Kang; Hyung Chul Lee; Je-Jung Lee; Mi-Na Hong; Myung-Jin Park; Yun-Sil Lee; Hyung-Do Choi; Nam Kim; Young-Gyu Ko; Jae-Seon Lee

2014-03-01T23:59:59.000Z

145

ESTIMATING GROUND-LEVEL SOLAR RADIATION AND EVAPOTRANSPIRATION IN PUERTO RICO  

E-Print Network [OSTI]

REMOTE SENSING Eric. W. Harmsen1 , John Mecikalski2 , Vanessa Acaron3 and Jayson Maldonado3 1 Department insolation, other meteorological variables (e.g., net radiation, soil heat flux, air temperature dew point remote sensing product. As a practical example of the use of the methodology, the Hargraeves-Samani ETo

Gilbes, Fernando

146

Gamma-Emitting Radionuclides in Newborns, Infants, and Children  

Science Journals Connector (OSTI)

...Isotopes Radiation Effects Radiation Monitoring Rubidium Thyroid...PLACENTA POTASSIUM ISOTOPES RADIATION EFFECTS RADIATION MONITORING RUBIDIUM THYROID...primary gamma photons from naturally occuring K" and fission prod-uct...

N. S. Macdonald; D. L. Hutchinson; D. L. Moyer; R. A. Chez

1963-09-13T23:59:59.000Z

147

Radiation source rate estimation through data assimilation of gamma dose rate measurements for operational nuclear emergency response systems  

Science Journals Connector (OSTI)

This paper presents an evaluation of an innovative data assimilation method that has been recently developed in NCSR Demokritos for estimating an unknown emission rate of radionuclides in the atmosphere, with real-scale experimental data. The efficient algorithm is based on the assimilation of gamma dose rate measured data in the Lagrangian atmospheric dispersion model DIPCOT and uses variational principles. The DIPCOT model is used in the framework of the nuclear emergency response system (ERS) RODOS. The evaluation is performed by computational simulations of dispersion of Ar-41 that was emitted routinely by the Australian Nuclear Science and Technology Organisation's (ANSTO) previous research reactor, HIFAR, located in Sydney, Australia. In this paper the algorithm is evaluated against a more complicated case than the others used in previous studies: there was only one monitoring station available each day and the site topography is characterised as moderately complex. Overall the estimated release rate approaches the real one to a very satisfactory degree as revealed by the statistical indicators of errors.

Vasiliki Tsiouri; Spyros Andronopoulos; Ivan Kovalets; Leisa L. Dyer; John G. Bartzis

2012-01-01T23:59:59.000Z

148

Gamma-ray binaries  

E-Print Network [OSTI]

Recent observations have shown that some compact stellar binaries radiate the highest energy light in the universe. The challenge has been to determine the nature of the compact object and whether the very high energy gamma-rays are ultimately powered by pulsar winds or relativistic jets. Multiwavelength observations have shown that one of the three gamma-ray binaries known so far, PSR B1259-63, is a neutron star binary and that the very energetic gamma-rays from this source and from another gamma-ray binary, LS I +61 303, may be produced by the interaction of pulsar winds with the wind from the companion star. At this time it is an open question whether the third gamma-ray binary, LS 5039, is also powered by a pulsar wind or a microquasar jet, where relativistic particles in collimated jets would boost the energy of the wind from the stellar companion to TeV energies.

I. F. Mirabel

2006-10-24T23:59:59.000Z

149

Partial widths and gamma-ray decay of the 2883- and 5037-keV levels in Sc41  

Science Journals Connector (OSTI)

Proton and ?-ray decay widths for the 7/2+ resonance at 2883 keV excitation in Sc41 have been deduced from measurements of ??? and the (p,?) resonance strength. Our results are ??=0.058±0.007 eV and ?p=0.090±0.011 eV. Angular distributions measured for the 5037 (92+)?2883 keV and 2883?0 (72-) keV transitions confirm the J=72 assignment for the 2883-keV level. The linear polarization was measured for the 2883?0 keV transition and confirms the positive parity assignment. In addition, the (p,?) strength for the 5037-keV level was measured, and our strength results for both resonances are lower than those of Youngblood, Wildenthal, and Class by a factor of 1.4.[NUCLEAR REACTIONS Ca40(p,?), Ep=1.84,4.05 MeV; measured ?(E?,?), Q, P(90?), resonance strengths, I?. Sc41 deduced levels, J?, ??, ?p, CSp2. Enriched target.

R. L. Kozub; B. E. Cooke; J. R. Leslie; B. C. Robertson

1977-07-01T23:59:59.000Z

150

Gamma ray burst outflows and afterglows.  

E-Print Network [OSTI]

?? We carry out a theoretical investigation of jet propagation in Gamma Ray Bursts and examine the jitter radiation mechanism as a means of producing… (more)

Morsony, Brian J.

2009-01-01T23:59:59.000Z

151

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

E-Print Network [OSTI]

indiv. indiv. Gilbertetal. (Hanford & Combined) Gilbertetal.on both radiation and the Hanford facility. The data used toG. Radiation exposures of Hanford workers dying from cancer

Britton, Julie

2010-01-01T23:59:59.000Z

152

Nuclear radiation-warning detector that measures impedance  

DOE Patents [OSTI]

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.

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

2013-06-04T23:59:59.000Z

153

RADIATION SENSITIVITY & PROCESSING OF DNA DAMAGE FOLLOWING LOW DOSES OF GAMMA-RAY ALPHA PARTICLES & HZE IRRADIATION OF NORMAL DSB REPAIR DEFICIENT CELLS  

SciTech Connect (OSTI)

Non-homologous end joining (NHEJ) predominates in the repair of DNA double strand breaks (DSB) over homologous recombination (HR). NHEJ occurs throughout the cell cycle whereas HR occurs in late S/G2 due to the requirement of a sister chromatid (Rothkamm et al, Mol Cell Biol 23 5706-15 [2003]). To date evidence obtained with DSB repair deficient cells using pulsed-field gel electrophoresis has revealed the major pathway throughout all phases of the cell cycle for processing high dose induced DSBs is NHEJ (Wang et al, Oncogene 20 2212-24 (2001); Pluth et al, Cancer Res. 61 2649-55 [2001]). These findings however were obtained at high doses when on average >> 20-30 DSBs are formed per cell. The contribution of the repair pathways (NHEJ and HR) induced in response to DNA damage during the various phases of the cell cycle may depend upon the dose (the level of initial DSBs) especially since low levels of DSBs are induced at low dose. To date, low dose studies using NHEJ and HR deficient mutants have not been carried out to address this important question with radiations of different quality. The work presented here leads us to suggest that HR plays a relatively minor role in the repair of radiation-induced prompt DSBs. SSBs lead to the induction of DSBs which are associated specifically with S-phase cells consistent with the idea that they are formed at stalled replication forks in which HR plays a major role in repair. That DNA-PKcs is in some way involved in the repair of the precursors to replication-induced DSB remains an open question. Persistent non-DSB oxidative damage also leads to an increase in RAD51 positive DSBs. Both simple and complex non-DSB DNA damage may therefore contribute to indirect DSBs induced by ionising radiation at replication forks.

O'Neil, Peter

2009-05-15T23:59:59.000Z

154

Gamma ray camera  

DOE Patents [OSTI]

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.

Perez-Mendez, Victor (Berkeley, CA)

1997-01-01T23:59:59.000Z

155

Gamma ray camera  

DOE Patents [OSTI]

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.

Perez-Mendez, V.

1997-01-21T23:59:59.000Z

156

Gamma Irradiation | ORNL Neutron Sciences  

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

Gamma Irradiation Gamma Irradiation Gamma Irradiation Facility Gamma irradiation chamber Gamma irradiation chamber. The HFIR Gamma Irradiation Facility is an experimental facility designed to irradiate materials with gamma radiation from spent fuel elements. The facility chamber is stainless steel and is made of 0.065-thick tubing to maximize the internal dimensions of the chamber. This allows for the largest samples possible that can still fit inside the cadmium post of the spent fuel loading station positions. The interior chamber is approximately 3.75 inches inside diameter and accommodates samples up to 25 inches long. There are two configurations for the chamber assembly, with the only difference being the plugs. The uninstrumented configuration has a top plug that is used for installation of the samples, to support the inert gas

157

Radiation: Facts, Risks and Realities  

E-Print Network [OSTI]

of Radiation 3 Understanding Radiation Risks 6 Naturally Occurring (Background) Radiation 7 Man-Made Radiation, beta particles and gamma rays. Other types, such as x-rays, can occur naturally or be machine-produced. Scientists have also learned that radiation sources are naturally all around us. Radiation can come from

158

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)

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).

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

1996-06-01T23:59:59.000Z

159

Definition: Gamma Log | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Gamma Log Jump to: navigation, search Dictionary.png Gamma Log Gamma logging is a method of measuring naturally occurring gamma radiation to characterize the rock or sediment in a borehole or drill hole. It is a wireline logging method used in mining, mineral exploration, water-well drilling, for formation evaluation in oil and gas well drilling and for other related purposes. Different types of rock emit different amounts and different spectra of natural gamma radiation.[1] View on Wikipedia Wikipedia Definition Gamma ray logging is a method of measuring naturally occurring gamma radiation to characterize the rock or sediment in a borehole or drill hole. It is a wireline logging method used in mining, mineral exploration,

160

Predicting underwater radiated noise levels due to the first offshore wind turbine installation in the United States  

Science Journals Connector (OSTI)

Noise generated by offshore impact pile driving radiates into the air water and sediment. Predicting noise levels around the support structures at sea is required to estimate the effects of the noise on marine life. Based on high demands developing renewable energy source the United States will begin the first pile driving within one to two years. It is necessary to investigate acoustic impact using our previously verified coupled Finite Element (Commercial FE code Abaqus) and Monterey Miami Parabolic Equation (2D MMPE) models [J. Acoust. Soc. Am. 131(4) 3392 (2012)]. In the present study we developed a new coupled FE-MMPE model for the identification of zone of injury due to offshore impact pile driving. FE analysis produced acoustic pressure outputs on the surface of the pile which are used as a starting field for a long range 2D MMPE propagation model. It calculates transmission loss for N different azimuthal directions as function of distance from the location of piling with the inputs of corresponding bathymetry and sediment properties. We will present predicted zone of injury by connecting N different distances of equivalent level fishes may get permanent injury due to the first offshore wind farm installation in the United States.

James H. Miller

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Predicting underwater radiated noise levels due to the first offshore wind turbine installation in the U.S.  

Science Journals Connector (OSTI)

Noise generated by offshore impact pile driving radiates into the air water and sediment. Predicting noise levels around the support structures at sea is required to estimate the effects of the noise on marine life. Based on high demands developing renewable energy source the United States will begin the first pile driving within one to two years. It is necessary to investigate acoustic impact using our previously verified coupled Finite Element (Commercial FE code Abaqus) and Monterey Miami Parabolic Equation (2D MMPE) models (J. Acoust. Soc. Am. 131(4) p. 3392 2012). In the present study we developed a new coupled FE-MMPE model for the identification of zone of injury due to offshore impact pile driving. FE analysis produced acoustic pressure outputs on the surface of the pile which are used as a starting field for a long range 2D MMPE propagation model. It calculates transmission loss for N different azimuthal directions as function of distance from the location of piling with the inputs of corresponding bathymetry and sediment properties. We will present predicted zone of injury by connecting N different distances of equivalent level fishes may get permanent injury due to the first offshore wind farm installation in the U.S..

Huikwan Kim; James H. Miller; Gopu R. Potty

2013-01-01T23:59:59.000Z

162

The Feasibility of Establishing a De Minimis Level of Radiation Dose and a Regulatory Cutoff Policy for Nuclear Regulation  

Science Journals Connector (OSTI)

This report discusses the feasibility of a de minimis policy for radiation exposure guidance and regulation. This policy would establish a threshold below which regulation of radiation sources, practices, or e...

Joyce P. Davis

1987-01-01T23:59:59.000Z

163

Plutonium radiation surrogate  

DOE Patents [OSTI]

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.

Frank, Michael I. (Dublin, CA)

2010-02-02T23:59:59.000Z

164

Statistical correlation between hourly and daily values of solar radiation on horizontal surface at sea level in the Italian climate  

E-Print Network [OSTI]

219- Statistical correlation between hourly and daily values of solar radiation on horizontal- nalières du rayonnement solaire. Abstract. 2014 The knowledge of hourly data of solar radiation is required data measured in Italian stations and propose a method to estimate hourly solar radiation

Boyer, Edmond

165

Theoretical study of ionization profiles of molecular clouds near supernova remnants: Tracing the hadronic origin of GeV gamma radiation  

E-Print Network [OSTI]

Context: Since a few years, signatures of supernova remnants associated with molecular clouds have been detected in gamma rays. Whether these gamma rays are generated by cosmic ray electrons or by cosmic ray protons is usually not known. The detection of hadronic ionization signatures in spatial coincidence with gamma ray signatures can help to unambiguously identify supernova remnants as sources of cosmic ray protons. Methods: In order to calculate hadronic signatures from cosmic ray-induced ionization for an examination of the origin of the observed gamma rays, the transport equation for cosmic ray protons propagating in a molecular cloud, including the relevant momentum loss processes, is solved analytically and the proton flux at any position in the cloud is determined. Results: Since the solution of the transport equation is obtained for arbitrary source functions, it can be used for a variety of supernova remnants. The corresponding theoretical ionization rate, as a function of the penetration depth, is...

Schuppan, Florian; Tjus, Julia Becker

2014-01-01T23:59:59.000Z

166

RADIATION CARCINOGENESIS IN MAN: INFLUENCE OF DOSE-RESPONSE MODELS AND RISK PROJECTION MODELS IN THE ESTIMATION OF RISK COEFFICIENTS FOLLOWING EXPOSURE TO LOW-LEVEL RADIATION  

E-Print Network [OSTI]

RADIATION CARCINOGENESIS IN MAN: INFLUENCE OF DOSE-RESPONSE MODELS AND RISK PROJECTION MODELS IN THE ESTIMATIONRADIATION CARCINOGENESIS IN HAN: INFLUENCE OF DOSE-RESPONSE MODELS AND RISK PROJECTION MODELS IN THE ESTIMATION

Fabrikant, J.I.

2010-01-01T23:59:59.000Z

167

Effects of Substerilization Doses of Co60 Gamma Radiation on the Cold-Storage Life Extension of Shucked Soft-Shelled Clams and Haddock Fillets  

Science Journals Connector (OSTI)

...000 rad of ionizing radiation. In the dose range from 200,000...000 rad of ionizing radiation. In the dose range from 200,000...000 rad of ionizing radiation. Nevertheless...indicate that in the dose range from 400,000...

E. B. Masurovsky; S. A. Goldblith; J. T. R. Nickerson

1963-05-01T23:59:59.000Z

168

Radiation and Background Levels in a CLIC Detector due to Beam-Beam Effects Optimisation of Detector Geometries and Technologies  

E-Print Network [OSTI]

The high charge density---due to small beam sizes---and the high energy of the proposed CLIC concept for a linear electron--positron collider with a centre-of-mass energy of up to 3~TeV lead to the production of a large number of particles through beam-beam interactions at the interaction point during every bunch crossing (BX). A large fraction of these particles safely leaves the detector. A still significant amount of energy will be deposited in the forward region nonetheless, which will produce secondary particles able to cause background in the detector. Furthermore, some particles will be created with large polar angles and directly cause background in the tracking detectors and calorimeters. The main sources of background in the detector, either directly or indirectly, are the incoherent $mathrm{e}^{+}mathrm{e}^{-}$ pairs and the particles from $gammagamma ightarrow$ hadron events. The background and radiation levels in the detector have to be estimated, to study if a detector is feasible, that can han...

Sailer, André; Lohse, Thomas

2013-01-10T23:59:59.000Z

169

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

E-Print Network [OSTI]

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

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

2015-01-23T23:59:59.000Z

170

Composition for radiation shielding  

DOE Patents [OSTI]

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.

Kronberg, James W. (Aiken, SC)

1994-01-01T23:59:59.000Z

171

Gamma Log | Open Energy Information  

Open Energy Info (EERE)

Gamma Log Gamma Log Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Gamma Log Details Activities (6) Areas (6) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Log Techniques Parent Exploration Technique: Well Log Techniques Information Provided by Technique Lithology: provides information on changes in rock type near the wellbore from changes in measured gamma radiation Stratigraphic/Structural: using multiple gamma logs over an area, the depth to the sandstone and shale layers can be correlated over larger areas Hydrological: Thermal: Cost Information Low-End Estimate (USD): 0.2525 centUSD 2.5e-4 kUSD 2.5e-7 MUSD 2.5e-10 TUSD / foot Median Estimate (USD): 0.3838 centUSD

172

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

E-Print Network [OSTI]

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

Joe Justina, -

2012-10-19T23:59:59.000Z

173

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

E-Print Network [OSTI]

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

Zhang, Bing

174

BWR radiation control: plant demonstration  

SciTech Connect (OSTI)

The first year's progress is presented for a four-year program intended to implement and evaluate BRAC radiation reduction operational guidelines at the Vermont Yankee BWR and to document the results in sufficient detail to provide guidance to other BWR owners. Past operational, chemistry and radiation level data have been reviewed to provide a historical base of reference. Extensive sampling and chemistry monitoring systems have been installed to evaluate plant chemistry status and the effects of program implemented changes. Radiation surveys and piping gamma scans are being performed at targeted locations to quantify radiation level trends and to identify and quantify piping isotopics. Contact radiation levels on the recirculation line at Vermont Yankee have been increasing at a rate of 175 mR/h-EFPY since 1978. A materials survey of feedwater and reactor components in contact with the process liquid has been performed to identify sources of corrosion product release, particularly cobalt and nickel. A feedwater oxygen injection system has been installed to evaluate the effects of oxygen control on feedwater materials corrosion product releases. A baseline performance evaluation of the condensate treatment and reactor water cleanup systems has been completed. Data on organics and ionics at Vermont Yankee have been obtained. A methodology of BWR feedwater system layup during extended outages was developed, and an evaluation performed of layup and startup practices utilized at Vermont Yankee during the fall 1980 and 1981 refueling outages.

Palino, G.F.; Hobart, R.L.; Wall, P.S.; Sawochka, S.G.

1982-11-01T23:59:59.000Z

175

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

E-Print Network [OSTI]

Two versions of the neutron-gamma variance to mean (Feynman-alpha method or Feynman-Y function) formula for either gamma detection only or total neutron-gamma detection, respectively, are derived and compared in this paper. The new formulas have a particular importance for detectors of either gamma photons or detectors sensitive to both neutron and gamma radiation. If applied to a plastic or liquid scintillation detector, the total neutron-gamma detection Feynman-Y expression corresponds to a situation where no discrimination is made between neutrons and gamma particles. The gamma variance to mean formulas are useful when a detector of only gamma radiation is used or when working with a combined neutron-gamma detector at high count rates. The theoretical derivation is based on the Chapman-Kolmogorov equation with inclusion of general reactions and passage intensities for neutrons and gammas, but with the inclusion of prompt reactions only. A one energy group approximation is considered. The comparison of the ...

Chernikova, Dina; Avdic, Senada; Pázsit, Imre; Nordlund, Anders

2014-01-01T23:59:59.000Z

176

Patient radiation doses in interventional cardiology in the U.S.: Advisory data sets and possible initial values for U.S. reference levels  

SciTech Connect (OSTI)

Purpose: To determine patient radiation doses from interventional cardiology procedures in the U.S and to suggest possible initial values for U.S. benchmarks for patient radiation dose from selected interventional cardiology procedures [fluoroscopically guided diagnostic cardiac catheterization and percutaneous coronary intervention (PCI)]. Methods: Patient radiation dose metrics were derived from analysis of data from the 2008 to 2009 Nationwide Evaluation of X-ray Trends (NEXT) survey of cardiac catheterization. This analysis used deidentified data and did not require review by an IRB. Data from 171 facilities in 30 states were analyzed. The distributions (percentiles) of radiation dose metrics were determined for diagnostic cardiac catheterizations, PCI, and combined diagnostic and PCI procedures. Confidence intervals for these dose distributions were determined using bootstrap resampling. Results: Percentile distributions (advisory data sets) and possible preliminary U.S. reference levels (based on the 75th percentile of the dose distributions) are provided for cumulative air kerma at the reference point (K{sub a,r}), cumulative air kerma-area product (P{sub KA}), fluoroscopy time, and number of cine runs. Dose distributions are sufficiently detailed to permit dose audits as described in National Council on Radiation Protection and Measurements Report No. 168. Fluoroscopy times are consistent with those observed in European studies, but P{sub KA} is higher in the U.S. Conclusions: Sufficient data exist to suggest possible initial benchmarks for patient radiation dose for certain interventional cardiology procedures in the U.S. Our data suggest that patient radiation dose in these procedures is not optimized in U.S. practice.

Miller, Donald L.; Hilohi, C. Michael; Spelic, David C. [Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993 (United States)

2012-10-15T23:59:59.000Z

177

Thermoluminescence response of new KClXBr1?X:EuCl3 sintered phosphors exposed to beta and gamma radiation  

Science Journals Connector (OSTI)

......the dosimetric response for samples of...4. Dosimetric response of composition...understand the radiation storage capability of each...thermoluminescence response of KClXBr1-X...calculation of activation energies and frequency factors from glow......

R. Bernal; E. Cruz-Zaragoza; C. Cruz-Vázquez; S. E. Burruel-Ibarra; M. J. Rivera-Flores; M. Barboza-Flores

2006-09-01T23:59:59.000Z

178

Curcumin Regulates Low-Linear Energy Transfer {gamma}-Radiation-Induced NF{kappa}B-Dependent Telomerase Activity in Human Neuroblastoma Cells  

SciTech Connect (OSTI)

Purpose: We recently reported that curcumin attenuates ionizing radiation (IR)-induced survival signaling and proliferation in human neuroblastoma cells. Also, in the endothelial system, we have demonstrated that NF{kappa}B regulates IR-induced telomerase activity (TA). Accordingly, we investigated the effect of curcumin in inhibiting IR-induced NF{kappa}B-dependent hTERT transcription, TA, and cell survival in neuroblastoma cells. Methods and Materials: SK-N-MC or SH-SY5Y cells exposed to IR and treated with curcumin (10-100 nM) with or without IR were harvested after 1 h through 24 h. NF{kappa}B-dependent regulation was investigated either by luciferase reporter assays using pNF{kappa}B-, pGL3-354-, pGL3-347-, or pUSE-I{kappa}B{alpha}-Luc, p50/p65, or RelA siRNA-transfected cells. NF{kappa}B activity was analyzed using an electrophoretic mobility shift assay and hTERT expression using the quantitative polymerase chain reaction. TA was determined using the telomerase repeat amplification protocol assay and cell survival using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltertrazolium bromide and clonogenic assay. Results: Curcumin profoundly inhibited IR-induced NF{kappa}B. Consequently, curcumin significantly inhibited IR-induced TA and hTERT mRNA at all points investigated. Furthermore, IR-induced TA is regulated at the transcriptional level by triggering telomerase reverse transcriptase (TERT) promoter activation. Moreover, NF{kappa}B becomes functionally activated after IR and mediates TA upregulation by binding to the {kappa}B-binding region in the promoter region of the TERT gene. Consistently, elimination of the NF{kappa}B-recognition site on the telomerase promoter or inhibition of NF{kappa}B by the I{kappa}B{alpha} mutant compromises IR-induced telomerase promoter activation. Significantly, curcumin inhibited IR-induced TERT transcription. Consequently, curcumin inhibited hTERT mRNA and TA in NF{kappa}B overexpressed cells. Furthermore, curcumin enhanced the IR-induced inhibition of cell survival. Conclusions: These results strongly suggest that curcumin inhibits IR-induced TA in an NF{kappa}B dependent manner in human neuroblastoma cells.

Aravindan, Natarajan, E-mail: naravind@ouhsc.ed [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Veeraraghavan, Jamunarani; Madhusoodhanan, Rakhesh; Herman, Terence S. [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Natarajan, Mohan [Department of Otolaryngology, Head and Neck Surgery, University of Texas Health Sciences Center at San Antonio, San Antonio, TX (United States)

2011-03-15T23:59:59.000Z

179

Development of autonomous gamma dose logger for environmental monitoring  

SciTech Connect (OSTI)

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.

Jisha, N. V.; Krishnakumar, D. N.; Surya Prakash, G.; Kumari, Anju; Baskaran, R.; Venkatraman, B. [Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India)

2012-03-15T23:59:59.000Z

180

Application of the gamma evaluation method in Gamma Knife film dosimetry  

SciTech Connect (OSTI)

Purpose: Gamma Knife (GK) radiosurgery is a minimally invasive surgical technique for the treatment of intracranial lesions. To minimize neurological deficits, submillimeter accuracy is required during treatment delivery. In this paper, the delivery accuracy of GK radiosurgery was assessed with the gamma evaluation method using planning dose distribution and film measurement data. Methods: Single 4, 8, and 16 mm and composite shot plans were developed for evaluation using the GK Perfexion (PFX) treatment planning system (TPS). The planning dose distributions were exported as digital image communications in medicine - radiation therapy (DICOM RT) files using a new function of GK TPS. A maximum dose of 8 Gy was prescribed for four test plans. Irradiation was performed onto a spherical solid water phantom using Gafchromic EBT2 films in the axial and coronal planes. The exposed films were converted to absolute dose based on a 4th-order polynomial calibration curve determined using ten calibration films. The film measurement results and planning dose distributions were registered for further analysis in the same Leksell coordinate using in-house software. The gamma evaluation method was applied to two dose distributions with varying spatial tolerance (0.3-2.0 mm) and dosimetric tolerance (0.3-2.0%), to verify the accuracy of GK radiosurgery. The result of gamma evaluation was assessed using pass rate, dose gamma index histogram (DGH), and dose pass rate histogram (DPH). Results: The 20, 50, and 80% isodose lines found in film measurements were in close agreement with the planning isodose lines, for all dose levels. The comparison of diagonal line profiles across the axial plane yielded similar results. The gamma evaluation method resulted in high pass rates of >95% within the 50% isodose line for 0.5 mm/0.5% tolerance criteria, in both the axial and coronal planes. They satisfied 1.0 mm/1.0% criteria within the 20% isodose line. Our DGH and DPH also showed that low isodose lines exhibited inferior gamma indexes and pass rates compared with higher isodose lines. Conclusions: The gamma evaluation method was applicable to GK radiosurgery. For all test plans, planning dose distribution and film measurement met the tolerance criteria of 0.5 mm/0.5% within the 50% isodose line which are used for marginal dose prescription.

Park, Jeong-Hoon; Han, Jung Ho; Kim, Chae-Yong; Oh, Chang Wan; Lee, Do-Heui; Suh, Tae-Suk; Gyu Kim, Dong; Chung, Hyun-Tai [Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam 463-707, Korea and Department of Biomedical Engineering, College of Medicine, Catholic University of Korea Seoul 137-701 (Korea, Republic of); Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam 463-707, Korea and Department of Neurosurgery, College of Medicine, Seoul National University, Seoul 110-799 (Korea, Republic of); Department of Neurosurgery, Asan Medical Center, College of Medicine, University of Ulsan, Seoul 138-736 (Korea, Republic of); Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Department of Neurosurgery, College of Medicine, Seoul National University, Seoul 110-799 (Korea, Republic of)

2011-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Gamma-ray events thunderclouds  

E-Print Network [OSTI]

stage of rocket-triggered lightning #12;The gamma-ray flash occurred at the same time the upward leader radiation is also produced by natural lightning during the stepped leader phase. · Dwyer et al. 2003, 2004 found that x-rays are also produced by triggered lightning dart leaders. · At present, the only viable

California at Berkeley, University of

182

Astrophysical S factor for the radiative capture (12)N(p,gamma)(13)O determined from the (14)N((12)N,(13)O)(13)C proton transfer reaction  

E-Print Network [OSTI]

The cross section of the radiative proton capture reaction on the drip line nucleus (12)N was investigated using the asymptotic normalization coefficient (ANC) method. We have used the (14)N((12)N,(13)O)(13)C proton transfer reaction at 12 Me...

Banu, A.; Al-Abdullah, T.; Fu, C.; Gagliardi, Carl A.; McCleskey, M.; Mukhamedzhanov, A. M.; Tabacaru, G.; Trache, L.; Tribble, Robert E.; Zhai, Y.; Carstoiu, F.; Burjan, V.; Kroha, V.

2009-01-01T23:59:59.000Z

183

Species richness and abundance of forest birds in relation to radiation at Chernobyl  

Science Journals Connector (OSTI)

...estimated to the nearest 10% of ground coverage within a distance...sand. The presence of open water within a distance of 50 m was...beta and gamma radiation at ground level directly at each point...Chernobyl accident and their remediation: twenty years of experienceNew...

2007-01-01T23:59:59.000Z

184

Assessment of gamma dose rates from terrestrial exposure in Serbia and Montenegro  

Science Journals Connector (OSTI)

......obtained in this study, the radiation hazard was found to be...area. INTRODUCTION Gamma radiation emitted from naturally occuring radioisotopes, such as...Norwegian population from naturally occuring radiation and from Chernobyl fallout......

S. Dragovic; Lj. Jankovic; A. Onjia

2006-12-01T23:59:59.000Z

185

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

SciTech Connect (OSTI)

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 ?-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.

Kim, In Gyu, E-mail: igkim@kaeri.re.kr [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Department of Radiation Biotechnology and Applied Radioisotope, University of Science and Technology (UST), 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Kim, Seo Yoen [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of) [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Biomedical Translational Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Kim, Hyun A; Kim, Jeong Yul [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of)] [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Lee, Jae Ha; Choi, Soo Im [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of) [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Department of Radiation Biotechnology and Applied Radioisotope, University of Science and Technology (UST), 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Han, Jeong Ran; Kim, Kug Chan [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of)] [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600 (Korea, Republic of); Cho, Eun Wie [Biomedical Translational Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of)] [Biomedical Translational Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of)

2014-01-03T23:59:59.000Z

186

Gamma radiolysis of chlorinated hydrocarbons  

SciTech Connect (OSTI)

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.

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

1992-01-01T23:59:59.000Z

187

Gamma radiolysis of chlorinated hydrocarbons  

SciTech Connect (OSTI)

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.

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

1992-08-01T23:59:59.000Z

188

Assessment of the radiological impact of gamma and radon dose rates at former U mining sites in Central Asia  

Science Journals Connector (OSTI)

An assessment of the radiological situation due to exposure to gamma radiation, radon and thoron was carried out at selected former uranium mining and processing sites in the Central Asian countries of Kazakhstan, Kyrgyzstan, Uzbekistan and Tajikistan. Gamma dose rate measurements were made using various field instruments and radon/thoron measurements were carried out using discriminative radon (222Rn)/thoron (220Rn) solid state nuclear track detectors (SSNTD). The detectors were exposed for an extended period of time, including at least three seasonal periods in a year, in different outdoor and indoor public and residential environments at the selected uranium legacy sites. The results showed that gamma, Rn and Tn doses were in general low, which consequently implies a low/relatively low radiological risk. The major radiation hazard is represented by abandoned radioactive filtration material that was being used as insulation by some Minkush residents (Kyrgyzstan) for a longer period of time. Annual radiation doses of several hundred mSv could be received as a consequence of using this material domestically. In addition, the gamma and Rn/Tn dose rates at Digmai, Tajikistan, could reach values of several 10 mSv/a. The doses of ionizing radiation deriving from external radiation (gamma dose rate), indoor radon and thoron with their short-lived progenies in several cases exceeded the recommended annual effective dose threshold level of 10 mSv. At none of the sites investigated did the individual annual effective doses exceed 30 mSv, the internationally recommended value for considering intervention. Current doses of ionizing radiation do not represent a serious hazard to the health of the resident public, but this issue should be adequately addressed to further reduce needless exposure of the resident public to ionizing radiation.

P. Stegnar; I. Shishkov; M. Burkitbayev; B. Tolongutov; M. Yunusov; R. Radyuk; B. Salbu

2013-01-01T23:59:59.000Z

189

Solar irradiance changes and photobiological effects at Earth's surface following astrophysical ionizing radiation events  

E-Print Network [OSTI]

Astrophysical ionizing radiation events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in surface-level solar ultraviolet radiation. Simulations of the atmospheric effects of a variety of events (such as supernovae, gamma-ray bursts, and solar proton events) have been previously published, along with estimates of biological damage at Earth's surface. In this work, we employed the TUV radiative transfer model to expand and improve calculations of surface-level irradiance and biological impacts following an ionizing radiation event. We considered changes in surface-level UVB, UVA, and photosynthetically active radiation (visible light) for clear-sky conditions and fixed aerosol parameter values. We also considered a wide range of biological effects on organisms ranging from humans to phytoplankton. We found that past work overestimated UVB irradiance, but that relative estimates for increase in exposure to DNA damaging radi...

Thomas, Brian C; Snyder, Brock R

2015-01-01T23:59:59.000Z

190

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)

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.

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

2010-12-22T23:59:59.000Z

191

Determination of the properties of nuclear energy levels of La¹³? and Pr¹?¹ by the resonance fluorescence of neutron capture gamma rays  

E-Print Network [OSTI]

DE ERMINATION OF THE PROPERTIES OF NUCLEAR ENEPGY LEVELS OF La~ AND Pr-"' BY THE RESCNANCE FLUORESCENCE CF Ni". UTRON CAPTURE BAI'IMA RAYS A Thesis William Bradley Wilson Submitted to the Graduate College of Texas ASM University in partial... fulfil'men o. the reouirement for ti. e degr e of Master of Science January, 1969 MaJ'or Sub) ect Nuclea Eng. '. u:eering DE' EPM1INATION OF THE PROPERTIES OF NUCLEAR ENERGY LEVELS OF La ~ AND Pr'" BY THE RFSONANCE FLUORESCENCE OF NEUTRON CAP URE...

Wilson, William Bradley

2012-06-07T23:59:59.000Z

192

Medical radiation protection in next decade  

Science Journals Connector (OSTI)

......towards increasing radiation safety levels. Whether...users whenever the radiation dose to the patient...human errors and software-related problems...global view of radiation protection in medicine...increasing radiation safety levels. Whether......

Madan M. Rehani; Eliseo Vano

2011-09-01T23:59:59.000Z

193

GammaCam Technology Demonstration at ORNL Buildings 3026C and 3026D  

Broader source: Energy.gov [DOE]

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

194

Pulsed pyroelectric crystal-powered gamma source  

SciTech Connect (OSTI)

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.

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

2013-04-19T23:59:59.000Z

195

Gamma-ray observations of the Crab Region using a coded-aperture telescope  

SciTech Connect (OSTI)

The region of the Galactic anticenter, including the Crab Nebula, was observed during a balloon flight of the University of New Hampshire Directional Gamma-Ray Telescope employing the coded-aperture imaging technique to image celestial gamma-radiation between 160 keV and 9.3 MeV. The background systematics are treated with a simple and relatively straightforward correction procedure. The results demonstrate that the coded-aperture procedure is a viable approach for imaging not only point sources of radiation, but also extended sources of emission. The results for the Crab's photon spectrum are consistent with a power-law spectrum. Upper limits on the flux levels of line emission at 405 keV and 1050 keV and on the flux from the X-ray binary source A0535 + 26 and diffuse Galactic emission from the anticenter region are derived. 35 references.

Mcconnell, M.L.; Dunphy, P.P.; Forrest, D.J.; Chupp, E.L.; Owens, A.

1987-10-01T23:59:59.000Z

196

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

E-Print Network [OSTI]

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

Tomonori Totani

1998-10-14T23:59:59.000Z

197

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

E-Print Network [OSTI]

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

Daniele Fargion

1999-06-28T23:59:59.000Z

198

Composition for radiation shielding  

DOE Patents [OSTI]

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.

Kronberg, J.W.

1994-08-02T23:59:59.000Z

199

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

SciTech Connect (OSTI)

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

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

1995-09-01T23:59:59.000Z

200

Gamma Ray Bursts  

E-Print Network [OSTI]

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

Stahl, Bennett

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Colour and lipid oxidation changes in dry-cured loins from free-range reared and intensively reared pigs as affected by ionizing radiation dose level  

Science Journals Connector (OSTI)

The effect of irradiation (0, 5 and 10 kGy) of vacuum-packaged Iberian dry-cured loin slices from pigs fed on concentrate (CON) or free-range reared (FRG) was studied in relation to colour changes, TBA-RS and hexanal content. Both, ionizing radiation and type of loin had a significant effect on the instrumental colour parameters of the samples. Irradiation resulted in significantly higher a*-values in both sets of loins, indicating a redder colour. Numerically calculated total colour difference (?E) changes were significantly less intense in CON vacuum-packaged dry-cured loin slices than in FRG samples and changed significantly at 10 kGy dose levels in both types of samples. TBA-RS numbers were significantly affected by irradiation dose and type of loin and increased linearly with dose in both types of slices. Increments in TBA-RS numbers in FRG loin slices was dose-dependent and was closely related to the type of dry-cured loin. Irradiation of dry-cured loin slices significantly increased hexanal contents in both groups of loins and the increases were dose-dependent and greater in FRG samples than in CON samples. Differences in the characteristics of the raw material and initial lipid oxidation level could play an important role in the irradiation-induced changes in vacuum-packaged dry-cured loin slices.

A. Carrasco; R. Tárrega; M.R. Ramírez; F.J. Mingoarranz; R. Cava

2005-01-01T23:59:59.000Z

202

RadTracker: Optical Imaging of High Energy Radiation Tracks  

SciTech Connect (OSTI)

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.

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

2007-03-02T23:59:59.000Z

203

Novel Ways to Probe the Universe with Gamma-Ray Bursts and Quasars  

Science Journals Connector (OSTI)

I consider novel ways by which Gamma-Ray Bursts (GRBs) and quasars can be used... $\\alpha$ radiation which probes the neutral in...

Abraham Loeb

2002-01-01T23:59:59.000Z

204

Study on great northern beans (Phaseolus vulgaris): effect of drum drying process on bean flour properties and effect on gamma radiation on bean starch properties  

SciTech Connect (OSTI)

Great Northern bean (Phaseolus vulgaris L.) drum dried flours at native pH of 6.54, pH 6 and 7 showed reduced activities of trypsin inhibitor, ..cap alpha..-amylase inhibitor, hemagglutinating titer, and nitrogen solubility. Electrophoretic analyses showed a slight modification of the native bean proteins, and the presence of at least four trypsin inhibitors. The study of the effect of 2.5-20 kGy irradiation doses on Great Northern beans showed essentially no modification of the electrophoretic mobility of the storage proteins or the trypsin inhibitors. Nitrogen solubility and hemagglutinating activity were essentially unchanged. With the 20 kGy dose, decrease in ..cap alpha..-amylase inhibitor activity, decrease reactive/available lysine content, and decrease cooking time of the irradiated beans after 11 months of storage were observed. Taste panel results indicated that the control and 20 kGy irradiated bean were significantly different at 5% level. At 20 kGy dose, the beans developed a partially water soluble brown color.

Rayas-Solis, P.

1988-01-01T23:59:59.000Z

205

Lesson 4 - Ionizing Radiation | Department of Energy  

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

4 - Ionizing Radiation 4 - Ionizing Radiation Lesson 4 - Ionizing Radiation Lesson Three showed that unstable isotopes emit energy as they become more stable. This energy is known as radiation. This lesson explores forms of radiation, where radiation is found, how we detect and measure radiation, what sources of radiation people are exposed to, whether radiation is harmful, and how we can limit our exposure. Specific topics covered in this lesson include: Types of radiation Non-ionizing Ionizing Forms of ionizing radiation Alpha particles Beta particles Gamma rays Radiation Decay chain Half-life Dose Radiation measurements Sources of radiation Average annual exposure Lesson 4 - Ionizing Radiation.pptx More Documents & Publications DOE-HDBK-1130-2008 DOE-HDBK-1130-2008 DOE-HDBK-1130-2007

206

Process for gamma ray induced degradation of polychlorinated biphenyls  

DOE Patents [OSTI]

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.

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

1998-01-01T23:59:59.000Z

207

Process for gamma ray induced degradation of polychlorinated biphenyls  

DOE Patents [OSTI]

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.

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

1998-08-25T23:59:59.000Z

208

Gamma–ray bursts  

Science Journals Connector (OSTI)

...R. Priest and N. O. Weiss Gamma-ray bursts Martin J. Rees Institute of...Road, Cambridge CB3 0HA, UK Gamma-ray bursts, an enigma for more than 25...gamma-rays|neutron stars| Gamma-ray bursts By Martin J. Rees Institute...

2000-01-01T23:59:59.000Z

209

Time encoded radiation imaging  

DOE Patents [OSTI]

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.

Marleau, Peter; Brubaker, Erik; Kiff, Scott

2014-10-21T23:59:59.000Z

210

Gamma ray generator  

DOE Patents [OSTI]

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.

Firestone, Richard B; Reijonen, Jani

2014-05-27T23:59:59.000Z

211

accelerated radiative transfer: Topics by E-print Network  

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

Dominated Outflows Astrophysics (arXiv) Summary: Plasma outflows from gamma-ray bursts (GRB), pulsar winds, relativistic jets, and ultra-intense laser targets radiate...

212

Lefvre M., Cros S., Albuisson M., Wald L., 2003. Developing a database using Meteosat data for the de-livery of solar radiation assessments at ground level. In Proceedings of the 23rd EARSeL Annual Symposium  

E-Print Network [OSTI]

, oceanogra- phy and limnology applications, urban air quality studies, sizing of space borne sensors, solar for the de- livery of solar radiation assessments at ground level. In Proceedings of the 23rd EARSeL Annual, Rotterdam, Netherlands, pp. 485-489. Developing a database using METEOSAT data for the delivery of solar

Paris-Sud XI, Université de

213

Actively driven thermal radiation shield  

DOE Patents [OSTI]

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.

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

2002-01-01T23:59:59.000Z

214

Gamma-emitting Materials for Industry  

Science Journals Connector (OSTI)

... , p. 717). A paper dealing with the supply and uses of radium and radon for industry is now being distributed by the Ministry to trade associations, professional institutes ... Points of interest arising from this paper are the different physical properties of radium and radon. Though they both emit gamma-rays of identical quality, the radiation of the former ...

1949-06-04T23:59:59.000Z

215

Gamma Ray Imaging for Environmental Remediation  

SciTech Connect (OSTI)

This program is the development of germanium strip detectors for environmental remediation. It is a collaboration between the Naval Research Laboratory and Lawrence Berkeley National Lab. The goal is to develop detectors that are simultaneously capable of excellent spectroscopy and imaging of gamma radiation.

B.F. Philips; R.A. Kroeger: J.D. Kurfess: W.N. Johnson; E.A. Wulf; E. I. Novikova

2004-11-12T23:59:59.000Z

216

Ultrahigh Energy Cosmic Rays and Prompt TeV Gamma Rays from Gamma Ray Bursts  

E-Print Network [OSTI]

Gamma Ray Bursts (GRBs) have been proposed as one {\\it possible} class of sources of the Ultrahigh Energy Cosmic Ray (UHECR) events observed up to energies $\\gsim10^{20}\\ev$. The synchrotron radiation of the highest energy protons accelerated within the GRB source should produce gamma rays up to TeV energies. Here we briefly discuss the implications on the energetics of the GRB from the point of view of the detectability of the prompt TeV gamma rays of proton-synchrotron origin in GRBs in the up-coming ICECUBE muon detector in the south pole.

Pijushpani Bhattacharjee; Nayantara Gupta

2003-05-12T23:59:59.000Z

217

Radiation Detection Computational Benchmark Scenarios  

SciTech Connect (OSTI)

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

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

2013-09-24T23:59:59.000Z

218

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

E-Print Network [OSTI]

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

Jackman, Charles H.

219

Search for the radiative transitions $?(3770)\\to??_c$ and $??_c(2S)$  

E-Print Network [OSTI]

By using a 2.92 fb$^{-1}$ data sample taken at $\\sqrt{s} = 3.773$ GeV with the BESIII detector operating at the BEPCII collider, we search for the radiative transitions $\\psi(3770)\\to\\gamma\\eta_c$ and $\\gamma\\eta_c(2S)$ through the hadronic decays $\\eta_c(\\eta_c(2S))\\to K^0_SK^\\pm\\pi^\\mp$. No significant excess of signal events above background is observed. We set upper limits at a 90% confidence level for the product branching fractions to be $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c)\\times \\mathcal{B}(\\eta_c\\to K^0_SK^\\pm\\pi^\\mp) < 1.6\\times10^{-5}$ and $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c(2S))\\times \\mathcal{B}(\\eta_c(2S)\\to K^0_SK^\\pm\\pi^\\mp) < 5.6\\times10^{-6}$. Combining our result with world-average values of $\\mathcal{B}(\\eta_c(\\eta_c(2S))\\to K^0_SK^\\pm\\pi^\\mp)$, we find the branching fractions $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c) < 6.8\\times10^{-4}$ and $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c(2S)) < 2.0\\times10^{-3}$ at a 90% confidence level.

M. Ablikim; M. N. Achasov; X. C. Ai; O. Albayrak; M. Albrecht; D. J. Ambrose; F. F. An; Q. An; J. Z. Bai; R. Baldini Ferroli; Y. Ban; D. W. Bennett; J. V. Bennett; M. Bertani; J. M. Bian; E. Boger; O. Bondarenko; I. Boyko; S. Braun; R. A. Briere; H. Cai; X. Cai; O. Cakir; A. Calcaterra; G. F. Cao; S. A. Cetin; J. F. Chang; G. Chelkov; G. Chen; H. S. Chen; J. C. Chen; M. L. Chen; S. J. Chen; X. Chen; X. R. Chen; Y. B. Chen; H. P. Cheng; X. K. Chu; Y. P. Chu; D. Cronin-Hennessy; H. L. Dai; J. P. Dai; D. Dedovich; Z. Y. Deng; A. Denig; I. Denysenko; M. Destefanis; W. M. Ding; Y. Ding; C. Dong; J. Dong; L. Y. Dong; M. Y. Dong; S. X. Du; J. Z. Fan; J. Fang; S. S. Fang; Y. Fang; L. Fava; C. Q. Feng; C. D. Fu; O. Fuks; Q. Gao; Y. Gao; C. Geng; K. Goetzen; W. X. Gong; W. Gradl; M. Greco; M. H. Gu; Y. T. Gu; Y. H. Guan; L. B. Guo; T. Guo; Y. P. Guo; Z. Haddadi; S. Han; Y. L. Han; F. A. Harris; K. L. He; M. He; Z. Y. He; T. Held; Y. K. Heng; Z. L. Hou; C. Hu; H. M. Hu; J. F. Hu; T. Hu; G. M. Huang; G. S. Huang; H. P. Huang; J. S. Huang; L. Huang; X. T. Huang; Y. Huang; T. Hussain; C. S. Ji; Q. Ji; Q. P. Ji; X. B. Ji; X. L. Ji; L. L. Jiang; L. W. Jiang; X. S. Jiang; J. B. Jiao; Z. Jiao; D. P. Jin; S. Jin; T. Johansson; A. Julin; N. Kalantar-Nayestanaki; X. L. Kang; X. S. Kang; M. Kavatsyuk; B. Kloss; B. Kopf; M. Kornicer; W. Kuehn; A. Kupsc; W. Lai; J. S. Lange; M. Lara; P. Larin; M. Leyhe; C. H. Li; Cheng Li; Cui Li; D. Li; D. M. Li; F. Li; G. Li; H. B. Li; J. C. Li; Jin Li; K. Li; K. Li; P. R. Li; Q. J. Li; T. Li; W. D. Li; W. G. Li; X. L. Li; X. N. Li; X. Q. Li; Z. B. Li; H. Liang; Y. F. Liang; Y. T. Liang; D. X. Lin; B. J. Liu; C. L. Liu; C. X. Liu; F. H. Liu; Fang Liu; Feng Liu; H. B. Liu; H. H. Liu; H. M. Liu; J. Liu; J. P. Liu; K. Liu; K. Y. Liu; P. L. Liu; Q. Liu; S. B. Liu; X. Liu; Y. B. Liu; Z. A. Liu; Zhiqiang Liu; Zhiqing Liu; H. Loehner; X. C. Lou; G. R. Lu; H. J. Lu; H. L. Lu; J. G. Lu; Y. Lu; Y. P. Lu; C. L. Luo; M. X. Luo; T. Luo; X. L. Luo; M. Lv; X. R. Lyu; F. C. Ma; H. L. Ma; Q. M. Ma; S. Ma; T. Ma; X. Y. Ma; F. E. Maas; M. Maggiora; Q. A. Malik; Y. J. Mao; Z. P. Mao; J. G. Messchendorp; J. Min; T. J. Min; R. E. Mitchell; X. H. Mo; Y. J. Mo; H. Moeini; C. Morales Morales; K. Moriya; N. Yu. Muchnoi; H. Muramatsu; Y. Nefedov; F. Nerling; I. B. Nikolaev; Z. Ning; S. Nisar; X. Y. Niu; S. L. Olsen; Q. Ouyang; S. Pacetti; M. Pelizaeus; H. P. Peng; K. Peters; J. L. Ping; R. G. Ping; R. Poling; M. Qi; S. Qian; C. F. Qiao; L. Q. Qin; N. Qin; X. S. Qin; Y. Qin; Z. H. Qin; J. F. Qiu; K. H. Rashid; C. F. Redmer; M. Ripka; G. Rong; X. D. Ruan; A. Sarantsev; K. Schoenning; S. Schumann; W. Shan; M. Shao; C. P. Shen; X. Y. Shen; H. Y. Sheng; M. R. Shepherd; W. M. Song; X. Y. Song; S. Spataro; B. Spruck; G. X. Sun; J. F. Sun; S. S. Sun; Y. J. Sun; Y. Z. Sun; Z. J. Sun; Z. T. Sun; C. J. Tang; X. Tang; I. Tapan; E. H. Thorndike; M. Tiemens; D. Toth; M. Ullrich; I. Uman; G. S. Varner; B. Wang; D. Wang; D. Y. Wang; K. Wang; L. L. Wang; L. S. Wang; M. Wang; P. Wang; P. L. Wang; Q. J. Wang; S. G. Wang; W. Wang; X. F. Wang; Y. D. Wang; Y. F. Wang; Y. Q. Wang; Z. Wang; Z. G. Wang; Z. H. Wang; Z. Y. Wang; D. H. Wei; J. B. Wei; P. Weidenkaff; S. P. Wen; M. Werner; U. Wiedner; M. Wolke; L. H. Wu; N. Wu; Z. Wu; L. G. Xia; Y. Xia; D. Xiao; Z. J. Xiao; Y. G. Xie; Q. L. Xiu; G. F. Xu; L. Xu; Q. J. Xu; Q. N. Xu; X. P. Xu; Z. Xue; L. Yan; W. B. Yan; W. C. Yan; Y. H. Yan; H. X. Yang; L. Yang; Y. Yang; Y. X. Yang; H. Ye; M. Ye; M. H. Ye; B. X. Yu; C. X. Yu; H. W. Yu; J. S. Yu; S. P. Yu; C. Z. Yuan; W. L. Yuan; Y. Yuan; A. Yuncu; A. A. Zafar; A. Zallo; S. L. Zang; Y. Zeng; B. X. Zhang; B. Y. Zhang; C. Zhang; C. B. Zhang; C. C. Zhang; D. H. Zhang; H. H. Zhang; H. Y. Zhang; J. J. Zhang; J. Q. Zhang; J. W. Zhang; J. Y. Zhang; J. Z. Zhang; S. H. Zhang; X. J. Zhang; X. Y. Zhang; Y. Zhang; Y. H. Zhang; Z. H. Zhang; Z. P. Zhang; Z. Y. Zhang; G. Zhao; J. W. Zhao; Lei Zhao; Ling Zhao; M. G. Zhao; Q. Zhao; Q. W. Zhao; S. J. Zhao; T. C. Zhao; X. H. Zhao; Y. B. Zhao; Z. G. Zhao; A. Zhemchugov; B. Zheng; J. P. Zheng; Y. H. Zheng; B. Zhong; L. Zhou; Li Zhou; X. Zhou; X. K. Zhou; X. R. Zhou; X. Y. Zhou; K. Zhu; K. J. Zhu; X. L. Zhu; Y. C. Zhu; Y. S. Zhu; Z. A. Zhu; J. Zhuang; B. S. Zou; J. H. Zou

2014-05-13T23:59:59.000Z

220

Cataractogenic effects of proton radiation  

E-Print Network [OSTI]

of proton radiation damage. The purpose of this study was (1) to determine the relative cataractogenic effects of different proton en- ergies, (2) to determine the relative cataractogenic effects of different radiation doses and (3) to determine... Laboratory in 1945 and 1946. Ten victims were exposed to various doses of moderately fast neutrons and hard gamma rays. In the eight survivors, two radiation cataracts resulted (15). In 1948 it was reported that five nuclear physicists with a common...

Kyzar, James Ronald

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Atomic Radiation (Illinois)  

Broader source: Energy.gov [DOE]

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

222

Fiber fed x-ray/gamma ray imaging apparatus  

DOE Patents [OSTI]

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.

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

1992-01-01T23:59:59.000Z

223

Russian Health Studies Program - Relationship to Other Radiation...  

Office of Environmental Management (EM)

the Mayak workers had long-term exposures (10 to 30 years) to plutonium, gamma, and neutron radiation. This combination of radiation types over a working lifetime is more...

224

Angular and Energy Characteristics of Gamma Field at the New Safe Confinement Construction Sit  

SciTech Connect (OSTI)

To results of measurements of angular y and energy distribution of gamma-radiation at the cites of New Safe Confinement erection. The data analysis permitted to identify the main sources of gamma-radiation and to systematize the obtained results.

Batiy, Valeriy; Glebkin, S; Pavlovskiy, L; Pravdyvyi, O; Rudko, Vladimir; Shcherbin, Vladimir; Stojanov, O; Schmieman, Eric A.

2005-08-08T23:59:59.000Z

225

Amelioration of radiation-induced hematopoietic and gastrointestinal damage by Ex-RAD® in mice  

Science Journals Connector (OSTI)

......subsyndrome [5, 6]. Other radiation-countermeasure drugs...gamma-tocotrienol, a naturally occurring vitamin E analog, protected mice from radiation-induced pancytopenia...that protect against radiation-induced hematopoietic...30] in mouse model. Naturally occurring vitamin E......

Sanchita P. Ghosh; Shilpa Kulkarni; Michael W. Perkins; Kevin Hieber; Roli L. Pessu; Kristen Gambles; Manoj Maniar; Tzu-Cheg Kao; Thomas M. Seed; K. Sree Kumar

2012-07-01T23:59:59.000Z

226

Vinflunine (VFL) versus vinorelbine (VRL) and their interaction with radiation in vitro, preliminary results  

Science Journals Connector (OSTI)

...their interaction with radiation in vitro, preliminary...but differs from the naturally occuring compounds in its chemical...between VRL/VFL and radiation, cells were incubated...24h immediately before radiation (Co-60gamma rays...

Cindy Simoens; Filip Lardon; Christel M. De Pooter; Fabienne Breillout; and Jan B. Vermorken

2005-05-01T23:59:59.000Z

227

The whole-body counting facility at the Swedish Radiation Safety Authority after relocation  

Science Journals Connector (OSTI)

......the Swedish Radiation Safety Authority new location...funded by the Swedish Radiation Safety Authority. ACKNOWLEDGMENTS...Measurements of gamma-radiation from the human body...ORTEC. MCA emulator software version 6.0. 2000......

L. del Risco Norrlid; I. Östergren

2011-03-01T23:59:59.000Z

228

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

SciTech Connect (OSTI)

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}.

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

2011-06-02T23:59:59.000Z

229

Gamma-emitting radionuclides in the shallow marine sediments off the Sindh coast, Arabian Sea  

Science Journals Connector (OSTI)

......Pakistan), the Bay of Bengal(18) and...absorbed gamma radiation outdoor dose rates (D...Norwegian Radiation Protection...estuary and the Bay of Bengal. Health...evaluation of the radiation hazard...Assessment of dose rate and...G. E. Estimation of radiation......

M. Akram; Riffat M. Qureshi; Nasir Ahmad; Tariq Jamal Solaija

2006-07-01T23:59:59.000Z

230

Gamma?ray burst spectroscopy  

Science Journals Connector (OSTI)

The statistics and physical properties of gamma ray burst spectral features are presented following a brief review of early theoretical predictions of and experimental searches for such emission. The ?100 observations of 50 keV absorption and 400 keV emission features constitute the largest data base on neutron star lines. Although the statistical significance of individual observations is often weak and interpretation of these features as cyclotron absorption and annihilation radiation poses some theoretical problems it is clear that future observations may have far?reaching implications.

K. Hurley

1988-01-01T23:59:59.000Z

231

Estimate of radiation damage to low-level electronics of the RF system in the LHC cavities arising from beam gas collisions  

Science Journals Connector (OSTI)

......Report No. A 335 Nuclear Instruments and Methods...Annual Conference on Nuclear and Space Radiation...from various elements-vacuum chambers, cryogenic...European Organization for Nuclear Research (CERN...Carlo Method Particle Accelerators instrumentation Protons......

A. Butterworth; A. Ferrari; E. Tsoulou; V. Vlachoudis; T. Wijnands

2005-12-20T23:59:59.000Z

232

BWR radiation control: plant demonstration. Volume 2. Appendixes  

SciTech Connect (OSTI)

The first year's progress is presented for a four-year program intended to implement and evaluate BRAC radiation reduction operational guidelines at the Vermont Yankee BWR and to document the results in sufficient detail to provide guidance to other BWR owners. Past operational, chemistry and radiation level data have been reviewed to provide a historical base of reference. Extensive sampling and chemistry monitoring systems have been installed to evaluate plant chemistry status and the effects of program implemented changes. Radiation surveys and piping gamma scans are being performed at targeted locations to quantify radiation level trends and to identify and quantify piping isotopics. Contact radiation levels on the recirculation line at Vermont Yankee have been increasing at a rate of 175 mR/h-EFPY since 1978. A materials survey of feedwater and reactor components in contact with the process liquid has been performed to identify sources of corrosion product release, particularly cobalt and nickel. A feedwater oxygen injection system has been installed to evaluate the effects of oxygen control on feedwater materials corrosion product releases. A baseline performance evaluation of the condensate treatment and reactor water cleanup systems has been completed. Data on organics and ionics at Vermont Yankee have been obtained. A methodology of BWR feedwater system layup during extended outages was developed, and an evaluation performed of layup and startup practices utilized at Vermont Yankee during the fall 1980 and 1981 refueling outages.

Palino, G.F.; Hobart, R.L.; Wall, P.S.; Sawochka, S.G.

1982-11-01T23:59:59.000Z

233

The photonuclear neutron and gamma-ray backgrounds in the fast ignition experiment  

SciTech Connect (OSTI)

In the fast-ignition scheme, very hard x-rays (hereinafter referred to as {gamma}-rays) are generated by Bremsstrahlung radiation from fast electrons. Significant backgrounds were observed around the deuterium-deuterium fusion neutron signals in the experiment in 2010. In this paper the backgrounds were studied in detail, based on Monte Carlo simulations, and they were confirmed to be {gamma}-rays from the target, scattered {gamma}-rays from the experimental bay walls ({gamma}{sup Prime }-rays), and neutrons generated by ({gamma}, n) reactions in either the target vacuum chamber or the diagnostic instruments ({gamma}-n neutrons).

Arikawa, Y.; Nagai, T.; Hosoda, H.; Abe, Y.; Kojima, S.; Fujioka, S.; Sarukura, N.; Nakai, M.; Shiraga, H.; Azechi, H. [Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka Suita (Japan); Ozaki, T. [National Institution Fusion Science, 322-6 Oroshi-cho, Toki-city, Gifu (Japan)

2012-10-15T23:59:59.000Z

234

Gamma-ray burst data from DMSP satellites  

SciTech Connect (OSTI)

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.

Terrell, J.; Klebesadel, R.W.; Lee, P. (Los Alamos National Lab., NM (United States)); Griffee, J.W. (Sandia National Labs., Albuquerque, NM (United States))

1991-01-01T23:59:59.000Z

235

Gamma-ray burst data from DMSP satellites  

SciTech Connect (OSTI)

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.

Terrell, J.; Klebesadel, R.W.; Lee, P. [Los Alamos National Lab., NM (United States); Griffee, J.W. [Sandia National Labs., Albuquerque, NM (United States)

1991-12-31T23:59:59.000Z

236

Search for the Decay J/psi -> gamma + invisible  

E-Print Network [OSTI]

A search for J/psi radiative decay to weakly interacting neutral final states was performed using the CLEO-c detector at CESR. A total of 3.7 x 10^{6} tagged J/psi events was collected at the psi(2S) resonance and used to study the decay J/psi -> gamma+X, where X is a narrow state that is invisible to the detector. No significant signal was observed and upper limits on the branching fraction were set for masses m_X up to 960 MeV/c^2. The upper limit corresponding to m_X=0 is 4.3x 10^{-6} at the 90% confidence level.

The CLEO Collaboration; J. Insler

2010-03-01T23:59:59.000Z

237

Radiation effects on reactor pressure vessel supports  

SciTech Connect (OSTI)

The purpose of this report is to present the findings from the work done in accordance with the Task Action Plan developed to resolve the Nuclear Regulatory Commission (NRC) Generic Safety Issue No. 15, (GSI-15). GSI-15 was established to evaluate the potential for low-temperature, low-flux-level neutron irradiation to embrittle reactor pressure vessel (RPV) supports to the point of compromising plant safety. An evaluation of surveillance samples from the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) had suggested that some materials used for RPV supports in pressurized-water reactors could exhibit higher than expected embrittlement rates. However, further tests designed to evaluate the applicability of the HFIR data to reactor RPV supports under operating conditions led to the conclusion that RPV supports could be evaluated using traditional method. It was found that the unique HFIR radiation environment allowed the gamma radiation to contribute significantly to the embrittlement. The shielding provided by the thick steel RPV shell ensures that degradation of RPV supports from gamma irradiation is improbable or minimal. The findings reported herein were used, in part, as the basis for technical resolution of the issue.

Johnson, R.E. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Engineering Technology; Lipinski, R.E. [Idaho National Engineering Lab., Rockville, MD (United States)

1996-05-01T23:59:59.000Z

238

Gamma-Ray Studies in Boron-10  

Science Journals Connector (OSTI)

Gamma rays emanating from the 7.56-Mev level of B10 were analyzed with a five-crystal pair spectrometer. Cascade gamma rays were investigated by recording the spectra in coincidence with the 2.40, 0.72, 2.15, and 5.41-Mev gamma-ray transitions. The branching ratios for the decay of the 7.56-Mev level were found to be 76%, 9%, and 15% for 6.84, 5.41, and 2.40-Mev gamma rays, respectively. For the 2.15-Mev level, the respective branching ratios for 2.15, 1.43, and 0.41-Mev gamma rays were shown to be 16%, 29%, and 55%. The partial width for the 3.01-Mev transition was found to be less than 1% of the total width of the 5.16-Mev state in B10. Combining this result with the data of Meyer-Schützmeister and Hanna, the gamma-ray width of the 5.16-Mev level was found to be 0.51 ev and the alpha width 32level is quite small, this result is shown to be consistent with the alpha transition being isotopic spin allowed. The conflict between our result ??3.01?<0.01 and other evidence requiring larger relative partial gamma-ray widths may be resolved if the 5.16-Mev state in B10 is assumed to be a doublet.

Esther L. Sprenkel and James W. Daughtry

1961-11-01T23:59:59.000Z

239

Standards for Protection Against Radiation (Michigan)  

Broader source: Energy.gov [DOE]

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

240

Harnessing a radiation inducible promoter of Deinococcus radiodurans for enhanced precipitation of uranium  

Science Journals Connector (OSTI)

Abstract Bioremediation is an attractive option for the treatment of radioactive waste. We provide a proof of principle for augmentation of uranium bioprecipitation using the radiation inducible promoter, Pssb from Deinococcus radiodurans. Recombinant cells of D. radiodurans carrying acid phosphatase gene, phoN under the regulation of Pssb when exposed to 7 kGy gamma radiation at two different dose rates of 56.8 Gy/min and 4 Gy/min, showed 8–9 fold increase in acid phosphatase activity. Highest whole cell PhoN activity was obtained after 2 h in post irradiation recovery following 8 kGy of high dose rate radiation. Such cells showed faster removal of high concentrations of uranium than recombinant cells expressing PhoN under a radiation non-inducible deinococcal promoter, PgroESL and could precipitate uranium even after continuous exposure to 0.6 Gy/min gamma radiation for 10 days. Radiation induced recombinant D. radiodurans cells when lyophilized retained high levels of PhoN activity and precipitated uranium efficiently. These results highlight the importance of using a suitable promoter for removal of radionuclides from solution.

Chitra Seetharam Misra; Rita Mukhopadhyaya; Shree Kumar Apte

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Low Dose Radiation Program: Radiation Biology and the Radiation Research  

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

Biology and the Radiation Research Program Biology and the Radiation Research Program The Department of Energy (DOE) and its predecessor organizations, Energy Research and Development Agency (ERDA) and Atomic Energy Commission (AEC), always have been concerned about the health effects of ionizing radiation. Extensive research has been conducted under their sponsorship at all levels of biological organization from molecules to man. Over the past 60 years, studies using every type of radiation source have included exposure to both external radiation sources and to internally deposited radioactive materials. These exposures used different dose patterns and distributions delivered over a wide range of experimental times. This extensive research provided the basis for the new Low Dose Radiation Research Program, linking

242

Gamma Ray Bursts Sudden, intense flashes of gamma rays  

E-Print Network [OSTI]

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

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

243

Patterns of cell division, DNA base compositions, and fine structures of some radiation-resistant vegetative bacteria found in food.  

Science Journals Connector (OSTI)

...29. Thornley, M. J. 1963. Radiation resistance among bac- VOL...Glauert. 1968. Fine structure and radiation resistance in Acinetobacter studies...Maxcy. 1971. Impact of low doses of gamma radiation and storage of the microflora...

S W Sanders; R B Maxcy

1979-01-01T23:59:59.000Z

244

Gamma ray burst positrons  

Science Journals Connector (OSTI)

The international network of gamma ray burst detectors has provided redundant localizations for six gamma ray bursts with accuracies in the arcminute range. Catalog radio soft X?ray and optical searches have been performed for some of these events. The results of these searches are reviewed. Although radio X?ray and optical candidates are found in the error boxes no clear association between gamma ray bursts and other forms of emission has emerged to date. Optical radio searches are continuing.

K. Hurley

1982-01-01T23:59:59.000Z

245

Effect of surface treatments on radiation buildup in steam generators  

SciTech Connect (OSTI)

Test coupons of typical PWR materials of construction were prepared using a number of pretreatments to minimize radiation buildup. The coupons were then exposed to primary coolant at the Doel-2 PWR in Belgium. The exposure periods for the coupons ranged from one to three fuel cycles. After removal from the primary system, doserate and gamma spectroscopy measurements were made to determine the radioactivity levels on the coupons. Varying levels of success were achieved for the preconditioning techniques tested. Electropolishing alone provided some degree of resistance to radiation buildup on the treated surface and electropolishing plus passivation was shown to be even better. Radiation buildup resistance of the palladium-coated coupons was poor; radiation levels on these coupons were even higher than on the untreated reference coupons. The poor performance of the palladium-coated coupons was possibly due to the method used to apply the coating. In contrast to palladium coating, very encouraging results were achieved with chromium plating plus passivation. Preliminary results show that this technique can inhibit activity deposition by as much as a factor of ten. 4 refs., 64 figs., 26 tabs.

Asay, R.H. (Radiological and Chemical Technology, Inc., Santa Clara, CA (United States)); Pick, M.E. (Nuclear Electric plc, Berkeley (United Kingdom). Berkeley Nuclear Labs.); Roofthooft, R. (Laboratoire Belge de l'Industrie Electrique (LABORELEC), Linkebeek (Belgium)); van Melsen, C. (Energy Invest, Beersel (Belgium))

1991-11-01T23:59:59.000Z

246

Gamma irradiation effects in W films  

SciTech Connect (OSTI)

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.

Claro, Luiz H. [Instituto de Estudos Avancados - IEAv, Rod. dos Tamoios, km 5,5, CEP: 12228-840, Sao Jose dos Campos, SP (Brazil) and Faculdade de Tecnologia Sao Francisco - FATESF, Av. Siqueira Campos, 1174, CEP: 12207-000, Jacarei (Brazil); Santos, Ingrid A. [Instituto de Estudos Avancados - IEAv, Rod. dos Tamoios, km 5,5, CEP: 12228-840, Sao Jose dos Campos, SP (Brazil); Silva, Cassia F. [Faculdade de Tecnologia Sao Francisco - FATESF, Av. Siqueira Campos, 1174, CEP: 12207-000, Jacarei, SP (Brazil)

2013-05-06T23:59:59.000Z

247

Dual Gamma Neutron Directional Elpasolite Detector  

SciTech Connect (OSTI)

Some applications, particularly in homeland security, require detection of both neutron and gamma radiation. Typically, this is accomplished with a combination of two detectors registering neutrons and gammas separately. We have investigated a new type of neutron/gamma (n/?) directional detection capability. We explored a new class of scintillator, cerium (Ce)-doped Elpasolites such as Cs2LiYCl6:Ce (CLYC), Cs2LiLaCl6 (CLLC), Cs2LiLaBr6:Ce (CLLB), or Cs2LiYBr6:Ce (CLYB). These materials are capable of providing energy resolution as good as 2.9% at 662 keV (FWHM), which is better than that of NaI:Tl. Because they contain 6Li, Elpasolites can also detect thermal neutrons. In the energy spectra, the full energy thermal neutron peak appears near or above 3 GEEn MeV. Thus, very effective pulse height discrimination is possible. In addition, the core-to-valence luminescence (CVL) provides Elpasolites with different temporal responses under gamma and neutron excitation, and, therefore, may be exploited for effective pulse shape discrimination. For instance, the CLLC emission consists of two main components: (1) CVL spanning from 220 nm to 320 nm and (2) Ce emission found in the range of 350 to 500 nm. The former emission is of particular interest because it appears only under gamma excitation. It is also very fast, decaying with a 2 ns time constant. The n/? discrimination capability of Elpasolite detectors may be optimized by tuning the cerium doping content for maximum effect on n/? pulse shape differences. The resulting Elpasolite detectors have the ability to collect neutron and gamma data simultaneously, with excellent discrimination. Further, an array of four of these Elpasolites detectors will perform directional detection in both the neutron and gamma channels simultaneously.

Guss, P. P.; Mukhopadhyay, S.

2013-09-01T23:59:59.000Z

248

Gamma ray bursts  

Science Journals Connector (OSTI)

The time histories size spectrum spatial distribution and repetition rates of gamma ray bursts are reviewed briefly. Evidence for a neutron star origin for gamma ray bursts may be found in many of these aspects of bursters. New results from optical searches are described. Substantial progress has been made recently in the optical identificaiton of the 1978 November 19 burst.

K. Hurley

1983-01-01T23:59:59.000Z

249

Low Dose Radiation Program: Links - Agencies with Radiation Regulatory  

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

Agencies with Radiation Regulatory Concerns and Involvement Agencies with Radiation Regulatory Concerns and Involvement Biological Effects of Low Level Exposures (BELLE) Canadian Nuclear Safety Commission Center for Risk Excellence Health Protection Agency The Health Risks of Extraterrestrial Environments International Commission on Radiation Units and Measurements, Inc. International Commission on Radiological Protection (ICRP) International Radiation Protection Association (IRPA) NASA Space Radiation Program National Academy of Sciences (NAS) Nuclear and Radiation Studies Board National Aeronautics and Space Administration (NASA) NASA OBRR Task Book Publication National Council on Radiation Protection (NCRP) National Institute of Environmental Health Sciences (NIEHS) National Toxicology Program (NTP) Occupational Safety and Health Administration (OSHA)

250

Optical gamma thermometer  

DOE Patents [OSTI]

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.

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

2013-08-06T23:59:59.000Z

251

Gamma-ray Astronomy: Implications for Fundamental Physics  

E-Print Network [OSTI]

Gamma-ray Astronomy studies cosmic accelerators through their electromagnetic radiation in the energy range between ~100 MeV and ~100 TeV. The present most sensitive observations in this energy band are performed, from space, by the Large Area Telescope onboard the Fermi satellite and, from Earth, by the Imaging Air Cherenkov Telescopes MAGIC, H.E.S.S. and VERITAS. These instruments have revolutionized the field of Gamma-ray Astronomy, discovering different populations of gamma-ray emitters and studying in detail the non-thermal astrophysical processes producing this high-energy radiation. The scientific objectives of these observatories include also questions of fundamental physics. With gamma-ray instruments we study the origin of Galactic cosmic rays, testing the hypothesis or whether they are mainly produced in supernova explosions. Also, we obtain the most sensitive measurement of the cosmic electron-positron spectrum between 20 GeV and 5 TeV. By observing the gamma-ray emission from sources at cosmological distances, we learn about the intensity and evolution of the extragalactic background light, and perform tests of Lorentz Invariance. Moreover, we can search for dark matter by looking for gamma-ray signals produced by its annihilation or decay in over-density sites. In this paper, we review the most recent results produced with the current generation of gamma-ray instruments in these fields of research.

Javier Rico

2011-11-28T23:59:59.000Z

252

E-Print Network 3.0 - annihilation radiation telescope Sample...  

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

Collection: Physics 3 MPI Kernphysik, Heidelberg Humboldt Univ. Berlin Summary: Gamma ray bursts Cosmology Diffuse extragalactic radiation fields via cutoff in AGN spectra and...

253

Point-like gamma ray sources as signatures of distant accelerators of ultra high energy cosmic rays  

E-Print Network [OSTI]

We discuss the possibility of observing distant accelerators of ultra high energy cosmic rays in synchrotron gamma rays. Protons propagating away from their acceleration sites produce extremely energetic electrons during photo-pion interactions with cosmic microwave background photons. If the accelerator is embedded in a magnetized region, these electrons will emit high energy synchrotron radiation. The resulting synchrotron source is expected to be point-like and detectable in the GeV-TeV energy range if the magnetic field is at the nanoGauss level.

S. Gabici; F. A. Aharonian

2005-05-22T23:59:59.000Z

254

Inelastic cross sections from gamma-ray measurements  

SciTech Connect (OSTI)

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

Nelson, Ronald Owen [Los Alamos National Laboratory

2010-12-06T23:59:59.000Z

255

SRNL Deploys Innovative Radiation Mapping Device | Department of Energy  

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

SRNL Deploys Innovative Radiation Mapping Device SRNL Deploys Innovative Radiation Mapping Device SRNL Deploys Innovative Radiation Mapping Device November 3, 2011 - 12:00pm Addthis The Savannah River National Laboratory completed successful deployments of the RadBall, a gamma radiation-mapping device. The Savannah River National Laboratory completed successful deployments of the RadBall, a gamma radiation-mapping device. AIKEN, S.C. - The Savannah River National Laboratory (SRNL), EM's national lab, has made strides with remote technology designed to reduce worker exposure while measuring radiation in contaminated areas. uilding on a successful collaboration with the United Kingdom's National Nuclear Laboratory, SRNL completed successful deployments of RadBall, a gamma radiation-mapping device, after testing the technology. The device

256

Radiation safety system  

Science Journals Connector (OSTI)

......occupational illness to personnel, major damage...acceptable levels. Selection of control measures...or equipment operating correctly in...99 103 to 104 Personnel life safety...and abnormal operating conditions under...radiation risk to personnel, public and...worker radiation training) reduces the......

Vaclav Vylet; James C. Liu; Lawrence S. Walker

2009-11-01T23:59:59.000Z

257

Radiation safety system  

Science Journals Connector (OSTI)

......disable this safety function and...circuits and software. Other required...source in case of radiation monitors. Feedback...from other non-safety systems to prevent...write and check software. The expected...logic systems for safety functions can...levels of prompt radiation hazard. ACS......

Vaclav Vylet; James C. Liu; Lawrence S. Walker

2009-11-01T23:59:59.000Z

258

Neutron And Gamma Detector Using An Ionization Chamber With An Integrated  

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

Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. Available for thumbnail of Feynman Center (505) 665-9090 Email Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. A conductive neutron-capturing layer is disposed on the interior surface of the cathode and a plastic housing surrounds the cathode. A plastic lid is attached to the housing and encloses the interior volume of the cathode forming an

259

Radiation: Radiation Control (Indiana)  

Broader source: Energy.gov [DOE]

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

260

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

SciTech Connect (OSTI)

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

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

2006-07-21T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Gamma-ray Astronomy  

E-Print Network [OSTI]

The relevance of gamma-ray astronomy to the search for the origin of the galactic and, to a lesser extent, the ultra-high-energy cosmic rays has long been recognised. The current renaissance in the TeV gamma-ray field has resulted in a wealth of new data on galactic and extragalactic particle accelerators, and almost all the new results in this field were presented at the recent International Cosmic Ray Conference (ICRC). Here I summarise the 175 papers submitted on the topic of gamma-ray astronomy to the 30th ICRC in Merida, Mexico in July 2007.

Jim Hinton

2007-12-20T23:59:59.000Z

262

Neutron counting and gamma spectroscopy with PVT detectors.  

SciTech Connect (OSTI)

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.

Mitchell, Dean James; Brusseau, Charles A.

2011-06-01T23:59:59.000Z

263

Use of gamma-ray spectroscopy for direct detection of thermal neutrons  

Science Journals Connector (OSTI)

A neutron detector based on detection of the prompt gamma-radiation emitted as a result of neutron interaction with a suitable neutron absorber is described. Boron-10 loaded polyethylene is used as the neutron...

F. Ghanbari; A. H. Mohagheghi

2001-05-01T23:59:59.000Z

264

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

E-Print Network [OSTI]

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

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

2004-01-01T23:59:59.000Z

265

Angular Signatures of Dark Matter in the Diffuse Gamma Ray Spectrum  

SciTech Connect (OSTI)

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.

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

2007-02-01T23:59:59.000Z

266

Bacterial stress response to environmental radiation relating to the Fukushima radiation discharge event, Japan: Will environmental bacteria alter their antibiotic susceptibility profile?  

Science Journals Connector (OSTI)

Antibiotic resistance in clinical pathogens in humans may be traced back to resistance mechanisms in environmental bacteria and any factors, which are likely to alter (upregulate) resistance in environmental organisms, is of potential and eventual consequence to human pathogens. Furthermore, sublethal doses of gamma radiation to environmental organisms may cause sublethal stress and a selective pressure, which may lead to mutational events that alter the bacterium's susceptibility profile. A gamma (?) radiation simulation experiment was performed to emulate the exposure of four environmental bacteria, including Listeria innocua, Bacillus subtilis, E. coli and Pseudomonas aeruginosa, to levels of radiation in and around Fukushima, Japan, equating to 1, 10 and 100 years equivalence exposure. Alteration to susceptibility to 14 antibiotics was measured as the primary endpoint. There was no significant alteration in the susceptibility of the Gram-positive organisms, whereas both Gram-negative organisms became slightly more susceptible to the antibiotics tested over time. These data indicate that such radiation exposure will not increase the antibiotic resistance profile of these organisms and hence not add to the global public health burden of increased antibiotic resistance in human bacterial pathogens.

Shigeyuki Nakanishi; John E. Moore; Motoo Matsuda; Colin E. Goldsmith; Wilson A. Coulter; Juluri R. Rao

2012-01-01T23:59:59.000Z

267

Influence of Extraterrestrial Radiation on Radiation Portal Monitors  

SciTech Connect (OSTI)

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

Keller, Paul E.; Kouzes, Richard T.

2009-06-01T23:59:59.000Z

268

Gamma-Ray Bursts  

E-Print Network [OSTI]

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

P. Meszaros

2006-05-30T23:59:59.000Z

269

A supersymmetric model of gamma ray bursts  

E-Print Network [OSTI]

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

L. Clavelli; G. Karatheodoris

2005-08-08T23:59:59.000Z

270

Low Dose Radiation Program: Links - Organizations Conducting Radiation  

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

Conducting Low Dose Radiation Research Conducting Low Dose Radiation Research DOE Low Dose Radiation Research Program DoReMi Integrating Low Dose Research High Level Expert Group (HLEG) on European Low Dose Risk Research Multidisciplinary European Low Dose Initiative (MELODI) RISC-RAD Radiosensitivity of Individuals and Susceptibility to Cancer induced by Ionizing Radiation United States Transuranium & Uranium Registries Organizations Conducting other Radiation Research Argonne National Laboratory (ANL) Armed Forces Radiology Research Institute (AFRRI) Atmospheric Radiation Measurement (ARM) Program Brookhaven National Laboratory (BNL) Center for Devices and Radiological Health (CDRH) Central Research Institute of Electric Power Industry (CRIEPI) Colorado State University Columbia University

271

Standard Test Method for Application of Ionization Chambers to Assess the Low Energy Gamma Component of Cobalt-60 Irradiators Used in Radiation-Hardness Testing of Silicon Electronic Devices  

E-Print Network [OSTI]

1.1 Low energy components in the photon energy spectrum of Co-60 irradiators lead to absorbed dose enhancement effects in the radiation-hardness testing of silicon electronic devices. These low energy components may lead to errors in determining the absorbed dose in a specific device under test. This method covers procedures for the use of a specialized ionization chamber to determine a figure of merit for the relative importance of such effects. It also gives the design and instructions for assembling this chamber. 1.2 This method is applicable to measurements in Co-60 radiation fields where the range of exposure rates is 7 × 10 ?6 to 3 × 10?2 C kg ?1 s?1 (approximately 100 R/h to 100 R/s). For guidance in applying this method to radiation fields where the exposure rate is >100 R/s, see Appendix X1. Note 1—See Terminology E170 for definition of exposure and its units. 1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information onl...

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

272

Coherence in Spontaneous Radiation Processes  

Science Journals Connector (OSTI)

By considering a radiating gas as a single quantum-mechanical system, energy levels corresponding to certain correlations between individual molecules are described. Spontaneous emission of radiation in a transition between two such levels leads to the emission of coherent radiation. The discussion is limited first to a gas of dimension small compared with a wavelength. Spontaneous radiation rates and natural line breadths are calculated. For a gas of large extent the effect of photon recoil momentum on coherence is calculated. The effect of a radiation pulse in exciting "super-radiant" states is discussed. The angular correlation between successive photons spontaneously emitted by a gas initially in thermal equilibrium is calculated.

R. H. Dicke

1954-01-01T23:59:59.000Z

273

First observations of Y(1S)->gamma pi(+)pi(-) and Y(1S)->gamma pi(0)pi(0)  

E-Print Network [OSTI]

We report on a study of exclusive radiative decays of the Y(1S) resonance collected with the CLEO II detector operating at the Cornell Electron Storage Ring. We present the first observation of the radiative decays Y(1S) --> gamma pi(+)pi(-) and Y(1...

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

1999-01-01T23:59:59.000Z

274

TL detectors for gamma ray dose measurements in criticality accidents  

Science Journals Connector (OSTI)

......both the neutron and the gamma...radiation field induced by criticality...with both neutron and photon...the neutron spectrum can improve...on neutron energy i.e...251017 fissions, t=35s...data about energy spectrum, the choice...shielding from thermal neutrons (containing......

Saveta Miljanic; Benjamin Zorko; Beatriz Gregori; Zeljka Knezevic

2007-07-01T23:59:59.000Z

275

Proposed Lymph Node Staging System Using the International Consensus Guidelines for Lymph Node Levels Is Predictive for Nasopharyngeal Carcinoma Patients From Endemic Areas Treated With Intensity Modulated Radiation Therapy  

SciTech Connect (OSTI)

Purpose: To propose a lymph node (N) staging system for nasopharyngeal carcinoma (NPC) based on the International Consensus Guidelines for lymph node (LN) levels and MRI-determined nodal variables. Methods and Materials: The MRI scans and medical records of 749 NPC patients receiving intensity modulated radiation therapy with or without chemotherapy were retrospectively reviewed. The prognostic significance of nodal level, laterality, maximal axial diameter, extracapsular spread, necrosis, and Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) size criteria were analyzed. Results: Nodal level and laterality were the only independent prognostic factors for distant failure and disease failure in multivariate analysis. Compared with unilateral levels Ib, II, III, and/or Va involvement (hazard ratio [HR] 1), retropharyngeal lymph node involvement alone had a similar prognostic value (HR 0.71; 95% confidence interval [CI] 0.43-1.17; P=.17), whereas bilateral levels Ib, II, III, and/or Va involvement (HR 1.65; 95% CI 1.06-2.58; P=.03) and levels IV, Vb, and/or supraclavicular fossa involvement (HR 3.47; 95% CI 1.92-6.29; P<.01) both significantly increased the HR for distant failure. Thus we propose that the N category criteria could be revised as follows: N0, no regional LN metastasis; N1, retropharyngeal lymph node involvement, and/or unilateral levels Ib, II, III, and/or Va involvement; N2, bilateral levels Ib, II, III, and/or Va involvement; N3, levels IV, Vb, and/or supraclavicular fossa involvement. Compared with the 7th edition of the UICC/AJCC criteria, the proposed N staging system provides a more satisfactory distinction between the HRs for regional failure, distant failure, and disease failure in each N category. Conclusions: The proposed N staging system defined by the International Consensus Guidelines and laterality is predictive and practical. However, because of no measurements of the maximal nodal diameter on MRI slices, the prognostic significance of LN size needs further evaluation.

Li, Wen-Fei; Sun, Ying; Mao, Yan-Ping; Chen, Lei; Chen, Yuan-Yuan; Chen, Mo [Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou (China)] [Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou (China); Liu, Li-Zhi [Imaging Diagnosis and Interventional Center, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou (China)] [Imaging Diagnosis and Interventional Center, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou (China); Lin, Ai-Hua [Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou (China)] [Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou (China); Li, Li [Imaging Diagnosis and Interventional Center, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou (China)] [Imaging Diagnosis and Interventional Center, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou (China); Ma, Jun, E-mail: majun2@mail.sysu.edu.cn [Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou (China)] [Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou (China)

2013-06-01T23:59:59.000Z

276

Factorization in B ---> V gamma decays  

SciTech Connect (OSTI)

The factorization properties of the radiative decays B {yields} V{gamma} are analyzed at leading order in 1/m{sub b} using the soft-collinear effective theory. It is shown that the decay amplitudes can be expressed in terms of a B {yields} V form factor evaluated at q{sup 2} = 0, light-cone distribution amplitudes of the B and V mesons, and calculable hard-scattering kernels. The renormalization-group equations in the effective theory are solved to resum perturbative logarithms of the different scales in the decay process. Phenomenological implications for the B {yields} K*{gamma} branching ratio, isospin asymmetry, and CP asymmetries are discussed, with particular emphasis on possible effects from physics beyond the Standard Model.

Becher, Thomas; /Fermilab; Hill, Richard J.; /SLAC; Neubert, Matthias; /Cornell U., LEPP

2005-03-01T23:59:59.000Z

277

Neutron-driven gamma-ray laser  

DOE Patents [OSTI]

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.

Bowman, Charles D. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

278

Factorization in B to V gamma Decays  

SciTech Connect (OSTI)

The factorization properties of the radiative decays B {yields} V{gamma} are analyzed at leading order in 1/mb using the soft-collinear effective theory. It is shown that the decay amplitudes can be expressed in terms of a B {yields} V form factor evaluated at q{sup 2} = 0, light-cone distribution amplitudes of the B and V mesons, and calculable hard-scattering kernels. The renormalization-group equations in the effective theory are solved to resume perturbative logarithms of the different scales in the decay process. Phenomenological implications for the B {yields} K*{gamma} branching ratio, isospin asymmetry, and CP asymmetries are discussed, with particular emphasis on possible effects from physics beyond the Standard Model.

Becher, T

2005-03-28T23:59:59.000Z

279

Nano {gamma}'/{gamma}'' composite precipitates in Alloy 718  

SciTech Connect (OSTI)

Nanoscale composite precipitates of Alloy 718 have been investigated with both high-resolution scanning transmission electron microscopy and phase field modeling. Chemical analysis via energy-dispersive x-ray spectroscopy allowed for the differentiation of {gamma}' and {gamma}'' particles, which is not otherwise possible through traditional Z-contrast methods. Phase field modeling was applied to determine the stress distribution and elastic interaction around and between the particles, respectively, and it was determined that a composite particle (of both {gamma}' and {gamma}'') has an elastic energy that is significantly lower than, for example, single {gamma}' and {gamma}'' precipitates which are non-interacting.

Phillips, P. J. [Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); McAllister, D.; Gao, Y.; Lv, D.; Williams, R. E. A.; Wang, Y.; Mills, M. J. [Department of Materials Science and Engineering, Ohio State University, Columbus, Ohio 43210 (United States); Peterson, B. [Honeywell Aerospace, Phoenix, Arizona 85034 (United States)

2012-05-21T23:59:59.000Z

280

High spins in gamma-soft nuclei  

SciTech Connect (OSTI)

Nuclei which are soft with respect to the ..gamma.. shape degree of freedom are expected to have many different structures coexisting in the near-yrast regime. In particular, the lowest rotational quasi-particle in a high-j shell exerts a strong polarizing effect on ..gamma... The ..gamma.. to which it drives is found to vary smoothly over a 180/sup 0/ range as the position of the Fermi level varies. This simple rule is seen to have a direct connection with the energy staggering of alternate spin states in rotational bands. A diagram is presented which provides a general theoretical reference for experimental tests of the relation between ..gamma.., spin staggering, configuration, and nucleon number. In a quasicontinuum spectrum, the coexistence of different structures are expected to make several unrelated features appear within any one slice of sum energy and multiplicity. However, it is also seen that the in-band moment of inertia may be similar for many bands of different ..gamma...

Leander, G.A.; Frauendorf, S.; May, F.R.

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Optomechanical design of a prompt gamma reaction history diagnostic  

SciTech Connect (OSTI)

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 to 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.

Kaufman, Morris I; Frogget, Brent C; Tunnel, Thomas W; Cox, Brian; Frayer, Daniel K; Ali, Zaheer; Herrmann, Hans

2009-09-10T23:59:59.000Z

282

Optomechanical design of a prompt gamma reaction history diagnostic  

SciTech Connect (OSTI)

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.

Hermann, Hans W [Los Alamos National Laboratory; Kaufman, Morris I [Los Alamos National Laboratory; Malone, Robert M [NSTEC; Frogget, Brent C [NSTEC; Tunnell, Thomas W [NSTEC; Cox, Brian [NSTEC; Frayer, Daniel K [NSTEC; Ali, Zaheer [NSTEC; Stoeffl, Wolfgang [LLNL

2009-01-01T23:59:59.000Z

283

Neutron and gamma irradiation damage to organic materials.  

SciTech Connect (OSTI)

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.

White, Gregory Von, II; Bernstein, Robert

2012-04-01T23:59:59.000Z

284

Vitamin E: tocopherols and tocotrienols as potential radiation countermeasures  

Science Journals Connector (OSTI)

......TUNEL (terminal deoxynucleotidyl transferase mediated dUTP nick end labeling)- and PUMA- (p53 upregulated modulator of apoptosis...gamma-radiation injury. The above results suggest that TS may merit further development using appropriate large animal models for......

Vijay K. Singh; Lindsay A. Beattie; Thomas M. Seed

2013-11-01T23:59:59.000Z

285

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]

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.

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

2001-01-01T23:59:59.000Z

286

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

SciTech Connect (OSTI)

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.

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

1991-06-01T23:59:59.000Z

287

Polarization mesurements of gamma ray bursts and axion like particles  

E-Print Network [OSTI]

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

Andre Rubbia; Alexander Sakharov

2008-09-03T23:59:59.000Z

288

Radiation tolerance of piezoelectric bulk single-crystal aluminum nitride  

SciTech Connect (OSTI)

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

David A. Parks; Bernhard R. Tittmann

2014-07-01T23:59:59.000Z

289

Si(001) vicinal surface oxidation in O2: Angle-resolved Si 2p core-level study using synchroton radiation  

Science Journals Connector (OSTI)

The aim of this work is to determine if, after oxidation in pure O2, a vicinal surface Si(001) miscut 5° towards the [110] direction, exhibits a preferential SiO2 formation on the [110] ledges. In a first stage, combining XPS (X-ray photoelectron spectroscopy) and LEED (low-energy electron diffraction) available in an auxiliary chamber, we examine the cleaning conditions leading to a non-faceted stepped Si surface with dominant (2 × 1) single domains. This surface preparation is reproduced in the synchroton facility chamber where ARPR-single-resolved photoemission spectroscopy) is performed: after cleaning the Si surface and studying the starting situation (san- states, initial contamination), an ultra-thin oxide film (? 1.5 × 1015 oxidised Si atoms/cm2) is grown at 785–800°C, under Torr of oxygen. The absence of anisotropy in the ARPES emission of the Si 2p core levels taken at the minimum electron escape depth (hv=130eV), points to no extra-growth of the oxide on the ledges. The in-depth distribution of the oxide states seems to be homogeneous, within the sensitivity of the probe. On the other hand, after partial thermal desorption of the ultra-thin oxide film in vacuum, a strong anisotropy in the emission of electrons from SiO2 is seen in areas where oxide patches coexist with bare silicon. It is shown that this ensues from a significant step bunching and (111) faceting of the surface. A correlation is made with SEM (scanning electron microscopy) images of the surface. The problem of step bunching, inasmuch as it can alter the interpretation of shadowing effects, is emphasized.

F. Rochet; H. Roulet; G. Dufour; S. Carniato; C. Guillot; N. Barrett; M. Froment

1992-01-01T23:59:59.000Z

290

Low Dose Radiation Research Program: DOE Lowdose Radiation Program Workshop  

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

Using a Low LET Electron Microbeam to Investigate Non-Targeted Using a Low LET Electron Microbeam to Investigate Non-Targeted Effects of Low Dose Radiation. Authors: William F. Morgan1 and Marianne B. Sowa2 Institutions: 1Radiation Oncology Research Laboratory, University of Maryland, Baltimore MD 21201 2 Chemical Structure and Dynamics, Pacific Northwest National Laboratory, Richland WA 99352 We have recently installed a low LET electron microbeam that generates energetic electrons to mimic radiation damage from gamma and x-ray sources. It has been designed such that high-energy electrons deposit energy in a pre-selected subset of cells leaving neighboring cells unirradiated (Figure 1). In this way it is possible to examine non-targeted effects associated with low dose radiation exposure including induced genomic instability and

291

Hybrid model of GeV-TeV gamma ray emission from Galactic Center  

E-Print Network [OSTI]

The observations of high energy $\\gamma$-ray emission from the Galactic center (GC) by HESS, and recently by Fermi, suggest the cosmic ray acceleration in the GC and possibly around the supermassive black hole. In this work we propose a lepton-hadron hybrid model to explain simultaneously the GeV-TeV $\\gamma$-ray emission. Both electrons and hadronic cosmic rays were accelerated during the past activity of the GC. Then these particles would diffuse outwards and interact with the interstellar gas and background radiation field. The collisions between hadronic cosmic rays with gas is responsible to the TeV $\\gamma$-ray emission detected by HESS. With fast cooling in the strong radiation field, the electrons would cool down and radiate GeV photons through inverse Compton scattering off the soft background photons. This scenario provides a natural explanation of the observed GeV-TeV spectral shape of $\\gamma$-rays.

Yi-Qing Guo; Qiang Yuan; Cheng Liu; Ai-Feng Li

2014-09-14T23:59:59.000Z

292

About Radiation  

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

Radiation Radiation What is radiation? Radiation is a form of energy that is a part of our everyday lives. All of us receive a "dose" of radiation each day. Most of the dose comes from naturally occurring radioactive materials such as uranium, thorium, radon, and certain forms of potassium and carbon. The air we breathe contains radon, the food we eat contains uranium and thorium from the soil, and our bodies contain radioactive forms of potassium and carbon. Cosmic radiation from the sun also contributes to our natural radiation dose. We also receive radiation doses from man-made sources such as X-rays, nuclear medical procedures, power plants, smoke detectors and older television sets. Some people, such as nuclear plant operators, flight crews, and nuclear medicine staff may also receive an occupational radiation dose.

293

Gamma Ray Bursts  

E-Print Network [OSTI]

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

Peter Mészáros

2012-04-12T23:59:59.000Z

294

Natural gamma radioactivity in the villages of Kanyakumari District, Tamil Nadu, India  

Science Journals Connector (OSTI)

......Terrestrial gamma radiation dose rate is also an important...contribution to the average dose rate received by the...population(6,7). The estimation of radiation dose distribution is important...side (Gulf of Mannar/Bay of Bengal coast). The district......

Jeni Chandar Padua; M. R. Basil Rose

2013-08-01T23:59:59.000Z

295

Gamma-ray burst models  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...J. Wijers and Martin Rees Gamma-ray burst models Andrew King * * ( ark...various possibilities for making gamma-ray bursts, particularly from close binaries...

2007-01-01T23:59:59.000Z

296

EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS  

SciTech Connect (OSTI)

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

Clark, E.

2011-09-22T23:59:59.000Z

297

Radiation prevents much cancer  

Science Journals Connector (OSTI)

Evidence reviewed here supports the concept that chronic exposure to ionising radiation can dramatically decrease cancer incidence and mortality. This evidence includes an inverse relationship between radiation levels and cancer induction and/or mortality in: over 200 million people in the USA; 200 million people in India; 10,000 residents of Taipei who live in cobalt-60 contaminated homes; high radiation areas of Ramsar, Iran; 12 million person-years of exposed and carefully selected control nuclear workers; almost 300,000 homes with radon in the USA; non-smokers in high radon areas of Saxony, Germany.

T.D. Luckey

2007-01-01T23:59:59.000Z

298

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

SciTech Connect (OSTI)

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

Brunk, J.L.

1995-09-01T23:59:59.000Z

299

Searches for Lepton Flavor Violation in the Decays tau+- ---> e+- gamma and tau+- ---> mu+- gamma  

SciTech Connect (OSTI)

Searches for lepton-flavor-violating decays of a {tau} lepton to a lighter mass lepton and a photon have been performed with the entire dataset of (963 {+-} 7) x 10{sup 6} {tau} decays collected by the BABAR detector near the {Upsilon}(4S), {Upsilon}(3S) and {Upsilon}(2S) resonances. The searches yield no evidence of signals and they set upper limits on the branching fractions of {Beta}({tau}{sup {+-}} {yields} e{sup {+-}}{gamma}) < 3.3 x 10{sup -8} and {Beta}({tau}{sup {+-}} {yields} {mu}{sup {+-}}{gamma}) < 4.4 x 10{sup -8} at 90% confidence level.

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; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; /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.; ,

2010-06-11T23:59:59.000Z

300

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

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

EPA/DOE STATEMENT: Radiation Monitors Confirm That No 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 detected. The U.S. Environmental Protection Agency RadNet system is designed to protect the public by notifying scientists, in near real time, of elevated levels of radiation so they can determine whether protective action is required. The EPA's system has not detected any radiation levels of concern. In addition to EPA's RadNet system, the U.S. Department of Energy has

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
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301

General formulae for f1 --> f2 gamma  

E-Print Network [OSTI]

At one-loop level the decay f1 --> f2 gamma, where f1 and f2 are two spin-1/2 particles with the same electric charge, is mediated by a boson B and a spin-1/2 fermion F. The boson B may have either spin 0 - interacting with the fermions through Dirac matrices 1 and gamma5 - or spin 1 - with V+A and V-A couplings to the fermions. I give general formulae for the one-loop electroweak amplitude of f1 --> f2 gamma in all these cases.

L. Lavoura

2003-02-25T23:59:59.000Z

302

Right-left asymmetry of radiation from fission induced by polarised neutrons  

E-Print Network [OSTI]

The effect of the right-left asymmetry is considered in the angular distribution of gamma quanta from fission of U-235 by polarised thermal neutrons, which depends on the polarisation of the neutrons with respect to the gamma-fission plane. Electric dipole radiation from fission fragments arising due to the Strutinsky-Denisov induced polarisation mechanism may give rise to such an effect. Earlier, this mechanism was shown to fit the non-statistical part observed in the gamma spectrum from spontaneous fission of Cf-252. The calculated value of the magnitude of the asymmetry parameter is on the level of 10$^{-4}$. That is in agreement with the current experimental data. A crucial experiment to give a more definite picture of the concrete mechanism would be determination of the energy of the quanta responsible for the asymmetry. Detection of the quanta with the energy of ~5 MeV approaching the giant dipole resonance is needed in order to identify prompt gamma rays emitted at the stage of fissioning.

F. F. Karpeshin

2009-02-09T23:59:59.000Z

303

Right-left asymmetry of radiation from fission induced by polarised neutrons  

E-Print Network [OSTI]

The effect of the right-left asymmetry is considered in the angular distribution of gamma quanta from fission of U-235 by polarised thermal neutrons, which depends on the polarisation of the neutrons with respect to the gamma-fission plane. Electric dipole radiation from fission fragments arising due to the Strutinsky-Denisov induced polarisation mechanism may give rise to such an effect. Earlier, this mechanism was shown to fit the non-statistical part observed in the gamma spectrum from spontaneous fission of Cf-252. The calculated value of the magnitude of the asymmetry parameter is on the level of 10$^{-4}$. That is in agreement with the current experimental data. A crucial experiment to give a more definite picture of the concrete mechanism would be determination of the energy of the quanta responsible for the asymmetry. Detection of the quanta with the energy of ~5 MeV approaching the giant dipole resonance is needed in order to identify prompt gamma rays emitted at the stage of fissioning.

Karpeshin, F F

2009-01-01T23:59:59.000Z

304

The Galactic gamma-ray club  

E-Print Network [OSTI]

The exclusive Galactic gamma-ray club has opened up to new members. Supernova remnants, pulsar wind nebulae, and massive binary systems hosting a compact object have recently joined the young pulsars as firmly established sources of gamma rays in the Milky Way. Massive young stellar clusters are on the waiting list to join the club. Only the fine imaging recently obtained at TeV energies could resolve specific sources. The samples are sparse, but raise exciting questions. The jet or pulsar-wind origin of the emission in binaries has been hotly debated, but it seems that both types of systems have been recently detected. The nature of the radiation in shock accelerators is still questioned: do nuclei contribute a lot, a little, or not to the gamma rays and what energy do they carry away from the shock budget? The acceleration process and the structural evolution of the pulsar winds are still uncertain. The magnetic field distribution in all these systems is a key, but poorly constrained, ingredient to model the multi-wavelength data, particle transport and electron ageing. It must, however, be determined in order to efficiently probe particle distributions and the acceleration mechanisms. The source samples soon to be expected from GLAST and the Cherenkov telescopes should bring new valuable test cases and they will, for the first time, shed statistical light on the collective behaviour of these different types of accelerators.

Isabelle A. Grenier

2008-04-02T23:59:59.000Z

305

Solution To The Gamma Ray Burst Mystery?  

E-Print Network [OSTI]

Photoexcitation and ionization of partially ionized heavy atoms in highly relativistic flows by interstellar photons, followed by their reemission in radiative recombination and decay, boost star-light into beamed $\\gamma$ rays along the flow direction. Repeated excitation/decay of highly relativistic baryonic ejecta from merger or accretion induced collapse of neutron stars in dense stellar regions (DSRs), like galactic cores, globular clusters and super star-clusters, can convert enough kinetic energy in such events in distant galaxies into cosmological gamma ray bursts (GRBs). The model predicts remarkably well all the main observed temporal and spectral properties of GRBs. Its success strongly suggests that GRBs are $\\gamma$ ray tomography pictures of DSRs in galaxies at cosmological distances with unprecedented resolution: A time resolution of $dt\\sim 1~ms$ in a GRB can resolve stars at a Hubble distance which are separated by only $D\\sim 10^{10}cm$. This is equivalent to the resolving power of an optical telescope with a diameter larger than one Astronomical Unit!

Nir J. Shaviv; Arnon Dar

1996-08-21T23:59:59.000Z

306

Design/installation and structural integrity assessment under the Federal Facility Agreement for Bethel Valley Low-Level Waste Collection and Transfer System upgrade for Building 2026 (High Radiation Level Analytical Laboratory) and Building 2099 (Monitoring and Control Station) at Oak Ridge National Laboratory  

SciTech Connect (OSTI)

This document presents a Design/Installation and Structural Integrity Assessment for a replacement tank system for portions of the Bethel Valley Low Level Waste (LLW) System, located at the Oak Ridge Reservation, Oak Ridge, Tennessee. This issue of the assessment covers the design aspects of the replacement tank system, and certifies that the design has sufficient structural integrity and is acceptable for the storing or treating of hazardous and/or radioactive substances. The present issue identifies specific activities that must be completed during the fabrication, installation, and testing of the replacement tank system in order to provide assurance that the final installation complies with governing requirements. Portions of the LLW system are several decades old, or older, and do not comply with current environmental protection regulations. Several subsystems of the LLW system have been designated to receive a state-of-the-art replacement and refurbishment. One such subsystem serves Building 2026, the High Radiation Level Analytical Laboratory. This assessment focuses on the scope of work for the Building 2026 replacement LLW Collection and Transfer System, including the provision of a new Monitoring and Control Station (Building 2099) to receive, store, and treat (adjust pH) low level radioactive waste.

Not Available

1994-10-01T23:59:59.000Z

307

Danger radiations  

ScienceCinema (OSTI)

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

None

2011-04-25T23:59:59.000Z

308

GROUND LEVEL INVESTIGATION OF ANOMALOUS RADIATION LEVELS IN NIAGARA...  

Office of Legacy Management (LM)

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-...

309

Measurement of the eta_b(1S) mass and the branching fraction for Upsilon(3S) --> gamma eta_b(1S)  

E-Print Network [OSTI]

We report evidence for the ground state of bottomonium, eta_b(1S), in the radiative decay Upsilon(3S) --> gamma eta_b in e^+e^- annihilation data taken with the CLEO III detector. Using 6 million Upsilon(3S) decays, and assuming Gamma(eta_b) = 10 MeV/c^2, we obtain B(Upsilon(3S) --> gamma eta_b) = (7.1 +- 1.8 +- 1.1) X 10^{-4}, where the first error is statistical and the second is systematic. The statistical significance is about 4 sigma. The mass is determined to be M(eta_b) = 9391.8 +- 6.6 +- 2.0 MeV/c^2, which corresponds to the hyperfine splitting Delta M_{hf}(1S)_b = 68.5 +- 6.6 +- 2.0 MeV/c^2. Using 9 million Upsilon(2S) decays, we place an upper limit on the corresponding Y(2S) decay, B(Y(2S) --> gamma eta_b) < 8.4 X 10^{-4} at 90 % confidence level.

The CLEO Collaboration; G. Bonvicini; D. Cinabro; A. Lincoln; M. J. Smith; P. Zhou; J. Zhu; P. Naik; J. Rademacker; D. M. Asner; K. W. Edwards; J. Reed; A. N. Robichaud; G. Tatishvili; E. J. White; R. A. Briere; H. Vogel; P. U. E. Onyisi; J. L. Rosner; J. P. Alexander; D. G. Cassel; R. Ehrlich; L. Fields; R. S. Galik; L. Gibbons; S. W. Gray; D. L. Hartill; B. K. Heltsley; J. M. Hunt; D. L. Kreinick; V. E. Kuznetsov; J. Ledoux; H. Mahlke-Krüger; J. R. Patterson; D. Peterson; D. Riley; A. Ryd; A. J. Sadoff; X. Shi; S. Stroiney; W. M. Sun; J. Yelton; P. Rubin; N. Lowrey; S. Mehrabyan; M. Selen; J. Wiss; M. Kornicer; R. E. Mitchell; M. R. Shepherd; C. M. Tarbert; D. Besson; T. K. Pedlar; J. Xavier; D. Cronin-Hennessy; K. Y. Gao; J. Hietala; R. Poling; P. Zweber; S. Dobbs; Z. Metreveli; K. K. Seth; B. J. Y. Tan; A. Tomaradze; S. Brisbane; J. Libby; L. Martin; A. Powell; P. Spradlin; C. Thomas; G. Wilkinson; H. Mendez; J. Y. Ge; D. H. Miller; I. P. J. Shipsey; B. Xin; G. S. Adams; D. Hu; B. Moziak; J. Napolitano; K. M. Ecklund; J. Insler; H. Muramatsu; C. S. Park; E. H. Thorndike; F. Yang; M. Artuso; S. Blusk; S. Khalil; R. Mountain; K. Randrianarivony; T. Skwarnicki; J. C. Wang; L. M. Zhang

2009-09-30T23:59:59.000Z

310

Order Module--RADIATION PROTECTION PROGRAMS GUIDE  

Broader source: Energy.gov [DOE]

The familiar level of this module is designed to provide the basic information related to DOEG 441.1-1C, Radiation Protection Programs Guide, as required in DOE-STD-1174-2003, Radiation Protection...

311

Muon Detection of TeV Gamma Rays from Gamma-Ray Bursts  

Science Journals Connector (OSTI)

Because of the limited size of the satellite-borne instruments, it has not been possible to observe the flux of gamma-ray bursts (GRBs) beyond GeV energy. We here show that it is possible to detect the GRB radiation of TeV energy and above by detecting the muon secondaries produced when the gamma rays shower in Earth's atmosphere. Observation is made possible by the recent commissioning of underground detectors (AMANDA, the Lake Baikal detector, and MILAGRO), which combine a low muon threshold of a few hundred GeV or less, with a large effective area of 103 m2 or more. Observations will not only provide new insights in the origin and characteristics of GRB, but they also will provide quantitative information on the diffuse infrared background.

J. Alvarez-Muñiz; F. Halzen

1999-01-01T23:59:59.000Z

312

Gamma doses from phospho-gypsum plaster-board  

SciTech Connect (OSTI)

The use of phospho-gypsum plaster-board and plaster cement in buildings as a substitute for natural gypsum may constitute an additional source of radiation exposure to both workers and members of the public, both from inhalation of radon progeny produced from radon which is exhaled from the plaster-board and from beta and gamma radiation produced by radioactive decay in the plaster-board. The calculations presented in this paper indicate that if phospho-gypsum sheets 1 cm thick containing a {sup 226}Ra concentration of 400 Bq kg{sup -1} are used to line the walls and ceiling of a room of dimensions up to 5 m {times} 5 m {times} 3 m, the annual effective dose from gamma radiation for a person continually occupying the room should not exceed approximately 0.13 mSv. This compares with a measured annual average effective dose from gamma radiation in Australian homes of 0.9 mSv. The annual effective dose from such thin sheets is directly proportional to the {sup 226}Ra concentration in the plaster-board. 13 refs., 6 figs.

O`Brien, R.S. [Australian Radiation Lab., Victoria (Australia)

1997-01-01T23:59:59.000Z

313

E-Print Network 3.0 - annihilation gamma rays Sample Search Results  

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

32 3 grid 74 94 3.05 ora SPEC ray tracing 650 array elements... .0 0.5 1.0 1.5 2.0 GammaGammaGammaGammaGammaGamma GammaGammaGammaGammaGammaGamma GammaGammaGamma...

314

E-Print Network 3.0 - atmospheric gamma rays Sample Search Results  

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

32 3 grid 74 94 3.05 ora SPEC ray tracing 650 array elements... .0 0.5 1.0 1.5 2.0 GammaGammaGammaGammaGammaGamma GammaGammaGammaGammaGammaGamma GammaGammaGamma...

315

High-precision (p,t) reaction to determine {sup 25}Al(p,{gamma}){sup 26}Si reaction rates  

SciTech Connect (OSTI)

Since the identification of ongoing {sup 26}Al production in the universe, the reaction sequence {sup 24}Mg(p,{gamma}){sup 25}Al({beta}{sup +{nu}}){sup 25}Mg(p,{gamma}){sup 26}Al has been studied intensively. At temperatures where the radiative capture on {sup 25}Al (t{sub 1/2}=7.2 s) becomes faster than the {beta}{sup +} decay, the production of {sup 26}Al can be reduced due to the depletion of {sup 25}Al. To determine the resonances relevant for the {sup 25}Al(p,{gamma}){sup 26}Si bypass reaction, we measured the {sup 28}Si(p,t){sup 26}Si reaction with high-energy precision using the Grand Raiden spectrometer at the Research Center for Nuclear Physics, Osaka. Several new energy levels were found above the p threshold and for known states excitation energies were determined with smaller uncertainties. The calculated stellar rates of the bypass reaction agree well with previous results, suggesting that these rates are well established.

Matic, A.; Berg, A. M. van den; Harakeh, M. N.; Woertche, H. J.; Berg, G. P. A.; Couder, M.; Goerres, J.; LeBlanc, P.; O'Brien, S.; Wiescher, M.; Fujita, K.; Hatanaka, K.; Sakemi, Y.; Shimizu, Y.; Tameshige, Y.; Tamii, A.; Yosoi, M.; Adachi, T.; Fujita, Y.; Shimbara, Y. [Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, NL-9747 AA Groningen (Netherlands); Department of Physics and the Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 560-0047 (Japan); Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); School of Physics, University of the Witwatersrand, P.O. Wits, Johannesburg 2050 (South Africa); Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan); Department of Physics and Astronomy, National Superconducting Cyclotron Laboratory and the Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824 (United States)

2010-08-15T23:59:59.000Z

316

Occupational radiation monitoring at a large medical center in Japan  

Science Journals Connector (OSTI)

Occupational radiation dose monitoring is a method of ensuring that radiation levels are within the regulatory limits. Our objective in this study was to evaluate the radiation doses experienced by personnel ...

Hussein Y. ALMasri; Yasumasa Kakinohana…

2014-07-01T23:59:59.000Z

317

Radiation effects on humans  

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

Radiation effects on humans Radiation effects on humans Name: Joe Kemna Location: N/A Country: N/A Date: N/A Question: I am trying to find information on radiation. I need the effects on humans, the damage it causes to the environment, and any extra information you might have on the subject. Thank you for your time. Replies: Your library should be a good place to start, but first you need to narrow your question a bit. "Radiation" means radio waves, heat, light (including the ultraviolet light that causes suntan and sunburn), and what's called "ionizing radiation." By far the major source of the first three is the Sun, while the last I believe comes principally from cosmic rays and various naturally radioactive elements like uranium and radon. The most significant manmade sources of exposure would --- I think --- be household wiring and appliances (radio), engines and heating devices (heat), lamps (light), and X-ray machines, flying at high altitude in airplanes, and living in well-insulated homes built over radon sources (ionizing radiation). Heat, light and ionizing radiation play vital roles in the ecology of the Earth. Radio, light (in particular "tanning" ultraviolet), and ionizing radiation have all been widely assumed at different times to be particularly good or particularly bad for human health. Some recent issues of public concern have been the effect of radio waves from electric transmission lines, the effect on skin cancer incidence from tanning and sunburns, the depletion of the ultraviolet-light-produced ozone in the upper atmosphere by chlorofluorocarbons (CFCs), "global warming" from the increased absorption of heat radiation from the surface by atmospheric carbon dioxide and methane, and the effect of a long exposure to low levels of ionizing radiation as for example the people of Eastern Europe are experiencing from the Chernobyl nuclear power plant accident.

318

LASER-PLASMA-ACCELERATOR-BASED GAMMA GAMMA COLLIDERS  

E-Print Network [OSTI]

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

Schroeder, C. B.

2010-01-01T23:59:59.000Z

319

Ionizing radiation detector  

DOE Patents [OSTI]

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

Thacker, Louis H. (Knoxville, TN)

1990-01-01T23:59:59.000Z

320

Fermi GBM Observations of Terrestrial Gamma-ray Flashes  

SciTech Connect (OSTI)

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

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

2011-09-21T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

RADIATION EFFECTS ON EPOXY CARBON FIBER COMPOSITE  

SciTech Connect (OSTI)

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

Hoffman, E

2008-05-30T23:59:59.000Z

322

The GAMMA-400 Space Mission  

E-Print Network [OSTI]

GAMMA-400 is a new space mission which will be installed on board the Russian space platform Navigator. It is scheduled to be launched at the beginning of the next decade. GAMMA-400 is designed to study simultaneously gamma rays (up to 3 TeV) and cosmic rays (electrons and positrons from 1 GeV to 20 TeV, nuclei up to 10$^{15}$-10$^{16}$ eV). Being a dual-purpose mission, GAMMA-400 will be able to address some of the most impelling science topics, such as search for signatures of dark matter, cosmic-rays origin and propagation, and the nature of transients. GAMMA-400 will try to solve the unanswered questions on these topics by high-precision measurements of the Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission and the spectra of cosmic-ray electrons + positrons and nuclei, thanks to excellent energy and angular resolutions.

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

2015-01-01T23:59:59.000Z

323

Audible radiation monitor  

SciTech Connect (OSTI)

This invention consists of a method and apparatus for monitoring ionizing radiation comprising radiation detectors in electrical connection with an isotopic analyzer and a device for producing chords to which each isotope is mapped so that the device produces a unique chord for each isotope. Preferably the chords are pleasing to the ear, except for chords representing unexpected isotopes, and are louder or softer depending on the level of radioactivity produced by each isotope, and musical instrument voices may be simulated in producing the chords as an aid to distinguishing similar-sounding chords. Because of the representation by chords, information regarding the level and composition of the radiation in an area can be conveyed to workers in that area more effectively and yet without distracting them.

Odell, D.M.C.

1992-12-31T23:59:59.000Z

324

EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS (REVISION 1)  

SciTech Connect (OSTI)

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

Clark, E.

2013-09-13T23:59:59.000Z

325

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

E-Print Network [OSTI]

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

Xu, Ren-Xin

326

Gamma-ray burst populations.  

E-Print Network [OSTI]

??Over the last fifty years the field of gamma-ray bursts has shown incredible growth, but the amassing of data has also left observers and theorists… (more)

Virgili, Francisco J.

2011-01-01T23:59:59.000Z

327

GeV Emission from Collisional Magnetized Gamma Ray Bursts  

E-Print Network [OSTI]

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

P. Mészáros; M. J. Rees

2011-04-26T23:59:59.000Z

328

Polarimetric performance of a Laue lens gamma-ray CdZnTe focal plane prototype  

SciTech Connect (OSTI)

A gamma-ray telescope mission concept [gamma ray imager (GRI)] based on Laue focusing techniques has been proposed in reply to the European Space Agency call for mission ideas within the framework of the next decade planning (Cosmic Vision 2015-2025). In order to optimize the design of a focal plane for this satellite mission, a CdZnTe detector prototype has been tested at the European Synchrotron Radiation Facility under an {approx}100% polarized gamma-ray beam. The spectroscopic, imaging, and timing performances were studied and in particular its potential as a polarimeter was evaluated. Polarization has been recognized as being a very important observational parameter in high energy astrophysics (>100 keV) and therefore this capability has been specifically included as part of the GRI mission proposal. The prototype detector tested was a 5 mm thick CdZnTe array with an 11x11 active pixel matrix (pixel area of 2.5x2.5 mm{sup 2}). The detector was irradiated by a monochromatic linearly polarized beam with a spot diameter of about 0.5 mm over the energy range between 150 and 750 keV. Polarimetric Q factors of 0.35 and double event relative detection efficiency of 20% were obtained. Further measurements were performed with a copper Laue monochromator crystal placed between the beam and the detector prototype. In this configuration we have demonstrated that a polarized beam does not change its polarization level and direction after undergoing a small angle (<1 deg.) Laue diffraction inside a crystal.

Curado da Silva, R. M. [Departmento de Fisica, Universidade de Coimbra, P-3000 Coimbra (Portugal); Center for Space Radiations, Univesite Catholique de Louvain (Belgium); Caroli, E.; Stephen, J. B.; Schiavone, F.; Donati, A.; Ventura, G. [Istituto di Astrofisica Spaziale e Fisica Cosmica-Bologna, Via Gobetti 101, I-40129 Bologna (Italy); Pisa, A.; Auricchio, N.; Frontera, F. [Dipartimento di Fisica, Universita di Ferrara, Ferrara (Italy); Del Sordo, S. [Istituto di Astrofisica Spaziale e Fisica Cosmica-Palermo, Via Ugo La Malfa 153, 90146 Palermo (Italy); Honkimaeki, V. [European Synchrotron Radiation Facility, Grenoble (France); Trindade, A. M. F. [Departmento de Fisica, Universidade de Coimbra, P-3000 Coimbra (Portugal)

2008-10-15T23:59:59.000Z

329

MODIFICATION OF SHIRT BUTTONS FOR RETROSPECTIVE RADIATION DOSIMETRY AFTER A RADIOLOGICAL EVENT  

E-Print Network [OSTI]

are presented for a personal radiation dosimeter in the form of a clothing button to provide gamma-ray dose estimation for clinically-significant external radiation exposures to the general public due of people might receive significant doses of radiation. The dose received by an individual from external

Brenner, David Jonathan

330

Radiation Treatment of Foods: II. Public Health Significance of Irradiation-Recycled Salmonella  

Science Journals Connector (OSTI)

...ES878 and its radiation- resistant mutant...deaths per 10 Dose per embryo embryos...that the more radiation-resistant types...em- ployed if dose rates are to...at sublethal doses of gamma energy...Salmonella, upon radiation recycling, may...detection and estimation of numbers of...

N. A. Epps; Edmund S. Idziak

1970-02-01T23:59:59.000Z

331

Physiological Responses of the Hyperthermophilic Archaeon “Pyrococcus abyssi” to DNA Damage Caused by Ionizing Radiation  

Science Journals Connector (OSTI)

...before and after radiation and was in good...performed at a sublethal dose of 2,000 Gy to...our preliminary estimation reveals that 0...been observed for radiation-resistant Chroococcidiopsis...caused by ionizing radiation. | The mechanisms...furiosus, survive high doses of ionizing gamma...

Edmond Jolivet; Fujihiko Matsunaga; Yoshizumi Ishino; Patrick Forterre; Daniel Prieur; Hannu Myllykallio

2003-07-01T23:59:59.000Z

332

Cooling of Accelerated Nucleons and Neutrino Emission in Gamma-Ray Bursts  

E-Print Network [OSTI]

Using Monte Carlo simulations, we demonstrate photopion production from Fermi-accelerated protons and the resulting neutrino production in gamma-ray bursts. Unless internal shocks occur at quite large distance from the center, ultra high-energy protons are depleted by photopion production and synchrotron radiation. Internal shocks at fiducial distance cause neutrino bursts, which accompany gamma-ray bursts originating from electromagnetic cascades.

Katsuaki Asano

2005-03-11T23:59:59.000Z

333

Spatial and Energy Distribution of Muons in Gamma-induced Air Showers  

E-Print Network [OSTI]

The FLUKA Monte Carlo program is used to calculate the effects of hadroproduction by primary gamma rays incident upon the earth's atmosphere; for the results presented in this paper, only primary angles at 0 degrees from zenith are considered. The FLUKA code is believed to be quite accurate in reproducing experimental photon hadroproduction data in the 1 GeV to 10 TeV energy range studied. The charged pions which are so produced can decay to muons with sufficient energy to reach ground level. The number of these muons and their radial and energy distribution are studied for incident gamma ray energies from 1 GeV to 10 TeV. The number of these muons is not negligible; they can, in certain circumstances, be used to study potential sources of gamma rays like gamma ray bursts. It is found, for example, that a 10 TeV incident primary gamma ray produces, on average, 3.4 muons which reach ground level; the gamma ray energy which produces the maximum number of muons at ground level depends on the spectral index of the primary gamma spectrum, a constant which describes how the primary gamma flux rises with decreasing primary energy. An example: for a differential spectral index of 2.7, there is a broad maximum number of muons coming from ~ 30 GeV primary gamma ray energy.

A. Fasso`; J. Poirier

2000-06-14T23:59:59.000Z

334

Integrated neutron/gamma-ray portal monitors for nuclear safeguards  

SciTech Connect (OSTI)

Radiation monitoring is one nuclear-safeguards measure used to protect against the theft of special nuclear materials (SNM) by pedestrians departing from SNM access areas. The integrated neutron/gamma-ray portal monitor is an ideal radiation monitor for the task when the SNM is plutonium. It achieves high sensitivity for detecting both bare and shielded plutonium by combining two types of radiation detector. One type is a neutron-chamber detector, comprising a large, hollow, neutron moderator that contains a single thermal-neutron proportional counter. The entrance wall of each chamber is thin to admit slow neutrons from plutonium contained in a moderating shield, while the other walls are thick to moderate fast neutrons from bare or lead-shielded plutonium so that they can be detected. The other type of detector is a plastic scintillator that is primarily for detecting gamma rays from small amounts of unshielded plutonium. The two types of detector are easily integrated by making scintillators part of the thick back wall of each neutron chamber or by inserting them into each chamber void. We compared the influence of the two methods of integration on detecting neutrons and gamma rays, and we examined the effectiveness of other design factors and the methods for signal detection as well.

Fehlau, P.E.

1993-09-01T23:59:59.000Z

335

Radiated relics  

Science Journals Connector (OSTI)

...and symbolic reenactment by exposing the objects to light, objects that have already been exposed to all of the energy of a thermonuclear blast: hard gamma rays, X-rays, ultra-violet light, visible light, and then infra-red light. The artist likens...

Rebecca Horne

2013-01-01T23:59:59.000Z

336

Laser-driven hole boring and gamma-ray emission in high-density plasmas  

E-Print Network [OSTI]

Ion acceleration in laser-produced dense plasmas is a key topic of many recent investigations thanks to its potential applications. Besides, at forthcoming laser intensities ($I \\gtrsim 10^{23} \\text{W}\\,\\text{cm}^{-2}$) interaction of laser pulses with plasmas can be accompanied by copious gamma-ray emission. Here we demonstrate the mutual influence of gamma-ray emission and ion acceleration during relativistic hole boring in high-density plasmas with ultra-intense laser pulses. If gamma-ray emission is abundant, laser pulse reflection and hole-boring velocity are lower and gamma-ray radiation pattern is narrower than in the case of low emission. Conservation of energy and momentum allows one to elucidate the effects of gamma-ray emission which are more pronounced at higher hole-boring velocities.

Nerush, Evgeny

2014-01-01T23:59:59.000Z

337

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

DOE Patents [OSTI]

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

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

2007-10-23T23:59:59.000Z

338

Measurement of the $\\Xi^0 \\rightarrow \\Lambda\\gamma$ Decay Asymmetry and Branching Fraction  

E-Print Network [OSTI]

In data taken with the NA48 experiment at the CERN SPS in 1999, 730 candidates of the weak radiative hyperon decay Xi0 -> Lambda gamma have been found with an estimated background of 58 +- 8 events. From these events the Xi0 -> Lambda gamma decay asymmetry has been determined to alpha(Xi0 -> Lambda gamma) = -0.78 +- 0.18_stat +- 0.06_syst, which is the first evidence of a decay asymmetry in Xi0 -> Lambda gamma. The branching fraction of the decay has been measured to be Br(Xi0 -> Lambda gamma) = (1.16 +- 0.05_stat +- 0.06_syst) x 10^-3.

Lai, A; Bevan, A; Dosanjh, R S; Gershon, T J; Hay, B; Kalmus, George Ernest; Lazzeroni, C; Munday, D J; Olaiya, E; Parker, M A; White, T O; Wotton, S A; Barr, G; Bocquet, G; Ceccucci, Augusto; Çuhadar-Dönszelmann, T; Cundy, Donald C; D'Agostini, Giulio; Doble, Niels T; Falaleev, V P; Gatignon, L; Gonidec, A; Gorini, B; Govi, G; Grafström, P; Kubischta, Werner; Lacourt, A; Norton, A; Palestini, S; Panzer-Steindel, B; Taureg, Hans; Velasco, M; Wahl, H; Cheshkov, C; Gaponenko, A N; Khristov, P Z; Kekelidze, V D; Madigozhin, D T; Molokanova, N A; Potrebenikov, Yu K; Tatishvili, G T; Tkachev, A L; Zinchenko, A I; Knowles, I; Martin, V; Sacco, R; Walker, A; Contalbrigo, M; Dalpiaz, Pietro; Duclos, J; Frabetti, P L; Gianoli, A; Martini, M; Petrucci, F; Savrié, M; Bizzeti, A; Calvetti, M; Collazuol, G; Graziani, G; Iacopini, E; Lenti, M; Martelli, F; Veltri, M; Becker, H G; Eppard, K; Eppard, M; Fox, H; Kalter, A; Kleinknecht, K; Koch, U; Köpke, L; Lopes da Silva, P; Marouelli, P; Pellmann, I A; Peters, A; Renk, B; Schmidt, S A; Schönharting, V; Schué, Yu; Wanke, R; Winhart, A; Wittgen, M; Chollet, J C; Fayard, L; Iconomidou-Fayard, L; Ocariz, J; Unal, G; Wingerter-Seez, I; Anzivino, Giuseppina; Cenci, P; Imbergamo, E; Lubrano, P; Mestvirishvili, A; Nappi, A; Pepé, M; Piccini, M; Bertanza, L; Carosi, R; Casali, R; Cerri, C; Cirilli, M; Costantini, F; Fantechi, R; Giudici, Sergio; Mannelli, I; Pierazzini, G M; Sozzi, M; Chèze, J B; Cogan, J; De Beer, M; Debu, P; Formica, A; Granier de Cassagnac, R; Mazzucato, E; Peyaud, B; Turlay, René; Vallage, B; Holder, M; Maier, A; Ziolkowski, M; Arcidiacono, R; Biino, C; Cartiglia, N; Guida, R; Marchetto, F; Menichetti, E; Pastrone, N; Nassalski, J P; Rondio, Ewa; Szleper, M; Wislicki, W; Wronka, S; Dibon, Heinz; Fischer, G; Jeitler, Manfred; Markytan, Manfred; Mikulec, I; Neuhofer, Günther; Pernicka, Manfred; Taurok, Anton; Widhalm, L

2004-01-01T23:59:59.000Z

339

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

SciTech Connect (OSTI)

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

Fan, Yi-Zhong; Piran, Tsvi

2011-11-29T23:59:59.000Z

340

Plasma Radiation  

Science Journals Connector (OSTI)

... JUST over ten years ago the first book on plasma physics as a subject in its own right appeared; in a gradually swelling stream ... been surprisingly few monographs. One topic which has had scant coverage in any form is plasma radiation (except for spectral-line radiation which has been dealt with very fully in ...

T. J. M. BOYD

1967-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

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

E-Print Network [OSTI]

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

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

2010-03-23T23:59:59.000Z

342

Comparison of 2D and 3D gamma analyses  

SciTech Connect (OSTI)

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

Pulliam, Kiley B.; Huang, Jessie Y.; Howell, Rebecca M.; Followill, David; Kry, Stephen F., E-mail: sfkry@mdanderson.org [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States); Bosca, Ryan [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States)] [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States); O’Daniel, Jennifer [Department of Radiation Oncology, Duke University, Durham, North Carolina 27705 (United States)] [Department of Radiation Oncology, Duke University, Durham, North Carolina 27705 (United States)

2014-02-15T23:59:59.000Z

343

7 - Estimation of Radiation Doses  

Science Journals Connector (OSTI)

Abstract Radiation doses to the Japanese population from inhalation of contaminated air, external irradiation, terrestrial and marine food contamination are estimated and compared with other sources of anthropogenic (global fallout, Chernobyl accident), natural (radionuclides in food, cosmic radiation) and medical applications (X-ray tests, CT-tests, etc.) of ionizing radiation. The estimated doses from inhalation, ingestion of terrestrial and marine food, and radiation exposure from radioactive clouds and deposited radionuclides were generally below the levels which could cause health damage of the Japanese population, as well as of the world population. The estimated total radiation doses to fish and shellfish in coastal waters during the largest radionuclide releases were by a factor of 10 lower than the baseline safe level postulated for the marine organisms, therefore no harmful effects are expected for the marine ecosystem as well.

Pavel P. Povinec; Katsumi Hirose; Michio Aoyama

2013-01-01T23:59:59.000Z

344

Evidence for penguin-diagram decays: First observation of B -> K*(892)gamma  

E-Print Network [OSTI]

We have observed the decays B0 --> K*(892)0gamma and B- --> K*(892)-gamma, which are evidence for the quark-level process b --> sgamma. The average branching fraction is (4.5 +/- 1.5 +/- 0.9) x 10(-5). This value is ...

Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kwak, Nowhan; Lam, H.

1993-08-01T23:59:59.000Z

345

High resolution x-ray and gamma ray imaging using diffraction lenses with mechanically bent crystals  

DOE Patents [OSTI]

A method for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation is provided. High quality mechanically bent diffracting crystals of 0.1 mm radial width are used for focusing the radiation and directing the radiation to an array of detectors which is used for analyzing their addition to collect data as to the location of the source of radiation. A computer is used for converting the data to an image. The invention also provides for the use of a multi-component high resolution detector array and for narrow source and detector apertures.

Smither, Robert K. (Hinsdale, IL)

2008-12-23T23:59:59.000Z

346

Radiation dosimeter  

DOE Patents [OSTI]

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

Fox, Richard J. (Oak Ridge, TN)

1983-01-01T23:59:59.000Z

347

Radiation dosimeter  

DOE Patents [OSTI]

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

Fox, R.J.

1981-09-01T23:59:59.000Z

348

EPR dosimetry in a mixed neutron and gamma radiation field  

Science Journals Connector (OSTI)

......radicals induced by ionizing...of radio-induced free radicals...Mura, the neutron dose component...neutrons of energy comparable to fission spectrum(15...component of thermal neutron in the SILENE...34 for fission neutrons...shape line spectrum modification...SILENE neutron energies. Nevertheless......

F. Trompier; P. Fattibene; D. Tikunov; A. Bartolotta; A. Carosi; M. C. Doca

2004-08-01T23:59:59.000Z

349

Gamma-ray Laser and Radiation from Collimated Particles  

E-Print Network [OSTI]

The motion of channeled particles is accompanied by the photon emission. This feature can be used for the stimulated generation of high energy photons, but the required density of channeled particles must be very high.

Kovalev, Gennady V

2014-01-01T23:59:59.000Z

350

Semiconductor gamma radiation detectors: band structure effects in energy resolution  

E-Print Network [OSTI]

high precision and in a broad energy range, the number of created pairs N is just proportional (referred to as the pair excitation energy). For semiconductor materials the pair excitation energy becomes important in the search for materials with improved energy resolution. #12;Theoretical models used

Luryi, Serge

351

Gamma bursts from neutron stars and stellar flares  

Science Journals Connector (OSTI)

If gamma bursts are locally galactic then the implied fluxes from a localized region of a neutron star surface are closed to the blackbody limit even at the extreme temperatures (of the order of 109 degrees) inferred from gamma?burst spectra. One reasonable model is the accretion of an astroid or comet (Harwit and Salpeter 1973) onto a magnetized neutron star. What is frequently described as tidal disruption instead becomes gravitational compression. Matter landing on a neutron star releases a specific energy density of several times c2/10. This energy density is ample to give rise to the inferred temperatures of 108 to 109 degrees. However radiation stress greatly exceeds the gravitational stress even at the neutron star surface and a near instantaneous adiabatic expansion of the hot surface layers cools them and terminates the release of any high temperature radiation. The effective temperature of the radiation then becomes roughly the Eddington limit of 2×107 degrees. Only by the restraint of the free surface expansion by a strong magnetic field (several times 1012 gauss) can the high temperature emission take place. The radiation from such a constrained plasma is not yet understood. The cooling mechanism is analogous to the collapse phase of solar and stellar flares.

Stirling A. Colgate

1982-01-01T23:59:59.000Z

352

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

SciTech Connect (OSTI)

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

Atwood, W. B. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Baldini, L. [Universita di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bregeon, J.; Pesce-Rollins, M.; Sgro, C.; Tinivella, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bruel, P. [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Palaiseau (France); Chekhtman, A. [Center for Earth Observing and Space Research, College of Science, George Mason University, Fairfax, VA 22030 (United States); Cohen-Tanugi, J. [Laboratoire Univers et Particules de Montpellier, Universite Montpellier 2, CNRS/IN2P3, F-34095 Montpellier (France); Drlica-Wagner, A.; Omodei, N.; Rochester, L. S.; Usher, T. L. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Granot, J. [Department of Natural Sciences, The Open University of Israel, 1 University Road, P.O. Box 808, Ra'anana 43537 (Israel); Longo, F. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Razzaque, S. [Department of Physics, University of Johannesburg, Auckland Park 2006 (South Africa); Zimmer, S., E-mail: melissa.pesce.rollins@pi.infn.it, E-mail: nicola.omodei@stanford.edu, E-mail: granot@openu.ac.il [Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden)

2013-09-01T23:59:59.000Z

353

Radiation Minimum Temperatures  

Science Journals Connector (OSTI)

Frost resulting from cooling of vegetation by nocturnal radiation is a serious agricultural problem. Because of the number of variables involved attacks on this problem from a purely theoretical point of view have met with only moderate success. It seems logical to suppose that an instrument might be devised which would speed up the natural radiation processes and enable an observer to obtain in a few hours a measure of the cooling which occurs naturally over a period of 12 to 14 hr. Such an instrument could serve as a frost warning device. This paper describes the construction of a radiation device and presents experimental evidence to show that it can be used as a predictor of freezing temperatures at vegetation level.

Francis K. Davis Jr.

1957-01-01T23:59:59.000Z

354

Cross-calibration of the Transition Radiation Detector of AMS-02 for an Energy Measurement of Cosmic-Ray Ions  

E-Print Network [OSTI]

Since May 2011 the AMS-02 experiment is installed on the International Space Station and is observing cosmic radiation. It consists of several state-of-the-art sub-detectors, which redundantly measure charge and energy of traversing particles. Due to the long exposure time of AMS-02 of many years the measurement of momentum for protons and ions is limited systematically by the spatial resolution and magnetic field strength of the silicon tracker. The maximum detectable rigidity for protons is about 1.8~TV, for helium about 3.6~TV. We investigate the possibility to extend the range of the energy measurement for heavy nuclei ($Z\\geq2$) with the transition radiation detector (TRD). The response function of the TRD shows a steep increase in signal from the level of ionization at a Lorentz factor $\\gamma$ of about 500 to $\\gamma\\approx20000$, where the transition radiation signal saturates. For heavy ions the signal fluctuations in the TRD are sufficiently small to allow an energy measurement with the TRD beyond t...

Obermeier, Andreas

2014-01-01T23:59:59.000Z

355

Appendix G. Radiation Appendix G. Radiation  

E-Print Network [OSTI]

-made sources. People are exposed to naturally occurring radiation constantly. For example, cosmic radiation of radiation and its effects on the environment and biological systems. Radiation comes from natural and humanAppendix G. Radiation #12;#12;Appendix G. Radiation This appendix presents basic facts about

Pennycook, Steve

356

Solar Radiation, its Measurement and Application in Solar Energy Utilization Programme  

Science Journals Connector (OSTI)

The electromagnetic radiation emitted by the sun, covers a very large range of wavelengths, from radiowaves through the visible to X-rays and gamma rays. But 99 percent of this energy is contained in the region 0...

A. Mani

1987-01-01T23:59:59.000Z

357

SciTech Connect: Betatron Radiation from a Beam Driven Plasma...  

Office of Scientific and Technical Information (OSTI)

oscillation of electrons in a beam-driven plasma wake provide a uniquely intense and high-energy source of hard X-rays and gamma rays. This betatron radiation is interesting not...

358

Special nuclear material radiation monitors for the 1980's  

SciTech Connect (OSTI)

During the two decades that automatic gamma-radiation monitors have been applied to detecting special nuclear material (SNM), little attention has been devoted to how well the monitors perform in plant environments. Visits to 11 DOE facilities revealed poor information flow between developers, manufacturers, and maintainers of SNM radiation monitors. To help users achieve best performance from their monitors or select new ones, Los Alamos National Laboratory developed a hand-held monitor user's guide, calibration manuals for some commercial SNM pedestrian monitors, and an application guide for SNM pedestrian monitors. In addition, Los Alamos evaluated new commercial SNM monitors, considered whether to apply neutron detection to SNM monitoring, and investigated the problem of operating gamma-ray SNM monitors in variable plutonium gamma-radiation fields. As a result, the performance of existing SNM monitors will improve and alternative monitoring methods will become commerciallly available during the 1980s. 9 refs., 6 figs., 1 tab.

Fehlau, P.E.

1985-01-01T23:59:59.000Z

359

Assessing exposure to radiation  

SciTech Connect (OSTI)

Since the founding of Lawrence Livermore National Laboratory, we have been world leaders in evaluating the risks associated with radiation. Ultrasensitive tools allow us not only to measure radionuclides present in the body but also to reconstruct the radiation dose from past nuclear events and to project the levels of radiation that will still be present in the body for 50 years after the initial intake. A variety of laboratory procedures, including some developed here, give us detailed information on the effects of radiation at the cellular level. Even today, we are re-evaluating the neutron dose resulting from the bombing at Hiroshima. Our dose reconstruction and projection capabilities have also been applied to studies of Nagasaki, Chernobyl, the Mayak industrial complex in the former Soviet Union, the Nevada Test Site, Bikini Atoll, and other sites. We are evaluating the information being collected on individuals currently working with radioactive material at Livermore and elsewhere as well as previously collected data on workers that extends back to the Manhattan Project.

Walter, K.

1997-01-01T23:59:59.000Z

360

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

E-Print Network [OSTI]

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

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

2012-08-27T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
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361

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

SciTech Connect (OSTI)

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

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

2012-10-10T23:59:59.000Z

362

Gamma-gamma directional correlation measurements in 84Kr following thermal neutron capture by natural krypton  

Science Journals Connector (OSTI)

Directional correlations of gamma-ray cascades in 84Kr have been measured following thermal neutron capture by a pressurised natural krypton gas target. Gamma-ray singles spectra were measured up to 5.5 MeV and the correlation data were obtained for the energy range 0.2-2.5 MeV. A decay scheme was developed on the basis of coincidence measurements. The data allow spin-parity assignments to be made to most levels lying below 3.5 MeV and multipole mixing ratios to be evaluated for the more intense transitions. The results are fitted to the SU(5) limit of the IBM-1 and to the IBM-2 and are also compared with the predictions of the dynamic deformation model which indicates that 84Kr is the only krypton isotope with a prolate equilibrium shape. A possible mixed symmetry 2+ state at 2.623 MeV is identified.

S A Hamada; W D Hamilton; F Hoyler

1987-01-01T23:59:59.000Z

363

Study Z gamma events and limits on anomalous ZZ gamma and Z gamma gamma couplings in pp(-) collisions at root s=1.96 Tev  

E-Print Network [OSTI]

We present a measurement of the Z gamma production cross section and limits on anomalous ZZ gamma and Z gamma gamma couplings for form-factor scales of Lambda=750 and 1000 GeV. The measurement is based on 138 (152) candidates ...

Baringer, Philip S.; Bean, Alice; Christofek, L.; Coppage, Don; Gardner, J.; Hensel, Carsten; Jabeen, S.; Wilson, Graham Wallace

2005-07-01T23:59:59.000Z

364

Modeling gamma-ray bursts.  

E-Print Network [OSTI]

??Discovered serendipitously in the late 1960s, gamma-ray bursts (GRBs) are huge explosions of energy that happen at cosmological distances. They provide a grand physical playground… (more)

Maxham, Amanda

2011-01-01T23:59:59.000Z

365

COMPACT CdZnTe-BASED GAMMA CAMERA FOR PROSTATE CANCER IMAGING  

SciTech Connect (OSTI)

In this paper, we discuss the design of a compact gamma camera for high-resolution prostate cancer imaging using Cadmium Zinc Telluride (CdZnTe or CZT) radiation detectors. Prostate cancer is a common disease in men. Nowadays, a blood test measuring the level of prostate specific antigen (PSA) is widely used for screening for the disease in males over 50, followed by (ultrasound) imaging-guided biopsy. However, PSA tests have a high false-positive rate and ultrasound-guided biopsy has a high likelihood of missing small cancerous tissues. Commercial methods of nuclear medical imaging, e.g. PET and SPECT, can functionally image the organs, and potentially find cancer tissues at early stages, but their applications in diagnosing prostate cancer has been limited by the smallness of the prostate gland and the long working distance between the organ and the detectors comprising these imaging systems. CZT is a semiconductor material with wide band-gap and relatively high electron mobility, and thus can operate at room temperature without additional cooling. CZT detectors are photon-electron direct-conversion devices, thus offering high energy-resolution in detecting gamma rays, enabling energy-resolved imaging, and reducing the background of Compton-scattering events. In addition, CZT material has high stopping power for gamma rays; for medical imaging, a few-mm-thick CZT material provides adequate detection efficiency for many SPECT radiotracers. Because of these advantages, CZT detectors are becoming popular for several SPECT medical-imaging applications. Most recently, we designed a compact gamma camera using CZT detectors coupled to an application-specific-integrated-circuit (ASIC). This camera functions as a trans-rectal probe to image the prostate gland from a distance of only 1-5 cm, thus offering higher detection efficiency and higher spatial resolution. Hence, it potentially can detect prostate cancers at their early stages. The performance tests of this camera have been completed. The results show better than 6-mm resolution at a distance of 1 cm. Details of the test results are discussed in this paper.

CUI, Y.; LALL, T.; TSUI, B.; YU, J.; MAHLER, G.; BOLOTNIKOV, A.; VASKA, P.; DeGERONIMO, G.; O'CONNOR, P.; MEINKEN, G.; JOYAL, J.; BARRETT, J.; CAMARDA, G.; HOSSAIN, A.; KIM, K.H.; YANG, G.; POMPER, M.; CHO, S.; WEISMAN, K.; SEO, Y.; BABICH, J.; LaFRANCE, N.; AND JAMES, R.B.

2011-10-23T23:59:59.000Z

366

Cellular response of the primate (M. mulatta) spleen to bone marrow transplantation in gamma irradiated recipients  

E-Print Network [OSTI]

. They further stated that this disease was due to the combined effects of late radiation damage, immunologic reaction of the graft against the host and impaired immunologic defense against micro- organisms. Foreign bone marrow treatment was effective only... physicists who had been experimenting with a source that emitted neutron and gamma rays. Five of these physicists were exposed to lethal doses of ioniz- ing radiation. Hemograms taken on October 30, 1958, showed total aplasia. Supportive therapy had...

Fraunfelter, Frank Clare

1966-01-01T23:59:59.000Z

367

End-to-end calculation of the radiation characteristics of VVER-1000 spent fuel assemblies  

SciTech Connect (OSTI)

The results of end-to-end calculation of the radiation characteristics of VVER-1000 spent nuclear fuel are presented. Details of formation of neutron and gamma-radiation sources are analyzed. Distributed sources of different types of radiation are considered. A comparative analysis of calculated radiation characteristics is performed with the use of nuclear data from different ENDF/B and EAF files and ANSI/ANS and ICRP standards.

Linge, I. I.; Mitenkova, E. F., E-mail: mit@ibrae.ac.ru; Novikov, N. V. [Russian Academy of Sciences, Nuclear Safety Institute (Russian Federation)

2012-12-15T23:59:59.000Z

368

On the possible effects of gluon number fluctuations on {gamma}{gamma} collisions at high energies  

SciTech Connect (OSTI)

We investigate the effects of the fluctuations on the total {gamma}{gamma}, {gamma}*{gamma}* cross sections and the real photon structure function F{sup {gamma}}{sub 2}(x,Q{sup 2}), considering a saturation phenomenological model for the dipole-dipole cross section and scattering amplitude with fluctuations included.

Goncalves, V. P.; De Santana Amaral, J. T. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Caixa Postal 354, 96010-900, Pelotas, RS (Brazil)

2013-03-25T23:59:59.000Z

369

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

E-Print Network [OSTI]

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

California at Santa Cruz, University of

370

The radiation-tolerant x-ray monitor  

SciTech Connect (OSTI)

A vacuum photoelectric detector (monitor) (VPD) designed for plasma tomography, megnetohydrodynamics monitoring, and imaging with the help of thermal x-ray radiation on the ITER facility is described. Laboratory experiments demonstrate that VPD has high sensitivity to thermal x rays and low sensitivity to hard gamma rays and neutrons. The results of tests of a prototype of this monitor on a {sup 60}Co source of gamma rays, on nuclear reactor and its calibration using radiation from an x-ray tube, and tests of its serviceability on the T-10 facility are presented.

Gott, Yu. V.; Stepanenko, M. M. [Nuclear Fusion Institute, Russian Research Center 'Kurchatov Institute', Kurchatov Sq. 1, Moscow 123182 (Russian Federation)

2008-10-15T23:59:59.000Z

371

Frequency ratio method for seismic modeling of Gamma Doradus stars  

E-Print Network [OSTI]

A method for obtaining asteroseismological information of a Gamma Doradus oscillating star showing at least three pulsation frequencies is presented. This method is based on a first-order asymptotic g-mode expression, in agreement with the internal structure of Gamma Doradus stars. The information obtained is twofold: 1) a possible identification of the radial order n and degree l of observed frequencies (assuming that these have the same l), and 2) an estimate of the integral of the buoyancy frequency (Brunt-Vaisala) weighted over the stellar radius along the radiative zone. The accuracy of the method as well as its theoretical consistency are also discussed for a typical Gamma Doradus stellar model. Finally, the frequency ratios method has been tested with observed frequencies of the Gamma Doradus star HD 12901. The number of representative models verifying the complete set of constraints (the location in the HR diagram, the Brunt-Vaisala frequency integral, the observed metallicity and frequencies and a re...

Moya, A; Amado, P J; Martin-Ruiz, S; Garrido, R

2004-01-01T23:59:59.000Z

372

A Case Study Correlating Innovative Gamma Ray Scanning Detection Systems Data to Surface Soil Gamma Spectrometry Results - 13580  

SciTech Connect (OSTI)

HydroGeoLogic (HGL), Inc. completed a United States Environmental Protection Agency (USEPA) study to characterize radiological contamination at a site near Canoga Park, California. The characterized area contained 470 acres including the site of a prototype commercial nuclear reactor and other nuclear design, testing, and support operations from the 1950's until 1988 [1]. The site history included radiological releases during operation followed by D and D activities. The characterization was conducted under an accelerated schedule and the results will support the project remediation. The project has a rigorous cleanup to background agenda and does not allow for comparison to risk-based guidelines. To target soil sample locations, multiple lines of evidence were evaluated including a gamma radiation survey, geophysical surveys, historical site assessment, aerial photographs, and former worker interviews. Due to the time since production and decay, the primary gamma emitting radionuclide remaining is cesium-137 (Cs-137). The gamma ray survey covered diverse, rugged terrain using custom designed sodium iodide thallium-activated (NaI(Tl)) scintillation detection systems. The survey goals included attaining 100% ground surface coverage and detecting gamma radiation as sensitively as possible. The effectiveness of innovative gamma ray detection systems was tested by correlating field Cs-137 static count ratios to Cs-137 laboratory gamma spectrometry results. As a case study, the area encompassing the former location of the first nuclear power station in the U. S. was scanned, and second by second global positioning system (GPS)-linked gamma spectral data were evaluated by examining total count rate and nuclide-specific regions of interest. To compensate for Compton scattering from higher energy naturally occurring radionuclides (U-238, Th-232 and their progeny, and K-40), count rate ratios of anthropogenic nuclide-specific regions of interest to the total count rate were calculated. From the scanning data, locations with observed Cs-137 ratios exceeding six standard deviations above the mean ratio were mapped in high resolution [2]. Field teams returned to those locations to collect static count measurements using the same detection systems. Soil surface samples were collected at 30 locations and analyzed for Cs-137. An exponential correlation was identified between Cs-137 concentrations in surface soil and field-scanned Cs-137 ratios. The data indicate field minimum detectable concentration (MDC) of Cs-137 at 0.02 Bq/g (0.5 pCi/g) or lower depending on contaminant distribution in soil. (authors)

Thompson, Shannon; Rodriguez, Rene; Billock, Paul [HydroGeoLogic, Inc., 11107 Sunset Hills Road, Suite 400, Reston, VA 20190 (United States)] [HydroGeoLogic, Inc., 11107 Sunset Hills Road, Suite 400, Reston, VA 20190 (United States); Lit, Peter [Nomad Science Group, 7738 Nautilus Shell Street, Las Vegas, NV 89139 (United States)] [Nomad Science Group, 7738 Nautilus Shell Street, Las Vegas, NV 89139 (United States)

2013-07-01T23:59:59.000Z

373

An Intelligent Radiation Detector System For Remote Monitoring  

Science Journals Connector (OSTI)

A unique real?time gamma radiation detector and spectroscopic analyzer specifically designed for a “Homeland Security Radiological Network” has been developed by the Environmental Measurements Laboratory (EML). The Intelligent Radiation Detector’s (IRD) sensitivity and rapid sampling cycle assure up?to?the minute radiological data which will indicate fast changes in atmospheric radioactivity. In addition an immediate alert will occur within seconds to signal rapid changes in activity or levels elevated beyond a preset. This feature is particularly valuable to detect radioactivity from moving vehicles. The IRD also supplies spectral data which allows the associated network computer to identify the specific radionuclides detected and to distinguish between natural and manmade radioactivity. To minimize cost and maximize rapid availability the IRD uses readily available “off the shelf” components combined with an inexpensive unique detector housing made of PVC plastic pipe. Reliability with no required maintenance is inherent in the IRD which operates automatically and unattended on a “24/7” basis. A prototype unit installed on EML’s roof has been in continuous operation since November 27 2001.

Norman Latner; Norman Chiu; Colin G. Sanderson

2002-01-01T23:59:59.000Z

374

Radiation receiver  

DOE Patents [OSTI]

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

Hunt, A.J.

1983-09-13T23:59:59.000Z

375

Measurements of B to V(Gamma) Decays  

SciTech Connect (OSTI)

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

Yarritu, Aaron K.; /Stanford U., Phys. Dept.; ,

2010-09-02T23:59:59.000Z

376

Radionuclide neutron sources in calibration laboratory—neutron and gamma doses and their changes in time  

Science Journals Connector (OSTI)

......radiation require the determination of this component...been applied for the determination of neutron ambient...equivalent rate and for the determination of neutron and gamma...nominal decay of the main isotope. After 15-20 y...blocks, enclosing the boron or helium proportional......

K. Józefowicz; N. Golnik; P. Tulik; M. Zielczynski

2007-08-01T23:59:59.000Z

377

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

DOE Patents [OSTI]

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

Smither, Robert K. (Hinsdale, IL)

2011-05-17T23:59:59.000Z

378

74Exploring Nuclear Decay and Radiation Dose The devastating earthquake  

E-Print Network [OSTI]

74Exploring Nuclear Decay and Radiation Dose The devastating earthquake that struck northern Japan vent radioactive gas and dust clouds into the environment. Although the initial radiation levels were extremely high, the natural decay of the radioactive compounds will cause the radiation levels at any given

379

Neutron and Gamma Probe Application to Hanford Tank 241-SY-101  

SciTech Connect (OSTI)

A neutron (moisture-sensitive) and gamma (in-situ radiation) probe technique has been utilized at a number of Hanford radioactive waste tanks for many years. This technology has been adapted for use in tank 241-SY-101's two Multifunction Instrument Trees (MITs) which have a hollow dry-well center opening two inches (51 cm) in diameter. These probes provide scans starting within a few inches of the tank bottom and traversing up through the top of the tank revealing a variety of waste features as a function of tank elevation. These features have been correlated with void fraction data obtained independently from two other devices, the Retained Gas Sampler (RGS) and the Void Fraction Instrument (VFI). The MIT probes offer the advantage of nearly continuous count-rate versus elevation scans and they can be operated significantly more often and at lower cost than temperature probes or the RGS or VFI devices while providing better depth resolution. The waste level in tank 241-SY-101 had been rising at higher rates than expected during 1998 and early 1999 indicating an increasing amount of trapped gas in the waste. The use of the MIT probes has assisted in evaluating changes in crust thickness and level and also in estimating relative changes in gas stored in the crust. This information is important in assuring that the tank remains in a safe configuration and will support safe waste transfer when those operations take place.

CANNON, N.S.

2000-02-01T23:59:59.000Z

380

Gamma-ray bursts, axion emission and string theory dilaton  

E-Print Network [OSTI]

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

O. Bertolami

1999-01-14T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Gamma Ray Mirrors for Direct Measurement of Spent Nuclear Fuel  

SciTech Connect (OSTI)

Direct measurement of the amount of Pu and U in spent nuclear fuel represents a challenge for the safeguards community. Ideally, the characteristic gamma-ray emission lines from different isotopes provide an observable suitable for this task. However, these lines are generally lost in the fierce flux of radiation emitted by the fuel. The rates are so high that detector dead times limit measurements to only very small solid angles of the fuel. Only through the use of carefully designed view ports and long dwell times are such measurements possible. Recent advances in multilayer grazing-incidence gamma-ray optics provide one possible means of overcoming this difficulty. With a proper optical and coating design, such optics can serve as a notch filter, passing only narrow regions of the overall spectrum to a fully shielded detector that does not view the spent fuel directly. We report on the design of a mirror system and a number of experimental measurements.

Pivovaroff, Dr. Michael J. [Lawrence Livermore National Laboratory (LLNL)] [Lawrence Livermore National Laboratory (LLNL); Ziock, Klaus-Peter [ORNL] [ORNL; Harrison, Mark J [ORNL] [ORNL; Soufli, Regina [Lawrence Livermore National Laboratory (LLNL)] [Lawrence Livermore National Laboratory (LLNL)

2014-01-01T23:59:59.000Z

382

Radiation Management Act (Oklahoma) | Department of Energy  

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

Radiation Management Act (Oklahoma) Radiation Management Act (Oklahoma) Radiation Management Act (Oklahoma) < Back Eligibility Utility Investor-Owned Utility Program Info State Oklahoma Program Type Environmental Regulations Provider Oklahoma Department of Environmental Quality This Act establishes The Department of Environmental Quality as the designated official agency of the State of Oklahoma for all regulatory activities for the use of atomic energy and sources of radiation, except for the use of sources of radiation by diagnostic x-ray facilities. It also states rules for permits and fees related to the establishment of standards for safe levels of protection against radiation; the maintenance and submission of records; the determination, prevention and control of radiation hazards; the reporting of radiation accidents; the handling,

383

Overview of the gamma reaction history diagnostic for the national ignition facility (NIF)  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) has a need for measuring gamma radiation as part of a nuclear diagnostic program. A new gamma-detection diagnostic uses 900 off-axis parabolic mirrors to rel ay Cherenkov light from a volume of pressurized gas. This non imaging optical system has the high-speed detector placed at a stop position with the Cherenkov light delayed until after the prompt gammas have passed through the detector. Because of the wavelength range (250 to 700 nm), the optical element surface finish was a key design constraint. A cluster of four channels (each set to a different gas pressure) will collect the time histories for different energy ranges of gammas.

Kim, Yong Ho [Los Alamos National Laboratory; Evans, Scott C [Los Alamos National Laboratory; Herrmann, Hans W [Los Alamos National Laboratory; Mack, Joseph M [Los Alamos National Laboratory; Young, Carl S [Los Alamos National Laboratory; Malone, Robert M [Los Alamos National Laboratory; Cox, Brian C [Los Alamos National Laboratory; Frogget, Brent C [Los Alamos National Laboratory; Kaufman, Morris I [Los Alamos National Laboratory; Tunnell, Thomas W [Los Alamos National Laboratory; Tibbitts, Aric [Los Alamos National Laboratory; Palagi, Martin J [NST/LAS VEGAS; Stoeffl, Wolfgang [LLNL

2010-01-01T23:59:59.000Z

384

Digital discrimination of neutrons and gamma-rays in organic scintillation detectors using moment analysis  

SciTech Connect (OSTI)

Digital discrimination of neutron and gamma-ray events in an organic scintillator has been investigated by moment analysis. Signals induced by an americium-beryllium (Am/Be) isotropic neutron source in a stilbene crystal detector have been sampled with a flash analogue-to-digital converter (ADC) of 1 GSamples/s sampling rate and 10-bit vertical resolution. Neutrons and gamma-rays have been successfully discriminated with a threshold corresponding to gamma-ray energy about 217 keV. Moment analysis has also been verified against the results assessed by a time-of-flight (TOF) measurement. It is shown that the classification of neutrons and gamma-rays afforded by moment analysis is consistent with that achieved by digital TOF measurement. This method has been applied to analyze the data acquired from the stilbene crystal detector in mixed radiation field of the HL-2A tokamak deuterium plasma discharges and the results are described.

Xie Xufei; Zhang Xing; Yuan Xi; Chen Jinxiang; Li Xiangqing; Zhang Guohui; Fan Tieshuan [School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing (China); Yuan Guoliang; Yang Jinwei; Yang Qingwei [Southwestern Institute of Physics, Chengdu (China)

2012-09-15T23:59:59.000Z

385

Overview of the Gamma Reaction History Diagnostic for the National Ignition Facility (NIF)  

SciTech Connect (OSTI)

The National Ignition Facility (NIF) has a need for measuring gamma radiation as part of a nuclear diagnostic program. A new gamma-detection diagnostic uses 90º off-axis parabolic mirrors to relay Cherenkov light from a volume of pressurized gas. This nonimaging optical system has the high-speed detector placed at a stop position with the Cherenkov light delayed until after the prompt gammas have passed through the detector. Because of the wavelength range (250 to 700 nm), the optical element surface finish was a key design constraint. A cluster of four channels (each set to a different gas pressure) will collect the time histories for different energy ranges of gammas.

Malone, R M; Frogget, B C; Kaufman, M I; Tibbitts, A; Tunnell, T W; Evans, S C; Herrmann, H W; Kim, Y H; Mack, J M; Young, C S; McGillivray, K D; Palagi, M J

2010-09-01T23:59:59.000Z

386

Radiation Detector R&D | Global and Regional Solutions  

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

Radiation Detector and Nonproliferation R&D Group Radiation Detector and Nonproliferation R&D Group A major element in nonproliferation, arms control verification, nuclear materials safeguards and homeland security is the ability to detect, identify and measure nuclear, radioactive and chemical materials. BNL has a significant and world-class capability in radiation detection including the design and fabrication of advanced detector systems for scientific R&D and nonproliferation applications that has evolved over more than six decades. To support nonproliferation, arms control, safeguards and homeland security, BNL has focused on advanced radiation detector systems that offer room temperature operation with high energy resolution for gamma-ray detectors, imaging and direction indicating capabilities for both gamma-ray

387

Radiation Protection Act (Pennsylvania)  

Broader source: Energy.gov [DOE]

This Act combines the radiation safety provisions of The Atomic Energy Development and Radiation Control Act and the Environmental Radiation Protection Act, and empowers the Department of...

388

AGATA - Advanced Gamma Tracking Array  

E-Print Network [OSTI]

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

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

2011-11-24T23:59:59.000Z

389

ON THE RECENTLY DISCOVERED CORRELATIONS BETWEEN GAMMA-RAY AND X-RAY PROPERTIES OF GAMMA-RAY BURSTS  

SciTech Connect (OSTI)

Recently, many correlations between the prompt {gamma}-ray emission properties and the X-ray afterglow properties of gamma-ray bursts (GRBs) have been inferred from a comprehensive analysis of the X-ray light curves of more than 650 GRBs measured with the Swift X-Ray Telescope (Swift/XRT) during the years 2004-2010. We show that these correlations are predicted by the cannonball (CB) model of GRBs. They result from the dependence of GRB observables on the bulk motion Lorentz factor and viewing angle of the jet of highly relativistic plasmoids (CBs) that produces the observed radiations by interaction with the medium through which it propagates. Moreover, despite their different physical origins, long GRBs (LGRBs) and short-hard bursts (SHBs) in the CB model share similar kinematic correlations, which can be combined into triple correlations satisfied by both LGRBs and SHBs.

Dado, Shlomo; Dar, Arnon [Physics Department, Technion, Haifa 32000 (Israel)

2013-09-20T23:59:59.000Z

390

Gamma Industry Processing Alliance Overview | Department of Energy  

Office of Environmental Management (EM)

Gamma Industry Processing Alliance Overview Gamma Industry Processing Alliance Overview Gamma Industry Processing Alliance Overview More Documents & Publications 2011 NTSF Meeting...

391

Graphite Gamma Scan Results  

SciTech Connect (OSTI)

This report documents the measurement and data analysis of the radio isotopic content for a series of graphite specimens irradiated in the first Advanced Graphite Creep (AGC) experiment, AGC-1. This is the first of a series of six capsules planned as part of the AGC experiment to fully characterize the neutron irradiation effects and radiation creep behavior of current nuclear graphites. The AGC-1 capsule was irradiated in the Advanced Test Reactor (ATR) at INL at approximately 700 degrees C and to a peak dose of 7 dpa (displacements per atom). Details of the irradiation conditions and other characterization measurements performed on specimens in the AGC-1 capsule can be found in “AGC-1 Specimen Post Irradiation Data Report” ORNL/TM 2013/242. Two specimens from six different graphite types are analyzed here. Each specimen is 12.7 mm in diameter by 25.4 mm long. The isotope with the highest activity was 60Co. Graphite type NBG-18 had the highest content of 60Co with an activity of 142.89 µCi at a measurement distance of 47 cm.

Mark W. Drigert

2014-04-01T23:59:59.000Z

392

Gamma ray bursts: The future  

Science Journals Connector (OSTI)

Gamma-ray bursts are the most dramatic and powerful cosmic explosions known. They also continue to be the most puzzling. Thanks to breakthrough observations over the last decade however a picture has emerged of gamma-ray bursts being at cosmological distances and capable of releasing more than 10 51 ergs of energy within seconds. Despite the emergence of this picture the physical origin of bursts is still unknown and the classification of different types of bursts is still in its infancy. Further understanding of gamma-ray bursts requires the wise use of our current resources and the development of new observational capabilities. We outline the current state of our knowledge of bursts and describe the present and future instrumentation which will enable us to understand these baffling blasts.

N. Gehrels; D. Macomb

2000-01-01T23:59:59.000Z

393

Atomistic simulations of radiation damage in amorphous metal alloys  

E-Print Network [OSTI]

While numerous fundamental studies have characterized the atomic-level radiation response mechanisms in irradiated crystalline alloys, comparatively little is known regarding the mechanisms of radiation damage in amorphous ...

Baumer, Richard E. (Richard Edward)

2013-01-01T23:59:59.000Z

394

Neutrinos from Gamma Ray Bursts  

E-Print Network [OSTI]

We show that the detection of neutrinos from a typical gamma ray burst requires a kilometer-scale detector. We argue that large bursts should be visible with the neutrino telescopes under construction. We emphasize the 3 techniques by which neutrino telescopes can perform this search: by triggering on i) bursts of muons from muon neutrinos, ii) muons from air cascades initiated by high energy gamma rays and iii) showers made by relatively low energy ($\\simeq 100\\,\\mev$) electron neutrinos. Timing of neutrino-photon coincidences may yield a measurement of the neutrino mass to order $10^{-5}$~eV, an interesting range in light of the solar neutrino anomaly.

F. Halzen; G. Jaczko

1996-02-07T23:59:59.000Z

395

sin 2 beta + gamma Measurements  

SciTech Connect (OSTI)

I report on the most recent measurements done to constrain sin(2{beta}+{gamma}) with neutral B mesons. Direct measurements of 2{beta} + {gamma} will provide a precise test of the standard model predictions with higher statistics. Present constraints come from studies of B {yields} D{sup (*){+-}}{pi}{sup {-+}}/{rho}{sup {-+}} decays done by BABAR and Belle collaborations with full and inclusive techniques to reconstruct B mesons. B {yields} D{sup 0(*)}K{sup 0} decays are also very promising but statistics are too low to give any constraint at the moment.

Therin, G; /Paris U., VI-VII

2005-06-24T23:59:59.000Z

396

Gamma-ray Imaging Methods  

SciTech Connect (OSTI)

In this document we discuss specific implementations for gamma-ray imaging instruments including the principle of operation and describe systems which have been built and demonstrated as well as systems currently under development. There are several fundamentally different technologies each with specific operational requirements and performance trade offs. We provide an overview of the different gamma-ray imaging techniques and briefly discuss challenges and limitations associated with each modality (in the appendix we give detailed descriptions of specific implementations for many of these technologies). In Section 3 we summarize the performance and operational aspects in tabular form as an aid for comparing technologies and mapping technologies to potential applications.

Vetter, K; Mihailescu, L; Nelson, K; Valentine, J; Wright, D

2006-10-05T23:59:59.000Z

397

A Topological Structure in the Set of Classical Free Radiation Electromagnetic Fields  

E-Print Network [OSTI]

The aim of this work is to proceed with the development of a model of topological electromagnetism in empty space, proposed by one of us some time ago and based on the existence of a topological structure associated with the radiation fields in standard Maxwell's theory. This structure consists in pairs of complex scalar fields, say $\\phi$ and $\\theta$, that can be interpreted as maps $\\phi,\\theta: S^3\\mapsto S^2$, the level lines of which are orthogonal to one another, where $S^3$ is the compactified physical 3-space $R^3$, with only one point at infinity, and $S^2$ is the 2-sphere identified with the complete complex plane. These maps were discovered and studied in 1931 by the German mathematician H. Hopf, who showed that the set of all of them can be ordered in homotopy classes, labeled by the so called Hopf index, equal to $\\gamma=\\pm 1,\\,\\pm 2,\\,\\cdots ,\\, \\pm k,...$ but without $\\gamma=0$. In the model presented here and at the level of the scalars $\\phi$ and $\\theta$, the equations of motion are highly nonlinear; however there is a transformation of variables that converts exactly these equations (not by truncation!) into the linear Maxwell's ones for the magnetic and electric fields $\\B$ and $\\E$.

A. F. Ranada; A. Tiemblo

2014-07-29T23:59:59.000Z

398

Gamma-ray bursts and terrestrial planetary atmospheres  

E-Print Network [OSTI]

We describe results of modeling the effects of gamma-ray bursts (GRBs) within a few kiloparsecs of an Earth-like planet. A primary effect is generation of nitrogen oxide compounds which deplete ozone. Ozone depletion leads to an increase in solar UVB radiation at the surface, enhancing DNA damage, particularly in marine microorganisms such as phytoplankton. In addition, we expect increased atmospheric opacity due to buildup of nitrogen dioxide produced by the burst and enhanced precipitation of nitric acid. We review here previous work on this subject and discuss recent developments.

Thomas, B C; Thomas, Brian C.; Melott, Adrian L.

2006-01-01T23:59:59.000Z

399

Gamma-ray free-electron lasers: Quantum fluid model  

E-Print Network [OSTI]

A quantum fluid model is used to describe the interacion of a nondegenerate cold relativistic electron beam with an intense optical wiggler taking into account the beam space-charge potential and photon recoil effect. A nonlinear set of coupled equations are obtained and solved numerically. The numerical results shows that in the limit of plasma wave-breaking an ultra-high power radiation pulse are emitted at the$\\gamma$-ray wavelength range which can reach an output intensity near the Schwinger limit depending of the values of the FEL parameters such as detuning and input signal initial phase at the entrance of the interaction region.

Silva, H M

2014-01-01T23:59:59.000Z

400

High energy Gamma-Ray Bursts as a result of the collapse and total annihilation of neutralino clumps  

E-Print Network [OSTI]

Rare astrophysical events - cosmological gamma-ray bursts with energies over GeV - are considered as an origin of information about some SUSY parameters. The model of generation of the powerful gamma-ray bursts is proposed. According to this model the gamma-ray burst represents as a result of the collapse and the total annihilation of the neutralino clump. About 80 % of the clump mass radiates during about 100 second at the final stage of annihilation. The annihilation spectrum and its characteristic energies are calculated in the framework of Split Higgsino model.

R. S. Pasechnik; V. A. Beylin; V. I. Kuksa; G. M. Vereshkov

2006-02-20T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Soil radioactivity levels and radiological risk assessment in the highlands of Hunza, Pakistan  

Science Journals Connector (OSTI)

......will require some additional remediation of the soil. Similar to external...dose rate in air at 1 m above ground level. It is calculated as...gamma-dose at 1 m height above the ground level due to the presence of...gamma-ray spectrometry. Water Air Soil Pollut. (2010......

Manzoor Ali; Sajid Iqbal; Mohammad Wasim; Mohammad Arif; Farhan Saif

2013-03-01T23:59:59.000Z

402

The Diverse Environments of Gamma-Ray Bursts  

E-Print Network [OSTI]

Galaxies of Dark Gamma-Ray Bursts: Observational Constraintsof a Very Bright Gamma- Ray Burst in a Galactic Halo 3.11.3 Gamma-Ray Burst Classi?cation . . . . . . 1.4 Gamma-Ray

Perley, Daniel Alan

2011-01-01T23:59:59.000Z

403

A Study of Radiative Bottomonium Transitions using Converted Photons  

SciTech Connect (OSTI)

The authors use (111 {+-} 1) million {Upsilon}(3S) and (89 {+-} 1) million {Upsilon}(2S) events recorded by the BABAR detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions betwen bottomonium states using photons that have been converted to e{sup +}e{sup -} pairs by the detector material. They observe {Upsilon}(3S) {yields} {gamma}{chi}{sub b0,2}(1P) decay, make precise measurements of the branching fractions for {chi}{sub b1,2}(1P, 2P) {yields} {gamma}{Upsilon}(1S) and {chi}{sub b1,2}(2P) {yields} {gamma}{Upsilon}(2S) decays, and search for radiative decay to the {eta}{sub b}(1S) and {eta}{sub b}(2S) states.

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

2011-08-15T23:59:59.000Z

404

Pulsed Gamma-Ray-Burst Afterglows  

E-Print Network [OSTI]

provides a candidate for the central engine of the gamma-ray burst (GRB) mechanism, both long and short

J. Middleditch

2009-01-01T23:59:59.000Z

405

Light Curves of Swift Gamma Ray Bursts  

E-Print Network [OSTI]

Recent observations from the Swift gamma-ray burst mission indicate that a fraction of gamma ray bursts are characterized by a canonical behaviour of the X-ray afterglows. We present an effective theory which allows us to account for X-ray light curves of both (short - long) gamma ray bursts and X-ray rich flashes. We propose that gamma ray bursts originate from massive magnetic powered pulsars.

Paolo Cea

2006-09-22T23:59:59.000Z

406

Periodicities in gamma ray bursts  

Science Journals Connector (OSTI)

Gamma ray burst models based on magnetic neutron stars face a problem of account for the scarcity of observed periods. Both this scarcity and the typical period found when any is detected are explained if the neutron stars are accreting in binary systems

Kent S. Wood

1984-01-01T23:59:59.000Z

407

Neutron Capture Gamma-Ray Libraries for Nuclear Applications  

SciTech Connect (OSTI)

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. this can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research project. EGAF is being used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy and is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. They are investigating the capture spectra from higher energy neutrons experimentally using surrogate reactions and modeling this with Hauser-Feshbach codes. This can then be used to benchmark CASINO, a version of DICEBOX modified for neutron capture at higher energy. This can be used to simulate spectra from neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modeling of unknown assemblies.

Sleaford, B W; Firestone, R B; Summers, N; Escher, J; Hurst, A; Krticka, M; Basunia, S; Molnar, G; Belgya, T; Revay, Z; Choi, H D

2010-11-04T23:59:59.000Z

408

The Universe Viewed in Gamma-Rays 1 Properties of Gamma-ray Bursts Localized by  

E-Print Network [OSTI]

The Universe Viewed in Gamma-Rays 1 Properties of Gamma-ray Bursts Localized by the HETE-2 and localize Gamma-ray bursts (GRBs) in wide field of view. HETE-2 have been localized about 20 GRBs per year hours after the burst. 1. The High Energy Transient Explorer 2 Gamma-ray burst (GRB) is the most

Enomoto, Ryoji

409

Very high-energy gamma rays from gamma-ray bursts  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...high-energy gamma rays from gamma-ray bursts Paula M Chadwick * * ( p.m...progress makes the detection of a gamma-ray burst at the highest energies much...

2007-01-01T23:59:59.000Z

410

Environment/Health/Safety (EHS): Radiation Protection Group  

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

Radiation Protection Group Radiation Protection Group Under the direction of Radiological Control Manager (RCM) David Kestell, the Radiation Protection Group (RPG) provides radiation safety-related technical assistance to the lab community to ensure that all work is performed safely, efficiently and in compliance with applicable regulations and guidelines. BELLA facility BELLA facility BELLA facility BELLA facility BELLA NDCX NDCX Gretina Gamma particle device PET Scanner APEX APEX APEX LASER LASER Rifle, CO Rifle, CO The group: Authorizes work with radioactive material and radiation-producing machines Manages the site inventory of radioactive and nuclear material Provides coverage for: Radiological operations Radiological engineering and shielding design Internal / external dosimetry services Radiation Safety and Transportation training

411

New Remote Method for Estimation of Contamination Levels of Reactor Equipment - 13175  

SciTech Connect (OSTI)

Projects for decommissioning of shutdown reactors and reactor facilities carried out in several countries, including Russia. In the National Research Centre 'Kurchatov Institute' decontamination and decommissioning of the research reactor MR (Material Testing Reactor) has been initiated. The research reactor MR has a long history and consists of nine loop facilities for experiments with different kinds of fuel. During the operation of main and auxiliary equipment of reactors it was subjected to strong radioactive contamination. The character of this contamination requires individual strategies for the decontamination work. This requires information about the character of the distribution of radioactive contamination of equipment in the premises. A detailed radiation survey of these premises using standard dosimetric equipment is almost impossible because of high levels of radiation and high-density of the equipment that does not allow identifying the most active fragments using standard tools of measurement. The problem can be solved using the method of remote measurements of distribution of radioactivity with help of the collimated gamma-ray detectors. For radiation surveys of the premises of loop installations remotely operated spectrometric collimated system was used [1, 2, 3]. As a result of the work, maps of the distribution of activity and dose rate for surveyed premises were plotted and superimposed on its photo. The new results of measurements in different areas of the reactor and at its loop installations, with emphasis on the radioactive survey of highly-contaminated samples, are presented. (authors)

Danilovich, Alexey; Ivanov, Oleg; Potapov, Victor; Semenov, Sergey; Semin, Ilya; Smirnov, Sergey; Stepanov, Vyacheslav; Volkovich, Anatoly [National Research Centre 'Kurchatov Institute', Moscow (Russian Federation)] [National Research Centre 'Kurchatov Institute', Moscow (Russian Federation)

2013-07-01T23:59:59.000Z

412

A proof of the Gamma test  

Science Journals Connector (OSTI)

...research-article Research Article A proof of the Gamma test Dafydd Evans Antonia J. Jones Department...dataset of input-output vectors, the Gamma test estimates the variance of the noise on...derivatives. We present a proof of the Gamma test under fairly weak hypotheses. nonlinear...

2002-01-01T23:59:59.000Z

413

Gamma-ray burst theory after Swift  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...J. Wijers and Martin Rees Gamma-ray burst theory after Swift Tsvi Piran...relativistic blast wave model for gamma-ray bursts (GRBs). Together with the...

2007-01-01T23:59:59.000Z

414

Gamma-ray bursts and cosmology  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...J. Wijers and Martin Rees Gamma-ray bursts and cosmology D.Q Lamb...current status of the use of gamma-ray bursts (GRBs) as probes of the early...

2007-01-01T23:59:59.000Z

415

Radiator Labs | Department of Energy  

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

Radiator Labs Radiator Labs National Clean Energy Business Plan Competition Radiator Labs Columbia University More than 14 million housing units, or 10 percent of the national housing stock, is heated by steam and hot water. Steam heating, which represents the majority of this market, is particularly inefficient, and is characterized by a central source of steam generation with a convective distribution system via a network of pipes and radiators. There is no way to control heat transfer through this network, so building managers configure boiler systems to treat a building as a single zone keeping the coldest apartment above a minimum statutory temperature. This results in overheating of the other spaces in the building due to differences in exposure, level of insulation, distribution system heating,

416

Radiator Labs | Department of Energy  

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

Competition » Radiator Labs Competition » Radiator Labs National Clean Energy Business Plan Competition Radiator Labs Columbia University More than 14 million housing units, or 10 percent of the national housing stock, is heated by steam and hot water. Steam heating, which represents the majority of this market, is particularly inefficient, and is characterized by a central source of steam generation with a convective distribution system via a network of pipes and radiators. There is no way to control heat transfer through this network, so building managers configure boiler systems to treat a building as a single zone keeping the coldest apartment above a minimum statutory temperature. This results in overheating of the other spaces in the building due to differences in exposure, level of insulation, distribution system heating,

417

Radiator Labs | Department of Energy  

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

Competition » Radiator Labs Competition » Radiator Labs National Clean Energy Business Plan Competition Radiator Labs Columbia University More than 14 million housing units, or 10 percent of the national housing stock, is heated by steam and hot water. Steam heating, which represents the majority of this market, is particularly inefficient, and is characterized by a central source of steam generation with a convective distribution system via a network of pipes and radiators. There is no way to control heat transfer through this network, so building managers configure boiler systems to treat a building as a single zone keeping the coldest apartment above a minimum statutory temperature. This results in overheating of the other spaces in the building due to differences in exposure, level of insulation, distribution system heating,

418

TeV Burst of Gamma-Ray Bursts and Ultra High Energy Cosmic Rays  

E-Print Network [OSTI]

Some recent experiments detecting very high energy (VHE) gamma-rays above 10-20 TeV independently reported VHE bursts for some of bright gamma-ray bursts (GRBs). If these signals are truly from GRBs, these GRBs must emit a much larger amount of energy as VHE gamma-rays than in the ordinary photon energy range of GRBs (keV-MeV). We show that such extreme phenomena can be reasonably explained by synchrotron radiation of protons accelerated to \\sim 10^{20-21} eV, which has been predicted by Totani (1998a). Protons seem to carry about (m_p/m_e) times larger energy than electrons, and hence the total energy liberated by one GRB becomes as large as \\sim 10^{56} (\\Delta \\Omega / 4 \\pi) ergs. Therefore a strong beaming of GRB emission is highly likely. Extension of the VHE spectrum beyond 20 TeV gives a nearly model-independent lower limit of the Lorentz factor of GRBs, as $\\gamma \\gtilde 500$. Furthermore, our model gives the correct energy range and time variability of ordinary keV-MeV gamma-rays of GRBs by synchrotron radiation of electrons. Therefore the VHE bursts of GRBs strongly support the hypothesis that ultra high energy cosmic rays observed on the Earth are produced by GRBs.

Tomonori Totani

1998-10-14T23:59:59.000Z

419

Low Dose Radiation Program: Links - Online Literature  

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

Online Literature Online Literature Journals, Books and other Publications Armed Forces Radiobiology Research Institute Chornobyl Center for Nuclear Safety Radioactive Waste and Radioecology "Insight" Magazine Central Research Institute of the Electric Power Industry (CRIEPI) News: Aiming at an information center on low dose radiation research Health Physics International Journal of Radiation Biology Iranian Journal of Radiation Research Journal of Radiological Protection National Council on Radiation Protection and Measurements Radiation Research U.S. Department of Energy (DOE) Information Bridge Reports Animal Cancer Tests and Human Cancer Risk Assessment: A Broad Perspective Effects of Ionizing Radiation: Atomic Bomb Survivors and Their Children (1945-1995) Health Effects of Exposure to Low Levels of Ionizing Radiation: BEIR

420

Open questions regarding implications of radioadaptive response in the estimation of the risks of low-level exposures in nuclear workers  

Science Journals Connector (OSTI)

Substantial data indicate that increased levels of chromosome aberrations in lymphocytes can be used to predict cancer risk in humans. One may conclude that a dose of ionising radiation sufficient to produce a certain level of cell damage increases production of antioxidants and repair enzymes that decrease either the frequency of chromosome aberrations or the cancer risk. People in some areas of Ramsar, a city in northern Iran, receive an annual radiation dose from background radiation that is more than five times higher than the 20 mSv yr-1 that is permitted for radiation workers. If an annual radiation dose of a few hundred mSv is detrimental to health, causing genetic abnormalities or an increased risk of cancer, it should be evident in these people, while cytogenetic studies show no significant differences between people in the high background compared to people in normal background areas. Although there is not yet solid epidemiological information, most local physicians in Ramsar report anecdotally there is no increase in the incidence rates of cancer or leukemia in their area. On the other hand, there are no data to indicate a significant increase of cancer incidence in other High Background Radiation Areas (HBRAs) around the world. Furthermore, several studies show a significant decrease of cancer death rates in areas with high backgrounds. To assess the possible induction of an adaptive response, an in vitro challenge dose of 1.5 Gy of gamma rays was administered to the lymphocytes of the inhabitants as well as those of a neighbouring area. Lymphocytes of Ramsar residents showed a significantly reduced radiation sensitivity for chromosome aberrations compared to those of residents in normal background areas. Given the apparent lack of ill effects in the populations of these high dose-rate areas, these data further suggest that current dose limits are overly conservative.

S.M.J. Mortazavi; T. Ikushima

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Neutron/gamma coupled library generation and gamma transport calculation with KARMA 1.2  

SciTech Connect (OSTI)

KAERI has developed a lattice transport calculation code KARMA and its multi-group cross section library generation system. Recently, the multi-group cross section library generation system has included a gamma cross section generation capability and KARMA also has been improved to include a gamma transport calculation module. This paper addresses the multi-group gamma cross section generation capability for the KARMA 1.2 code and the preliminary test results of the KARMA 1.2 gamma transport calculations. The gamma transport calculation with KARMA 1.2 gives the gamma flux, gamma smeared power, and gamma energy deposition distributions. The results of the KARMA gamma calculations were compared with those of HELIOS and they showed that KARMA 1.2 gives reasonable gamma transport calculation results. (authors)

Hong, S. G. [Dept. of Nuclear Engineering, Kyung Hee Univ., 446-701 Deogyeong-daero, GiHeung-gu, Yongin, Gyeonggi-do (Korea, Republic of); Kim, K. S.; Cho, J. Y.; Lee, K. H. [Korea Atomic Energy Research Inst., 305-353 Duckjin-dong, Yuseong-gu, Daejon (Korea, Republic of)

2012-07-01T23:59:59.000Z

422

PERFORMANCE OF RADIATION SURVEY METERS IN X- AND GAMMA-RADIATION FIELDS  

Science Journals Connector (OSTI)

......1 Vinca Institute of Nuclear Sciences, University...chambers are used widely in nuclear power industry but also...and compliance with regulatory requirements(9...in Vinca Institute of Nuclear Sciences in Laboratory...International Electrotechnical Commision, IEC 1017-2(12......

Sandra Ceklic; Danijela Arandjic; Milos Zivanovic; Olivera Ciraj-Bjelac; Djordje Lazarevic

2014-07-01T23:59:59.000Z

423

Gamma-Ray Emission in Dissipative Pulsar Magnetospheres: From Theory to Fermi Observations  

E-Print Network [OSTI]

We compute the patterns of $\\gamma$-ray emission due to curvature radiation in dissipative pulsar magnetospheres. Our ultimate goal is to construct macrophysical models that are able to reproduce the observed $\\gamma$-ray light-curve phenomenology recently published in the Second Fermi Pulsar Catalog. We apply specific forms of Ohm's law on the open field lines using a broad range for the macroscopic conductivity values that result in solutions ranging, from near-vacuum to near Force-Free. Using these solutions, we generate model $\\gamma$-ray light curves by calculating realistic trajectories and Lorentz factors of radiating particles, under the influence of both the accelerating electric fields and curvature radiation-reaction. We further constrain our models using the observed dependence of the phase-lags between the radio and $\\gamma$-ray emission on the $\\gamma$-ray peak-separation. We perform a statistical comparison of our model radio-lag vs peak-separation diagram and the one obtained for the Fermi standard pulsars. We find that for models of uniform conductivity over the entire open magnetic field line region, agreement with observations favors higher values of this parameter. We find, however, significant improvement in fitting the data with models that employ a hybrid form of conductivity; specifically, infinite conductivity interior to the light-cylinder and high but finite conductivity on the outside. In these models the $\\gamma$-ray emission is produced in regions near the equatorial current sheet but modulated by the local physical properties. These models have radio-lags near the observed values and statistically best reproduce the observed light-curve phenomenology. Additionally, these models produce GeV photon cut-off energies.

Constantinos Kalapotharakos; Alice K. Harding; Demosthenes Kazanas

2014-07-27T23:59:59.000Z

424

Radiating gravastars  

SciTech Connect (OSTI)

Considering a Vaidya exterior spacetime, we study dynamical models of prototype gravastars, made of an infinitely thin spherical shell of a perfect fluid with the equation of state p = ?, enclosing an interior de Sitter spacetime. We show explicitly that the final output can be a black hole, an unstable gravastar, a stable gravastar or a 'bounded excursion' gravastar, depending on how the mass of the shell evolves in time, the cosmological constant and the initial position of the dynamical shell. This work presents, for the first time in the literature, a gravastar that emits radiation.

Chan, R. [Coordenação de Astronomia e Astrofísica, Observatório Nacional, Rua General José Cristino, 77, São Cristóvão 20921-400, Rio de Janeiro, RJ (Brazil); Silva, M.F.A. da [Departamento de Física Teórica, Instituto de Física, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier 524, Maracanã 20550-900, Rio de Janeiro - RJ (Brazil); Rocha, Jaime F. Villas da [Instituto de Biociências, Departamento de Ciências Naturais, Universidade Federal do Estado do Rio de Janeiro, Av. Pasteur 458, Urca, CEP 22290-240, Rio de Janeiro, RJ (Brazil); Wang, Anzhong, E-mail: chan@on.br, E-mail: mfasnic@gmail.com, E-mail: jfvroch@pq.cnpq.br, E-mail: anzhong_wang@baylor.edu [GCAP-CASPER, Department of Physics, Baylor University, Waco, TX 76798 (United States)

2011-10-01T23:59:59.000Z

425

Cellular response to low dose radiation: Role of phosphatidylinositol-3 kinase like kinases  

SciTech Connect (OSTI)

It is increasingly realized that human exposure either to an acute low dose or multiple chronic low doses of low LET radiation has the potential to cause different types of cancer. Therefore, the central theme of research for DOE and NASA is focused on understanding the molecular mechanisms and pathways responsible for the cellular response to low dose radiation which would not only improve the accuracy of estimating health risks but also help in the development of predictive assays for low dose radiation risks associated with tissue degeneration and cancer. The working hypothesis for this proposal is that the cellular mechanisms in terms of DNA damage signaling, repair and cell cycle checkpoint regulation are different for low and high doses of low LET radiation and that the mode of action of phosphatidylinositol-3 kinase like kinases (PIKK: ATM, ATR and DNA-PK) determines the dose dependent cellular responses. The hypothesis will be tested at two levels: (I) Evaluation of the role of ATM, ATR and DNA-PK in cellular response to low and high doses of low LET radiation in simple in vitro human cell systems and (II) Determination of radiation responses in complex cell microenvironments such as human EpiDerm tissue constructs. Cellular responses to low and high doses of low LET radiation will be assessed from the view points of DNA damage signaling, DNA double strand break repair and cell cycle checkpoint regulation by analyzing the activities (i.e. post-translational modifications and kinetics of protein-protein interactions) of the key target proteins for PI-3 kinase like kinases both at the intra-cellular and molecular levels. The proteins chosen for this proposal are placed under three categories: (I) sensors/initiators include ATM ser1981, ATR, 53BP1, gamma-H2AX, MDC1, MRE11, Rad50 and Nbs1; (II) signal transducers include Chk1, Chk2, FANCD2 and SMC1; and (III) effectors include p53, CDC25A and CDC25C. The primary goal of this proposal is to elucidate the differences in cellular defense mechanisms between low and high doses of low LET radiation and to define the radiation doses where the cellular DNA damage signaling and repair mechanisms tend to shift. This information is critically important to address and advance some of the low dose research program objectives of DOE. The results of this proposed study will lead to a better understanding of the mechanisms for the cellular responses to low and high doses of low LET radiation. Further, systematic analysis of the role of PIKK signaling pathways as a function of radiation dose in tissue microenvironment will provide useful mechanistic information for improving the accuracy of radiation risk assessment for low doses. Knowledge of radiation responses in tissue microenvironment is important for the accurate prediction of ionizing radiation risks associated with cancer and tissue degeneration in humans.

Balajee, A.S.; Meador, J.A.; Su, Y.

2011-03-24T23:59:59.000Z

426

Thermonuclear Reaction Rate of 23Mg(p,gamma)24$Al  

E-Print Network [OSTI]

Updated stellar rates for the reaction 23Mg(p,gamma)24Al are calculated by using all available experimental information on 24Al excitation energies. Proton and gamma-ray partial widths for astrophysically important resonances are derived from shell model calculations. Correspondences of experimentally observed 24Al levels with shell model states are based on application of the isobaric multiplet mass equation. Our new rates suggest that the 23Mg(p,gamma)24Al reaction influences the nucleosynthesis in the mass A>20 region during thermonuclear runaways on massive white dwarfs.

H. Herndl; M. Fantini; C. Iliades; P. M. Endt; H. Oberhummer

1998-06-05T23:59:59.000Z

427

BWR (boiling-water reactor) radiation control: In-plant demonstration at Vermont Yankee: Final report  

SciTech Connect (OSTI)

Results of the RP1934 program, which was established by EPRI in 1981 to demonstrate the adequacy of BRAC program (RP819) principles for BWR radiation control at Vermont Yankee, are presented. Evaluations were performed of the effectiveness of optimization of purification system performance, control of feedwater dissolved oxygen concentrations, minimization of corrosion product and ionic transport, and improved startup, shutdown, and layup practices. The impact on shutdown radiation levels of these corrective actions was assessed based on extensive primary system radiation survey and component gamma scan data. Implementation of the BRAC recommendations was found to be insufficient to reduce the rate of activity buildup on out-of-core surfaces at Vermont Yankee, and additional corrective actions were found necessary. Specifically, replacement of cobalt-bearing materials in the control rod drive pins and rollers and feedwater regulating valves was pursued as was installation of electropolished 316 stainless steel during a recirculation piping replacement program. Aggressive programs to further reduce copper concentrations in the reactor water by improving condensate demineralizer efficiency and to minimize organic ingress to the power cycle by reducing organic concentrations in recycled radwaste also were undertaken. Evaluations of the impact on activity buildup of several pretreatment processes including prefilming in moist air, preexposure to high temperature water containing zinc, and electropolishing also were performed in a test loop installed in the reactor water cleanup system. A significant beneficial impact of electropolishing was shown to be present for periods up to 6000 hours.

Palino, G.F.; Hobart, R.L.; Sawochka, S.G.

1987-10-01T23:59:59.000Z

428

Lightweight aerial vehicles for monitoring, assessment and mapping of radiation anomalies  

Science Journals Connector (OSTI)

Abstract The Fukushima Daiichi nuclear power plant (FDNPP) incident released a significant mass of radioactive material into the atmosphere. An estimated 22% of this material fell out over land following the incident. Immediately following the disaster, there was a severe lack of information not only pertaining to the identity of the radioactive material released, but also its distribution as fallout in the surrounding regions. Indeed, emergency aid groups including the UN did not have sufficient location specific radiation data to accurately assign exclusion and evacuation zones surrounding the plant in the days and weeks following the incident. A newly developed instrument to provide rapid and high spatial resolution assessment of radionuclide contamination in the environment is presented. The device consists of a low cost, lightweight, unmanned aerial platform with a microcontroller and integrated gamma spectrometer, GPS and LIDAR. We demonstrate that with this instrument it is possible to rapidly and remotely detect ground-based radiation anomalies with a high spatial resolution (<1 m). Critically, as the device is remotely operated, the user is removed from any unnecessary or unforeseen exposure to elevated levels of radiation.

J.W. MacFarlane; O.D. Payton; A.C. Keatley; G.P.T. Scott; H. Pullin; R.A. Crane; M. Smilion; I. Popescu; V. Curlea; T.B. Scott

2014-01-01T23:59:59.000Z

429

Low Dose Radiation Research Program: Dual Regulation of JB6 Transformation  

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

Dual Regulation of JB6 Transformation by Low Dose Gamma Radiation. Dual Regulation of JB6 Transformation by Low Dose Gamma Radiation. Authors: Thomas J. Weber,1 Lye M. Markillie,1 William B. Chrisler,1 Xingye C. Lei,1 and Nancy H. Colburn2 Institutions: 1Molecular Biosciences, Pacific Northwest National Laboratory. 2Gene Regulation Section, Basic Research Laboratory, National Cancer Institute JB6 mouse epidermal cells have been instrumental in defining the molecular mechanisms associated with neoplastic transformation in response to known tumor promoters. JB6 cells exhibit a clonal growth response to oxygen free radicals suggesting this model may also be useful for radiation research. Treatment of JB6 cells with 2 and 20 cGy gamma radiation resulted in a weak, but dose-dependent increase in anchorage-independent growth observed

430

Public Understanding of Cleanup Levels DRAFT FAQ Public Involvement...  

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

A. Future land use directly affects the amount of radiation that a person, animal, or ecosystem (also called "receptors") will receive. Generally, clean up levels may be lower...

431

Gamma-ray identification of nuclear weapon materials  

SciTech Connect (OSTI)

There has been an accelerating national interest in countering nuclear smuggling. This has caused a corresponding expansion of interest in the use of gamma-ray spectrometers for checkpoint monitoring, nuclear search, and within networks of nuclear and collateral sensors. All of these are fieldable instruments--ranging from large, fixed portal monitors to hand-held and remote monitoring equipment. For operational reasons, detectors with widely varying energy resolution and detection efficiency will be employed. In many instances, such instruments must be sensitive to weak signals, always capable of recognizing the gamma-ray signatures from nuclear weapons materials (NWM), often largely insensitive to spectral alteration by radiation transport through intervening materials, capable of real-time implementation, and able to discriminate against signals from commonly encountered legitimate gamma-ray sources, such as radiopharmaceuticals. Several decades of experience in classified programs have shown that all of these properties are not easily achieved and successful approaches were of limited scope--such as the detection of plutonium only. This project was originally planned as a two-year LDRD-ER. Since funding for 1997 was not sustained, this is a report of the first year's progress.

Gosnell, T. B., LLNL; Hall, J. M.; Jam, C. L.; Knapp, D. A.; Koenig, Z. M.; Luke, S. J.; Pohl, B. A.; Schach von Wittenau, A.; Wolford, J. K.

1997-02-03T23:59:59.000Z

432

Spectral Lags of Gamma-Ray Bursts from Primordial Black Hole (PBH) Evaporations  

E-Print Network [OSTI]

Primordial Black Holes (PBHs), which may have been created in the early Universe, are predicted to be detectable by their Hawking radiation. PBHs with an initial mass of 5.0 * 10^14 g should be expiring today with a burst of high energy particles. Evaporating PBHs in the solar neighborhood are candidate Gamma-Ray Bursts (GRBs) progenitors. We propose spectral lag, which is the temporal delay between the high energy photon pulse and the low energy photon pulse, as a possible method to detect PBH evaporation events with the Fermi Gamma-ray Space Telescope Observatory.

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

2009-08-14T23:59:59.000Z

433

Population Studies of Gamma Ray Sources Using Stacking Analysis at Low Galactic Latitudes  

SciTech Connect (OSTI)

We studied the problem of the treatment of uncertainties in the diffuse gamma radiation apparent in stacking analysis of EGRET data at low Galactic latitudes for several classes of sources like PSRs. For those classes of sources we co-added maps of counts, exposure and diffuse background, and residuals, in varying numbers for different sub-categories. Finally we tested for gamma-ray excess emission in those maps and attempt to quantify the systematic biases in such approach. Such kinds of analysis will support and provide confidence in the classification processes of sources and source populations in the GLAST era.

Cillis, Analia N.; /NASA, Goddard; Reimer, Olaf; /Stanford U., HEPL /KIPAC, Menlo Park; Torres, Diego F.; /ICREA, Barcelona /Barcelona, Autonoma U.

2007-11-13T23:59:59.000Z

434

Absorbed Gamma?Ray Doses due to Natural Radionuclides in Building Materials  

Science Journals Connector (OSTI)

This work is devoted to the application of high?resolution gamma?ray spectrometry in the study of the effective dose coming from naturally occurring radionuclides namely 40 K 232 Th and 238 U present in building materials such as sand cement and granitic gravel. Four models were applied to estimate the effective dose and the hazard indices. The maximum estimated effective dose coming from the three reference rooms considered is 0.90(45) mSv/yr and maximum internal hazard index is 0.77(24) both for the compact clay brick reference room. The principal gamma radiation sources are cement sand and bricks.

Vitor A. P. Aguiar; Nilberto H. Medina; Ramon H. Moreira; Marcilei A. G. Silveira

2010-01-01T23:59:59.000Z

435

Hard x-ray or gamma ray laser by a dense electron beam  

E-Print Network [OSTI]

A coherent x-ray or gamma ray can be created from a dense electron beam propagating through an intense laser undulator. It is analyzed by using the Landau damping theory which suits better than the conventional linear analysis for the free electron laser, as the electron beam energy spread is high. The analysis suggests that the currently available physical parameters would enable the generation of the coherent gamma ray of up to 100 keV. The electron quantum diffraction suppresses the FEL action, by which the maximum radiation energy to be generated is limited.

S. Son; S. J. Moon

2012-02-12T23:59:59.000Z

436

Absorbed Gamma-Ray Doses due to Natural Radionuclides in Building Materials  

SciTech Connect (OSTI)

This work is devoted to the application of high-resolution gamma-ray spectrometry in the study of the effective dose coming from naturally occurring radionuclides, namely {sup 40}K, {sup 232}Th and {sup 238}U, present in building materials such as sand, cement, and granitic gravel. Four models were applied to estimate the effective dose and the hazard indices. The maximum estimated effective dose coming from the three reference rooms considered is 0.90(45) mSv/yr, and maximum internal hazard index is 0.77(24), both for the compact clay brick reference room. The principal gamma radiation sources are cement, sand and bricks.

Aguiar, Vitor A. P.; Medina, Nilberto H. [Instituto de Fisica, Universidade de Sao Paulo, SP (Brazil); Moreira, Ramon H.; Silveira, Marcilei A. G. [Departamento de Fisica, Centro Universitario da FEI, Sao Bernardo do Campo, SP (Brazil)

2010-05-21T23:59:59.000Z

437

Short-term effects of Gamma Ray Bursts on oceanic photosynthesis  

E-Print Network [OSTI]

We continue our previous work on the potential short-term influence of a gamma ray bursts on Earth's biosphere, focusing on the only important short-term effect on life: the ultraviolet flash which occurs as a result of the retransmission of the {\\gamma} radiation through the atmosphere. Thus, in this work we calculate the ultraviolet irradiances penetrating the first hundred meters of the water column, for Jerlov's ocean water types I, II and III. Then we estimate the UV flash potential for photosynthesis inhibition, showing that it can be important in a considerable part of the water column with light enough for photosynthesis to be done, the so called photic zone.

Penate, Liuba; Cardenas, Rolando; Agusti, Susana

2010-01-01T23:59:59.000Z

438

Natural radioactivity and radiation exposure at the Minjingu phosphate mine in Tanzania  

Science Journals Connector (OSTI)

In this paper the results of studies on activity and ambient radiation background around the Minjingu phosphate mine in Tanzania are presented. The outdoor dose rate in air and the activity levels of samples from and outside the mine were determined by thermoluminiscent dosimeters and a gamma spectrometer system with a Hyper Pure germanium detector system respectively. The determination of activity was made for the 226 Ra, 228 Ra, 228 Th and 40 K radionuclides. High concentrations of radium-226 were observed in phosphate rock (5760±107 Bq kg-1 ), waste rock (4250±98 Bq kg-1 ), wild leaf vegetation (650±11 Bq kg-1 ), edible leaf vegetation (393±9 Bq kg-1 ), surface water (4.7±0.4 mBq l-1 ) and chicken feed (4±0.1 Bq kg-1 ) relative to selected control sites. These findings suggest a radiation health risk particularly when the samples are ingested, because the internal exposure may give rise to an effective dose exceeding 20 mSv which is the annual limit of intake of natural radionuclides recommended by the ICRP. On the other hand, the radiation dose from ambient air over five years at the phosphate mine ranges from 1375 to 1475 nGy h-1 with an average of 1415 nGy h-1 . The average is about 28 times that of the global average background radiation from terrestrial sources, and about 12 times the allowed average dose limit for public exposure over five consecutive years. Future investigations on the occupancy factor, external dose rate and radon and radon progeny exposure in drinking water, buildings and activity content in the locally grown foodstuffs are proposed, for the realistic quantification of the overall exposure of workers and public at Minjingu, and remedial measures for future radiation safety.

Firmi P Banzi; Leonard D Kifanga; Felician M Bundala

2000-01-01T23:59:59.000Z

439

Order Module--NNSA OCCUPATIONAL RADIATION PROTECTION  

Broader source: Energy.gov [DOE]

The familiar level of this module is designed to provide the basic information to meet the requirements that are related to 10 CFR 835, “Occupational Radiation Protection,” in the following DOE...

440

Natural and Radiation Carcinogenesis in Man. III. Radiation Carcinogenesis  

Science Journals Connector (OSTI)

...mice. NATURAL AND RADIATION CARCINOGENESIS IN MAN. 3. RADIATION CARCINOGENESIS. | Journal Article | Japan Neoplasms etiology Neoplasms, Radiation-Induced Radiation Genetics | JAPAN NEOPLASM ETIOLOGY NEOPLASMS, RADIATION-INDUCED RADIATION...

1965-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation levels" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

DNA-PK inhibition causes a low level of H2AX phosphorylation and homologous recombination repair in Medaka (Oryzias latipes) cells  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer We investigated the effect of DNA-PK inhibition on DSB repair using fish cells. Black-Right-Pointing-Pointer A radiation sensitive mutant RIC1 strain showed a low level of DNA-PK activity. Black-Right-Pointing-Pointer DNA-PK dysfunction leads defects in HR repair and DNA-PKcs autophosphorylation. Black-Right-Pointing-Pointer DNA-PK dysfunction leads a slight increase in the number of 53BP1 foci after DSBs. Black-Right-Pointing-Pointer DNA-PK dysfunction leads an alternative NHEJ that depends on 53BP1. -- Abstract: Nonhomologous end joining (NHEJ) and homologous recombination (HR) are known as DNA double-strand break (DSB) repair pathways. It has been reported that DNA-PK, a member of PI3 kinase family, promotes NHEJ and aberrant DNA-PK causes NHEJ deficiency. However, in this study, we demonstrate that a wild-type cell line treated with DNA-PK inhibitor and a mutant cell line with dysfunctional DNA-PK showed decreased HR efficiency in fish cells (Medaka, Oryzias latipes). Previously, we reported that the radiation-sensitive mutant RIC1 strain has a defect in the Histone H2AX phosphorylation after {gamma}-irradiation. Here, we showed that a DNA-PK inhibitor, NU7026, treatment resulted in significant reduction in the number of {gamma}H2AX foci after {gamma}-irradiation in wild-type cells, but had no significant effect in RIC1 cells. In addition, RIC1 cells showed significantly lower levels of DNA-PK kinase activity compared with wild-type cells. We investigated NHEJ and HR efficiency after induction of DSBs. Wild-type cells treated with NU7026 and RIC1 cells showed decreased HR efficiency. These results indicated that aberrant DNA-PK causes the reduction in the number of {gamma}H2AX foci and HR efficiency in RIC1 cells. We performed phosphorylated DNA-PKcs (Thr2609) and 53BP1 focus assay after {gamma}-irradiation. RIC1 cells showed significant reduction in the number of phosphorylated DNA-PKcs foci and no deference in the number of 53BP1 foci compared with wild-type cells. These results suggest that low level of DNA-PK activity causes aberrant DNA-PKcs autophosphorylation in RIC1 cells. It is known that 53BP1 is involved in both DNA-PK dependent and independent NHEJ. Therefore we suggest that DNA-PK independent NHEJ repair DSBs under the condition of decreased DNA-PK activity, which causes reduction of HR efficiency.

Urushihara, Yusuke [Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562 (Japan)] [Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562 (Japan); Kobayashi, Junya [Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto 606-8501 (Japan)] [Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto 606-8501 (Japan); Matsumoto, Yoshihisa [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550 (Japan)] [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Komatsu, Kenshi [Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto 606-8501 (Japan)] [Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto 606-8501 (Japan); Oda, Shoji [Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562 (Japan)] [Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562 (Japan); Mitani, Hiroshi, E-mail: mitani@k.u-tokyo.ac.jp [Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562 (Japan)] [Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562 (Japan)

2012-12-14T23:59:59.000Z

442

NNSA to Conduct Aerial Radiation Assessment Survey over Joint...  

National Nuclear Security Administration (NNSA)

of naturally occurring radiation to establish baseline levels is a normal part of security and emergency preparedness. This assessment is not in response to an incident or...

443

Gamma Industry Processing Alliance Overview  

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

NATIONAL NATIONAL STAKEHOLDERS TRANSPORTATION FORUM WHO IS GIPA? * Alliance made up of 15 companies from the Medical Device Manufacturers, Cobalt source , manufacturers and one industrial processing company Represents all the major gamma processing * Represents all the major gamma processing facilities within the US to the regulatory bodies such as the USNRC. * Member of International Irradiation Association (iiA) WHO IS GIPA? An alliance created to advocate the development of An alliance created to advocate the development of responsible regulations that enhance the safe and secure management of Cobalt-60 sources and related irradiation processing facilities related irradiation processing facilities. APRIL 15, 2010 PRESENTATION TITLE WORLD SUPPLIERS OF COBALT 60 COBALT 60 * Nordion Inc

444

Adaptors for radiation detectors  

DOE Patents [OSTI]

Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

Livesay, Ronald Jason

2014-04-22T23:59:59.000Z

445

Are gamma ray bursts nearby?  

Science Journals Connector (OSTI)

The possibility is considered that the intrinsic luminosity function of gamma ray bursters has sufficient scatter that the ln?N?ln?S relation of observed bursts not be dominated by geometric effects favoring large volumes but rather be dominated by nearby intrinsically faint bursts. It is shown that the distribution of bursts on the sky would be very granular with a significant fraction of them coming from the two or three nearest sources. Possible solutions and alternatives are briefly discussed.

David Eichler

1994-01-01T23:59:59.000Z

446

Gamma-ray burst afterglows  

E-Print Network [OSTI]

Extended, fading emissions in multi-wavelength are observed following Gamma-ray bursts (GRBs). Recent broad-band observational campaigns led by the Swift Observatory reveal rich features of these GRB afterglows. Here we review the latest observational progress and discuss the theoretical implications for understanding the central engine, composition, and geometric configuration of GRB jets, as well as their interactions with the ambient medium.

Bing Zhang

2006-11-24T23:59:59.000Z

447

Radiation Safety  

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

Brotherhood of Locomotive Brotherhood of Locomotive Engineers & Trainmen Scott Palmer BLET Radiation Safety Officer New Hire Training New Hire study topics * GCOR * ABTH * SSI * Employee Safety * HazMat * Railroad terminology * OJT * 15-week class * Final test Hazardous Materials * Initial new-hire training * Required by OSHA * No specified class length * Open book test * Triennial module Locomotive Engineer Training A little bit older...a little bit wiser... * Typically 2-4 years' seniority * Pass-or-get-fired promotion * Intensive program * Perpetually tested to a higher standard * 20 Weeks of training * 15 of that is OJT * General Code of Operating Rules * Air Brake & Train Handling * System Special Instructions * Safety Instructions * Federal Regulations * Locomotive Simulators * Test Ride * Pass test with 90% Engineer Recertification

448

Neutrinos from Gamma Ray Bursts  

Science Journals Connector (OSTI)

The observed fluxes of cosmic rays and gamma rays are used to infer the maximum allowed high-energy neutrino flux allowed for Gamma Ray Bursts (GRBs) following Reference [1]. It is shown that if GRBs produce the ultrahigh-energy cosmic rays they should contribute (a) at least 10% of the extragalactic gamma ray background between 3 MeV and 30 GeV contrary to their observed energy flux which is only a minute fraction of this flux and (b) a cumulative neutrino flux a factor of 20 below the AMANDA-?2000 limit on isotropic neutrinos. This could have two implications either GRBs do not produce the ultrahigh energy cosmic rays [2 3] or that the GRBs are strongly beamed and emit most of their power at energies well above 100 GeV [4] implausibly increasing the energy requirements but consistent with the marginal detections of a few low-redshift GRBs by MILAGRITO [5] HEGRA-AIROBICC [6] and the Tibet-Array [7]. All crucial measurements to test the models will be available in the next few years. These are measurements of (i) high-energy neutrinos with AMANDA-ICECUBE or an enlarged ANTARES/NESTOR ocean detector (ii) GRB redshifts from HETE-2 follow-up studies and (iii) GRB spectra above 10 GeV with low-threshold imaging air Cherenkov telescopes such as MAGIC and the space telescopes AGILE and GLAST.

Karl Mannheim

2001-01-01T23:59:59.000Z

449

Neutrinos from Gamma Ray Bursts  

E-Print Network [OSTI]

The observed fluxes of cosmic rays and gamma rays are used to infer the maximum allowed high-energy neutrino flux allowed for Gamma Ray Bursts (GRBs), following Mannheim, Protheroe, and Rachen (2000). It is shown that if GRBs produce the ultrahigh-energy cosmic rays, they should contribute (a) at least 10% of the extragalactic gamma ray background between 3 MeV and 30 GeV, contrary to their observed energy flux which is only a minute fraction of this flux, and (b) a cumulative neutrino flux a factor of 20 below the AMANDA (Neutrino 2000) limit on isotropic neutrinos. This could have two implications, either GRBs do not produce the ultrahigh energy cosmic rays or that the GRBs are strongly beamed and emit most of their power at energies well above 100 GeV implausibly increasing the energy requirements, but consistent with the marginal detections of a few low-redshift GRBs by MILAGRITO, HEGRA-AIROBICC, and the Tibet-Array. All crucial measurements to test the models will be available in the next few years. These are measurements of (i) high-energy neutrinos with AMANDA-ICECUBE or an enlarged ANTARES/NESTOR ocean detector, (ii) GRB redshifts from HETE-2 follow-up studies, and (iii) GRB spectra above 10 GeV with low-threshold imaging air Cherenkov telescopes such as MAGIC and the space telescopes AGILE and GLAST.

Karl Mannheim

2000-10-18T23:59:59.000Z

450

BNL NASA Space Radiation Laboratory  

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

Dosimetry Calibration: Primary Ion Chamber Dosimetry Calibration: Primary Ion Chamber Dosimetry Calibration: Secondary Ion Chamber Dosimetry Calibration: Secondary Ion Chamber with Gain Dosimetry Calibration: Scintillator Based Dosimetry Dosimetry Calibration: Primary Ion Chamber The primary method of calibrating the dose delivered at NSRL is via a small ion chamber called a "Calibration Ion Chamber" (aka EGG counter) produced by Far West Technology. This is an air-filled bulb with electrodes for collecting ionization inside a tissue-equivalent plastic cap. The Calibration Ion Chamber is sent back to the manufacturer yearly to be calibrated using a standard gamma ray source (Cs-137). The calibration is based on a standard defied by the International Commission on Radiation Units and Measurements (ICRU) and reported in their ICRU Report 59, 15 December 1998.

451

Alpha-beta radiation detector  

DOE Patents [OSTI]

The invention is based in part on the discovery that a plastic housing that is lightweight is surprisingly efficient inasmuch as background signals from any gamma radiation are significantly reduced by using a plastic housing instead of a metal housing. A further aspect of the present invention is the profile of the housing as a bi-linear approximation to a parabola resulting in full optical response from any location on the scintillation material to the photomultiplier tube. A yet further aspect of the present invention is that the survey probe is resistant to magnetic fields. A yet further aspect of the present invention is the use of a snap-fit retaining bracket that overcomes the need for multiple screws.

Fleming, Dale M. (Richland, WA); Simmons, Kevin L. (Kennewick, WA); Froelich, Thomas J. (West Richland, WA); Carter, Gregory L. (Richland, WA)

1998-01-01T23:59:59.000Z

452

Localization of Gamma-Ray Bursts using the Fermi Gamma-Ray Burst Monitor  

E-Print Network [OSTI]

The Fermi Gamma-ray Burst Monitor (GBM) has detected over 1400 Gamma-Ray Bursts (GRBs) since it began science operations in July, 2008. We use a subset of over 300 GRBs localized by instruments such as Swift, the Fermi Large Area Telescope, INTEGRAL, and MAXI, or through triangulations from the InterPlanetary Network (IPN), to analyze the accuracy of GBM GRB localizations. We find that the reported statistical uncertainties on GBM localizations, which can be as small as 1 degree, underestimate the distance of the GBM positions to the true GRB locations and we attribute this to systematic uncertainties. The distribution of systematic uncertainties is well represented (68% confidence level) by a 3.7 degree Gaussian with a non-Gaussian tail that contains about 10% of GBM-detected GRBs and extends to approximately 14 degrees. A more complex model suggests that there is a dependence of the systematic uncertainty on the position of the GRB in spacecraft coordinates, with GRBs in the quadrants on the Y-axis better l...

Connaughton, V; Goldstein, A; Meegan, C A; Paciesas, W S; Preece, R D; Wilson-Hodge, C A; Gibby, M H; Greiner, J; Gruber, D; Jenke, P; Kippen, R M; Pelassa, V; Xiong, S; Yu, H -F; Bhat, P N; Burgess, J M; Byrne, D; Fitzpatrick, G; Foley, S; Giles, M M; Guiriec, S; van der Horst, A J; von Kienlin, A; McBreen, S; McGlynn, S; Tierney, D; Zhang, B -B

2014-01-01T23:59:59.000Z

453

Chemistry related to isolation of high-level nuclear waste  

Science Journals Connector (OSTI)

Chemistry related to isolation of high-level nuclear waste ... This article discusses the isolation of high-level nuclear waste. ... Radioactivity, Radiation, and the Chemistry of Nuclear Waste ...

Darleane C. Hoffman; Gregory R. Choppin

1986-01-01T23:5