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1

Gamma-Ray Exposure Rate Distribution in a Steam Generator  

Science Conference Proceedings (OSTI)

Gamma-ray exposure rate measurements were made with thermoluminescent dosimeters to determine the relative contribution of various surface areas in a steam generator to the overall radiation levels. The measurements were compared with analytic predictions based on discrete ordinates and point kernel techniques, and assessments of the radiation source inventory of the various surfaces were developed.

1983-05-01T23:59:59.000Z

2

Comparison of radon fluxes with gamma-radiation exposure rates and soil /sup 226/Ra concentrations  

Science Conference Proceedings (OSTI)

Radon fluxes and contact gamma-radiation-exposure rates were measured at the grid points of rectangular grids on three properties in Edgemont, South Dakota that were known to have deposits of residual radioactivity relatively near to the surface. The coefficient of determination, r/sup 2/, between the radon fluxes and the contact gamma-radiation-exposure rates varied from 0.89 to 0.31 for the three properties. The property having the highest fluxes and residual radioactivity of relatively uniform depth showed the highest correlation between fluxes and exposure rates, and the property having residual radioactivity that varied considerably in depth showed the lowest. Correlations between fluxes and /sup 226/Ra concentrations measured in boreholes that varied in depth from 60 to 195 cm were lower than those between fluxes and exposure rates, indicating that exposure rates are better than /sup 226/Ra measurements for detecting elevated radon fluxes from near-surface deposits. Measurements made on one property at two different times indicated that if the average flux were determined from a large number (40) of measurements at one time, the average flux at a later time could be estimated from a few measurements using the assumption that the change in the flux at individual locations will be equal to the change in the average flux. Flux measurements around two buildings showing elevated indoor radon-daughter concentrations, but around which no residual radioactivity had been discovered by /sup 226/Ra and gamma-radiation measurements, provided no clear indication of the presence of such material, possibly because none was present.

Young, J.A.; Thomas, V.W.

1984-04-01T23:59:59.000Z

3

Results of calculations of external gamma radiation exposure rates from local fallout and the related radionuclide compositions of selected US Pacific events  

SciTech Connect

This report presents data on calculated gamma radiation exposure rates and local surface deposition of related radionuclides resulting from selected US Pacific events. Results of the calculations of relative external gamma radiation exposure rate and related radionuclide ground deposition are given in six appendices. The output of the calculation has 30 decay times: 10 from 1 to 21 h, 10 from 1 to 300 d, and 10 from 1 to 50 y. For each of these times and for zero time, there are values of the external gamma radiation exposure rate normalized to 1 mR/h, 1 m above the surface, 12 h after the event; the associated values of ..mu..Ci/m/sup 2/ for each radionuclide; and the total ..mu..Ci/m/sup 2/. Surface roughness effects are simulated by using Beck's values of (mR/h)/..mu..Ci/m/sup 2/) for a relaxation length of 0.16 g/cm/sup 2/. Fractionation effects, simulated by the removal of a fraction of the refractory nuclides from the calculation, were found for unfractionated debris and for debris with 0.5 and 0.1 of the refractory elements present. Each Appendix contains three sets of 11 pages of calculated results relating to one event in Table 1. Each set of 11 pages is marked page 2 through page 12. Page 2 of each set gives the external gamma-ray exposure rates and associated values of total microcuries per square meter at 30 decay intervals and at zero time. The value for each activation product at zero time is the result of a measurement. The measurements were performed on debris samples taken by aircraft approximately 1 to 4 h after detonation. When no measurement exists, the value appears as zero. Fission products were calculated from the fissioning nuclides and neutron energy spectra. Calculated values for each radionuclide at various decay intervals are given.

Hicks, H.G.

1984-02-01T23:59:59.000Z

4

SCINTILLATION EXPOSURE RATE DETECTOR  

DOE Patents (OSTI)

A radiation detector for gamma and x rays is described. The detector comprises a scintillation crystal disposed between a tantalum shield and the input of a photomultiplier tube, the crystal and the shield cooperating so that their combined response to a given quantity of radiation at various energy levels is substantially constant.

Spears, W.G.

1960-11-01T23:59:59.000Z

5

Neutrino Event Rates from Gamma Ray Bursts  

E-Print Network (OSTI)

We recalculate the diffuse flux of high energy neutrinos produced by Gamma Ray Bursts (GRB) in the relativistic fireball model. Although we confirm that the average single burst produces only ~10^{-2} high energy neutrino events in a detector with 1 km^2 effective area, i.e. about 10 events per year, we show that the observed rate is dominated by burst-to-burst fluctuations which are very large. We find event rates that are expected to be larger by one order of magnitude, likely more, which are dominated by a few very bright bursts. This greatly simplifies their detection.

F. Halzen; D. W. Hooper

1999-08-12T23:59:59.000Z

6

Reaction Rate Sensitivity of the gamma-Process Path  

E-Print Network (OSTI)

The location of the (gamma,p)/(gamma,n) and (gamma,alpha)/(gamma,n) line at gamma-process temperatures is discussed, using recently published reaction rates based on global Hauser-Feshbach calculations. The results can directly be compared to previously published, classic gamma-process discussions. The nuclei exhibiting the largest sensitivity to uncertainties in nuclear structure and reaction parameters are specified.

T. Rauscher

2004-07-16T23:59:59.000Z

7

Modeling indoor exposures to VOCs and SVOCs as ventilation rates...  

NLE Websites -- All DOE Office Websites (Extended Search)

Modeling indoor exposures to VOCs and SVOCs as ventilation rates vary Title Modeling indoor exposures to VOCs and SVOCs as ventilation rates vary Publication Type Conference Paper...

8

The Exposure Rate Conversion Factor for Nuclear Fallout  

SciTech Connect

Nuclear fallout is comprised of approximately 2000 radionuclides. About 1000 of these radionuclides are either primary fission products or activated fission products that are created during the burn process. The exposure rate one meter above the surface produced by this complex mixture of radionuclides varies rapidly with time since many of the radionuclides are short-lived and decay numerous times before reaching a stable isotope. As a result, the mixture of radionuclides changes rapidly with time. Using a new code developed at the Lawrence Livermore National Laboratory, the mixture of radionuclides at any given point in time can be calculated. The code also calculates the exposure rate conversion factor (ECF) for all 3864 individual isotopes contained in its database based on the total gamma energy released per decay. Based on the combination of isotope mixture and individual ECFs, the time-dependent variation of the composite exposure rate conversion factor for nuclear fallout can be easily calculated. As example of this new capability, a simple test case corresponding to a 10 kt, uranium-plutonium fuel has been calculated. The results for the time-dependent, composite ECF for this test case are shown in Figure 1. For comparison, we also calculated the composite exposure rate conversion factor using the conversion factors found in Federal Guidance Report No.12 (FGR-12) published by ORNL, which contains the conversion factors for approximately 1000 isotopes. As can be noted from Figure 1, the two functions agree reasonably well at times greater than about 30 minutes. However, they do not agree at early times since FGR-12 does not include all of the short-lived isotopes that are produced in nuclear fallout. It should also be noted that the composite ECF at one hour is 19.7 R/hr per Ci/m{sup 2}. This corresponds to 3148 R/hr per 1 kt per square mile, which agrees reasonably well with the value of 3000 R/hr per 1 kt per square mile as quoted by Glasstone. We have also tabulated the top 50 contributors to the exposure rate at various points in time following a detonation. These major contributors are given in Table 1.

Spriggs, G D

2009-02-11T23:59:59.000Z

9

Light Stau Phenomenology and the Higgs \\gamma\\gamma Rate  

Science Conference Proceedings (OSTI)

Recently, an excess of events consistent with a Higgs boson with mass of about 125 GeV was reported by the CMS and ATLAS experiments. This Higgs boson mass is consistent with the values that may be obtained in minimal supersymmetric extensions of the Standard Model (SM), with both stop masses less than a TeV and large mixing. The apparently enhanced photon production rate associated with this potential Higgs signal may be the result of light staus with large mixing. Large stau mixing and large coupling of the staus to the SM-like Higgs boson may be obtained for large values of tan {beta} and moderate to large values of the Higgsino mass parameter, {mu}. We study the phenomenological properties of this scenario, including precision electroweak data, the muon anomalous magnetic moment, Dark Matter, and the evolution of the soft supersymmetry-breaking parameters to high energies. We also analyze the possible collider signatures of light third generation sleptons and demonstrate that it is possible to find evidence of their production at the 8 TeV and the 14 TeV LHC. The most promising channel is stau and tau sneutrino associated production, with the sneutrino decaying into a W boson plus a light stau.

Carena, Marcela; Gori, Stefania; Shah, Nausheen R.; Wagner, Carlos E.M.; Wang, Lian-Tao

2012-05-01T23:59:59.000Z

10

Total Gamma Count Rate Analysis Method for Nondestructive Assay Characterization  

Science Conference Proceedings (OSTI)

A new approach to nondestructively characterize waste for disposal, based on total gamma response, has been developed at the Idaho Cleanup Project by CH2M-WG Idaho, LLC and Idaho State University, and is called the total gamma count rate analysis method. The total gamma count rate analysis method measures gamma interactions that produce energetic electrons or positrons in a detector. Based on previous experience with waste assays, the radionuclide content of the waste container is then determined. This approach potentially can yield minimum detection limits of less than 10 nCi/g. The importance of this method is twofold. First, determination of transuranic activity can be made for waste containers that are below the traditional minimum detection limits. Second, waste above 10 nCi/g and below 100 nCi/g can be identified, and a potential path for disposal resolved.

Cecilia R. Hoffman; Yale D. Harker

2006-03-01T23:59:59.000Z

11

High rate 4. pi. beta. -. gamma. coincidence counting system  

SciTech Connect

A high count rate 4..pi.. ..beta..-..gamma.. coincidence counting system for the determination of absolute disintegration rates of short half-life radionuclides is described. With this system the dead time per pulse is minimized by not stretching any pulses beyond the width necessary to satisfy overlap coincidence requirements. The equations used to correct for the ..beta.., ..gamma.., and coincidence channel dead times and for accidental coincidences are presented but not rigorously developed. Experimental results are presented for a decaying source of /sup 56/Mn initially at 2 x 10/sup 6/ d/s and a set of /sup 60/Co sources of accurately known source strengths varying from 10/sup 3/ to 2 x 10/sup 6/ d/s. A check of the accidental coincidence equation for the case of two independent sources with varying source strengths is presented.

Johnson, L.O.; Gehrke, R.J.

1978-01-01T23:59:59.000Z

12

The Gamma Ray Burst Rate at High Photon Energies  

E-Print Network (OSTI)

Some gamma-ray burst (GRB) spectra exhibit high energy tails with the highest photon energy detected at 18 GeV. The spectral slope of the high-energy tails is sufficiently flat in nu F_nu to consider the possibility of their detection at still higher energies. We calculate how many bursts can reasonably be expected above a given energy threshold for a cosmological distribution of bursts satisfying the observed apparent brightness distribution. The crucial point is that the gamma-ray absorption by pair production in the intergalactic diffuse radiation field eliminates bursts from beyond the gamma-ray horizon tau ~ 1, thus drastically reducing the number of bursts at high energies. Our results are consistent with the non-detection of bursts by current experiments in the 100 GeV to 100 TeV energy range. For the earth-bound detector array MILAGRO, we predict a maximal GRB rate of ~ 10 events per year. The Whipple Observatory can detect, under favorable conditions, ~1 event per year. The event rate for the HEGRA array is ~ 0.01 per year. Detection of significantly higher rates of bursts would severely challenge cosmological burst scenarios.

Karl Mannheim; Dieter Hartmann; Burkhardt Funk

1996-05-17T23:59:59.000Z

13

Potential radiological exposure rates resulting from hypothetical dome failure at Tank W-10  

SciTech Connect

The main plant area at Oak Ridge National Laboratory (ORNL) contains 12 buried Gunite tanks that were used for the storage and transfer of liquid radioactive waste. Although the tanks are no longer in use, they are known to contain some residual contaminated sludges and liquids. In the event of an accidental tank dome failure, however unlikely, the liquids, sludges, and radioactive contaminants within the tank walls themselves could create radiation fields and result in above-background exposures to workers nearby. This Technical Memorandum documents a series of calculations to estimate potential radiological exposure rates and total exposures to workers in the event of a hypothetical collapse of a Gunite tank dome. Calculations were performed specifically for tank W-10 because it contains the largest radioactivity inventory (approximately half of the total activity) of all the Gunite tanks. These calculations focus only on external, direct gamma exposures for prescribed, hypothetical exposure scenarios and do not address other possible tank failure modes or routes of exposure. The calculations were performed with established, point-kernel gamma ray modeling codes.

Not Available

1994-07-01T23:59:59.000Z

14

Correlation of External Exposure and Dose Equivalent Rates with Uranium Surface Contamination  

SciTech Connect

This report provides both calculated estimates and measured values of exposure in air and tissue dose from external penetrating radiation at a distance of 1 m from uranium contamination on surfaces at the Oak Ridge Y-12 Plant, in support of the Y-12 Site Radiological Characterization Study. Calculated values are based on the total energy from gamma rays and X rays emitted by uranium and its shordaughters at secular equilibrium. Results of a small number of measurements are provided for comparison. Dose rate values derived here are limited to those of external penetrating radiation from distributed sources with limited surface area and from point sources.

Ashley, J.C.; Bogard, J.S.; Brown, K.S.; England, C.A.; Hamm, R.N.; Turner, J.E.

1999-06-01T23:59:59.000Z

15

Revealing Type Ia supernova physics with cosmic rates and nuclear gamma rays  

E-Print Network (OSTI)

Type Ia supernovae (SNIa) remain mysterious despite their central importance in cosmology and their rapidly increasing discovery rate. The progenitors of SNIa can be probed by the delay time between progenitor birth and explosion as SNIa. The explosions and progenitors of SNIa can be probed by MeV nuclear gamma rays emitted in the decays of radioactive nickel and cobalt into iron. We compare the cosmic star formation and SNIa rates, finding that their different redshift evolution requires a large fraction of SNIa to have large delay times. A delay time distribution of the form t^{-1.0 +/- 0.3} provides a good fit, implying 50% of SNIa explode more than ~ 1 Gyr after progenitor birth. The extrapolation of the cosmic SNIa rate to z = 0 agrees with the rate we deduce from catalogs of local SNIa. We investigate prospects for gamma-ray telescopes to exploit the facts that escaping gamma rays directly reveal the power source of SNIa and uniquely provide tomography of the expanding ejecta. We find large improvements relative to earlier studies by Gehrels et al. in 1987 and Timmes & Woosley in 1997 due to larger and more certain SNIa rates and advances in gamma-ray detectors. The proposed Advanced Compton Telescope, with a narrow-line sensitivity ~ 60 times better than that of current satellites, would, on an annual basis, detect up to ~ 100 SNIa (3 sigma) and provide revolutionary model discrimination for SNIa within 20 Mpc, with gamma-ray light curves measured with ~ 10 sigma significance daily for ~ 100 days. Even more modest improvements in detector sensitivity would open a new and invaluable astronomy with frequent SNIa gamma-ray detections.

Shunsaku Horiuchi; John F. Beacom

2010-06-30T23:59:59.000Z

16

The Rates of Hypernovae and Gamma-Ray Bursts: Implications for their Progenitors  

E-Print Network (OSTI)

A critical comparison of estimates for the rates of hypernovae (HNe) and gamma-ray bursts (GRBs) is presented. Within the substantial uncertainties, the estimates are shown to be quite comparable and give a Galactic rate of $10^{-6}$ -- $10^{-5} $yr$^{-1}$ for both events. These rates are several orders of magnitude lower than the rate of core-collapse supernovae, suggesting that the evolution leading to a HN/GRB requires special circumstances, very likely due to binary interactions. Various possible binary channels are discussed, and it is shown that these are generally compatible with the inferred rates.

Ph. Podsiadlowski; P. A. Mazzali; K. Nomoto; D. Lazzati; E. Cappellaro

2004-03-17T23:59:59.000Z

17

Advanced Computational Approaches for Characterizing Stochastic Cellular Responses to Low Dose, Low Dose Rate Exposures  

SciTech Connect

OAK - B135 This project final report summarizes modeling research conducted in the U.S. Department of Energy (DOE), Low Dose Radiation Research Program at the Lovelace Respiratory Research Institute from October 1998 through June 2003. The modeling research described involves critically evaluating the validity of the linear nonthreshold (LNT) risk model as it relates to stochastic effects induced in cells by low doses of ionizing radiation and genotoxic chemicals. The LNT model plays a central role in low-dose risk assessment for humans. With the LNT model, any radiation (or genotoxic chemical) exposure is assumed to increase one¡¯s risk of cancer. Based on the LNT model, others have predicted tens of thousands of cancer deaths related to environmental exposure to radioactive material from nuclear accidents (e.g., Chernobyl) and fallout from nuclear weapons testing. Our research has focused on developing biologically based models that explain the shape of dose-response curves for low-dose radiation and genotoxic chemical-induced stochastic effects in cells. Understanding the shape of the dose-response curve for radiation and genotoxic chemical-induced stochastic effects in cells helps to better understand the shape of the dose-response curve for cancer induction in humans. We have used a modeling approach that facilitated model revisions over time, allowing for timely incorporation of new knowledge gained related to the biological basis for low-dose-induced stochastic effects in cells. Both deleterious (e.g., genomic instability, mutations, and neoplastic transformation) and protective (e.g., DNA repair and apoptosis) effects have been included in our modeling. Our most advanced model, NEOTRANS2, involves differing levels of genomic instability. Persistent genomic instability is presumed to be associated with nonspecific, nonlethal mutations and to increase both the risk for neoplastic transformation and for cancer occurrence. Our research results, based on applications of NEOTRANS2, indicate that nonlinear threshold-type, dose-response relationships for excess stochastic effects (problematic nonlethal mutations, neoplastic transformation) should be expected after exposure to low linear energy transfer (LET) gamma rays or gamma rays in combination with high-LET alpha radiation. Similar thresholds are expected for low-dose-rate low-LET beta irradiation. We attribute the thresholds to low-dose, low-LET radiation induced protection against spontaneous mutations and neoplastic transformations. The protection is presumed mainly to involve selective elimination of problematic cells via apoptosis. Low-dose, low-LET radiation is presumed to trigger wide-area cell signaling, which in turn leads to problematic bystander cells (e.g., mutants, neoplastically transformed cells) selectively undergoing apoptosis. Thus, this protective bystander effect leads to selective elimination of problematic cells (a tissue cleansing process in vivo). However, this protective bystander effects is a different process from low-dose stimulation of the immune system. Low-dose, low-LET radiation stimulation of the immune system may explain why thresholds for inducing excess cancer appear much larger (possibly more than 100-fold larger) than thresholds for inducing excess mutations and neoplastic transformations, when the dose rate is low. For ionizing radiation, the current risk assessment paradigm is such that the relative risk (RR) is always ¡Ý 1, no matter how small the dose. Our research results indicate that for low-dose or low-dose-rate, low-LET irradiation, RR < 1 may be more the rule than the exception. Directly tied to the current RR paradigm are the billion-dollar cleanup costs for radionuclide-contaminated DOE sites. Our research results suggest that continued use of the current RR paradigm for which RR ¡Ý 1 could cause more harm than benefit to society (e.g., by spreading unwarranted fear about phantom excess risks associated with low-dose low-LET radiation). Such phantom risks also may arise from risk assessments conducted for com

Scott, Bobby, R., Ph.D.

2003-06-27T23:59:59.000Z

18

Advanced Computational Approaches for Characterizing Stochastic Cellular Responses to Low Dose, Low Dose Rate Exposures  

Science Conference Proceedings (OSTI)

OAK - B135 This project final report summarizes modeling research conducted in the U.S. Department of Energy (DOE), Low Dose Radiation Research Program at the Lovelace Respiratory Research Institute from October 1998 through June 2003. The modeling research described involves critically evaluating the validity of the linear nonthreshold (LNT) risk model as it relates to stochastic effects induced in cells by low doses of ionizing radiation and genotoxic chemicals. The LNT model plays a central role in low-dose risk assessment for humans. With the LNT model, any radiation (or genotoxic chemical) exposure is assumed to increase one¡¯s risk of cancer. Based on the LNT model, others have predicted tens of thousands of cancer deaths related to environmental exposure to radioactive material from nuclear accidents (e.g., Chernobyl) and fallout from nuclear weapons testing. Our research has focused on developing biologically based models that explain the shape of dose-response curves for low-dose radiation and genotoxic chemical-induced stochastic effects in cells. Understanding the shape of the dose-response curve for radiation and genotoxic chemical-induced stochastic effects in cells helps to better understand the shape of the dose-response curve for cancer induction in humans. We have used a modeling approach that facilitated model revisions over time, allowing for timely incorporation of new knowledge gained related to the biological basis for low-dose-induced stochastic effects in cells. Both deleterious (e.g., genomic instability, mutations, and neoplastic transformation) and protective (e.g., DNA repair and apoptosis) effects have been included in our modeling. Our most advanced model, NEOTRANS2, involves differing levels of genomic instability. Persistent genomic instability is presumed to be associated with nonspecific, nonlethal mutations and to increase both the risk for neoplastic transformation and for cancer occurrence. Our research results, based on applications of NEOTRANS2, indicate that nonlinear threshold-type, dose-response relationships for excess stochastic effects (problematic nonlethal mutations, neoplastic transformation) should be expected after exposure to low linear energy transfer (LET) gamma rays or gamma rays in combination with high-LET alpha radiation. Similar thresholds are expected for low-dose-rate low-LET beta irradiation. We attribute the thresholds to low-dose, low-LET radiation induced protection against spontaneous mutations and neoplastic transformations. The protection is presumed mainly to involve selective elimination of problematic cells via apoptosis. Low-dose, low-LET radiation is presumed to trigger wide-area cell signaling, which in turn leads to problematic bystander cells (e.g., mutants, neoplastically transformed cells) selectively undergoing apoptosis. Thus, this protective bystander effect leads to selective elimination of problematic cells (a tissue cleansing process in vivo). However, this protective bystander effects is a different process from low-dose stimulation of the immune system. Low-dose, low-LET radiation stimulation of the immune system may explain why thresholds for inducing excess cancer appear much larger (possibly more than 100-fold larger) than thresholds for inducing excess mutations and neoplastic transformations, when the dose rate is low. For ionizing radiation, the current risk assessment paradigm is such that the relative risk (RR) is always ¡Ý 1, no matter how small the dose. Our research results indicate that for low-dose or low-dose-rate, low-LET irradiation, RR fear about phantom excess risks associated with low-dose low-LET radiation). Such phantom risks also may arise from risk assessments conducted for com

Scott, Bobby, R., Ph.D.

2003-06-27T23:59:59.000Z

19

Estimation of compact binary coalescense rates from short gamma-ray burst redshift measurements  

E-Print Network (OSTI)

Short gamma-ray bursts are believed to originate from the merger of two compact objects. If this scenario is correct, these bursts will be accompanied by the emission of strong gravitational waves, detectable by current or planned GW detectors, such as LIGO and Virgo. No detection of a gravitational wave has been made up to date. In this paper I will use a set of observed redshift measurements of short gamma-ray bursts to fit a model in order to determine the rate of such merger events in the nearby universe. Various corrections will be included in that calculation, as the field-of-view of the satellite missions, the beaming factors of gamma-ray bursts and other parameters. The computed rate estimations will be compared to other rate estimations, based on observations on binary neutron stars and population synthesis models. Given the upper limit established by LIGO/Virgo measurements, it is possible to draw conclusions on the beaming angle of gamma-ray bursts.

Alexander Dietz

2010-11-09T23:59:59.000Z

20

Towards a global fit to extract the B->Xs gamma decay rate and Vub  

E-Print Network (OSTI)

The total B->Xs gamma decay rate and the CKM-matrix element Vub play an important role in finding indirect evidence for new physics affecting the flavor sector of the Standard Model, complementary to direct searches at the LHC and Tevatron. Their determination from inclusive B-meson decays requires the precise knowledge of the parton distribution function of the b quark in the B meson, called the shape function. We implement a new model-independent framework for the shape function with reliable uncertainties based on an expansion in a suitable set of basis functions. We present the current status of a global fit to BaBar and Belle data to extract the shape function and the B->Xs gamma decay rate.

Florian U. Bernlochner; Heiko Lacker; Zoltan Ligeti; Iain W. Stewart; Frank J. Tackmann; Kerstin Tackmann

2010-11-26T23:59:59.000Z

Note: This page contains sample records for the topic "gamma exposure rates" 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

Influence of cooling rate on the development of multiple generations of {gamma}' precipitates in a commercial nickel base superalloy  

Science Conference Proceedings (OSTI)

The compositional and microstructural evolution of different generations of {gamma}' precipitates during the continuous cooling of a commercial nickel base superalloy, Rene88DT, has been characterized by three dimensional atom probe tomography coupled with energy-filtered transmission electron microscopy studies. After solutionizing in the single {gamma} phase field, continuous cooling at a very high rate results in a monomodal size distribution of {gamma}' precipitates with a high nucleation density and non-equilibrium compositions. In contrast, a relatively slower cooling rate ({approx} 24 deg. C/min) results in a multi-modal size distribution of {gamma}' precipitates with the larger first generation primary precipitates exhibiting close to equilibrium composition, along with the smaller scale secondary {gamma}' precipitates, exhibiting non-equilibrium composition (excess of Co and Cr, depleted in Al and Ti). The composition of the {gamma} matrix near these precipitates also exhibits similar trends with the composition being closer to equilibrium near the primary precipitates as compared to the secondary precipitates. - Highlights: {yields} Effect of cooling rate on the precipitation of {gamma}' particles in commercial nickel base superalloy. {yields} Couples EFTEM and 3DAP studies to determine the composition and morphology of {gamma}' precipitates. {yields} Determination of near and far field compositional variations within the gamma matrix leading to subsequent precipitation.

Singh, A.R.P. [Center for Advanced Research and Technology and Department of Materials Science and Engineering, University of North Texas, Denton, TX (United States); Nag, S., E-mail: nag.soumya@gmail.com [Center for Advanced Research and Technology and Department of Materials Science and Engineering, University of North Texas, Denton, TX (United States); Hwang, J.Y. [Center for Advanced Research and Technology and Department of Materials Science and Engineering, University of North Texas, Denton, TX (United States); Viswanathan, G.B.; Tiley, J. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Dayton, OH (United States); Srinivasan, R. [ExxonMobil Research and Engineering Company, Annandale, NJ (United States); Fraser, H.L. [Center for the Accelerated Maturation of Materials and Department of Materials Science and Engineering, The Ohio State University, Columbus, OH (United States); Banerjee, R. [Center for Advanced Research and Technology and Department of Materials Science and Engineering, University of North Texas, Denton, TX (United States)

2011-09-15T23:59:59.000Z

22

Exclusive Measurements of the b to s gamma Transition Rate and Photon Energy Spectrum  

SciTech Connect

We use 429 fb{sup -1} of e{sup +}e{sup -} collision data collected at the {Upsilon}(4S) resonance with the BABAR detector to measure the radiative transition rate of b {yields} s{gamma} with a sum of 38 exclusive final states. The inclusive branching fraction with a minimum photon energy of 1.9 GeV is found to be {Beta}({bar B} {yields} Xs{gamma}) = (3.29 {+-} 0.19 {+-} 0.48) x 10{sup -4} where the first uncertainty is statistical and the second is systematic. We also measure the first and second moments of the photon energy spectrum and extract the best fit values for the heavy-quark parameters, m{sub b} and {mu}{sub {pi}}{sup 2}, in the kinetic and shape function models.

Lees, J.P.; Poireau, V.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Palano, A.; /Bari U. /INFN, Bari; Eigen, G.; Stugu, B.; /Bergen U.; Brown, David Nathan; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; /LBL, Berkeley /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum; Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; McKenna, J.A.; /British Columbia U.; Khan, A.; /Brunel U.; Blinov, V.E.; Buzykaev, A.R.; /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. /Ferrara U. /INFN, Ferrara /Frascati /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. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U., Comp. Sci. Dept. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Naples U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U.; /more authors..

2012-08-30T23:59:59.000Z

23

Dose-rate conversion factors for external exposure to photons and electrons  

SciTech Connect

Dose-rate conversion factors for external exposure to photons and electrons have been calculated for approximately 500 radionuclides of potential importance in environmental radiological assessments. The dose-rate factors were obtained using the DOSFACTER computer code. The results given in this report incorporate calculation of electron dose-rate factors for radiosensitive tissues of the skin, improved estimates of organ dose-rate factors for photons, based on organ doses for monoenergetic sources at the body surface of an exposed individual, and the spectra of scattered photons in air from monoenergetic sources in an infinite, uniformly contaminated atmospheric cloud, calculation of dose-rate factors for other radionuclides in addition to those of interest in the nuclear fuel cycle, and incorporation of updated radioactive decay data for all radionuclides. Dose-rate factors are calculated for three exposure modes - immersion in contaminated air, immersion in contaminated water, and exposure at a height of 1 m above a contaminated ground surface. The report presents the equations used to calculate the external dose-rate factors for photons and electrons, documentation of the revised DOSFACTER computer code, and a complete tabulation of the calculated dose-rate factors. 30 refs., 12 figs.

Kocher, D.C.

1981-08-01T23:59:59.000Z

24

Measurement of environmental radiation exposure rates from Vernita, Hanford Reach, and Richland area shores. Addendum 1  

SciTech Connect

Environmental radiation exposure rate measurements are taken on and around the Hanford Site for Pacific Northwest Laboratory`s Hanford Site Surface Environmental Surveillance Project. In 1992, environmental radiation exposure rate measurements were taken from shoreline and island areas ranging from Vernita, along the Hanford Reach, down to the Richland Pumphouse. Measurements were taken primarily at locations known or expected to have elevated exposure rates as determined by examination of aerial photographs depicting radiation exposure measurements. Results from the 1992 survey indicated radiation exposure rates taken from the Hanford Reach area were elevated in comparison to the measurements taken from the Vernita area with ranges of 8 to 28 {mu}R/hr and 4 to 11 {mu}R/hr, respectively. In January 1994, additional shoreline radiation exposure rate measurements were taken from the Vernita, Hanford Reach, and Richland areas to determine the relationship of radiation exposure rates along the Richland area shores when compared to Vernita and Hanford Reach area exposure rates (measurements along the Richland area were not collected during the 1992 survey). This report discusses the 1994 results and is an addendum to the report that discussed the 1992 survey. An analysis of variance indicated a significant location interaction at a p-value of 0.0014. To determine differences between paried locations a post-hoc comparison of location means was performed on log transformed data using the Scheff{acute e}`s F-test. This test indicated a significant difference between Hanford Reach and Richland area means with a mean difference of 0.075 /{mu}R/hr and a p-value of 0.0014. No significant difference was found between Hanford Reach and Vernita area means: The mean difference was 0.031 {mu}R/hr and the p-value was 0.3138. No significant difference was found between Vernita and Richland area means with a mean difference of 0.044 {mu}R/hr and a p-value of 0.1155.

Cooper, A.T.

1995-02-01T23:59:59.000Z

25

Thermonuclear reaction rate of 18O(p,gamma)19F  

E-Print Network (OSTI)

For stars between 0.8-8.0 solar masses, nucleosynthesis enters its final phase during the asymptotic giant branch (AGB) stage. During this evolutionary period, grain condensation occurs in the stellar atmosphere, and the star experiences significant mass loss. The production of presolar grains can often be attributed to this unique stellar environment. A subset of presolar oxide grains features dramatic 18O depletion that cannot be explained by the standard AGB star burning stages and dredge-up models. An extra mixing process, referred to as "cool bottom processing" (CBP), was proposed for low-mass AGB stars. The 18O depletion observed within certain stellar environments and within presolar grain samples may result from the 18O+p processes during CBP. We report here on a study of the 18O(p,gamma)19F reaction at low energies. Based on our new results, we found that the resonance at Er = 95 keV (lab) has a negligible affect on the reaction rate at the temperatures associated with CBP. We also determined that the direct capture S-factor is almost a factor of 2 lower than the previously recommended value at low energies. An improved thermonuclear reaction rate for 18O(p,gamma)19F is presented.

M. Q. Buckner; C. Iliadis; J. M. Cesaratto; C. Howard; T. B. Clegg; A. E. Champagne; S. Daigle

2012-12-05T23:59:59.000Z

26

RECONCILING THE GAMMA-RAY BURST RATE AND STAR FORMATION HISTORIES  

SciTech Connect

While there are numerous indications that gamma-ray bursts (GRBs) arise from the deaths of massive stars, the GRB rate does not follow the global cosmic star formation rate and, within their hosts, GRBs are more concentrated in regions of very high star formation. We explain both puzzles here. Using the publicly available VESPA database of the Sloan Digital Sky Survey (SDSS) Data Release 7 spectra, we explore a multi-parameter space in galaxy properties such as stellar mass, metallicity, and dust to find the subset of galaxies that reproduces the GRB rate recently obtained by Wanderman and Piran. We find that only galaxies with present stellar masses below <10{sup 10} M{sub Sun} and low metallicity reproduce the observed GRB rate. This is consistent with direct observations of GRB hosts and provides an independent confirmation of the nature of GRB hosts. Because of the significantly larger sample of SDSS galaxies, we compute their correlation function and show that they are anti-biased with respect to dark matter: they are in filaments and voids. Using recent observations of massive stars in local dwarfs we show how the fact that GRB host galaxies are dwarfs can explain the observation that GRBs are more concentrated in regions of high star formation than are supernovae. Finally, we explain these results using new theoretical advances in the field of star formation.

Jimenez, Raul [ICREA and ICC, University of Barcelona (IEEC-UB), Marti i Franques 1, Barcelona E-08024 (Spain); Piran, Tsvi, E-mail: raul.jimenez@icc.ub.edu, E-mail: tsvi.piran@huji.ac.il [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)

2013-08-20T23:59:59.000Z

27

THEORETICAL REACTION RATES OF {sup 12}C({alpha}, {gamma}){sup 16}O BELOW T{sub 9} = 3  

Science Conference Proceedings (OSTI)

The astrophysical reaction rates of {sup 12}C({alpha},{gamma}){sup 16}O below T{sub 9} = 3, calculated from the potential model, are provided in tabular form and as analytic expressions. The uncertainties of the reaction rates are estimated by using variations of the model parameters.

Katsuma, M. [Advanced Mathematical Institute, Osaka City University, Osaka 558-8585 (Japan)

2012-02-01T23:59:59.000Z

28

COMPACT OBJECT COALESCENCE RATE ESTIMATION FROM SHORT GAMMA-RAY BURST OBSERVATIONS  

SciTech Connect

Recent observational and theoretical results suggest that short-duration gamma-ray bursts (SGRBs) originate from the merger of compact binary systems of two neutron stars or a neutron star and a black hole. The observation of SGRBs with known redshifts allows astronomers to infer the merger rate of these systems in the local universe. We use data from the SWIFT satellite to estimate this rate to be in the range {approx}500-1500 Gpc{sup -3} yr{sup -1}. This result is consistent with earlier published results which were obtained through alternative approaches. We estimate the number of coincident observations of gravitational-wave signals with SGRBs in the advanced gravitational-wave detector era. By assuming that all SGRBs are created by neutron star-neutron star (neutron star-black hole) mergers, we estimate the expected rate of coincident observations to be in the range {approx_equal} 0.2-1 ({approx_equal} 1-3) yr{sup -1}.

Petrillo, Carlo Enrico [Dipartimento di Scienze Fisiche, Universita di Napoli ''Federico II'', Compl. Univ. Monte S. Angelo, Ed. N, Via Cinthia, I-80126 Napoli (Italy); Dietz, Alexander; Cavaglia, Marco [Department of Physics and Astronomy, University of Mississippi University, MS 38677-1848 (United States)

2013-04-20T23:59:59.000Z

29

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

SciTech Connect

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

Trani, Daniela [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, District of Columbia (United States) [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, District of Columbia (United States); Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia (United States); Maastricht Radiation Oncology (MaastRO) Lab, GROW-School for Oncology and Developmental Biology, University of Maastricht (Netherlands); Moon, Bo-Hyun [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, District of Columbia (United States) [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, District of Columbia (United States); Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia (United States); Kallakury, Bhaskar; Hartmann, Dan P. [Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia (United States)] [Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia (United States); Datta, Kamal [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, District of Columbia (United States) [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, District of Columbia (United States); Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia (United States); Fornace, Albert J., E-mail: af294@georgetown.edu [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, District of Columbia (United States); Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia (United States); Center of Excellence in Genomic Medicine Research (CEGMR), King Abdulaziz University, Jeddah (Saudi Arabia)

2013-01-01T23:59:59.000Z

30

Investigation of exposure rates and radionuclide and trace metal distributions along the Hanford Reach of the Columbia River  

SciTech Connect

Studies have been conducted to investigate exposure rates, and radionuclide and trace metal distributions along the Columbia River where it borders the Hanford Site. The last major field study was conducted in 1979. With recently renewed interest in various land use and resource protection alternatives, it is important to have data that represent current conditions. Radionuclides and trace metals were surveyed in Columbia River shoreline soils along the Hanford Site (Hanford Reach). The work was conducted as part of the Surface Environmental Surveillance Project, Pacific Northwest Laboratory. The survey consisted of taking exposure rate measurements and soil samples primarily at locations known or expected to have elevated exposure rates.

Cooper, A.T.; Woodruff, R.K.

1993-09-01T23:59:59.000Z

31

Activation, Heating and Exposure Rates for Mo?99 Experiments with 25?Disk Targets  

Science Conference Proceedings (OSTI)

An MCNPX model of the 25-disk target assembly inside the vacuum cube inside the shielded box was prepared. This was used to calculate heating and photon and neutron fluxes throughout the model. Production rates for photonuclear reaction products were calculated using the photon fluxes and ENDF/B-VII cross sections. Measured isomer to ground state yield ratios were used where available. Where not available the new correlation between spin deficit and isomer to ground state yield ratios presented at AccApp'11 was used. The photonuclear production rates and neutron fluxes were input to CINDER2008 for transmutation calculations. A cross section update file was used to supply (n,n') reactions missing from CINDER2008 libraries. Decay photon spectra produced by CINDER2008 were then used to calculate exposure rates using the MCNPX model. Two electron beam irradiations were evaluated. The first was for a thermal test at 15 MeV with 1300 {micro}A incident on one target end and the second was for a production test at 35 MeV with 350 {micro}A incident on both target ends (700 {micro}A total current on target). For the thermal test 1, 2, 3, 4, 5 and 6 h irradiation times were simulated, each followed by decay time steps out to 42 days. For the production test 6, 12, 18, 24, 30 and 36 h irradiation times were simulated followed by the same decay periods. For all simulations beam FWHMs in x and y were both assumed to be 6 mm. Simulations were run for Mo-100 enriched and natural Mo targets for both tests. It is planned that thermal test will be run for 4 h with natural target disks and production test will be run for 24 h with enriched target disks. Results for these two simulations only are presented in this report. Other results can be made available upon request. Post irradiation exposure rates were calculated at 30 cm distances from left, right, front and back of the following configurations: (1) Shielded box with everything in it (beam pipes, cooling pipes, vacuum cube, target housing weldment and target assembly), (2) Shielded box with everything in it except the target assembly, (3) Shielded box with nothing in it, (4) Target assembly taken outside of shielded box, (5) Target disks in cradle (target assembly with thermocouple weldment and flange removed), (6) Empty cradle, and (7) Target disks alone. Decay photon spectra from the CINDER2008 calculations were used as sources for the exposure rate calculations in the same model used for the flux calculations with beam on. As components were removed to simulate the seven cases considered the material compositions were changed to air and their respective sources were turned off. The MCNPX model geometry is plotted in Figure 1. The left and right detector locations for cases 1, 2 and 3 were 30 cm from the shielded box walls and 30 cm from the beam pipe openings in the left and right sides of the model (they are not in the beam line). A zoomed in plot of the target assembly alone is in Figure 2. Exposure rates for the seven cases are plotted as a function of time after irradiation in Figures 3, 4 and 5. To aid in comparison between the cases, all of these figures have been plotted using the same scale. Figures 3 and 4 are respectively the thermal and production test results for cases 1 through 6. Figure 5 includes case 7 results for both. Differences between cases 1 and 2 for both tests are not statistically significant showing that activation of components other than the target assembly, many of which are also shielding the target assembly, dominates exposure rates outside the shielded box. Case 3 shows the contribution from activation of the shield box itself. In front where shielded box wall is thickest box activation accounts for essentially all of the exposure rate outside. Differences between cases 4 and 5 are also minimal, showing that the contribution to target assembly exposure rates from the thermocouple flange and weldment are small compared to the target disks and cradle. From the numerical results the contribution is about 1%. Results for case 6, the cradle itself, are ini

Kelsey, Charles T. IV [Los Alamos National Laboratory

2012-05-09T23:59:59.000Z

32

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

Science Conference Proceedings (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

33

The Swift short gamma-ray burst rate density: prospects for detecting binary neutron star mergers by aLIGO  

E-Print Network (OSTI)

Presently only 30% of short gamma ray bursts (SGRBs) have accurate redshifts, and this sample is highly biased by the limited sensitivity of {\\it Swift} to detect SGRBs. We account for the dominant biases to calculate a realistic SGRB rate density out to $z = 0.5$ using the {\\it Swift} sample of peak fluxes, redshifts, and those SGRBs with a beaming angle constraint from X-ray/optical observations. Assuming a significant fraction of binary neutron star mergers produce SGRBs, we calculate lower and upper detection rate limits of (1-180) per Yr by an advanced LIGO and Virgo coincidence search. Our detection rate is compatible with extrapolations using Galactic pulsar observations and population synthesis.

David Coward; Eric Howell; Tsvi Piran; Giulia Stratta; Marica Branchesi; Omer Bromberg; Bruce Gendre; Ronald Burman; Dafne Guetta

2012-06-22T23:59:59.000Z

34

Spermatogonia survival in mice after exposure to low doses of $^{60}$Co gamma-ray neutrons of 14 MeV and 400 MeV and neutrons from a Pu Be source  

E-Print Network (OSTI)

Spermatogonia survival in mice after exposure to low doses of $^{60}$Co gamma-ray neutrons of 14 MeV and 400 MeV and neutrons from a Pu

Quintiliani, M; Baarli, Johan

1977-01-01T23:59:59.000Z

35

Estimating farfield organic chemical exposures, intake rates and intake fractions to human age classes  

Science Conference Proceedings (OSTI)

This study describes the development and application of the Farfield Human Exposure (FHX) model. This screening level model brings together information on chemical partitioning, degradation, environmental fate and transport, and food web bioaccumulation ... Keywords: Bioaccumulation, Biotransformation, Exposure assessment, Human health, Multimedia modelling, Organic chemicals

Jon A. Arnot; Don Mackay; Roger Sutcliffe; Belinda Lo

2010-10-01T23:59:59.000Z

36

Estimated effective dose rates from radon exposure in workplaces and residences within Los Alamos county in New Mexico  

SciTech Connect

Many millions of office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the workplace are lacking. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were then used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about nine times greater exposure at home than while in the office (691 mrem yr{sup -1} versus 78 mrem yr{sup -1}). The estimated effective dose rate for a more homebound person was 896 mrem yr{sup -1}. These effective dose rates are contrasted against the 100 mrem yr{sup -1} threshold for regulation of a 'radiological worker' defined in the Department of Energy regulations occupational exposure and the 10 mrem yr{sup -1} air pathway effective public dose limit regulated by the Environmental Protection Agency.

Whicker, Jeffrey J [Los Alamos National Laboratory; Mcnaughton, Michael [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

37

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

Science Conference Proceedings (OSTI)

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

Cheryl G. Burrell, Ph.D.

2012-05-14T23:59:59.000Z

38

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

Science Conference Proceedings (OSTI)

The absorbed dose rates in air due to terrestrial radionuclides were estimated from aerial gamma spectrometric data for an area of 48

Rodrigo O. Bastos; Carlos R. Appoloni; José P. P. Pinese

2008-01-01T23:59:59.000Z

39

THE INFLUENCE OF UNCERTAINTIES IN THE {sup 15}O({alpha}, {gamma}){sup 19}Ne REACTION RATE ON MODELS OF TYPE I X-RAY BURSTS  

SciTech Connect

We present a Monte Carlo calculation of the astrophysical rate of the {sup 15}O({alpha}, {gamma}){sup 19}Ne reaction based on an evaluation of published experimental data. By considering the likelihood distributions of individual resonance parameters derived from measurements, estimates of upper and lower limits on the reaction rate at the 99.73% confidence level are derived in addition to the recommended, median value. These three reaction rates are used as input for three separate calculations of Type I X-ray bursts (XRBs) using spherically symmetric, hydrodynamic simulations of an accreting neutron star. In this way the influence of the {sup 15}O({alpha}, {gamma}){sup 19}Ne reaction rate on the peak luminosity, recurrence time, and associated nucleosynthesis in models of Type I XRBs is studied. Contrary to previous findings, no substantial effect on any of these quantities is observed in a sequence of four bursts when varying the reaction rate between its lower and upper limits. Rather, the differences in these quantities are comparable to the burst-to-burst variations with a fixed reaction rate, indicating that uncertainties in the {sup 15}O({alpha}, {gamma}){sup 19}Ne reaction rate do not strongly affect the predictions of this Type I XRB model.

Davids, Barry [TRIUMF, Vancouver, BC V6T 2A3 (Canada); Cyburt, Richard H. [Joint Institute for Nuclear Astrophysics and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Jose, Jordi [Departament de Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya and Institut d'Estudis Espacials de Catalunya, Barcelona (Spain); Mythili, Subramanian [Physics Department, George Mason University, Fairfax, VA (United States)

2011-07-01T23:59:59.000Z

40

Non-destructive method for determining neutron exposure  

DOE Patents (OSTI)

A non-destructive method for determination of neutron exposure in an object, such as a reactor pressure vessel, is based on the observation of characteristic gamma-rays emitted by activation products in the object by using a unique continuous gamma-ray spectrometer. The spectrometer views the object through appropriate collimators to determine the absolute emission rate of these characteristic gamma-rays, thereby ascertaining the absolute activity of given activation products in the object. These data can then be used to deduce the spatial and angular dependence of neutron exposure at regions of interest within the object.

Gold, R.; McElroy, W.N.

1983-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "gamma exposure rates" 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

Impact of a revised $^{25}$Mg(p,$\\gamma$)$^{26}$Al reaction rate on the operation of the Mg-Al cycle  

E-Print Network (OSTI)

Proton captures on Mg isotopes play an important role in the Mg-Al cycle active in stellar H-burning regions. In particular, low-energy nuclear resonances in the $^{25}$Mg(p,$\\gamma$)$^{26}$Al reaction affect the production of radioactive $^{26}$Al$^{gs}$ as well as the resulting Mg/Al abundance ratio. Reliable estimations of these quantities require precise measurements of the strengths of low-energy resonances. Based on a new experimental study performed at LUNA, we provide revised rates of the $^{25}$Mg(p,$\\gamma$)$^{26}$Al$^{gs}$ and the $^{25}$Mg(p,$\\gamma$)$^{26}$Al$^{m}$ reactions with corresponding uncertainties. In the temperature range 50 to 150 MK, the new recommended rate of the $^{26}$Al$^{m}$ production is up to 5 times higher than previously assumed. In addition, at T$=100$ MK, the revised total reaction rate is a factor of 2 higher. Note that this is the range of temperature at which the Mg-Al cycle operates in an H-burning zone. The effects of this revision are discussed. Due to the significa...

Straniero, O; Strieder, F; Bemmerer, D; Broggini, C; Caciolli, A; Corvisiero, P; Costantini, H; Cristallo, S; DiLeva, A; Formicola, A; Elekes, Z; Fülöp, Zs; Gervino, G; Guglielmetti, A; Gustavino, C; Gyürky, Gy; Junker, M; Lemut, A; Limata, B; Marta, M; Mazzocchi, C; Menegazzo, R; Piersanti, L; Prati, P; Roca, V; Rolfs, C; Alvarez, C Rossi; Somorjai, E; Terrasi, F; Trautvetter, H P

2012-01-01T23:59:59.000Z

42

Concentration of leucogenenol in the serum of dogs following their exposure to lethal $gamma$ radiation from cobalt-60  

SciTech Connect

>Three male and 3 female dogs were exposed in the AFRRI whole body irradiator to 350 rads of cobalt-60 gamma -radiation at approximately 39.5 rads/ min. Prior to and at intervals following irradiation, a sample of serum was obtained from each dog and assayed for its leucogenenol content. Before irradiation the average concentration of leucogenenol in the serum was 10.5 plus or minus 6 mu g/liter. The day after irradiation the average concentration in 5 dogs fell to 0.002 mu g/liter and in 1 dog to 1.5 mu g/liter. However, 2 days after irradiation the average concentration in all dogs was elevated to 41 plus or minus 10 mu g/liter. The concentration of leucogenenol in the serum then declined so that 7 days after irradiation it was 0.47 plus or minus 0.24 mu g/liter. Leucogenenol was not measureable (< 0.001 mu g/liter) in each dog's serum for approximately 4 days before the dog died. Individual dogs survived for from 1;3 to 20 days after irradiation. (auth)

Rice, F.A.; Chen, C.G.; Rene, A.A.

1973-12-01T23:59:59.000Z

43

RATES  

NLE Websites -- All DOE Office Websites (Extended Search)

Marketing > RATES Marketing > RATES RATES Current Rates Past Rates 2006 2007 2008 2009 2010 2011 2012 Rates Schedules Power CV-F13 CPP-2 Transmissions CV-T3 CV-NWT5 PACI-T3 COTP-T3 CV-TPT7 CV-UUP1 Ancillary CV-RFS4 CV-SPR4 CV-SUR4 CV-EID4 CV-GID1 Future and Other Rates SNR Variable Resource Scheduling Charge FY12-FY16 (October 1, 2012) SNR Rates Process Calendar (PDF - 171K) Procedures Informal Process Transmission Action Items List (PDF - 144K) Power Action Item List updated on 4-27-10 (PDF - 155K) Power Action Item List (Quick links to relevant documents) Formal Process Rates Brochure (01/11/2011) (PDF - 900K) Appendix A - Federal Register Notice (01/03/2011) (PDF - 8000K) Appendix B - Central Valley Project Power Repayment Study (PDF - 22,322K) Appendix C - Development of the CVP Cost of Service Study (PDF - 2038K)

44

RATES  

NLE Websites -- All DOE Office Websites (Extended Search)

Planning & Projects Planning & Projects Power Marketing Rates You are here: SN Home page > Power Marketing > RATES Rates and Repayment Services Rates Current Rates Power Revenue Requirement Worksheet (FY 2014) (Oct 2013 - Sep 2014) (PDF - 30K) PRR Notification Letter (Sep 27, 2013) (PDF - 959K) FY 2012 FP% True-Up Calculations(PDF - 387K) Variable Resource Scheduling Charge FY12-FY16 (October 1, 2012) PRR Forecast FY14-FY17 (May 23, 2013) (PDF - 100K) Forecasted Transmission Rates (May 2013) (PDF - 164K) Past Rates 2013 2012 2011 2010 2009 Historical CVP Transmission Rates (April 2013) (PDF - 287K) Rate Schedules Power - CV-F13 - CPP-2 Transmission - CV-T3 - CV-NWT5 - PACI-T3 - COTP-T3 - CV-TPT7 - CV-UUP1 Ancillary - CV-RFS4 - CV-SPR4 - CV-SUR4 - CV-EID4 - CV-GID1 Federal Register Notices - CVP, COTP and PACI

45

RATES  

NLE Websites -- All DOE Office Websites (Extended Search)

RATES RATES Rates Document Library SNR Rates Process Calendar (PDF - 171K) Procedures Informal Process Transmission Action Items List (PDF - 144K) Power Action Item List updated on 4-27-10 (PDF - 155K) Power Action Item List (Quick links to relevant documents) Formal Process Rates Brochure (01/11/2011) (PDF - 900K) Appendix A - Federal Register Notice (01/03/2011) (PDF - 8000K) Appendix B - Central Valley Project Power Repayment Study (PDF - 22,322K) Appendix C - Development of the CVP Cost of Service Study (PDF - 2038K) Appendix D - Western Transmission System Facilities Map (PDF - 274K) Appendix E - Estimated FY12 FP and BR Customer (PDF - 1144K) Appendix F - Forecasted Replacements and Additions FY11 - FY16 (PDF - 491K) Appendix G - Definitions (PDF - 1758K) Appendix H - Acronyms (PDF - 720K)

46

High Exposure Facility Technical Description  

Science Conference Proceedings (OSTI)

The High Exposure Facility is a collimated high-level gamma irradiator that is located in the basement of the 318 building. It was custom developed by PNNL back in 1982 to meet the needs for high range radiological instrument calibrations and dosimeter irradiations. At the time no commercially available product existed that could create exposure rates up to 20,000 R/h. This document is intended to pass on the design criteria that was employed to create this unique facility, while maintaining compliance with ANSI N543-1974, "General Safety Standard for Installations Using Non-Medical X-Ray and Sealed Gamma-Ray Sources, Energies up to 10 MeV."

Carter, Gregory L.; Stithem, Arthur R.; Murphy, Mark K.; Smith, Alex K.

2008-02-12T23:59:59.000Z

47

DEPENDENCE OF s-PROCESS NUCLEOSYNTHESIS IN MASSIVE STARS ON TRIPLE-ALPHA AND {sup 12}C({alpha}, {gamma}){sup 16}O REACTION RATE UNCERTAINTIES  

Science Conference Proceedings (OSTI)

We have studied the sensitivity of s-process nucleosynthesis in massive stars to {+-}2{sigma} variations in the rates of the triple-{alpha} and {sup 12}C({alpha}, {gamma}){sup 16}O reactions. We simulated the evolution of massive stars from H burning through Fe-core collapse, followed by a supernova explosion. We found that the production factors of s-process nuclides between {sup 58}Fe and {sup 96}Zr change strongly with changes in the He burning reaction rates; using the Lodders solar abundances rather than those of Anders and Grevesse reduces s-process nucleosynthesis; later burning phases beyond core He burning and shell C burning have a significant effect on post-explosive production factors. We also discuss the implications of the uncertainties in the helium burning rates for evidence of a new primary neutron capture process (LEPP) in massive stars.

Tur, Clarisse; Austin, Sam M. [National Superconducting Cyclotron Laboratory, Michigan State University, 1 Cyclotron Laboratory, East Lansing, MI 48824-1321 (United States); Heger, Alexander [School of Physics and Astronomy, University of Minnesota, Twin Cities, Minneapolis, MN 55455-0149 (United States)], E-mail: tur@nscl.msu.edu, E-mail: austin@nscl.msu.edu, E-mail: alex@physics.umn.edu

2009-09-10T23:59:59.000Z

48

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

49

Two effects relevant for the study of astrophysical reaction rates: {gamma} transitions in capture reactions and Coulomb suppression of the stellar enhancement  

Science Conference Proceedings (OSTI)

Nucleosynthesis processes involve reactions on several thousand nuclei, both close to and far off stability. The preparation of reaction rates to be used in astrophysical investigations requires experimental and theoretical input. In this context, two interesting aspects are discussed: (i) the relevant {gamma} transition energies in astrophysical capture reactions, and (ii) the newly discovered Coulomb suppression of the stellar enhancement factor. The latter makes a number of reactions with negative Q value more favorable for experimental investigation than their inverse reactions, contrary to common belief.

Rauscher, Thomas [Departement Physik, Universitaet Basel, CH-4056 Basel (Switzerland)

2009-01-28T23:59:59.000Z

50

Work to save dose: contrasting effective dose rates from radon exposure in workplaces and residences against the backdrop of public and occupational limits  

Science Conference Proceedings (OSTI)

Office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the non-mine workplaces are lacking. Additionally, there are few, if any, comparative analyses of radon exposures at more 'typical' workplace with residential exposures within the same county. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about 8 times greater exposure at home than while in the office (2.3 mSv yr-! versus 0.3 mSv yr-!). The estimated effective dose rate for a more homebound person was about 3 mSv yr-!. Estimating effective doses from background radon exposure in the same county as Los Alamos National Laboratory, with thousands of'radiological workers,' highlights interesting contrasts in radiation protection standards that span public and occupational settings. For example, the effective dose rate from background radon exposure in unregulated office spaces ranged up to 1.1 mSv yr-!, which is similar to the 1 mSv yr-! threshold for regulation ofa 'radiological worker,' as defined in the Department of Energy regulations for occupational exposure. Additionally, the estimated average effective dose total of> 3 mSv yf! from radon background exposure in homes stands in contrast to the 0.1 mSv yr-! air pathway effective public dose limit regulated by the Environmental Protection Agency for radioactive air emissions.

Whicker, Jeffrey J [Los Alamos National Laboratory; Mcnaughton, Michael W [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

51

Non-destructive method for determining neutron exposure and constituent concentrations of a body  

DOE Patents (OSTI)

A non-destructive method for determination of neutron exposure and constituent concentrations in an object, such as a reactor pressure vessel, is based on the observation of characteristic gamma-rays emitted by activation products in the object by using a unique continuous gamma-ray spectrometer. The spectrometer views the object through appropriate collimators to determine the absolute emission rate of these characteristic gamma-rays, thereby ascertaining the absolute activity of given activation products in the object. These data can then be used to deduce the spatial and angular dependence of neutron exposure or the spatial constituent concentrations at regions of interest within the object.

Gold, R.; McElroy, W.N.

1984-02-22T23:59:59.000Z

52

A Comparison of Gamma and Lognormal Distributions for Characterizing Satellite Rain Rates from the Tropical Rainfall Measuring Mission  

Science Conference Proceedings (OSTI)

This study investigates the spatial characteristics of nonzero rain rates to develop a probability density function (PDF) model of precipitation using rainfall data from the Tropical Rainfall Measuring Mission (TRMM) satellite. The minimum ?2 ...

Hye-Kyung Cho; Kenneth P. Bowman; Gerald R. North

2004-11-01T23:59:59.000Z

53

Plutonium-aerosol emission rates and potential inhalation exposure during cleanup and treatment test at Area 11, Nevada Test Site  

SciTech Connect

A Cleanup and Treatment (CAT) test was conducted in 1981 at Area 11, Nevada Test Site. Its purpose was to evaluate the effectiveness of using a large truck-mounted vacuum cleaner similar to those used to clean paved streets for cleaning radiological contamination from the surface of desert soils. We found that four passes with the vehicle removed 97% of the alpha contamination and reduced resuspension by 99.3 to 99.7%. Potential exposure to cleanup workers was slight when compared to natural background exposure. 7 refs., 1 fig., 2 tabs.

Shinn, J.H.; Homan, D.N.

1985-08-13T23:59:59.000Z

54

Gamma/neutron analysis for SNM signatures at high-data rates(greater than 107 cps) for single-pulse active interrogation  

SciTech Connect

We are developing a high data gamma/neutron spectrometer suitable for active interrogation of special nuclear materials (SNM) activated by a single burst from an intense source. We have tested the system at Naval Research Laboratory's (NRL) Mercury pulsed-power facility at distances approaching 10 meters from a depleted uranium (DU) target. We have found that the gamma-ray field in the target room 'disappears' 10 milliseconds after the x-ray flash, and that gamma ray spectroscopy will then be dominated by isomeric states/beta decay of fission products. When a polyethylene moderator is added to the DU target, a time-dependent signature of the DU is produced by thermalized neutrons. We observe this signature in gamma-spectra measured consecutively in the 0.1-1.0 ms time range. These spectra contain the Compton edge line (2.2 MeV) from capture in hydrogen, and a continuous high energy gamma-spectrum from capture or fission in minority constituents of the DU.

Forman L.; Dioszegi, I.; Salwen, C.

2011-04-26T23:59:59.000Z

55

Low dose diagnostic radiation exposure and cancer risk in Trp53+/- mice  

NLE Websites -- All DOE Office Websites (Extended Search)

diagnostic radiation exposure and cancer risk in Trp53+/- mice diagnostic radiation exposure and cancer risk in Trp53+/- mice K Taylor, N Phan, ME Cybulski, L Laframboise, DR Boreham Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street West, Hamilton ON L8S 4K1 The cancer risk associated with exposure to low doses of ionizing radiation has traditionally been extrapolated from effects observed at high doses and high dose rates using a linear no threshold model. Based on this approach, it has been postulated that human exposure to medical imaging involving low doses of x-rays and gamma rays increase an individual's risk of developing cancer throughout their lifetime. Conversely, there is evidence that low doses of gamma radiation increase the latency period of cancer depending upon genotype, cancer type, and the magnitude of

56

Lung cancer mortality between 1950 and 1987 after exposure to fractionated moderate-dose-rate ionizing radiation in the Canadian fluoroscopy cohort study and a comparison with lung cancer mortality in the atomic bomb survivors study  

Science Conference Proceedings (OSTI)

Current lung cancer risk estimates after exposure to low-linear energy transfer radiation such as X rays are based on studies of people exposed to such radiation at high dose rates, for example the atomic bomb survivors. Radiobiology and animal experiments suggest that risks from exposure at low to moderate dose rates, for example medical diagnostic procedures, may be overestimated by such risk models, but data for humans to examine this issue are limited. In this paper we report on lung cancer mortality between 1950 and 1987 in a cohort of 64,172 Canadian tuberculosis patients, of whom 39% were exposed to highly fractionated multiple chest fluoroscopies leading to a mean lung radiation dose of 1.02 Sv received at moderate dose rates. These data have been used to estimate the excess relative risk per sievert of lung cancer mortality, and this is compared directly to estimates derived from 75,991 atomic bomb survivors. Based on 1,178 lung cancer deaths in the fluoroscopy study, there was no evidence of any positive association between risk and dose, with the relative risk at 1 Sv being 1.00 (95% confidence interval 0.94, 1.07), which contrasts with that based on the atomic bomb survivors, 1.60 (1.27, 1.99). The difference in effect between the two studies almost certainly did not arise by chance (P = 0.0001). This study provides strong support from data for humans for a substantial fractionation/dose-rate effect for low-linear energy transfer radiation and lung cancer risk. This implies that lung cancer risk from exposures to such radiation at present-day dose rates is likely to be lower than would be predicted by current radiation risk models based on studies of high-dose-rate exposures. 25 refs., 8 tabs.

Howe, G.R. [Univ. of Toronto, Ontario (Canada)

1995-06-01T23:59:59.000Z

57

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

58

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

59

Gamma radiation field intensity meter  

SciTech Connect

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

60

Gamma radiation field intensity meter  

SciTech Connect

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

Note: This page contains sample records for the topic "gamma exposure rates" 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

Radiation Risk from Chronic Low Dose-Rate Radiation Exposures: The Role of Life-Time Animal Studies - Workshop October 2005  

SciTech Connect

As a part of Radiation research conference, a workshop was held on life-long exposure studies conducted in the course of irradiation experiements done at Argonne National Laboratory between 1952-1992. A recent review article documents many of the issues discussed at that workshop.

Gayle Woloschak

2009-12-16T23:59:59.000Z

62

DRAFT - EXPOSURE FACTORS HANDBOOK - Update to Exposure Factors...  

NLE Websites -- All DOE Office Websites (Extended Search)

Atlanta, GA. exchange rate -- can be used by exposure assessors in ASHRAE. (1993) ASHRAE Handbook: Fundamentals. modeling indoor-air concentrations as one of the inputs to...

63

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

SciTech Connect

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

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

2008-08-07T23:59:59.000Z

64

Sandia National Laboratories: Research: Facilities: Gamma Irradiation  

NLE Websites -- All DOE Office Websites (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

65

Quality assurance for gamma knives  

SciTech Connect

This report describes and summarizes the results of a quality assurance (QA) study of the Gamma Knife, a nuclear medical device used for the gamma irradiation of intracranial lesions. Focus was on the physical aspects of QA and did not address issues that are essentially medical, such as patient selection or prescription of dose. A risk-based QA assessment approach was used. Sample programs for quality control and assurance are included. The use of the Gamma Knife was found to conform to existing standards and guidelines concerning radiation safety and quality control of external beam therapies (shielding, safety reviews, radiation surveys, interlock systems, exposure monitoring, good medical physics practices, etc.) and to be compliant with NRC teletherapy regulations. There are, however, current practices for the Gamma Knife not covered by existing, formalized regulations, standards, or guidelines. These practices have been adopted by Gamma Knife users and continue to be developed with further experience. Some of these have appeared in publications or presentations and are slowly finding their way into recommendations of professional organizations.

Jones, E.D.; Banks, W.W.; Fischer, L.E. [Lawrence Livermore National Lab., CA (United States)

1995-09-01T23:59:59.000Z

66

Optimal Coaddition of Imaging Data for Rapidly Fading Gamma-Ray Burst Afterglows  

E-Print Network (OSTI)

We present a technique for optimal coaddition of image data for rapidly varying sources, with specific application to gamma-ray burst (GRB) afterglows. Unweighted coaddition of rapidly fading afterglow lightcurve data becomes counterproductive relatively quickly. It is better to stop coaddition of the data once noise dominates late exposures. A better alternative is to optimally weight each exposure to maximize the signal-to-noise ratio (S/N) of the final coadded image data. By using information about GRB lightcurves and image noise characteristics, optimal image coaddition increases the probability of afterglow detection and places the most stringent upper limits on non-detections. For a temporal power law flux decay typical of GRB afterglows, optimal coaddition has the greatest potential to improve the S/N of afterglow imaging data (relative to unweighted coaddition), when the decay rate is high, the source count rate is low, and the background rate is high. The optimal coaddition technique is demonstrated ...

Morgan, A N; Roming, P W A; Nousek, J A; Koch, T S; Breeveld, A A; de Pasquale, M; Holland, S T; Kuin, N P M; Page, M J; Still, M

2008-01-01T23:59:59.000Z

67

Effects of ozone exposure on 'Golden' papaya fruit by photoacoustic phase-resolved method: Physiological changes associated with carbon dioxide and ethylene emission rates during ripening  

Science Conference Proceedings (OSTI)

This work addresses the effects of ozone activity on the physiology of 'Golden' papaya fruit. Depth profile analysis of double-layer biological samples was accomplished using the phase-resolved photoacoustic spectroscopy. The feasibility of the method was demonstrated by singling out the spectra of the cuticle and the pigment layers of papaya fruit. The same approach was used to monitor changes occurring on the fruit during ripening when exposed to ozone. In addition, one has performed real time studies of fluorescence parameters and the emission rates of carbon dioxide and ethylene. Finally, the amount of pigments and the changes in waxy cuticle have been monitored. Results indicate that a fruit deliberately subjected to ozone at a level of 6 ppmv underwent ripening sooner (at least 24-48 h) than a fruit stored at ambient conditions. Moreover, ozone caused a reduction in the maximum quantum yield of photosynthetic apparatus located within the skin of papaya fruit.

Correa, Savio Figueira; Brito Paiva, Luisa; Mota do Couto, Flavio; Gomes da Silva, Marcelo; Silva Sthel, Marcelo; Vargas, Helion [Laboratorio de Ciencias Fisicas, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Avenida Alberto Lamego 2000, Parque California 28013-602, Campos dos Goytacazes, Rio de Janeiro (Brazil); Mota, Leonardo [Laboratorio de Ciencias Fisicas, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Avenida Alberto Lamego 2000, Parque California 28013-602, Campos dos Goytacazes, Rio de Janeiro (Brazil); Fraunhofer Institut fuer Bauphysik, Nobelstrasse 12, Vaihingen 70569, Stuttgart, Baden Wuerttemberg (Germany); Goncalves de Oliveira, Jurandi [Laboratorio de Melhoramento Genetico Vegetal, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Avenida Alberto Lamego 2000, Parque California 28013-602, Campos dos Goytacazes, Rio de Janeiro (Brazil); Miklos, Andras [Fraunhofer Institut fuer Bauphysik, Nobelstrasse 12, Vaihingen 70569, Stuttgart, Baden Wuerttemberg (Germany)

2011-06-01T23:59:59.000Z

68

Evolution of Different Generations of Gamma Prime Precipitates in a ...  

Science Conference Proceedings (OSTI)

Depending on the cooling rate, either a single or multiple bursts of gamma prime .... in Metal Matrix Composites by In situ X-ray Synchrotron Tomography.

69

Microstructural Evolution of Different Generations of Gamma Prime ...  

Science Conference Proceedings (OSTI)

Depending on the cooling rate, either a single or multiple bursts of gamma prime .... Non-Destructive High Energy X-Ray Diffraction Microscopy Studies of Bulk ...

70

Prompt Optical Observations of Gamma-Ray Bursts  

E-Print Network (OSTI)

The Robotic Optical Transient Search Experiment (ROTSE) seeks to measure simultaneous and early afterglow optical emission from gamma-ray bursts (GRBs). A search for optical counterparts to six GRBs with localization errors of 1 square degree or better produced no detections. The earliest limiting sensitivity is mROTSE> 13.1 at 10.85 seconds (5 second exposure) after the gamma-ray rise, and the best limit is mROTSE> 16.0 at 62 minutes (897 second exposure). These are the most stringent limits obtained for GRB optical counterpart brightness in the first hour after the burst. Consideration of the gamma-ray fluence and peak flux for these bursts and for GRB990123 indicates that there is not a strong positive correlation between optical flux and gamma-ray emission. Subject headings: gamma rays: bursts, observations 1.

Carl Akerlof; Richard Balsano; Scott Barthelmy; Jeff Bloch; Paul Butterworth; Tom Cline; Ra Fletcher; Galen Gisler; John Heise; Jack Hills; Kevin Hurley; Robert Kehoe; Brian Lee; Stuart Marshall; Tim Mckay; Andrew Pawl; Luigi Piro; John Szymanski; Jim Wren

2000-01-01T23:59:59.000Z

71

Mouse Strain-Dependent Variations in Sensitivity to Induction of Gamma-H2AX Foci after Continuous Low Dose-Rate Irradiation: The Atm-/- vs Atm +/+ genotypes on Balb/c, 129S6, C57BL/6J, and A/J inbred strains  

NLE Websites -- All DOE Office Websites (Extended Search)

Mouse Strain-Dependent Variations in Sensitivity to Induction of Gamma-H2AX Foci Mouse Strain-Dependent Variations in Sensitivity to Induction of Gamma-H2AX Foci after Continuous Low Dose-Rate Irradiation: The Atm-/- vs Atm +/+ genotypes on Balb/c, 129S6, C57BL/6J, and A/J inbred strains. J.R.Brogan 1 , H. Nagasawa 1 , T.A Kato 1 , C.Fallgren 1 , T.Wade 1 . P.Genik 1 , J.B.Little 2 , J.S.Bedford 1 , and M.M.Weil 1 1 Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523; 2 Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston MA 02115 We have recently developed a 'low dose rate' gamma-H2AX assay that is sufficiently sensitive to distinguish differences in response for cells from normal Atm +/+ (mouse) or ATM+/+ (human) and the phenotypes associated with the corresponding

72

Gamma ray detector shield  

DOE Patents (OSTI)

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

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

1985-08-26T23:59:59.000Z

73

The Dose Rate Conversion Factors for Nuclear Fallout  

SciTech Connect

In a previous paper, the composite exposure rate conversion factor (ECF) for nuclear fallout was calculated using a simple theoretical photon-transport model. The theoretical model was used to fill in the gaps in the FGR-12 table generated by ORNL. The FGR-12 table contains the individual conversion factors for approximate 1000 radionuclides. However, in order to calculate the exposure rate during the first 30 minutes following a nuclear detonation, the conversion factors for approximately 2000 radionuclides are needed. From a human-effects standpoint, it is also necessary to have the dose rate conversion factors (DCFs) for all 2000 radionuclides. The DCFs are used to predict the whole-body dose rates that would occur if a human were standing in a radiation field of known exposure rate. As calculated by ORNL, the whole-body dose rate (rem/hr) is approximately 70% of the exposure rate (R/hr) at one meter above the surface. Hence, the individual DCFs could be estimated by multiplying the individual ECFs by 0.7. Although this is a handy rule-of-thumb, a more consistent (and perhaps, more accurate) method of estimating the individual DCFs for the missing radionuclides in the FGR-12 table is to use the linear relationship between DCF and total gamma energy released per decay. This relationship is shown in Figure 1. The DCFs for individual organs in the body can also be estimated from the estimated whole-body DCF. Using the DCFs given FGR-12, the ratio of the organ-specific DCFs to the whole-body DCF were plotted as a function of the whole-body DCF. From these plots, the asymptotic ratios were obtained (see Table 1). Using these asymptotic ratios, the organ-specific DCFs can be estimated using the estimated whole-body DCF for each of the missing radionuclides in the FGR-12 table. Although this procedure for estimating the organ-specific DCFs may over-estimate the value for some low gamma-energy emitters, having a finite value for the organ-specific DCFs in the table is probably better than having no value at all. A summary of the complete ECF and DCF values are given in Table 2.

Spriggs, G D

2009-02-13T23:59:59.000Z

74

BL Lacertae Objects and the Extragalactic Gamma-Ray Background  

E-Print Network (OSTI)

A tight correlation between gamma-ray and radio emission is found for a sample of BL Lacertae (BL Lac) objects detected by Fermi Gamma-ray Space Telescope (Fermi) and the Energetic Gamma-Ray Experiment Telescope (EGRET). The gamma-ray emission of BL Lac objects exhibits strong variability, and the detection rate of gamma-ray BL Lac objects is low, which may be related to the gamma-ray duty cycle of BL Lac objects. We estimate the gamma-ray duty cycle ~ 0.11, for BL Lac objects detected by EGRET and Fermi. Using the empirical relation of gamma-ray emission with radio emission and the estimated gamma-ray duty cycle, we derive the gamma-ray luminosity function (LF) of BL Lac objects from their radio LF. Our derived gamma-ray LF of BL Lac objects can almost reproduce that calculated with the recently released Fermi bright active galactic nuclei (AGN) sample. We find that about 45% of the extragalactic diffuse gamma-ray background (EGRB) is contributed by BL Lac objects. Combining the estimate of the quasar contri...

Li, Fan

2011-01-01T23:59:59.000Z

75

A Cautionary Note on Gamma Ray Burst Nearest Neighbor Statistics  

E-Print Network (OSTI)

In this letter we explore the suggestion of Quashnock and Lamb (1993) that nearest neighbor correlations among gamma ray burst positions indicate the possibility of burst repetitions within various burst sub-classes. With the aid of Monte Carlo calculations we compare the observed nearest neighbor distributions with those expected from an isotropic source population weighted by the published BATSE exposure map. The significance of the results are assessed via the Kolmogorov-Smirnov (K-S) test, as well as by a comparison to Monte Carlo simulations. The K-S results are in basic agreement with those of Quashnock and Lamb. However, as Narayan and Piran (1993) point out, and the Monte Carlo calculations confirm, the K-S test overestimates the significance of the observed distributions. We compare the sensitivity of these results to both the definitions of the assumed burst sub-classes and the burst positional errors. Of the two, the positional errors are more significant and indicate that the results of Quashnock and Lamb may be due to systematic errors, rather than any intrinsic correlation among the burst positions. Monte Carlo simulations also show that with the current systematic errors, the nearest neighbor statistic is not very sensitive to moderate repetition rates. Until the BATSE statistical and systematic errors are fully understood, the burst nearest neighbor correlations cannot be claimed to be significant evidence for burst repetitions. Subject Headings: gamma rays: bursts — methods: statistical

Michael A. Nowak

1993-01-01T23:59:59.000Z

76

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

SciTech Connect

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

Parra, S.A.

1994-11-30T23:59:59.000Z

77

Operational dose rate visualization techniques  

SciTech Connect

The analysis of the gamma ray dose rate in the vicinity of a radiation source can be greatly aided by the use of recent state-of-the-art visualization techniques. The method involves calculating dose rates at thousands of locations within a complex geometry system. This information is then processed to create contour plots of the dose rate. Additionally, when these contour plots are created, animations can be created that dynamically display the dose rate as the shields or sources are moved.

Schwarz, R.A.; Morford, R.J.; Carter, L.L.; Jones, G.B.; Greenborg, J.

1994-01-01T23:59:59.000Z

78

Energetics of Gamma Ray Bursts  

E-Print Network (OSTI)

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

Raul Jimenez; David Band; Tsvi Piran

2001-03-16T23:59:59.000Z

79

Exposure chamber  

DOE Patents (OSTI)

A chamber for exposing animals, plants, or materials to air containing gases or aerosols is so constructed that catch pans for animal excrement, for example, serve to aid the uniform distribution of air throughout the chamber instead of constituting obstacles as has been the case in prior animal exposure chambers. The chamber comprises the usual imperforate top, bottom and side walls. Within the chamber, cages and their associated pans are arranged in two columns. The pans are spaced horizontally from the walls of the chamber in all directions. Corresponding pans of the two columns are also spaced horizontally from each other. Preferably the pans of one column are also spaced vertically from corresponding pans of the other column. Air is introduced into the top of the chamber and withdrawn from the bottom. The general flow of air is therefore vertical. The effect of the horizontal pans is based on the fact that a gas flowing past the edge of a flat plate that is perpendicular to the flow forms a wave on the upstream side of the plate. Air flows downwardly between the chamber walls and the outer edges of the pan. It also flows downwardly between the inner edges of the pans of the two columns. It has been found that when the air carries aerosol particles, these particles are substantially uniformly distributed throughout the chamber.

Moss, Owen R. (Kennewick, WA)

1980-01-01T23:59:59.000Z

80

Gamma Radiation & X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Gamma Radiation and X-Rays 1. Gamma radiation and X-rays are electromagnetic radiation like visible light, radio waves, and ultraviolet light. These electromagnetic radiations...

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81

Measurements and Characterization of Neutron and Gamma Dose Quantities in the Vicinity of an Independent Spent Fuel Storage Installation  

SciTech Connect

As part of the decommissioning of the Maine Yankee Atomic Power Company (MYAPCo) nuclear power plant, the spent nuclear fuel is being temporarily stored in a dry cask storage facility on a portion of the original licensed property. Each of the spent nuclear fuel (SNF) storage casks hold approximately 25 spent fuel assemblies. Additional storage casks for the greater-than-Class C waste (GTCC) are also used. This waste is contained in 64 casks (60 SNF, 4 GTCC), each of which contain a substantial amount of concrete for shielding and structural purposes. The vertical concrete casks (VCCs) are typically separated by a distance of 4 and 6 feet. The storage casks are effective personnel radiation shields for most of the gamma and neutron radiation emitted from the fuel. However measurable gamma and neutron radiation levels are present in the vicinity of the casks. In order to establish a controlled area boundary around the facility such that a member of the public annual dose level of 0.25-mSv could be demonstrated, measurements of gamma and neutron dose equivalents were conducted. External gamma exposure rates were measured with a Pressurized Ion Chamber (PIC). Neutron absorbed dose and dose equivalent rates were measured with a Rossi-type tissue equivalent proportional counter (TEPC). Both gamma and neutron measurements were made at increasing distances from the facility as well as at a background location. The results of the measurements show that the distance to the 0.25-mSv per year boundary for 100% occupancy conditions varies from 321 feet to 441 feet from the geometric center of the storage pads, depending on the direction from the pad. For the TEPC neutron measurements, the average quality factor from the facilities was approximately 7.4. This quality factor compares well with the average quality factor of 7.6 that was measured during a calibration performed with a bare Cf-252 source. (authors)

Darois, E.L.; Keefer, D.G.; Plazeski, P.E. [Radiation Safety and Control Services, 91 Portsmouth Avenue, Stratham, NH 03885 (United States); Connell, J. [Maine Yankee Atomic Power Company, Wiscasset, ME 04568 (United States)

2006-07-01T23:59:59.000Z

82

X-Ray Observations of Gamma-Ray Burst Afterglows  

E-Print Network (OSTI)

The discovery by the BeppoSAX satellite of X-ray afterglow emission from the gamma-ray burst which occurred on 28 February 1997 produced a revolution in our knowledge of the gamma-ray burst phenomenon. Along with the discovery of X-ray afterglows, the optical afterglows of gamma-ray bursts were discovered and the distance issue was settled, at least for long $\\gamma$-ray bursts. The 30 year mystery of the gamma-ray burst phenomenon is now on the way to solution. Here I rewiew the observational status of the X-ray afterglow emission, its mean properties (detection rate, continuum spectra, line features, and light curves), and the X-ray constraints on theoretical models of gamma-ray bursters and their progenitors. I also discuss the early onset afterglow emission, the remaining questions, and the role of future X-ray afterglow observations.

Filippo Frontera

2004-06-25T23:59:59.000Z

83

Gamma' Formation in a Nickel-Base Disk Superalloy  

Science Conference Proceedings (OSTI)

first (primary) burst of nucleation during the solution quench. Model Formulation ..... gamma prime sizes at specific locations where cooling rates were measured by ..... Prinz, “Computer Aided X- Ray Analysis for Determining. Growth Kinetics of ...

84

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.

Hinton, Jim

2007-01-01T23:59:59.000Z

85

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

86

GAMMA RAYS FROM STAR FORMATION IN CLUSTERS OF GALAXIES  

SciTech Connect

Star formation in galaxies is observed to be associated with gamma-ray emission, presumably from non-thermal processes connected to the acceleration of cosmic-ray nuclei and electrons. The detection of gamma rays from starburst galaxies by the Fermi Large Area Telescope (LAT) has allowed the determination of a functional relationship between star formation rate and gamma-ray luminosity. Since star formation is known to scale with total infrared (8-1000 {mu}m) and radio (1.4 GHz) luminosity, the observed infrared and radio emission from a star-forming galaxy can be used to quantitatively infer the galaxy's gamma-ray luminosity. Similarly, star-forming galaxies within galaxy clusters allow us to derive lower limits on the gamma-ray emission from clusters, which have not yet been conclusively detected in gamma rays. In this study, we apply the functional relationships between gamma-ray luminosity and radio and IR luminosities of galaxies derived by the Fermi Collaboration to a sample of the best candidate galaxy clusters for detection in gamma rays in order to place lower limits on the gamma-ray emission associated with star formation in galaxy clusters. We find that several clusters have predicted gamma-ray emission from star formation that are within an order of magnitude of the upper limits derived in Ackermann et al. based on non-detection by Fermi-LAT. Given the current gamma-ray limits, star formation likely plays a significant role in the gamma-ray emission in some clusters, especially those with cool cores. We predict that both Fermi-LAT over the course of its lifetime and the future Cerenkov Telescope Array will be able to detect gamma-ray emission from star-forming galaxies in clusters.

Storm, Emma M.; Jeltema, Tesla E.; Profumo, Stefano [Department of Physics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)

2012-08-20T23:59:59.000Z

87

Gamma-ray events thunderclouds  

E-Print Network (OSTI)

Andromeda: A mission to determine the gamma-ray burst distance scale F.A. Harrison, W.R. Cook, T was submitted to the STEDI program, and will also be proposed as a NASA Small Explorer. Keywords: bursts, gamma-rays, small missions 1 SCIENTIFIC OBJECTIVES 1.1 Gamma-ray Bursts Gamma-ray bursts GRBs were discovered

California at Berkeley, University of

88

Soft gamma repeaters Kevin Hurley *  

E-Print Network (OSTI)

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

California at Berkeley, University of

89

Gamma Ray Pulsars: Observations  

E-Print Network (OSTI)

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

David J. Thompson

2001-01-03T23:59:59.000Z

90

Assessment of Time-course Exposures in BALB/c Mice Following...  

NLE Websites -- All DOE Office Websites (Extended Search)

Time-course Exposures in BALBc Mice Following 137 Cs Gamma Irradiation. K.M. Holmes 1 , A.D. Brown 2 , J.K. Wickliffe 3 B.E. Rodgers 1 . Dept. of 1 Life, Earth, and Environmental...

91

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

2006-05-09T23:59:59.000Z

92

Optimal Coaddition of Imaging Data for Rapidly Fading Gamma-Ray Burst Afterglows  

E-Print Network (OSTI)

We present a technique for optimal coaddition of image data for rapidly varying sources, with specific application to gamma-ray burst (GRB) afterglows. Unweighted coaddition of rapidly fading afterglow lightcurve data becomes counterproductive relatively quickly. It is better to stop coaddition of the data once noise dominates late exposures. A better alternative is to optimally weight each exposure to maximize the signal-to-noise ratio (S/N) of the final coadded image data. By using information about GRB lightcurves and image noise characteristics, optimal image coaddition increases the probability of afterglow detection and places the most stringent upper limits on non-detections. For a temporal power law flux decay typical of GRB afterglows, optimal coaddition has the greatest potential to improve the S/N of afterglow imaging data (relative to unweighted coaddition), when the decay rate is high, the source count rate is low, and the background rate is high. The optimal coaddition technique is demonstrated with applications to Swift Ultraviolet/Optical Telescope (UVOT) data of several GRBs, with and without detected afterglows.

A. N. Morgan; D. E. Vanden Berk; P. W. A. Roming; J. A. Nousek; T. S. Koch; A. A. Breeveld; M. de Pasquale; S. T. Holland; N. P. M. Kuin; M. J. Page; M. Still

2008-05-09T23:59:59.000Z

93

Observations of Gamma Ray Bursts with AGILE  

E-Print Network (OSTI)

The AGILE satellite, in orbit since 2007, localized up to October 2009 about 1 Gamma Ray Burst (GRB) per month with the hard X-ray imager SuperAGILE (18 - 60 keV) (with a rate reduced by a factor 2-3 in spinning mode) and is detecting around 1 GRB per week with the non-imaging Mini-Calorimeter (MCAL, 0.35 - 100 MeV). Up to October 2011 the AGILE Gamma Ray Imaging Detector firmly detected four GRBs in the energy band between 20 MeV and few GeV. In this paper we review the status of the GRBs observation with AGILE and discuss the upper limits in the gamma-ray band of the non-detected events.

Longo, F; Del Monte, E; Marisaldi, M; Fuschino, F; Giuliani, A

2011-01-01T23:59:59.000Z

94

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

Science Conference Proceedings (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

95

Development of a Low Dose Rate Irradiation Facility for Long...  

NLE Websites -- All DOE Office Websites (Extended Search)

Low Dose Rate Irradiation Facility for Long Term Animal Exposures at Colorado State University Michael Weil Colorado State University Abstract A low dose rate irradiation facility...

96

Rate Schedules  

Energy.gov (U.S. Department of Energy (DOE))

One of the major responsibilities of Southeastern is to design, formulate, and justify rate schedules. Repayment studies prepared by the agency determine revenue requirements and appropriate rate...

97

Measurement of the gamma gamma* --> eta and gamma gamma* --> eta' transition form factors  

SciTech Connect

We study the reactions e{sup +}e{sup -} {yields} e{sup +}e{sup -} {eta}{sup (/)} in the single-tag mode and measure the {gamma}{gamma}* {yields} {eta}{sup (/)} transition form factors in the momentum transfer range from 4 to 40 GeV{sup 2}. The analysis is based on 469 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.

del Amo Sanchez et al, P.

2011-02-07T23:59:59.000Z

98

Branching fractions for {psi}(2S){r_arrow}{gamma}{eta}{sup {prime}} and {gamma}{eta}  

SciTech Connect

We report first measurements of the branching fractions B({psi}{sub 2S}{r_arrow}{gamma}{eta}{sup {prime}})=(1.54{plus_minus}0.31{plus_minus}0.20){times}10{sup {minus}4} and B({psi}{sub 2S}{r_arrow}{gamma}{eta})=(0.53{plus_minus}0.31{plus_minus}0.08){times}10{sup {minus}4}. The {psi}(2S){r_arrow}{gamma}{eta}{sup {prime}} result is consistent with expectations of a model that considers the possibility of {eta}{sup {prime}}-{eta}{sub c}(2S) mixing. The ratio of the {psi}(2S){r_arrow}{gamma}{eta}{sup {prime}} and {psi}(2S){r_arrow}{gamma}{eta} rates is used to determine the pseudoscalar octet-singlet mixing angle. {copyright} {ital 1998} {ital The American Physical Society}

Bai, J.Z.; Bian, J.G.; Chai, Z.W.; Chen, G.P.; Chen, J.C.; Chen, Y.; Chen, Y.B.; Chen, Y.Q.; Cheng, B.S.; Cui, X.Z.; Ding, H.L.; Ding, L.Y.; Dong, L.Y.; Du, Z.Z.; Feng, S.; Gao, C.S.; Gao, M.L.; Gao, S.Q.; Gu, J.H.; Gu, S.D.; Gu, W.X.; Gu, Y.F.; Guo, Y.N.; Han, S.W.; Han, Y.; He, J.; He, J.T.; Hu, G.Y.; Hu, H.M.; Hu, J.L.; Hu, Q.H.; Hu, T.; Hu, X.Q.; Huang, J.D.; Huang, Y.Z.; Jiang, C.H.; Jin, Y.; Ke, Z.J.; Lai, Y.F.; Lang, P.F.; Li, C.G.; Li, D.; Li, H.B.; Li, J.; Li, P.Q.; Li, R.B.; Li, W.; Li, W.D.; Li, W.G.; Li, X.H.; Li, X.N.; Liu, H.M.; Liu, J.; Liu, J.H.; Liu, R.G.; Liu, Y.; Lu, F.; Lu, J.G.; Lu, J.Y.; Lu, L.C.; Luo, C.H.; Ma, A.M.; Ma, E.C.; Ma, J.M.; Mao, H.S.; Mao, Z.P.; Meng, X.C.; Nie, J.; Qi, N.D.; Qi, X.R.; Qiu, J.F.; Qu, Y.H.; Que, Y.K.; Rong, G.; Shao, Y.Y.; Shen, B.W.; Shen, D.L.; Shen, H.; Shen, X.Y.; Sheng, H.Y.; Shi, H.Z.; Song, X.F.; Sun, F.; Sun, H.S.; Tang, S.Q.; Tong, G.L.; Wang, F.; Wang, L.S.; Wang, L.Z.; Wang, M.; Wang, M.; Wang, P.; Wang, P.L.; Wang, S.M.; Wang, T.J.; Wang, Y.Y.; Wei, C.L.; Wu, Y.G.; Xi, D.M.; Xia, X.M.; Xie, P.P.; Xie, Y.; Xie, Y.H.; Xiong, W.J.; Xu, C.C.; Xu, G.F.; Xue, S.T.; Yan, J.; Yan, W.G.; Yang, C.M.; Yang, C.Y.; Yang, J.; Yang, X.F.; Ye, M.H.; Yi, K.; Yu, C.S.; Yu, C.X.; Yu, Z.Q.; Yu, Z.T.; Yuan, C.Z.; Yuan, Y.; Zhang, B.Y.; Zhang, C.C.; Zhang, D.H.; Zhang, D.; Zhang, H.L.; Zhang, J.; Zhang, J.L.; Zhang, J.W.; Zhang, L.S.; Zhang, Q.J.; Zhang, S.Q.; Zhang, Y.; Zhang, Y.Y.; Zhao, D.X.; Zhao, H.W.; Zhao, J.W.; Zhao, M.; Zhao, W.R.; Zhao, Z.G.; Zheng, J.P.; Zheng, L.S.; Zheng, Z.P.; Zhou, G.P.; Zhou, H.S.; Zhou, L.; Zhu, Q.M.; Zhu, Y.C.; Zhu, Y.S.; Zhuang, B.A. [Institute of High Energy Physics, Beijing 100039, Peoples Republic of (China)] [Institute of High Energy Physics, Beijing 100039, Peoples Republic of (China); Hitlin, D.G.; Kelsey, M.H.; Oyang, J.; Panetta, J.; Porter, F.; Weaver, M. [California Institute of Technology, Pasadena, California 91125 (United States)] [California Institute of Technology, Pasadena, California 91125 (United States); Chen, J.; Malchow, R.; Toki, W.; Yang, W. [Colorado State University, Fort Collins, Colorado 80523 (United States)] [Colorado State University, Fort Collins, Colorado 80523 (United States)

1998-11-01T23:59:59.000Z

99

Determination of thermal neutron capture gamma yields.  

E-Print Network (OSTI)

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

Harper, Thomas Lawrence

1969-01-01T23:59:59.000Z

100

Rates - WAPA-137 Rate Order  

NLE Websites -- All DOE Office Websites (Extended Search)

WAPA-137 Rate Order WAPA-137 Rate Order 2009 CRSP Management Center Customer Rates Second Step Presentation from the June 25, 2009, Customer Meeting Handout Materials from the June 25, 2009, Customer Meeting Customer Comment Letters ATEA CREDA Farmington ITCA AMPUA Rate Adjustment Information The second step of WAPA-137 SLCA/IP Firm Power, CRSP Transmission and Ancillary Services rate adjustment. FERC Approval of Rate Order No. WAPA-137 Notice Of Filing for Rate Order No. WAPA-137 Published Final FRN for Rate Order No. WAPA-137 Letter to Customers regarding the published Notice of Extension of Public Process for Rate Order No. WAPA-137 Published Extension of Public Process for Rate Order No. WAPA-137 FRN Follow-up Public Information and Comment Forum Flier WAPA-137 Customer Meetings and Rate Adjustment Schedule

Note: This page contains sample records for the topic "gamma exposure rates" 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

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

2012-04-09T23:59:59.000Z

102

Measurements of B -> V gamma Decays  

SciTech Connect

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

103

Relevant energy ranges for astrophysical reaction rates  

Science Conference Proceedings (OSTI)

Effective energy windows (Gamow windows) of astrophysical reaction rates for (p,gamma), (p,n), (p,alpha), (alpha,gamma), (alpha,n), (alpha,p), (n,gamma), (n,p), and (n,alpha) on targets with 10<=Z<=83 from proton to neutron dripline are calculated using theoretical cross sections. It is shown that widely used approximation formulas for the relevant energy ranges are not valid for a large number of reactions relevant to hydrostatic and explosive nucleosynthesis. The influence of the energy dependence of the averaged widths on the location of the Gamow windows is discussed and the results are presented in tabular form.

Rauscher, Thomas [Department of Physics, University of Basel, Klingelbergstr. 82, CH-4056 Basel (Switzerland)

2010-04-15T23:59:59.000Z

104

Energy Rating  

E-Print Network (OSTI)

Consistent, accurate, and uniform ratings based on a single statewide rating scale Reasonable estimates of potential utility bill savings and reliable recommendations on cost-effective measures to improve energy efficiency Training and certification procedures for home raters and quality assurance procedures to promote accurate ratings and to protect consumers Labeling procedures that will meet the needs of home buyers, homeowners, renters, the real estate industry, and mortgage lenders with an interest in home energy ratings

Cabec Conference; Rashid Mir P. E

2009-01-01T23:59:59.000Z

105

Insertion Rates  

Science Conference Proceedings (OSTI)

HOME > Insertion Rates. TECH HEADLINES. Research Explores a New Layer in Additive Manufacturin... Grand Opening Slated for Electron Microscopy Facility.

106

Delayed Nickel Decay in Gamma Ray Bursts  

E-Print Network (OSTI)

Recently observed emission lines in the X-ray afterglow of gamma ray bursts suggest that iron group elements are either produced in the gamma ray burst, or are present nearby. If this material is the product of a thermonuclear burn, then such material would be expected to be rich in Nickel-56. If the nickel remains partially ionized, this prevents the electron capture reaction normally associated with the decay of Nickel-56, dramatically increasing the decay timescale. Here we examine the consequences of rapid ejection of a fraction of a solar mass of iron group material from the center of a collapsar/hypernova. The exact rate of decay then depends on the details of the ionization and therefore the ejection process. Future observations of iron, nickel and cobalt lines can be used to diagnose the origin of these elements and to better understand the astrophysical site of gamma ray bursts. In this model, the X-ray lines of these iron-group elements could be detected in suspected hypernovae that did not produce an observable gamma ray burst due to beaming.

G. C. McLaughlin; R. A. M. J. Wijers

2002-05-19T23:59:59.000Z

107

Gamma Irradiation | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (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

108

Rate schedule  

NLE Websites -- All DOE Office Websites (Extended Search)

Firm Power Service Provided by Rate/Charges Firm Power Service Provided by Rate/Charges Rate/Charges Effective Through (or until superceded) Firm Sales (SLIP-F9) Composite Rate SLIP 29.62 mills/kWh 9/30/2015 Demand Charge SLIP $5.18/kW-month 9/30/2015 Energy Charge SLIP 12.19 mills/kWh 9/30/2015 Cost Recovery Charge (CRC) SLIP 0 mills/kWh 9/30/2015 Transmission Service Provided by Current Rates effective10/12 - 9/15 (or until superceded) Rate Schedule Effective Through Firm Point-to-Point Transmission (SP-PTP7) CRSP $1.14 per kW-month $13.69/kW-year $0.00156/kW-hour $0.04/kW-day $0.26/kW-week 10/1/2008-9/30/2015 Network Integration Transmission (SP-NW3) CRSP see rate schedule 10/1/2008-9/30/2015 Non-Firm Point-to-Point Transmission (SP-NFT6) CRSP see rate schedule 10/1/2008-9/30/2015 Ancillary Services Provided by Rate Rate Schedule

109

Gamma Dose Rate Near a New 252Cf Brachytherapy Source  

Science Conference Proceedings (OSTI)

Technical Paper / Special Issue on the 16th Biennial Topical Meeting of the Radiation Protection and Shielding Division / Radiation Transport and Protection

Eugene C. Fortune IV; Ian C. Gauld; C.-K. Chris Wang

110

Gamma Ray Bursts Sudden, intense flashes of gamma rays  

E-Print Network (OSTI)

. Sakamoto1,12 , C. L. Sarazin13 , P. Schady6,10 , M. Stamatikos1,12 & S. E. Woosley14 Gamma-ray bursts (GRBs. Identification of two classes of gamma-ray bursts. Astrophys. J. 413, L101­L104 (1993). 2. Fruchter, A. et al). 3. Woosley, S. E. Gamma-ray bursts from stellar mass accretion disks around black holes. Astrophys

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

111

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

112

Effects of radiation exposure on SRL 131 composition glass in a steam environment  

Science Conference Proceedings (OSTI)

Monoliths of SRL 131 borosilicate glass were irradiated in a saturated air-steam environment, at temperatures of 150{degree}C, to examine the effects of radiation on nuclear waste glass behavior. Half of the tests used actinide and Tc-99 doped glass and were exposed to an external ionizing gamma source, while the remaining glass samples were doped only with uranium and were reacted without any external radiation exposure. The effects of radiation exposure on glass alteration and secondary phase formation were determined by comparing the reaction rates and mineral paragenesis of the two sets of samples. All glass samples readily reacted with the water that condensed on their surfaces, producing a smectite clay layer within the first three days of testing. Additional crystalline phases precipitated on the altered glass surface with increasing reaction times, including zeolites, smectite, calcium and sodium silicates, phosphates, evaporitic salts, and uranyl silicates. Similar phases were produced on both the nonirradiated and irradiated samples; however, the quantity of precipitates was increased and the rate of paragenetic sequence development was accelerated in the latter. After 56 days of testing, the smectite layer developed at an average rate of {approximately}0.16 and 0.63 {mu}m/day for the nonirradiated and irradiated samples, respectively. These comparisons indicate that layer development is accelerated approximately four-fold due to the radiation exposure at high glass surface area/liquid volume (SA/V) conditions. This increase apparently occurs in response to the rapid concentration of radiolytic products, including nitric acid, in the thin films of water contacting the sample monoliths.

Wronkiewicz, D.J.; Bradley, C.R.; Bates, J.K. [Argonne National Lab., IL (United States); Wang, L.M. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Geology

1993-11-01T23:59:59.000Z

113

Radiation Leukemogenesis at Low Dose Rates  

SciTech Connect

The major goals of this program were to study the efficacy of low dose rate radiation exposures for the induction of acute myeloid leukemia (AML) and to characterize the leukemias that are caused by radiation exposures at low dose rate. An irradiator facility was designed and constructed that allows large numbers of mice to be irradiated at low dose rates for protracted periods (up to their life span). To the best of our knowledge this facility is unique in the US and it was subsequently used to study radioprotectors being developed for radiological defense (PLoS One. 7(3), e33044, 2012) and is currently being used to study the role of genetic background in susceptibility to radiation-induced lung cancer. One result of the irradiation was expected; low dose rate exposures are ineffective in inducing AML. However, another result was completely unexpected; the irradiated mice had a very high incidence of hepatocellular carcinoma (HCC), approximately 50%. It was unexpected because acute exposures are ineffective in increasing HCC incidence above background. This is a potential important finding for setting exposure limits because it supports the concept of an ?inverse dose rate effect? for some tumor types. That is, for the development of some tumor types low dose rate exposures carry greater risks than acute exposures.

Weil, Michael; Ullrich, Robert

2013-09-25T23:59:59.000Z

114

Simultaneous beta and gamma spectroscopy  

DOE Patents (OSTI)

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

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

2010-03-23T23:59:59.000Z

115

ANIMATION: Crystallography: Gamma Prime - TMS  

Science Conference Proceedings (OSTI)

Feb 9, 2007 ... This 21-second animation demonstrates the crystal structure of gamma prime in nickel based superalloys. SOURCE: Bhadeshia, H. K. D. H. ...

116

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

117

E6 Gamma Decay  

SciTech Connect

Rare electric hexacontatetrapole (E6) transitions are studied in the full (f{sub 7/2},f{sub 5/2},p{sub 3/2},p{sub 1/2}) shell-model basis. Comparison of theory to the results from the gamma decay in {sup 53}Fe and from inelastic electron scattering on {sup 52}Cr provides unique and interesting tests of the valence wavefunctions, the models used for energy density functionals and into the origin of effective charge.

Brown, B. Alex [Department of Physics and Astronomy, and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321 (United States); Rae, W. D. M. [Knollhouse, Garsington, Oxford, Oxfordshire, OX44 9DB (United Kingdom)

2011-05-06T23:59:59.000Z

118

Lecture 7Lecture 7 The GammaThe Gamma--RayRay  

E-Print Network (OSTI)

Milagro­A TeV Observatory for Gamma Ray Bursts B.L. Dingus and the Milagro Collaboration Los energy gamma-rays from gamma-ray bursts. The highest energy gamma rays supply very strong constraints on the nature of gamma-ray burst sources as well as fundamental physics. Because the highest energy gamma-rays

119

Electric Rate Alternatives to Cogeneration  

E-Print Network (OSTI)

This paper discusses electric rate alternatives to cogeneration for the industrial customer and attempts to identify the effects on the utility company, the industrial customer as well as remaining customers. It is written from the perspective of one company and its exposure to cogenerstion within its service territory.

Sandberg, K. R. Jr.

1988-09-01T23:59:59.000Z

120

Avian inhalation exposure chamber  

DOE Patents (OSTI)

An exposure system is designed for delivering gaseous material ranging in particle size from 0.4 micrometers to 20.0 micrometers uniformly to the heads of experimental animals, primarily birds. The system includes a vertical outer cylinder and a central chimney with animal holding bottles connected to exposure ports on the vertical outer cylinder. 2 figs.

Briant, J.K.; Driver, C.J.

1992-05-05T23:59:59.000Z

Note: This page contains sample records for the topic "gamma exposure rates" 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.


121

Avian inhalation exposure chamber  

DOE Patents (OSTI)

An exposure system for delivering gaseous material ranging in particle size from 0.4 micrometers to 20.0 micrometers uniformly to the heads of experimental animals, primarily birds. The system includes a vertical outer cylinder and a central chimney with animal holding bottles connected to exposure ports on the vertical outer cylinder.

Briant, James K. (P.O. Box 999, Richland, WA 99352); Driver, Crystal J. (P.O. Box 999, Richland, WA 99352)

1992-01-01T23:59:59.000Z

122

Rates and Repayment Services  

NLE Websites -- All DOE Office Websites (Extended Search)

Tariff Rates FY 2014 Rates and Rate Schedules FY 2013 Rates and Rate Schedules FY 2012 Rates and Rate Schedules FY 2011 Rates and Rate Schedules FY 2010 Rates and Rate Schedules FY...

123

EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS (REVISION 1)  

SciTech Connect

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

124

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

125

Gamma Ray Pulsars: Multiwavelength Observations  

E-Print Network (OSTI)

High-energy gamma rays are a valuable tool for studying particle acceleration and radiation in the magnetospheres of energetic pulsars. The seven or more pulsars seen by instruments on the Compton Gamma Ray Observatory (CGRO) show that: the light curves usually have double-peak structures (suggesting a broad cone of emission); gamma rays are frequently the dominant component of the radiated power; and all the spectra show evidence of a high-energy turnover. For all the known gamma-ray pulsars, multiwavelength observations and theoretical models based on such observations offer the prospect of gaining a broad understanding of these rotating neutron stars. The Gamma-ray Large Area Space Telescope (GLAST), now in planning for a launch in 2007, will provide a major advance in sensitivity, energy range, and sky coverage.

David J. Thompson

2003-12-10T23:59:59.000Z

126

Resonance strengths in the 14N(p,gamma)15O and 15N(p,alpha gamma)12C reactions  

E-Print Network (OSTI)

The 14N(p,gamma)15O reaction is the slowest reaction of the carbon-nitrogen-oxygen cycle of hydrogen burning in stars. As a consequence, it determines the rate of the cycle. The 15N(p,alpha gamma)12C reaction is frequently used in inverse kinematics for hydrogen depth profiling in materials. The 14N(p,gamma)15O and 15N(p,alpha gamma)12C reactions have been studied simultaneously, using titanium nitride targets of natural isotopic composition and a proton beam. The strengths of the resonances at Ep = 1058 keV in 14N(p,gamma)15O and at Ep = 897 and 430 keV in 15N(p,alpha gamma)12C have been determined with improved precision, relative to the well-known resonance at Ep = 278 keV in 14N(p,gamma)15O. The new recommended values are \\omega\\gamma = 0.352$\\pm$0.018, 362$\\pm$20, and 22.0$\\pm$0.9\\,eV for their respective strengths. In addition, the branching ratios for the decay of the Ep = 1058 keV resonance in 14N(p,gamma)15O have been redetermined. The data reported here should facilitate future studies of off-resona...

Marta, Michele; Bemmerer, Daniel; Beyer, Roland; Broggini, Carlo; Caciolli, Antonio; Erhard, Martin; Fülöp, Zsolt; Grosse, Eckart; Gyürky, György; Hannaske, Roland; Junghans, Arnd R; Menegazzo, Roberto; Nair, Chithra; Schwengner, Ronald; Szücs, Tamás; Vezzú, Simone; Wagner, Andreas; Yakorev, Dmitry

2010-01-01T23:59:59.000Z

127

First Direct Measurement of the {sup 17}F(p,{gamma}){sup 18}Ne Cross Section  

SciTech Connect

The rate of the {sup 17}F(p,{gamma}){sup 18}Ne reaction is important in various astrophysical events. A previous {sup 17}F(p,p){sup 17}F measurement identified a 3{sup +} state providing the strongest resonance contribution, but the resonance strength was unknown. We have directly measured the {sup 17}F(p,{gamma}){sup 18}Ne reaction using a mixed beam of {sup 17}F and {sup 17}O at ORNL. The resonance strength for the 3{sup +} resonance in {sup 18}Ne was found to be {omega}{gamma}=33{+-}14(stat){+-}17(syst) meV, corresponding to a {gamma} width of {gamma}{sub {gamma}}=56{+-}24(stat){+-}30(syst) meV. An upper limit on the direct capture of S(E){<=}65 keV b was determined at an energy of 800 keV.

Chipps, K. A.; Greife, U. [Colorado School of Mines, Golden, Colorado 80401 (United States); Bardayan, D. W.; Smith, M. S. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Blackmon, J. C. [Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Chae, K. Y.; Moazen, B. H.; Pittman, S. T. [University of Tennessee, Knoxville, Tennessee 37996 (United States); Hatarik, R.; Peters, W. A. [Rutgers University, New Brunswick, New Jersey 08901 (United States); Kozub, R. L.; Shriner, J. F. Jr. [Tennessee Technological University, Cookeville, Tennessee 38505 (United States); Matei, C. [Oak Ridge Associated Universities, Oak Ridge, Tennessee 37830 (United States); Nesaraja, C. D.; Pain, S. D. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); University of Tennessee, Knoxville, Tennessee 37996 (United States)

2009-04-17T23:59:59.000Z

128

Neutron counting and gamma spectroscopy with PVT detectors.  

SciTech Connect

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

129

T&E Protocol N42.38, 2009  

Science Conference Proceedings (OSTI)

... A monitor shall alarm when gamma-ray exposure rate (ie ... Is the visual indication for gammas different from the gamma monitoring alarm? ...

2011-09-19T23:59:59.000Z

130

VOC Exposure Metrics  

NLE Websites -- All DOE Office Websites (Extended Search)

6 6 VOC Exposure Metrics ... and "Sick Building Syndrome" Figure1: The elevated odds ratios (above unity) in this figure suggest that exposures to VOCs from water-based points and solvents are associated with a variety of sick building symptions (* indicates the OR is significant at p < 0.05; ** for p < 0.01). The indoors is often regarded as safe haven from problems associated with outdoor air pollution, but a growing number of reports have suggested that exposures in indoor environments may lead to health problems. One area in which evidence has been accumulating is the relationship between working in office buildings (as opposed to industrial exposure conditions) and a variety of health effects, such as eye, nose, and throat irritation and

131

Microenvironmental Exposures to VOCs  

NLE Websites -- All DOE Office Websites (Extended Search)

Microenvironmental Exposures to VOCs Microenvironmental Exposures to VOCs Speaker(s): Miranda Loh Date: February 1, 2006 - 12:00pm Location: 90-3122 The Boston Exposure Assessment in Microenvironments (BEAM) study was designed to examine the concentration distributions of VOCs in various microenvironments in and around Boston with the main objective of reducing the uncertainties in predicting exposure levels. A suite of VOC's with potential health effects including benzene, toluene, ethylbenzene, xylenes, several chlorinated compounds and aldehydes were collected in all microenvironments. Phase I. BEAM examined common non-residential microenvironments that have not been extensively studied, in particular, dining, shopping, and transportation microenvironments. Sampling using scripted activities in these microenvironments. For some compounds,

132

PWR Activity Transport and Source Term Assessment: Surface Activity Concentrations by Gamma Scanning  

Science Conference Proceedings (OSTI)

Measurement of surface isotopic concentrations, known as gamma scanning in the United States, is an invaluable tool in assessing variations in shutdown dose rates and the impacts of chemistry and operational changes.

2011-07-25T23:59:59.000Z

133

Relativistic Winds from Compact Gamma-Ray Sources: II. Pair Loading and Radiative Acceleration in Gamma-ray Bursts  

E-Print Network (OSTI)

We consider the effects of rapid pair creation by an intense pulse of gamma-rays propagating ahead of a relativistic shock. Side-scattered photons colliding with the main gamma-ray beam amplify the density of scattering charges. The acceleration rate of the pair-loaded medium is calculated, and its limiting bulk Lorentz factor related to the spectrum and compactness of the photon source. One obtains, as a result, a definite prediction for the relative inertia in baryons and pairs. The deceleration of a relativistic shock in the moving medium, and the resulting synchrotron emissivity, are compared with existing calculations for a static medium. The radiative efficiency is increased dramatically by pair loading. When the initial ambient density exceeds a critical value, the scattering depth traversed by the main gamma-ray pulse rises above unity, and the pulse is broadened. These considerations place significant constraints on burst progenitors: a pre-burst mass loss rate exceeding 10^{-5} M_\\odot per year is difficult to reconcile with individual pulses narrower than 10 s, unless the radiative efficiency is low. An anisotropic gamma-ray flux (on an angular scale \\Gamma^{-1} or larger) drives a large velocity shear that greatly increases the energy in the seed magnetic field forward of the propagating shock.

Christopher Thompson; Piero Madau

1999-09-06T23:59:59.000Z

134

Gamma ray spectroscopic analysis of building materials used in Tiruvannamalai, Tamilnadu, India  

SciTech Connect

Building materials cause direct radiation exposure because of their radium, thorium and potassium content. In this paper, samples of commonly used building materials in Tiruvannamalai, city, have been collected randomly over the city. The samples were tested for their radioactivity contents by using gamma spectroscopic measurements. All samples under investigation are within the recommended safety limit when used as building construction.

Ravisankar, R.; Vanasundari, K.; Suganya, M.; Chandrasekaran, A.; Raghu, Y.; Sivakumar, S.; Vijayagopal, P.; Meenakshisundaram, V. [Post Graduate and Research Department of Physics, Government Arts College, Tiruvannamalai-606603 (India); Department of Physics, Global Institute of Engineering and Technology, Vellore-632509, Tamilnadu (India); Department of Physics, Aarupadai Veedu Institute of Technology, Paiyanoor-603 104.Tamilnadu (India); Department of Physics, Arunai Engineering College, Tiruvannamalai-606603, Tamilnadu (India); Radiological Safety Division. Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

2012-06-05T23:59:59.000Z

135

Search for anomalous ZZ{gamma} and Z{gamma}{gamma} couplings with D0  

Science Conference Proceedings (OSTI)

A direct test of the Standard Model by searching for anomalous ZZ{gamma} and Z{gamma}{gamma} couplings is presented. The authors analyze p{bar p} {yields} ll{gamma} + X, (l = e,{mu}) events at {radical}s = 1.8 TeV with the D0d detector at the Fermilab Tevatron Collider. A fit to the transverse energy spectrum of the photon in the signal events, based on the data set corresponding to an integrated luminosity of 13.9 pb{sup {minus}1} (13.3 pb{sup {minus}1}) for the electron (muon) channel, yields the following 95% CL limits on the anomalous CP-conserving ZZ{gamma} couplings: -1.9 < h{sub 30}{sup Z} < 1.8 (h{sub 40}{sup Z} = 0), and -0.5 < h{sub 40}{sup Z} < 0.5 ({sub 30}{sup Z} = 0), for a form-factor scale {Lambda} = 500 GeV. Limits on the Z{gamma}{gamma} couplings and CP-violating couplings are also discussed.

Landsberg, G.

1995-05-01T23:59:59.000Z

136

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

137

Design and development of a portable gamma radiation monitor  

Science Conference Proceedings (OSTI)

A portable gamma radiation monitor has been designed and developed. The monitor can be used effectively in the dose range from 0.07 to 500 mGy/h due to gamma rays of energy greater than 65 keV. The monitor overestimated radiation doses and the uncertainty in the measured dose rate has been found to be {+-}30%. Provision has also been added to use the monitor as an installed radiation monitor. In installed mode, it can be operated from a remote location up to 1 km and the timing history can be stored on a personal computer.

Munir, M.; Khalid, M. [Health Physics Division, Directorate of Systems and Services, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Nilore, Islamabad 45650 (Pakistan); Ahmad, N.; Sohail, S.; Naveed, R. A.; Rafiq, M. Q. [Pakistan Institute of Engineering and Applied Sciences (PIEAS), P. O. Nilore, Islamabad 45650 (Pakistan)

2009-07-15T23:59:59.000Z

138

Gamma-Ray Burst Lines  

E-Print Network (OSTI)

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

Michael S. Briggs

1999-10-20T23:59:59.000Z

139

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

140

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 Bursts Apparently high gamma-ray efficiency. Highly magnetized flow? Roming et al., 2005 #12;Surprises

California at Santa Cruz, University of

Note: This page contains sample records for the topic "gamma exposure rates" 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

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

Science Conference Proceedings (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

142

Gamma Ray Bursts and CETI  

E-Print Network (OSTI)

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

Frank D. Smith Jr

1993-02-10T23:59:59.000Z

143

Rates and Repayment Services  

NLE Websites -- All DOE Office Websites (Extended Search)

Customer Letter - Preliminary Review of Drought Adder Component for 2011 Firm Power Rates 2010 Rates and Rate Schedule - Current * 2009 Rates and Rate Schedule 2008 Rates and...

144

Dose rate visualization of radioisotope thermoelectric generators  

DOE Green Energy (OSTI)

Advanced visualization techniques can be used to investigate gamma ray and neutron dose rates around complex dose rate intensive operations. A method has been developed where thousands of dose points are calculated using the MCNP(Monte Carlo N-Particle) computer code and then displayed to create color contour plots of the dose rate for complex geometries. Once these contour plots are created, they are sequenced together creating an animation to dynamically show how the dose rate changes with changes in the geometry or source over time.

Schwarz, R.A.; Kessler, S.F.; Tomaszewski, T.A.

1995-09-01T23:59:59.000Z

145

[sup 3]He neutron detector performance in mixed neutron gamma environments  

Science Conference Proceedings (OSTI)

A test program of the performance of 3He neutron proportional detectors with varying gas pressures, and their response to lligh level gamma-ray exposure in a mixed neutrodgamma environment, ha$ been performed Our intent was to identie the optimal gas pressure to reduce the gamma-ray sensitivity of these detectors. These detectors were manufxtured using materials to minimize their gamma response. Earlier work focused on 3He fill pressures of four atmospheres and above, whereas the present work focuses on a wider range of pressures. Tests have shown that reducing the .filling pressure will M e r increase the gamma-ray dose range in which the detectors can be operated.

Johnson, N. H. (Nathan H.); Beddingfield, D. H. (David H.)

2002-01-01T23:59:59.000Z

146

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. Subject headings: gamma-rays: bursts 1.

Paolo Cea

2006-01-01T23:59:59.000Z

147

Higgs Self-Coupling in gamma-gamma Collisions  

E-Print Network (OSTI)

To establish the Higgs mechanism experimentally, one has to determine the Higgs self-interaction potential responsible for the electroweak symmetry breaking. This requires a measurement of the trilinear and quadrilinear self-couplings of the Higgs particle, as predicted by the Standard Model (SM). We propose to measure the trilinear Higgs self-coupling in gamma-gamma collisions just above the kinematic threshold E_thr = 2M_H, where M_H is the Higgs mass. Our calculation reveals that the sensitivity of the cross-section sigma(gamma gamma -> HH) to the Higgs self-coupling is maximal near the 2M_H threshold for M_H = 115-150 GeV, and is larger than the sensitivities of sigma(e+e- -> ZHH) and sigma(e+e- -> nu nu HH) to this coupling for 2E_e H by constructing an X-band e-e- linac and a terawatt laser system in order to produce Compton-scattered gamma-ray beams for a 160-GeV photon collider (2E_e = 200 GeV); (b) add a positron source and repeat all measurements done at LEP and SLC with much better precision; and (c) subsequently install 70-MeV/m rf cavities in order to study e+e- -> H+Z, e+e- -> tt and gamma gamma -> H+H at 2E_e = 350 GeV. The total length of the linac would be about 7 km.

R. Belusevic; G. Jikia

2004-03-31T23:59:59.000Z

148

Gamma thermometer based reactor core liquid level detector  

DOE Patents (OSTI)

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

Burns, Thomas J. (Knoxville, TN)

1983-01-01T23:59:59.000Z

149

Heart Rate Variability (HRV) in Ambient Magnetic Fields  

Science Conference Proceedings (OSTI)

In a healthy individual, the rate at which the heart beats exhibits continuous variability. In prior research at Midwest Research Institute (MRI), exposure to intermittent, but not continuous, magnetic fields was associated with alterations in heart rate variability (HRV). This report describes additional studies specifically designed to address the potential effects of magnetic field exposure on HRV.

1998-12-17T23:59:59.000Z

150

Guidelines for Exposure Assessment  

NLE Websites -- All DOE Office Websites (Extended Search)

Z-92/001 Z-92/001 May 1992 Guidelines for Exposure Assessment Published on May 29, 1992, Federal Register 57(104):22888-22938 These guidelines replace the previously issued final Guidelines for Estimating Exposures (September 24, 1986), Federal Register 51(185):34042-34054, and the Proposed Guidelines for Exposure-Related Measurements (December 2, 1988), Federal Register 53(232):48830- 48853. Risk Assessment Forum U.S. Environmental Protection Agency Washington, DC DISCLAIMER This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. Note: This document represents the final guidelines. A number of editorial corrections have

151

Diffuse Gamma-Rays from Local Group Galaxies  

E-Print Network (OSTI)

Diffuse gamma-ray radiation in galaxies is produced by cosmic ray interactions with the interstellar medium. With the completion of EGRET observations, the only extragalactic object from which there has been a positive detection of diffuse gamma-ray emission is the Large Magellanic Cloud. We systematically estimate the expected diffuse gamma-ray flux from Local Group galaxies, and determine their detectability by new generation gamma-ray observatories such as GLAST. For each galaxy, the expected gamma-ray flux depends only on its total gas content and its cosmic ray flux. We present a method for calculating cosmic ray flux in these galaxies in terms of the observed rate of supernova explosions, where cosmic ray acceleration is believed to take place. The difficulty in deriving accurate supernova rates from observational data is a dominant uncertainty in our calculations. We estimate the gamma-ray flux for Local Group galaxies and find that our predictions are consistent with the observations for the LMC and with the observational upper limits for the Small Magellanic Cloud and M31. Both the Andromeda galaxy, with a flux of $\\sim 1.0 \\times 10^{-8}$ photons sec$^{-1}$ cm$^{-2}$ above 100 MeV, and the SMC, with a flux of $\\sim 1.7 \\times 10^{-8}$ photons sec$^{-1}$ cm$^{-2}$ above 100 MeV, are expected to be observable by GLAST. M33 is at the limit of detectability with a flux of $\\sim 0.11 \\times 10^{-8}$ sec$^{-1}$ cm$^{-2}$. Other Local Group galaxies are at least two orders of magnitude below GLAST sensitivity.

Vasiliki Pavlidou; Brian D. Fields

2001-05-11T23:59:59.000Z

152

Gamma-Ray Bursts from Radio-Quiet Quasars  

E-Print Network (OSTI)

We study positional coincidences between gamma-ray bursts in the BATSE 3B catalogue and quasars/AGN taken from the Veron-Cetty & Veron compilation. For most classes of AGN, for BL Lac objects and for radio-loud quasars, we find no excess coincidences above random expectation, and we give upper limits for their burst emission rate. However, surprising evidence is found for a positional correlation between gamma-ray bursts and radio-quiet quasars. A total of 134 selected bursts with a position error radius 99.7% to be associated with each other. An analysis of a smaller sample of well-localized interplanetary network gamma-ray burst positions supports this result. This correlation strongly favours the cosmological origin of gamma-ray bursts and enables to estimate its distance scale. The average luminosity of those gamma-ray bursts which we associate directly with radio-quiet quasars is of the order of 4*10^52 erg (assuming isotropic emission).

N. Schartel; H. Andernach; J. Greiner

1996-12-16T23:59:59.000Z

153

The Cosmic Stellar Birth and Death Rates  

E-Print Network (OSTI)

The cosmic stellar birth rate can be measured by standard astronomical techniques. It can also be probed via the cosmic stellar death rate, though until recently, this was much less precise. However, recent results based on measured supernova rates, and importantly, also on the attendant diffuse fluxes of neutrinos and gamma rays, have become competitive, and a concordant history of stellar birth and death is emerging. The neutrino flux from all past core-collapse supernovae, while faint, is realistically within reach of detection in Super-Kamiokande, and a useful limit has already been set. I will discuss predictions for this flux, the prospects for neutrino detection, the implications for understanding core-collapse supernovae, and a new limit on the contribution of type-Ia supernovae to the diffuse gamma-ray background.

John F. Beacom

2006-02-05T23:59:59.000Z

154

Alternative Exposure Metrics and Health  

Science Conference Proceedings (OSTI)

Exposure assessments are critical components of human health studies. These assessments may be geared toward defining where an environmental agent might be present, its levels or concentrations, the conditions under which exposure occurs, those exposed, and additional details of possible exposure scenarios. The assessments may also be used by epidemiologists to address potential linkages between the exposure and health outcomes.Electromagnetic field (EMF) exposure science has evolved due ...

2013-12-20T23:59:59.000Z

155

A Gamma-Ray Burst Trigger Toolkit  

E-Print Network (OSTI)

The detection rate of a gamma-ray burst detector can be increased by using a count rate trigger with many accumulation times ?t and energy bands ?E. Because a burst’s peak flux varies when averaged over different ?t and ?E, the nominal sensitivity (the numerical value of the peak flux) of a trigger system is less important than how much fainter a burst could be at the detection threshold as ?t and ?E are changed. The relative sensitivity of different triggers can be quantified by referencing the detection threshold back to the peak flux for a fiducial value of ?t and ?E. This mapping between peak flux values for different sets of ?t and ?E varies from burst to burst. Quantitative estimates of the burst detection rate for a given detector and trigger system can be based on the observed rate at a measured peak flux value in this fiducial trigger. Predictions of a proposed trigger’s burst detection rate depend on the assumed burst population, and these predictions can be wildly in error for triggers that differ significantly from previous missions. I base the fiducial rate on the BATSE observations: 550 bursts per sky above a peak flux of 0.3 ph cm ?2 s ?1 averaged over ?t=1.024 s and ?E=50–300 keV. Using a sample of 100 burst lightcurves I find that triggering on all possible values of ?t that are multiples of 0.064 s decreases the average threshold peak flux on the 1.024 s timescale by a factor of 0.6. Extending ?E to lower energies includes the large flux of the X-ray background, increasing the background count rate. Consequently a low energy ?E is advantageous only for very soft bursts. Whether a large fraction of the population of bright bursts is soft is disputed; the new population of X-ray Flashes is soft but relatively faint. Subject headings: gamma-rays: bursts

unknown authors

2002-01-01T23:59:59.000Z

156

Exclusive search for Higgs boson to gamma-gamma decay via vector boson fusion production mechanism.  

E-Print Network (OSTI)

??We perform an exclusive search for the Higgs boson to gamma-gamma decay via vector boson fusion. We utilize the characteristic features of vector boson fusion,… (more)

Rankin, Dylan Sheldon

2012-01-01T23:59:59.000Z

157

Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah Gamma Survey of a Permeable Reactive Barrier at...

158

Gamma Industry Processing Alliance Overview | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

159

Rates and Repayment Services  

NLE Websites -- All DOE Office Websites (Extended Search)

Rates Loveland Area Project Firm Power Rates Transmission and Ancillary Services Rates 2012 Rate Adjustment-Transmission and Ancillary Services 2010 Rate Adjustment-Firm Power 2009...

160

Rates and Repayment Services  

NLE Websites -- All DOE Office Websites (Extended Search)

Rates and Repayment Services Consolidated Rate Schedules FY 2014 Rates BCP Annual Rate Process Central Arizona Project Transmission Rate Process DSW Multiple System Transmission...

Note: This page contains sample records for the topic "gamma exposure rates" 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

Search for the b --> d gamma process  

E-Print Network (OSTI)

We report search results for the flavor-changing neutral current process b --> d gamma with a data sample containing 274 million B meson pairs accumulated at the Upsilon(4S) resonance with the Belle detector at KEKB. We studied the exclusive decays B- --> rho- gamma, B0bar --> rho0 gamma, and B0bar --> omega gamma, and find no significant signal. We set an upper limit for a combined branching fraction Br(B --> (rho,omega) gamma) rho- gamma assuming an isospin relation between the three modes.

K. Abe; for the Belle Collaboration

2004-08-27T23:59:59.000Z

162

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

163

Short Gamma Ray Bursts as possible electromagnetic counterpart of coalescing binary systems  

E-Print Network (OSTI)

Coalescing binary systems, consisting of two collapsed objects, are among the most promising sources of high frequency gravitational waves signals detectable, in principle, by ground-based interferometers. Binary systems of Neutron Star or Black Hole/Neutron Star mergers should also give rise to short Gamma Ray Bursts, a subclass of Gamma Ray Bursts. Short-hard-Gamma Ray Bursts might thus provide a powerful way to infer the merger rate of two-collapsed object binaries. Under the hypothesis that most short Gamma Ray Bursts originate from binaries of Neutron Star or Black Hole/Neutron Star mergers, we outline here the possibility to associate short Gamma Ray Bursts as electromagnetic counterpart of coalescing binary systems.

S. Capozziello; M. De Laurentis; I. De Martino; M. Formisano

2010-04-27T23:59:59.000Z

164

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

165

Radionuclide deposition and exposure in the Federal Republic of Germany after the Chernobyl accident  

SciTech Connect

Analyses of air, water, and foodstuff samples, together with in situ gamma spectrometric measurements in the Federal Republic of Germany, have documented the deposition and exposure consequences of the Chernobyl accident. In some cases, exposure values are significantly higher than background levels. Data compiled for the period from the initial identification of excess atmospheric radioactivity to the present, represent a unique resource for testing and validating models of environmental transport and human exposure. These data will serve as the bases for future studies of organism response, both somatic and genetic, to nuclear radiation. They will also prove useful in suggesting modifications to environmental sampling and monitoring systems. 14 refs., 13 figs., 4 tabs.

Winkelmann, I.; Haubelt, R.; Neumann, P.; Fields, D.E. (Bundesgesundheitsamt, Neuherberg (Germany, F.R.). Inst. fuer Strahlenhygiene; Oak Ridge National Lab., TN (USA))

1989-11-01T23:59:59.000Z

166

Studying Z/gamma*+Jet Production  

SciTech Connect

The production of jets in association with a Z/{gamma}* boson is an example of an important class of processes at hadron colliders, namely vector boson + jet (V + jet) production. Comparisons of measurements of this class of processes with theory predictions constitute an important, fundamental test of the Standard Model of particle physics, and of the theory of QCD in particular. While having a smaller cross section than other V +jet processes, Z/{gamma}*({yields} e{sup +}e{sup -}) + jets production, with Z/{gamma}* {yields} e{sup +}e{sup -}/{mu}{sup +}{mu}{sup -}, has a distinct experimental signature allowing for measurements characterized by low backgrounds and a direct, precise measurement of the properties of the decay products of the Z/{gamma}* boson. In this thesis, several new measurements of the properties of jets produced in association with a Z/{gamma}* boson in p{bar p} collisions at {radical}s = 1.96 TeV are presented. The cross section for Z/{gamma}*({yields} e{sup +}e{sup -}) + N jet production (N {le} 3) is measured, differential in the transverse momentum of the Nth jet in the event, normalized to the inclusive Z/{gamma}* cross section. Also, the cross section for Z/{gamma}*({yields} e{sup +}e{sup -}) + N jets (N {ge} 1) is measured, differential in the difference in azimuthal angle between the di-electron system and any jet in the event, normalized to unity. The data used in the measurements were collected by the D0 experiment located at the Tevatron Collider of the Fermi National Accelerator Laboratory and correspond to an integrated luminosity of 1.04 fb{sup -1}. The measured jet transverse momentum spectra are compared with the predictions of perturbative calculations at the next-to-leading order in the strong coupling constant. Given the low sensitivity of the calculations to model parameters, these comparisons represent a stringent test of perturbative QCD. One of the main goals currently being pursued in particle physics is the discovery of the only particle predicted by the Standard Model which has so far no been detected experimentally, namely the Higgs boson. It is assumed that the ATLAS and CMS experiments located at the Large Hadron Collider (LHC), a proton-proton collider at {radical}s = 14 TeV, will be able to detect the Higgs boson, or rule out its existence, within the next few years. The collisions delivered by the LHC will also be used to perform a long range of searches for other new particles, for instance particles predicted by models based on the principle of supersymmetry. The associated production of vector bosons with jets has relatively large production rates at the LHC and can produce a long list of different final states which can include charged leptons, missing transverse energy, as well as light- and heavy-flavour jets. This makes V + jet production a major source of background events to many searches for new particles. Most techniques used for estimating the expected number of background events to searches rely on passing the stable final-state particles of simulated hadron collisions generated using a so-called event generator code, through a simulation of the experimental detector system. The development of event generators which are capable of reliably predicting the properties of jets produced in association with a core process, e.g. the production of a vector boson, has been the subject of a large amount of research activity during the last ten years. These efforts have led to the appearance of the CKKW and MLM algorithms which are implemented in several event generators, among them SHERPA and ALPGEN + PYTHIA. The large data sample collected by the D0 experiment during Run II offers an excellent opportunity for validating these new event generators against experimental measurements of V + jet production. As argued above, the Z/{gamma}*({yields} e{sup +}e{sup -}) + jets process offers the combination of a clean experimental signature and large production rates, making it the process of choice for these studies.

Nilsen, Henrik Wold; /Freiburg U.

2009-07-01T23:59:59.000Z

167

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

168

Gamma ray astrophysics: the EGRET results  

E-Print Network (OSTI)

Cosmic gamma rays provide insight into some of the most dynamic processes in the Universe. At the dawn of a new generation of gamma-ray telescopes, this review summarizes results from the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory, the principal predecessor mission studying high-energy photons in the 100 MeV energy range. EGRET viewed a gamma-ray sky dominated by prominent emission from the Milky Way, but featuring an array of other sources, including quasars, pulsars, gamma-ray bursts, and many sources that remain unidentified. A central feature of the EGRET results was the high degree of variability seen in many gamma-ray sources, indicative of the powerful forces at work in objects visible to gamma-ray telescopes.

D J Thompson

2008-11-05T23:59:59.000Z

169

The Diverse Environments of Gamma-Ray Bursts  

E-Print Network (OSTI)

of a Very Bright Gamma- Ray Burst in a Galactic Halo 3.1Galaxies of Dark Gamma-Ray Bursts: Observational Constraints1.3 Gamma-Ray Burst Classi?cation . . . . . . 1.4 Gamma-Ray

Perley, Daniel Alan

2011-01-01T23:59:59.000Z

170

Rates & Repayment  

NLE Websites -- All DOE Office Websites (Extended Search)

Environmental Review-NEPA Financial Data Operations Planning & Projects Power Marketing Rates Rate Adjustments Transmission Ancillary Services Rates WAPA-137 Rate Order Environmental Review-NEPA Financial Data Operations Planning & Projects Power Marketing Rates Rate Adjustments Transmission Ancillary Services Rates WAPA-137 Rate Order Rates and Repayment Services Rates Current and Historical Rate Information Collbran Power Rates CRSP Power Rates CRSP Transmission System Rates CRSP Management Center interest rates Falcon-Amistad Power Rates Provo River Power Rates Rio Grande Power Rates Seedskadee Power Rates SLCA/IP Power Rates Rate Schedules & Supplemental Rate Information Current Rates for Firm Power, Firm & Non-firm Transmission Service, & Ancillary Services Current Transmission & Ancillary Services Rates Tariffs Components of the SLCA/IP Existing Firm Power Rate Cost Recovery Charge (CRC) Page MOA Concerning the Upper Colorado River Basin

171

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

2006-06-05T23:59:59.000Z

172

FUNDAMENTALS OF GAMMA TITANIUM ALUMINIDES: VI ...  

Science Conference Proceedings (OSTI)

FUNDAMENTALS OF GAMMA TITANIUM ALUMINIDES: Session VI: Microstructure/Property Relationships--Creep and Environmental Effects. Sponsored by: ...

173

FUNDAMENTALS OF GAMMA TITANIUM ALUMINIDES: IV ...  

Science Conference Proceedings (OSTI)

FUNDAMENTALS OF GAMMA TITANIUM ALUMINIDES: Session IV: Microstructure/Property Relationships--Strength, Plasticity, and Toughness. Sponsored by: ...

174

FUNDAMENTALS OF GAMMA TITANIUM ALUMINIDES: III ...  

Science Conference Proceedings (OSTI)

FUNDAMENTALS OF GAMMA TITANIUM ALUMINIDES: Session III: Processing, Microstructure and Properties. Sponsored by: MSD Flow & Fracture and Phase ...

175

FUNDAMENTALS OF GAMMA TITANIUM ALUMINIDES: V ...  

Science Conference Proceedings (OSTI)

FUNDAMENTALS OF GAMMA TITANIUM ALUMINIDES: Session V: Microstructure/Property Relationships--Fatigue, Fracture, and Damage Modeling.

176

Electrothermal controlled-exposure technology  

E-Print Network (OSTI)

A technology is presented for exposing the contents of microfabricated cavities in a substrate. These contents are hermetically sealed until exposure is triggered by an electronic signal. The exposure mechanism uses ...

Maloney, John Mapes

2006-01-01T23:59:59.000Z

177

High-Power Laser Pulse Recirculation for Inverse Compton Scattering-Produced Gamma-Rays  

Science Conference Proceedings (OSTI)

Inverse Compton scattering of high-power laser pulses on relativistic electron bunches represents an attractive method for high-brightness, quasi-monoenergetic {gamma}-ray production. The efficiency of {gamma}-ray generation via inverse Compton scattering is severely constrained by the small Thomson scattering cross section. Furthermore, repetition rates of high-energy short-pulse lasers are poorly matched with those available from electron accelerators, resulting in low repetition rates for generated {gamma}-rays. Laser recirculation has been proposed as a method to address those limitations, but has been limited to only small pulse energies and peak powers. Here we propose and experimentally demonstrate an alternative method for laser pulse recirculation that is uniquely capable of recirculating short pulses with energies exceeding 1 J. Inverse Compton scattering of recirculated Joule-level laser pulses has a potential to produce unprecedented peak and average {gamma}-ray brightness in the next generation of sources.

Jovanovic, I; Shverdin, M; Gibson, D; Brown, C

2007-04-17T23:59:59.000Z

178

Summary of Rad/Nuc CAPAT Efforts  

Science Conference Proceedings (OSTI)

... Scanning at airports – X-ray imaging ... Measure gamma-rays Count rate ... Radiological tests: exposure rate, background, false alarm, gamma ...

2012-12-05T23:59:59.000Z

179

LONG GAMMA-RAY TRANSIENTS FROM COLLAPSARS  

Science Conference Proceedings (OSTI)

In the collapsar model for common gamma-ray bursts (GRBs), the formation of a centrifugally supported disk occurs during the first {approx}10 s following the collapse of the iron core in a massive star. This only occurs in a small fraction of massive stellar deaths, however, and requires unusual conditions. A much more frequent occurrence could be the death of a star that makes a black hole and a weak or absent outgoing shock, but in a progenitor that only has enough angular momentum in its outermost layers to make a disk. We consider several cases where this is likely to occur-blue supergiants with low mass-loss rates, tidally interacting binaries involving either helium stars or giant stars, and the collapse to a black hole of very massive pair-instability supernovae. These events have in common the accretion of a solar mass or so of material through a disk over a period much longer than the duration of a common GRB. A broad range of powers is possible, 10{sup 47}-10{sup 50} erg s{sup -1}, and this brightness could be enhanced by beaming. Such events were probably more frequent in the early universe where mass-loss rates were lower. Indeed, this could be one of the most common forms of gamma-ray transients in the universe and could be used to study first generation stars. Several events could be active in the sky at any one time. Recent examples of this sort of event may have been the Swift transients Sw-1644+57, Sw-2058+0516, and GRB 101225A.

Woosley, S. E. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Heger, Alexander, E-mail: woosley@ucolick.org, E-mail: alex@physics.umn.edu [Minnesota Institute of Astrophysics, School of Physics and Astronomy, University of Minnesota, Twin Cities, Minneapolis, MN 55455 (United States)

2012-06-10T23:59:59.000Z

180

Using a Borated Panel to Form a Dual Neutron-Gamma Detector  

SciTech Connect

A borated polyethylene plane placed between a neutron source and a gamma spectrometer is used to form a dual neutron-gamma detection system. The polyethylene thermalizes the source neutrons so that they are captured by {sup 10}B to produce a flux of 478 keV gamma-rays that radiate from the plane. This results in a buildup of count rate in the detector over that from a disk of the same diameter as the detector crystal (same thickness as the panel). Radiation portal systems are a potential application of this technique.

Scott Wilde; Raymond Keegan

2008-06-20T23:59:59.000Z

Note: This page contains sample records for the topic "gamma exposure rates" 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

Stellar Sources of Gamma-ray Bursts  

E-Print Network (OSTI)

Correlation analysis of Swift gamma-ray burst coordinates and nearby star locations (catalog Gliese) reveals 4 coincidences with good angular accuracy. The random probability is 4\\times 10^{-5}, so evidencing that coincident stars are indeed gamma-ray burst sources. Some additional search of stellar gamma-ray bursts is discussed.

Luchkov, B I

2011-01-01T23:59:59.000Z

182

Fermi Observations of Gamma?ray Bursts  

Science Conference Proceedings (OSTI)

The gamma?ray emission mechanism of Gamma?ray bursts (GRBs) are still unknown. Fermi Gamma?ray Space Telescope successfully detected high?energy (> 100 MeV) emission from 17 GRBs since its launch. Fermi revealed the distinct temporal behaviors and extra spectral component from high?energy emission. These new observational results are driving many theoretical implications

Masanori Ohno; The Fermi?LAT collaborations; The GBM collaborations

2010-01-01T23:59:59.000Z

183

Multifrequency Observations of Gamma-Ray Burst  

E-Print Network (OSTI)

Neither a flaring nor a quiescent counterpart to a gamma-ray burst has yet been convincingly identified at any wavelength region. The present status of the search for counterparts of classical gamma-ray bursts is given. Particular emphasis is put on the search for flaring counterparts, i.e. emission during or shortly after the gamma-ray emission.

J. Greiner

1995-10-04T23:59:59.000Z

184

Gamma-Ray Burst Detection with INTEGRAL/SPI  

E-Print Network (OSTI)

The spectrometer SPI, one of the two main instruments of the INTEGRAL spacecraft, has strong capabilities in the field of Gamma-Ray Burst (GRB) detections. In its 16 deg field of view (FoV) SPI is able to trigger and to localize GRBs with an accuracy for strong bursts better than 1 deg. The expected GRB detection rate is about one per month.

Andreas von Kienlin; Nikolas Arend; Giselher Lichti; Andrew Strong; Paul Connell

2004-07-05T23:59:59.000Z

185

How to Tell a Jet from a Balloon: A Proposed Test for Beaming in Gamma Ray Bursts  

E-Print Network (OSTI)

If gamma ray bursts are highly collimated, the energy requirements of each event may be reduced by several (~ 4-6) orders of magnitude, and the event rate increased correspondingly. Extreme conditions in gamma ray bursters lead to highly relativistic motions (bulk Lorentz factors Gamma > 100). This results in strong forward beaming of the emitted radiation in the observer's rest frame. Thus, all information on gamma ray bursts comes from those ejecta emitted in a narrow cone (opening angle 1/Gamma) pointing towards the observer. We are at present ignorant of whether there are ejecta outside that cone or not. The recent detection of longer wavelength transients following gamma ray bursts allows an empirical test of whether gamma ray bursts are collimated jets or spherical fireballs. The bulk Lorentz factor of the burst ejecta will decrease with time after the event, as the ejecta sweep up the surrounding medium. Thus, radiation from the ejecta is beamed into an ever increasing solid angle as the burst remnant evolves. It follows that if gamma ray bursts are highly collimated, many more optical and radio transients should be observed without associated gamma rays than with them. Published supernova searches may contain enough data to test the most extreme models of gamma ray beaming. We close with a brief discussion of other possible consequences of beaming, including its effect on the evolution of burst remnants.

James E. Rhoads

1997-05-21T23:59:59.000Z

186

Neutron/gamma coupled library generation and gamma transport calculation with KARMA 1.2  

Science Conference Proceedings (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

187

Astrophysical relevance of {gamma} transition energies  

SciTech Connect

The relevant {gamma} energy range is explicitly identified where additional {gamma} strength must be located to have an impact on astrophysically relevant reactions. It is shown that folding the energy dependences of the transmission coefficients and the level density leads to maximal contributions for {gamma} energies of 2{<=}E{sub {gamma}}{<=}4 unless quantum selection rules allow isolated states to contribute. Under this condition, electric dipole transitions dominate. These findings allow us to more accurately judge the relevance of modifications of the {gamma} strength for astrophysics.

Rauscher, Thomas [Departement Physik, Universitaet Basel, CH-4056 Basel (Switzerland)

2008-09-15T23:59:59.000Z

188

Measurement of the gamma gamma* -> pi0 transition form factor  

SciTech Connect

We study the reaction e{sup +}e{sup -} {yields} e{sup +}e{sup -}{pi}{sup 0} in the single tag mode and measure the differential cross section d{sigma}/dQ{sup 2} and the {gamma}{gamma}* {yields} {pi}{sup 0} transition form factor in the mometum transfer range from 4 to 40 GeV{sup 2}. At Q{sup 2} > 10 GeV{sup 2} the measured form factor exceeds the asymptotic limit predicted by perturbative QCD. The analysis is based on 442 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.

Aubert, B.

2009-06-02T23:59:59.000Z

189

Gamma Ray Bursts as Probes of the First Stars  

E-Print Network (OSTI)

The redshift where the first stars formed is an important and unknown milestone in cosmological structure formation. The evidence linking gamma ray bursts (GRBs) with star formation activity implies that the first GRBs occurred shortly after the first stars formed. Gamma ray bursts and their afterglows may thus offer a unique probe of this epoch, because they are bright from gamma ray to radio wavelengths and should be observable to very high redshift. Indeed, our ongoing near-IR followup programs already have the potential to detect bursts at redshift z ~ 10. In these proceedings, we discuss two distinct ways of using GRBs to probe the earliest star formation. First, direct GRB counts may be used as a proxy for star formation rate measurements. Second, high energy cutoffs in the GeV spectra of gamma ray bursts due to pair production with high redshift optical and ultraviolet background photons contain information on early star formation history. The second method is observationally more demanding, but also more rewarding, because each observed pair creation cutoff in a high redshift GRB spectrum will tell us about the integrated star formation history prior to the GRB redshift.

James E. Rhoads

2001-11-01T23:59:59.000Z

190

Afterglows as Diagnostics of Gamma Ray Burst Beaming  

E-Print Network (OSTI)

Abstract. If gamma ray bursts are highly collimated, radiating into only a small fraction of the sky, the energy requirements of each event may be reduced by several (up to 4–6) orders of magnitude, and the event rate increased correspondingly. The large Lorentz factors (?> ? 100) inferred from GRB spectra imply relativistic beaming of the gamma rays into an angle ? 1/?. We are at present ignorant of whether there are ejecta outside this narrow cone. Afterglows allow empirical tests of whether GRBs are well-collimated jets or spherical fireballs. The bulk Lorentz factor decreases and radiation is beamed into an ever increasing solid angle as the burst remnant expands. It follows that if gamma ray bursts are highly collimated, many more optical and radio transients should be observed without associated gamma rays than with them. In addition, a burst whose ejecta are beamed into angle ?m undergoes a qualitative change in evolution when ??m < ? 1: Before this, ? ? r?3/2, while afterwards, ? ? exp(?r/r ?

James E. Rhoads

1997-01-01T23:59:59.000Z

191

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,

192

Assessing Potential Exposure from Truck Transport of Low-level Radioactive Waste to the Nevada Test Site  

SciTech Connect

This study has shown that, based upon measurements from industry standard radiation detection instruments, such as the RS model RSS-131 PICs in a controlled configuration, a person may be exposed to gamma radiation above background when in close proximity to some LLW trucks. However, in approximately half (47.7 percent) the population of trucks measured in this study, a person would receive no exposure above background at a distance of 1.0 m (3.3 ft) away from a LLW truck. An additional 206 trucks had net exposures greater than zero, but equal to or less than 1 {micro}R/h. Finally, nearly 80 percent of the population of trucks (802 of 1,012) had net exposures less than or equal to 10 {micro}R/h. Although there are no shipping or exposure standards at 1.0 m (3.3 ft) distance, one relevant point of comparison is the DOT shipping standard of 10 mrem/h at 2.0 m (6.6 ft) distance. Assuming a one-to-one correspondence between Roentgens and Rems, then 903 trucks (89.2 percent of the trucks measured) were no greater than one percent of the DOT standard at 1.0 m (3.3 ft). Had the distance at which the trucks been measured increased to 2.0 m (6.6 ft), the net exposure would be even less because of the increase in distance between the truck and the receptor. However, based on the empirical data from this study, the rate of decrease may be slower than for either a point or line source as was done for previous studies (Gertz, 2001; Davis et al., 2001). The highest net exposure value at 1.0 m (3.3 ft) distance, 11.9 mR/h, came from the only truck with a value greater than 10 mR/h at 1.0 m (3.3 ft) distance.

J. Miller; D. Shafer; K. Gray; B. Church; S.Campbell; B. Holz

2005-08-15T23:59:59.000Z

193

Gamma Industry Processing Alliance Overview  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

194

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

195

Integrated Environmental Assessment Part III: Exposure Assessment  

E-Print Network (OSTI)

of an Official ISEA Glossary,” Journal of Exposure AnalysisGeneva. IPCS (2001) Glossary of Exposure Assessment-Related

McKone, Thomas E.; Small, Mitchell J.

2006-01-01T23:59:59.000Z

196

Evidence for $\\eta_{c} \\rightarrow \\gamma\\gamma$ and Measurement of $J/\\psi\\rightarrow 3\\gamma$  

E-Print Network (OSTI)

The decay of $J/\\psi$ to three photons is studied using $\\psi^\\prime\\to\\pi^+\\pi^-J/\\psi$ in a sample of 106 million $\\psi^\\prime$ events collected with the BESIII detector. First evidence of the decay $\\eta_c\\to\\gamma\\gamma$ is reported, and the product branching fraction is determined to be $\\br{J/\\psi\\to\\gamma\\eta_c,\\eta_c\\to \\gamma\\gamma}=(4.5\\pm1.2\\pm0.6)\\times10^{-6}$, where the first error is statistical and the second systematic. The branching ratio for the direct decay is $\\br{J/\\psi\\to3\\gamma} = (11.3\\pm1.8\\pm2.0)\\times 10^{-6}$.

Ablikim, M; Ambrose, D J; An, F F; An, Q; An, Z H; Bai, J Z; Ban, Y; Becker, J; Bertani, M; Bian, J M; Boger, E; Bondarenko, O; Boyko, I; Briere, R A; Bytev, V; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, J C; Chen, M L; Chen, S J; Chen, Y B; Cheng, H P; Chu, Y P; Cronin-Hennessy, D; Dai, H L; Dai, J P; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; Ding, W M; Ding, Y; Dong, L Y; Dong, M Y; Du, S X; Fang, J; Fang, S S; Fava, L; Feldbauer, F; Feng, C Q; Ferroli, R B; Fu, C D; Fu, J L; Gao, Y; Geng, C; Goetzen, K; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, Y P; Han, Y L; Harris, F A; He, K L; He, M; He, Z Y; Held, T; Heng, Y K; Hou, Z L; Hu, H M; Hu, J F; Hu, T; Huang, G M; Huang, J S; Huang, X T; Huang, Y P; Hussain, T; Ji, C S; Ji, Q; Ji, X B; Ji, X L; Jiang, L L; Jiang, X S; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Jing, F F; Kalantar-Nayestanaki, N; Kavatsyuk, M; Kuehn, W; Lai, W; Lange, J S; Li, C H; Li, Cheng; Li, Cui; Li, D M; Li, F; Li, G; Li, H B; Li, J C; Li, K; Li, Lei; Li, Q J; Li, S L; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, X R; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Liao, X T; Liu, B J; Liu, C L; Liu, C X; Liu, C Y; Liu, F H; Liu, Fang; Liu, Feng; Liu, H; Liu, H B; Liu, H H; Liu, H M; Liu, H W; Liu, J P; Liu, K Y; Liu, Kai; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, X H; Liu, Y B; Liu, Z A; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H; Lu, G R; Lu, H J; Lu, J G; Lu, Q W; Lu, X R; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lv, M; Ma, C L; Ma, F C; Ma, H L; Ma, Q M; Ma, S; Ma, T; Ma, X Y; Ma, Y; Maas, F E; Maggiora, M; Malik, Q A; Mao, Y J; Mao, Z P; Messchendorp, J G; Min, J; Min, T J; Mitchell, R E; Mo, X H; Morales, C Morales; Motzko, C; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nicholson, C; Nikolaev, I B; Ning, Z; Olsen, S L; Ouyang, Q; Pacetti, S; Park, J W; Pelizaeus, M; Peng, H P; Peters, K; Ping, J L; Ping, R G; Poling, R; Prencipe, E; Qi, M; Qian, S; Qiao, C F; Qin, X S; Qin, Y; Qin, Z H; Qiu, J F; Rashid, K H; Rong, G; Ruan, X D; Sarantsev, A; Schaefer, B D; Schulze, J; Shao, M; Shen, C P; Shen, X Y; Sheng, H Y; Shepherd, M R; Song, X Y; Spataro, S; Spruck, B; Sun, D H; Sun, G X; Sun, J F; Sun, S S; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Toth, D; Ullrich, M; Varner, G S; Wang, B; Wang, B Q; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Q; Wang, Q J; Wang, S G; Wang, X L; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z Y; Wei, D H; Weidenkaff, P; Wen, Q G; Wen, S P; Werner, M; Wiedner, U; Wu, L H; Wu, N; Wu, S X; Wu, W; Wu, Z; Xia, L G; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, G M; Xu, H; Xu, Q J; Xu, X P; Xu, Z R; Xue, F; Xue, Z; Yan, L; Yan, W B; Yan, Y H; Yang, H X; Yang, Y; Yang, Y X; Ye, H; Ye, M; Ye, M H; Yu, B X; Yu, C X; Yu, J S; Yu, S P; Yuan, C Z; Yuan, Y; Zafar, A A; Zallo, A; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; 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, Y S; Zhang, Z P; Zhang, Z Y; Zhao, G; Zhao, H S; Zhao, J W; Zhao, K X; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, S J; Zhao, T C; Zhao, X H; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, Y H; Zhong, B; Zhong, J; Zhou, L; Zhou, X K; Zhou, X R; Zhu, C; Zhu, K; Zhu, K J; Zhu, S H; Zhu, X L; Zhu, X W; Zhu, Y C; Zhu, Y M; Zhu, Y S; Zhu, Z A; Zhuang, J; Zou, B S; Zou, J H

2012-01-01T23:59:59.000Z

197

Superfund Exposure Assessment Manual  

NLE Websites -- All DOE Office Websites (Extended Search)

1-881001 1-881001 OSWER Directive 9285.5-1 April 1988 Superfund Exposure Assessment Manual U.S. Environmental Protection Agency Office of Remedial Response Washington, DC 20460 Notice This report was prepared under contract to an agency of the United States Government. Neither the United States Government nor any of its employees, contractors, subcontractors, or their employees makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third party' s use of or the results of such use of any information, apparatus, product, or process disclosed in this report, or represents that its use by such third party would not infringe on privately owned rights. ii Table of Contents Chapter Page List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

198

GAMMA-RAY BURSTS FROM NEUTRON STAR BINARIES  

E-Print Network (OSTI)

We report on general relativistic hydrodynamic studies which indicate several new physical processes which may contribute to powering gamma-ray bursts in neutron star binaries. Relativistically driven compression, heating, and collapse of the individual stars can occur many seconds before inspiral and merger. This compression may produce a neutrino burst of ? 10 53 ergs lasting several seconds. The associated thermal neutrino emission produces an e + ? e ? pair plasma by ?¯? annihilation. We show first results of a simulated burst which produces ? 10 51 erg in ?-rays. We also discuss a preliminary study of the evolution of the magnetic field lines attached to the fluid as the stars orbit. We show that the relativistically driven fluid motion might lead to the formation of extremely strong magnetic fields ( ? 10 17 gauss) in and around the stars which could affect to the formation and evolution of a gamma-ray burst. It has been speculated for some time that inspiraling neutron stars could provide a power source for cosmological gamma-ray bursts. The rate of neutron star mergers (when integrated over the number of galaxies out to high redshift) could account for the observed GRB event rate. The possibility that at least some ?-ray bursts involve

G. J. Mathews

1997-01-01T23:59:59.000Z

199

Characteristics and effects of {gamma}-NiOOH on cell performance and a method to quantify it in nickel electrodes  

SciTech Connect

This study describes the characteristics and effects of gamma ({gamma})-NiOOH on cell performance and a method to quantify it in NiCd and NiMH battery systems. {gamma}-NiOOH is formed in nickel electrodes under conditions of aging, high percent overcharge, charge rates, and electrolyte concentrations. Formation of this phase results in swelling of the nickel electrode and leads to possible shorting due to fracturing. The fracturing of particles results in increased surface area. It also plays a role in drying the separator. All of these factors lead to cycle-life failure. These failure characteristics were measured in a NiCd cell as a function of charge and discharge cycles. A method to quantify {gamma}-NiOOH using x-ray diffraction was developed. It was found that the integrated peak intensities obtained from the 003 peak of {gamma}-NiOOH were approximately three times greater than that of the 001 peak of {beta}-NiOOH. These peaks were used since they were related to the highest intensities. This information was used in calculating the ratio of {gamma}/{gamma}+ {beta} in a charged NiOOH electrode. This technique allows one to quantify the amount of {gamma}-NiOOH as a function of cycles, rates, and different depths of discharge.

Singh, D. [Energizer Power Systems, Gainesville, FL (United States)

1998-01-01T23:59:59.000Z

200

Biomarkers of exposure to complex environmental mixtures  

E-Print Network (OSTI)

Maternal exposure to genotoxic chemicals may produce a variety of adverse birth outcomes. Depending on the dose and duration of exposure, adverse birth outcomes can range from premature or low-birth weight, to congenital abnormalities including neural tube defects (NTDs). The research described in this dissertation focused on several rural counties in Shanxi province, China. Shanxi has one of the highest rates of NTDs in the world. In 2005, the incidence of NTDs in the study counties ranged from 8 to 24 cases per 1,000 births. While some of these birth defects are likely to be related to nutrition, it is also suggested that environmental factors play a significant role. One such factor includes polycyclic aromatic hydrocarbon (PAH) exposure as a result of combustion of coal for indoor heating and cooking. Human populations in Shanxi depend heavily on coal as their main source of energy. This study determined the concentrations of PAHs in house dust, venous blood and placenta of study participants. Dust was collected from homes in the study site. Carcinogenic PAH levels in dust collected from kitchen floors ranged from 12 to 2,000 µg/m2. The genotoxic potential of dust was confirmed by shortterm bioassays. Median concentrations of total PAHs in placenta from children born with NTDs were elevated compared to matched controls and appeared to be associated with the risk of having a child with a NTD. Tobacco smoking was not associated with elevated levels of PAH biomarkers in this study population. Levels of bulky DNA adducts in placenta have also been quantified using 32P-postlabeling. Adduct levels do not appear to be significantly different between cases and controls and were not associated with deletions in enzymes GSTM1 or GSTT1. These data suggest that children born with NTDs may be at increased risk due to exposure to genotoxic PAHs. Studies with a larger number of subjects are needed to further elucidate the relationship between PAH exposure and adverse birth outcomes.

Naufal, Ziad Sami

2008-05-01T23:59:59.000Z

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201

Pollutant Exposure and Health Risk  

NLE Websites -- All DOE Office Websites (Extended Search)

TEMcKone@lbl.gov (510) 486-6163 Links Exposure and Risk Assessment Group Batteries and Fuel Cells Buildings Energy Efficiency Electricity Grid Energy Analysis Energy...

202

Gamma-Rays from Radio Galaxies: Fermi-Lat Observations  

E-Print Network (OSTI)

We review the high energy properties of Misaligned AGNs associated with gamma-ray sources detected by Fermi in 24 months of survey. Most of them are nearby emission low power radio galaxies (i.e FRIs) which probably have structured jets. On the contrary, high power radio sources (i.e FRIIs) with GeV emission are rare. The small number of FRIIs does not seem to be related to their higher redshifts. Assuming proportionality between the radio core flux and the gamma-ray flux, several of them are expected to be bright enough to be detected above 100 MeV in spite of their distance. We suggest that beaming/jet structural differences are responsible for the detection rate discrepancy observed between FRIs and FRIIs.

Grandi, Paola

2011-01-01T23:59:59.000Z

203

Black Stars and Gamma Ray Bursts  

E-Print Network (OSTI)

Stars that are collapsing toward forming a black hole but are frozen near the Schwarzschild horizon are termed ``black stars''. Collisions of black stars, in contrast to black hole collisions, may be sources of gamma ray bursts, whose basic parameters are estimated quite simply and are found to be consistent with observed gamma ray bursts. Black star gamma ray bursts should be preceded by gravitational wave emission similar to that from the coalescence of black holes.

Tanmay Vachaspati

2007-06-08T23:59:59.000Z

204

TESLA*HERA Based gamma-p and gamma-A Colliders  

E-Print Network (OSTI)

Main parameters and physics search potential of gamma-p and gamma-A colliders, which will be available due to constructing the TESLA linear electron-positron collider tangentially to the HERA proton ring, are discussed.

A. K. Ciftci; S. Sultansoy; O. Yavas

2000-07-05T23:59:59.000Z

205

A search for the rare decay. mu. /sup +/. -->. e/sup +/. gamma gamma  

SciTech Connect

An experimental search for the lepton-family number nonconserving decay, ..mu../sup +/ ..-->.. e/sup +/..gamma gamma.., has been conducted at the Clinton P. Anderson Meson Physics Facility (LAMPF) using the Crystal Box detector. The detector consists of a modular NaI(Tl) calorimeter, scintillator hodoscope, and a high-resolution, cylindrical drift chamber. It provides a large solid-angle for detecting three-body decays and has good resolutions in the time, position, and energy measurements to eliminate unwanted backgrounds. No evidence for ..mu../sup +/ ..-->.. e/sup +/..gamma gamma.. is found, giving an upper limit for the branching ratio of GAMMA(..mu.. ..-->.. e..gamma gamma..)/GAMMA(..mu.. ..-->.. e nu anti nu) less than or equal to 7.2 x 10/sup -11/ (90% C.L.). This result is an improvement of more than two orders of magnitude in the existing limit. 109 refs., 39 figs.

Grosnick, D.P.

1987-02-01T23:59:59.000Z

206

W{sub {gamma}} and Z{sub {gamma}} production at Tevatron  

Science Conference Proceedings (OSTI)

We present results from CDF and D0 on W{sub {gamma}} and Z{sub {gamma}} productions in p{bar p} collisions at {radical}s = 1.8 TeV. The goal of the analyses is to test the non-abelian self-couplings of the W, Z and photon, one of the most direct consequences of the SU(2){sub L} {direct_product} U(l){sub Y} gauge symmetry. We present direct measurements of WW{sub {gamma}} couplings and limits on ZZ{sub {gamma}} and Z{sub {gamma}{gamma}} couplings, based on p{bar p} {r_arrow} l{nu}{gamma} + X and p{bar p} {r_arrow} ll{gamma} + X events, respectively, observed during the 1992--1993 run of the Fermilab Tevatron Collider.

Aihara, H.

1995-05-01T23:59:59.000Z

207

A Remarkable Angular Distribution of the Intermediate Subclass of Gamma-Ray Bursts  

E-Print Network (OSTI)

In the article a test is developed, which allows to test the null-hypothesis of the intrinsic randomness in the angular distribution of gamma-ray bursts collected at the Current BATSE Catalog. The method is a modified version of the well-known counts-in-cells test, and fully eliminates the non-uniform sky-exposure function of BATSE instrument. Applying this method to the case of all gamma-ray bursts no intrinsic non-randomness is found. The test also did not find intrinsic non-randomnesses for the short and long gamma-ray bursts, respectively. On the other hand, using the method to the new intermediate subclass of gamma-ray bursts, the null-hypothesis of the intrinsic randomness for 181 intermediate gamma-ray bursts is rejected on the 96.4% confidence level. Taking 92 dimmer bursts from this subclass itself, we obtain the surprising result: This "dim" subclass of the intermediate subclass has an intrinsic non-randomness on the 99.3% confidence level. On the other hand, the 89 "bright" bursts show no intrinsic non-randomness.

A. Meszaros; Z. Bagoly; I. Horvath; L. G. Balazs; R. Vavrek

2000-03-20T23:59:59.000Z

208

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

209

Search for gamma ray burst counterparts  

Science Conference Proceedings (OSTI)

The confident detection of a Gamma Ray Burst counterpart would likely provide the much needed breakthrough in our understanding of the cause and site of bursts. As such

Bradley E. Schaefer

1994-01-01T23:59:59.000Z

210

Gamma TiAl Alloys 2014  

Science Conference Proceedings (OSTI)

Jul 15, 2013... for selective laser melting – from single track to fully dense specimens ... Rolling and Grinding of Thin Sheets of Beta-Solidified Gamma TiAl ...

211

DOE 2012 Occupational Radiation Exposure October 2013  

SciTech Connect

The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2012 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. Over the past 5-year period, the occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site. As an indicator of the overall amount of radiation dose received during the conduct of operations at DOE, the report includes information on collective total effective dose (TED). The TED is comprised of the effective dose (ED) from external sources, which includes neutron and photon radiation, and the internal committed effective dose (CED), which results from the intake of radioactive material into the body. The collective ED from photon exposure decreased by 23% between 2011 and 2012, while the neutron dose increased by 5%. The internal dose components of the collective TED decreased by 7%. Over the past 5-year period, 99.99% of the individuals receiving measurable TED have received doses below the 2 roentgen equivalent in man (rems) (20 millisievert [mSv]) TED administrative control level (ACL), which is well below the DOE regulatory limit of 5 rems (50 mSv) TED annually. The occupational radiation exposure records show that in 2012, DOE facilities continued to comply with DOE dose limits and ACLs and worked to minimize exposure to individuals. The DOE collective TED decreased 17.1% from 2011 to 2012. The collective TED decreased at three of the five sites with the largest collective TED. u Idaho Site – Collective dose reductions were achieved as a result of continuing improvements at the Advanced Mixed Waste Treatment Project (AMWTP) through the planning of drum movements that reduced the number of times a container is handled; placement of waste containers that created highradiation areas in a centralized location; and increased worker awareness of high-dose rate areas. In addition, Idaho had the largest decrease in the total number of workers with measurable TED (1,143 fewer workers). u Hanford Site (Hanford) – An overall reduction of decontamination and decommissioning (D&D) activities at the Plutonium Finishing Plant (PFP) and Transuranic (TRU) retrieval activities resulted in collective dose reductions. u Savannah River Site (SRS) – Reductions were achieved through ALARA initiatives employed site wide. The Solid Waste Management Facility used extended specialty tools, cameras and lead shield walls to facilitate removal of drums. These tools and techniques reduce exposure time through improved efficiency, increase distance from the source of radiation by remote monitoring, shield the workers to lower the dose rate, and reduce the potential for contamination and release of material through repacking of waste. Overall, from 2011 to 2012, there was a 19% decrease in the number of workers with measurable dose. Furthermore, due to a slight decrease in both the DOE workforce (7%) and monitored workers (10%), the ratio of workers with measurable doses to monitored workers decreased to 13%. Another primary indicator of the level of radiation exposure covered in this report is the average measurable dose, which normalizes the collective dose over the population of workers who actually received a measurable dose. The average measurable TED in

none,

2012-02-02T23:59:59.000Z

212

Gamma Ray Burst Central Engines  

E-Print Network (OSTI)

I review aspects of the theory of long-duration gamma-ray burst (GRB) central engines. I focus on the requirements of any model; these include the angular momentum of the progenitor, the power, Lorentz factor, asymmetry, and duration of the flow, and both the association and the non-association with bright supernovae. I compare and contrast the collapsar and millisecond proto-magnetar models in light of these requirements. The ability of the latter model to produce a flow with Lorentz factor ~100 while simultaneously maintaining a kinetic luminosity of ~10^50 ergs/s for a timescale of ~10-100 s is emphasized.

Todd A. Thompson

2008-07-04T23:59:59.000Z

213

Gravitational Waves versus X and Gamma Ray Emission in a Short Gamma-Ray Burst  

E-Print Network (OSTI)

The recent progress in the understanding the physical nature of neutron star equilibrium configurations and the first observational evidence of a genuinely short gamma-ray burst, GRB 090227B, allows to give an estimate of the gravitational waves versus the X and Gamma ray emission in a short gamma-ray burst.

F. G. Oliveira; Jorge A. Rueda; Remo Ruffini

2012-05-31T23:59:59.000Z

214

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

E-Print Network (OSTI)

The short gamma-ray burst ­ SGR giant flare connection Kevin Hurley University of California cosmic gamma-ray bursts. There are at least two general ways to approach this problem. One is statistical short gamma-ray bursts (GRBs) could actually be extragalactic giant magnetar flares is not new by any

Enomoto, Ryoji

215

Using (d,p{gamma}) as a surrogate reaction for (n,{gamma})  

SciTech Connect

To benchmark the validity of using the (d,p{gamma}) reaction as a surrogate for (n,{gamma}), the {sup 171,173}Yb(d,p{gamma}) reactions were measured with the goal to reproduce the known neutron capture cross section ratio of these nuclei. Preliminary surrogate results reproduced the measured values within 15%.

Hatarik, R.; Cizewski, J. A.; Hatarik, A. M.; O'Malley, P. D. [Department of Physics and Astronomy, Rutgers University, New Brunswick, NJ 08903 (United States); Bernstein, L. A.; Burke, J. T.; Bleuel, D. L.; Lesher, S. R. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Gibelin, J.; Phair, L. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Swan, T. [Department of Physics and Astronomy, Rutgers University, New Brunswick, NJ 08903 (United States); University of Surrey, Physics Department, Guildford GU2 7XH, Surrey (United Kingdom)

2009-01-28T23:59:59.000Z

216

CONSTRAINTS ON VERY HIGH ENERGY GAMMA-RAY EMISSION FROM GAMMA-RAY BURSTS R. Atkins,1,2  

E-Print Network (OSTI)

CONSTRAINTS ON VERY HIGH ENERGY GAMMA-RAY EMISSION FROM GAMMA-RAY BURSTS R. Atkins,1,2 W. Benbow,3 emission from gamma-ray bursts (GRBs) during the prompt emission phase. Detection of >100 GeV counterparts on potential GRB models. Subject headinggs: gamma rays: bursts -- gamma rays: observations 1. INTRODUCTION

California at Santa Cruz, University of

217

TEST RESULTS FROM GAMMA IRRADIATION OF ALUMINUM OXYHYDROXIDES  

DOE Green Energy (OSTI)

Hydrated metal oxides or oxyhydroxides boehmite and gibbsite that can form on spent aluminum-clad nuclear fuel assemblies during in-core and post-discharge wet storage were exposed as granular powders to gamma irradiation in a {sup 60}Co irradiator in closed laboratory test vessels with air and with argon as separate cover gases. The results show that boehmite readily evolves hydrogen with exposure up to a dose of 1.8 x 10{sup 8} rad, the maximum tested, in both a full-dried and moist condition of the powder, whereas only a very small measurable quantity of hydrogen was generated from the granular powder of gibbsite. Specific information on the test setup, sample characteristics, sample preparation, irradiation, and gas analysis are described.

Fisher, D.; Westbrook, M.; Sindelar, R.

2012-02-01T23:59:59.000Z

218

Observations of Gamma-Ray Bursts at Extreme Energies  

E-Print Network (OSTI)

of Gamma-Ray Bursts . . . . . . . . . . . . . Redshift-CRUZ OBSERVATIONS OF GAMMA-RAY BURSTS AT EXTREME ENERGIES ADedication xix Acknowledgments xx 1 Gamma-Ray Bursts 1.1

Aune, Taylor

2012-01-01T23:59:59.000Z

219

High temperature spectral gamma well logging  

Science Conference Proceedings (OSTI)

A high temperature spectral gamma tool has been designed and built for use in small-diameter geothermal exploration wells. Several engineering judgments are discussed regarding operating parameters, well model selection, and signal processing. An actual well log at elevated temperatures is given with spectral gamma reading showing repeatability.

Normann, R.A.; Henfling, J.A.

1997-01-01T23:59:59.000Z

220

Mouse Strain-Dependent Variations in Sensitivity to Induction of Gamma-H2AX  

NLE Websites -- All DOE Office Websites (Extended Search)

Mouse Strain-Dependent Variations in Sensitivity to Induction of Gamma-H2AX Mouse Strain-Dependent Variations in Sensitivity to Induction of Gamma-H2AX Foci after Continuous Low Dose-Rate Irradiation: The Atm-/- vs Atm +/+ genotypes on Balb/c, 129S6, C57BL/6J, and A/J inbred strains J.R. Brogan Colorado State University Abstract We have recently developed a ‘low dose rate’ gamma-H2AX assay that is sufficiently sensitive to distinguish differences in response for cells from normal Atm +/+ (mouse) or ATM+/+ (human) and the phenotypes associated with the corresponding heterozygous genotypes(1, 2). The assay is also capable of distinguishing mild hypersensitivities for cells from an appreciable proportion of apparently normal individuals(3). We used this assay to determine whether the genetic background of four commonly used

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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
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221

First direct measurement of resonance strengths in {sup 17}O({alpha},{gamma}){sup 21}Ne  

SciTech Connect

The reaction {sup 17}O({alpha},{gamma}){sup 21}Ne has been measured by in-beam {gamma} spectroscopy for the first time in the energy range E{sub {alpha}=}750-1650 keV using highly enriched anodized Ta{sub 2}({sup 17}O){sub 5} targets. Resonances were found at E{sub {alpha}=} 1002, 1386, and 1619 keV. Their strengths and primary {gamma}-ray branchings are given. The new results exclude the low reaction rate of Descouvemont and support the rate of Caughlan and Fowler. Implications for the neutron poisoning efficiency of {sup 16}O in the weak s-process are discussed.

Best, A.; Goerres, J.; Couder, M.; Boer, R. de; Falahat, S.; Kontos, A.; LeBlanc, P. J.; Li, Q.; O'Brien, S.; Sonnabend, K.; Talwar, R.; Uberseder, E.; Wiescher, M. [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

2011-05-15T23:59:59.000Z

222

HIGGS PHYSICS WITH A GAMMA GAMMA COLLIDER BASED ON CLIC 1*.  

SciTech Connect

We present the machine parameters and physics capabilities of the CLIC Higgs Experiment (CLICHE), a low-energy {gamma}{gamma} collider based on CLIC 1, the demonstration project for the higher-energy two-beam accelerator CLIC. CLICHE is conceived as a factory capable of producing around 20,000 light Higgs bosons per year. We discuss the requirements for the CLIC 1 beams and a laser backscattering system capable of producing a {gamma}{gamma} total (peak) luminosity of 2.0 (0.36) x 10{sup 34} cm{sup -2} s{sup -1} with E{sub CM}({gamma}{gamma}) 115 GeV. We show how CLICHE could be used to measure accurately the mass, {bar b}b, WW and {gamma}{gamma} decays of a light Higgs boson. We illustrate how these measurements may distinguish between the Standard Model Higgs boson and those in supersymmetric and more general two-Higgs-doublet models, complementing the measurements to be made with other accelerators. We also comment on other prospects in {gamma}{gamma} and e{sup -}{gamma} physics with CLICHE.

ASNER,D.; BURKHARDT,H.; DE ROECK,A.; ELLIS,J.; GRONBERG,J.; HEINEMEYER,S.; SCHMITT,M.; SCHULTE,D.; VELASCO,M.; ZIMMERMAN,F.

2001-11-01T23:59:59.000Z

223

Electronic equilibrium as a function of depth in tissue from Cobalt-60 point source exposures  

E-Print Network (OSTI)

The Nuclear Regulatory Commission has set the basic criteria for assessing skin dose stemming from hot particle contaminations. Compliance with IO CFR 20. 1 01 requires that exposure to the skin be evaluated over a I CM2 area at a depth of 0.007 cm. Skin exposure can arise from both the beta and gamma components of radioactive particles and gamma radiation can contribute significantly to skin doses. The gamma component of dose increases dramatically when layers of protective clothing are interposed between the hot particle source and the skin, and in cases where the hot particle is large in comparison to the range of beta particles. Once the protective clothing layer is thicker than the maximum range of the beta particles, skin dose is due solely to gamma radiation. Charged particle equilibrium is not established at shallow depths. The degree of electronic equilibrium establishment must be assessed for shallow doses to prevent the overassessment of skin dose because conventional fluence-to-dose conversion factors are not applicable. To assess the effect of electronic equilibrium, selected thicknesses of tissue equivalent material were interposed between radiochromic dye film and a 6OCo hot particle source and dose was measured as a function of depth. These measured values were then compared to models which are used to calculate charged particle equilibrium. The Miller-Reece model was found to agree closely with the experimental data while the Lantz-Lambert model overestimated dose at shallow depths.

Myrick, Jo Ann

1994-01-01T23:59:59.000Z

224

Gamma-Ray Bursts Above 1 GeV  

E-Print Network (OSTI)

One of the principal results obtained by the Compton Gamma Ray Observatory relating to the study of gamma-ray bursts was the detection by the EGRET instrument of energetic ($>$100 MeV) photons from a handful of bright bursts. The most extreme of these was the single 18 GeV photon from the GRB940217 source. Given EGRET's sensitivity and limited field of view, the detection rate implies that such high energy emission may be ubiquitous in bursts. Hence expectations that bursts emit out to at least TeV energies are quite realistic, and the associated target-of-opportunity activity of the TeV gamma-ray community is well-founded. This review summarizes the observations and a handful of theoretical models for generating GeV--TeV emission in bursts sources, outlining possible ways that future positive detections could discriminate between different scenarios. The power of observations in the GeV--TeV range to distinguish between spectral structure intrinsic to bursts and that due to the intervening medium between source and observer is also discussed.

Matthew G. Baring

1997-11-21T23:59:59.000Z

225

Gamma-Ray Lines from Radiative Dark Matter Decay  

E-Print Network (OSTI)

The decay of dark matter particles which are coupled predominantly to charged leptons has been proposed as a possible origin of excess high-energy positrons and electrons observed by cosmic-ray telescopes PAMELA and Fermi LAT. Even though the dark matter itself is electrically neutral, the tree-level decay of dark matter into charged lepton pairs will generically induce radiative two-body decays of dark matter at the quantum level. Using an effective theory of leptophilic dark matter decay, we calculate the rates of radiative two-body decays for scalar and fermionic dark matter particles. Due to the absence of astrophysical sources of monochromatic gamma rays, the observation of a line in the diffuse gamma-ray spectrum would constitute a strong indication of a particle physics origin of these photons. We estimate the intensity of the gamma-ray line that may be present in the energy range of a few TeV if the dark matter decay interpretation of the leptonic cosmic-ray anomalies is correct and comment on observational prospects of present and future Imaging Cherenkov Telescopes, in particular the CTA.

Mathias Garny; Alejandro Ibarra; David Tran; Christoph Weniger

2010-11-16T23:59:59.000Z

226

Epidemiology of accidental radiation exposures  

Science Conference Proceedings (OSTI)

Much of the information on the health effects of radiation exposure available to date comes from long-term studies of the atomic bombings in Hiroshima and Nagasaki. Accidental exposures, such as those resulting from the Chernobyl and Kyshtym accidents, have as yet provided little information concerning health effects of ionizing radiation. This paper will present the current state of our knowledge concerning radiation effects, review major large-scale accidental exposures and the types of studies that are needed. 64 refs., 3 tabs.

Cardis, E. [International Agency for Research on Cancer, Lyon (France)

1996-05-01T23:59:59.000Z

227

How to Tell a Jet from a Balloon: A Proposed Test for Beaming in Gamma-Ray Bursts  

E-Print Network (OSTI)

If gamma ray bursts are highly collimated, radiating into only a small fraction of the sky, the energy requirements of each event may be reduced by several ( ? 4–6) orders of magnitude, and the event rate increased correspondingly. Extreme conditions in gamma ray bursters lead to highly relativistic motions (bulk Lorentz factors ? ?> 100). This results in strong forward beaming of the emitted radiation in the observer’s rest frame. Thus, all information on gamma ray bursts comes from those ejecta emitted in a narrow cone (opening angle ? 1/?) pointing towards the observer. We are at present ignorant of whether there are ejecta outside that cone or not. The recent detection of longer wavelength transients following gamma ray bursts allows an empirical test of whether gamma ray bursts are well-collimated jets or spherical fireballs. The bulk Lorentz factor of the burst ejecta will decrease with time after the event, as the ejecta sweep up the surrounding medium. Thus, radiation from the ejecta is beamed into an ever increasing solid angle as the burst remnant evolves. It follows that if gamma ray bursts are highly collimated, many more optical and radio transients should be observed without associated gamma rays than with them. Published supernova searches may contain enough data to test the most extreme models of gamma ray beaming. We close with a brief discussion of other possible consequences of beaming, including its effect on the evolution of burst remnants.

James E. Rhoads

1997-01-01T23:59:59.000Z

228

Nickel-based superalloy operating temperature determination via analysis of gamma/gamma' microstructure and coating/base material interdiffusion  

E-Print Network (OSTI)

The average operating temperature of RENÉ N5® high pressure turbine blades was evaluated via [gamma]/[gamma]' microstructure and coating/base metal interdiffusion methods. The [gamma]' volume fraction was measured by point ...

Ham, Wendy D. (Wendy Decker)

2005-01-01T23:59:59.000Z

229

Data Center Rating Infrastructure Rating Development  

NLE Websites -- All DOE Office Websites (Extended Search)

in Portfolio Manager on June 7, 2010. The questions below are designed to help data center owners and operators better understand the rating and benchmark their buildings in...

230

SLAC National Accelerator Laboratory - Fermi's Latest Gamma-ray...  

NLE Websites -- All DOE Office Websites (Extended Search)

Fermi's Latest Gamma-ray Census Highlights Cosmic Mysteries By Francis Reddy, NASAGoddard Space Flight Center September 9, 2011 Every three hours, NASA's Fermi Gamma-ray Space...

231

Portable Gamma and Thermal Neutron Detector Using LiI(Eu) Crystals  

Science Conference Proceedings (OSTI)

Simultaneous detection of gamma rays and neutrons emanating from an unknown source has been of special significance and importance to consequence management and first responders since the earliest days of the program. Bechtel Nevada scientists have worked with 6LiI(Eu) crystals and 6Li glass to develop field-operable dual sensors that detect gamma rays and neutrons simultaneously. The prototype 6LiI(Eu) counter, which has been built and tested, is designed to collect data for periods of one second to more than eight hours. The collection time is controlled by thumbwheel switches. A fourpole, high pass filter at 90 KHz reduces microphonic noise from shock or vibration. 6LiI(Eu) crystals generate completely separable gamma-ray and thermal neutron responses. The 6LiI(Eu) rate meter consists of a single crystal 3.8 x 3.8 cm (1.5 x 1.5 in) with a 2.54-cm-(1-in-) thick, annular, high-density, polyethylene ring around the cylinder. Special features are (1) thermal and epithermal neutron detection (0.025eV to 250keV) and (2) typical gamma resolution of 8% at 661.6 keV. Monte Carlo N-Particle calculations for characteristics of gamma spectral behavior, neutron attenuation length, relative neutron and gamma detection efficiency are reported.

S. Mukhopadhyay

2003-06-01T23:59:59.000Z

232

Angular two-point correlation functions for cosmological gamma-ray burst model  

E-Print Network (OSTI)

We compute the angular two-point correlation functions of the gamma-ray bursts at cosmological distances. Since the gamma-ray burst emission mechanism is not yet established, we simply assume that the gamma-ray burst sources are associated with high-redshift galaxies in some way. Then on the basis of several simple models for the evolution of galaxy spatial correlations, we calculate the amplitude of angular two-point correlation functions on scales appropriate for the Compton Gamma Ray Observatory data. we find that in most cases the predicted correlations are difficult to detect with the current data rate and the angular resolution, but models in which the bursts preferentially occur at relatively low redshift ($z \\simlt 0.5$) predict correlation amplitudes on $\\theta \\sim 5^\\circ$ which will be marginally detectable with the Gamma Ray Observatory data in several years. If future observations detect a signal of angular correlations, it will imply useful information on the correlation of galaxies at high redshifts provided that the gamma-ray bursts are cosmological.

Shiho Kobayashi; Shin Sasaki; Yasushi Suto

1994-09-16T23:59:59.000Z

233

Thermal evolution behavior of carbides and {gamma} Prime precipitates in FGH96 superalloy powder  

SciTech Connect

The characteristics of rapidly solidified FGH96 superalloy powder and the thermal evolution behavior of carbides and {gamma} Prime precipitates within powder particles were investigated. It was observed that the reduction of powder size and the increase of cooling rate had transformed the solidification morphologies of atomized powder from dendrite in major to cellular structure. The secondary dendritic spacing was measured to be 1.02-2.55 {mu}m and the corresponding cooling rates were estimated to be in the range of 1.4 Multiplication-Sign 10{sup 4}-4.7 Multiplication-Sign 10{sup 5} K{center_dot}s{sup -1}. An increase in the annealing temperature had rendered the phase transformation of carbides evolving from non-equilibrium MC Prime carbides to intermediate transition stage of M{sub 23}C{sub 6} carbides, and finally to thermodynamically stable MC carbides. The superfine {gamma} Prime precipitates were formed at the dendritic boundaries of rapidly solidified superalloy powder. The coalescence, growth, and homogenization of {gamma}' precipitates occurred with increasing annealing temperature. With decreasing cooling rate from 650 Degree-Sign C{center_dot}K{sup -1} to 5 Degree-Sign C{center_dot}K{sup -1}, the morphological development of {gamma} Prime precipitates had been shown to proceed from spheroidal to cuboidal and finally to solid state dendrites. Meanwhile, a shift had been observed from dendritic morphology to recrystallized structure between 900 Degree-Sign C and 1050 Degree-Sign C. Moreover, accelerated evolution of carbides and {gamma}' precipitates had been facilitated by the formation of new grain boundaries which provide fast diffusion path for atomic elements. - Highlights: Black-Right-Pointing-Pointer Microstructural characteristic of FGH96 superalloy powder was investigated. Black-Right-Pointing-Pointer The relation between microstructure, particle size, and cooling rate was studied. Black-Right-Pointing-Pointer Thermal evolution behavior of {gamma} Prime and carbides in loose FGH96 powder was studied.

Zhang Lin, E-mail: zhanglincsu@163.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Liu Hengsan, E-mail: lhsj63@sohu.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); He Xinbo, E-mail: xb_he@163.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Rafi-ud-din, E-mail: rafiuddi@gmail.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Qu Xuanhui, E-mail: quxh@ustb.edu.cn [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Qin Mingli, E-mail: mlqin75@hotmail.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Li Zhou, E-mail: zhouli621@126.com [National Key Lab of High Temperature Structural Materials, Beijing Institute of Aeronautical Materials, Beijing, 100095 (China); Zhang Guoqing, E-mail: g.zhang@126.com [National Key Lab of High Temperature Structural Materials, Beijing Institute of Aeronautical Materials, Beijing, 100095 (China)

2012-05-15T23:59:59.000Z

234

INTERPLANETARY NETWORK LOCALIZATIONS OF KONUS SHORT GAMMA-RAY BURSTS  

SciTech Connect

Between the launch of the Global Geospace Science Wind spacecraft in 1994 November and the end of 2010, the Konus-Wind experiment detected 296 short-duration gamma-ray bursts (including 23 bursts which can be classified as short bursts with extended emission). During this period, the Interplanetary Network (IPN) consisted of up to 11 spacecraft, and using triangulation, the localizations of 271 bursts were obtained. We present the most comprehensive IPN localization data on these events. The short burst detection rate, {approx}18 yr{sup -1}, exceeds that of many individual experiments.

Pal'shin, V. D.; Svinkin, D. S.; Aptekar, R. L.; Golenetskii, S. V.; Frederiks, D. D.; Mazets, E. P.; Oleynik, P. P.; Ulanov, M. V. [Ioffe Physical Technical Institute, St. Petersburg, 194021 (Russian Federation); Hurley, K. [Space Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720-7450 (United States); Cline, T.; Trombka, J.; McClanahan, T. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Mitrofanov, I. G.; Golovin, D. V.; Kozyrev, A. S.; Litvak, M. L.; Sanin, A. B. [Space Research Institute, 84/32, Profsoyuznaya, Moscow 117997 (Russian Federation); Boynton, W.; Fellows, C.; Harshman, K., E-mail: val@mail.ioffe.ru [Department of Planetary Sciences, University of Arizona, Tucson, AZ 85721 (United States); and others

2013-08-15T23:59:59.000Z

235

Gamma-Ray Pulsar Visibility  

E-Print Network (OSTI)

PSR J0437-4715 is a millisecond pulsar (MSP) thought to be ``pair formation starved'' (having limited pair cascades due to magnetic photon absorption). Fortunately the general relativistic (GR) electrodynamical model under consideration applicable to this pulsar have few free parameters. We model PSR J0437-4715's visibility, using a 3D model which incorporates the variation of the GR E-field over the polar cap (PC), taking different observer and inclination angles into account. Using this pulsar as a case study, one may generalize to conducting a pulsar population visibility study. We lastly comment on the role of the proposed South African SKA (Square Kilometre Array) prototype, KAT (Karoo Array Telescope), for GLAST gamma-ray pulsar identification.

Venter, C

2005-01-01T23:59:59.000Z

236

Gamma-Ray Pulsar Visibility  

E-Print Network (OSTI)

PSR J0437-4715 is a millisecond pulsar (MSP) thought to be ``pair formation starved'' (having limited pair cascades due to magnetic photon absorption). Fortunately the general relativistic (GR) electrodynamical model under consideration applicable to this pulsar have few free parameters. We model PSR J0437-4715's visibility, using a 3D model which incorporates the variation of the GR E-field over the polar cap (PC), taking different observer and inclination angles into account. Using this pulsar as a case study, one may generalize to conducting a pulsar population visibility study. We lastly comment on the role of the proposed South African SKA (Square Kilometre Array) prototype, KAT (Karoo Array Telescope), for GLAST gamma-ray pulsar identification.

C. Venter; O. C. de Jager; A. Tiplady

2005-10-14T23:59:59.000Z

237

Tracking the Libor Rate  

E-Print Network (OSTI)

Investigating the Libor Rate,” mimeo. Abrantes-Metz, R. ,Libor data: Historial 1 month Libor rates, British Bankers1108R) Tracking the Libor Rate Rosa M. Abrantes-Metz , Sofia

Abrantes-Metz, Rosa; Villas-Boas, Sofia B.; Judge, George G.

2013-01-01T23:59:59.000Z

238

Compilation of Published PM2.5 Emission Rates for Cooking, Candles...  

NLE Websites -- All DOE Office Websites (Extended Search)

Compilation of Published PM2.5 Emission Rates for Cooking, Candles and Incense for Use in Modeling of Exposures in Residences Title Compilation of Published PM2.5 Emission Rates...

239

Towards a study of the {sup 22}Ne(p,{gamma}){sup 23}Na reaction at LUNA  

SciTech Connect

The {sup 22}Ne(p,{gamma}){sup 23}Na reaction is a part of the hydrogen burning NeNa cycle. In second-generation stars hydrogen burning may proceed via this cycle. The rate of the {sup 22}Ne(p,{gamma}){sup 23}Na reaction depends on the strength of several resonances in the energy range of the LUNA 400 kV accelerator which have never been observed in direct experiments. A related study is under preparation at LUNA.

Cavanna, Francesca; Depalo, Rosanna; Menzel, Marie-Luise [Dipartimento di fisica, Universita di Genova, and INFN Sezione di Genova, Genova (Italy); Dipartimento di fisica, Universita di Padova, and INFN Sezione di Padova, Padova (Italy); Helmholtz Zentrum Dresden-Rossendorf, Dresden (Germany); Collaboration: LUNA Collaboration

2012-11-20T23:59:59.000Z

240

2012 Rate Adjustments  

NLE Websites -- All DOE Office Websites (Extended Search)

Register Notices Meetings Brochure Brochure Addendum Customer Comment Letter Approved Rate Order FERC Confirmation If you have questions, call Rates and Repayment, 800-472-2306...

Note: This page contains sample records for the topic "gamma exposure rates" 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

Rail Coal Transportation Rates  

U.S. Energy Information Administration (EIA)

figure data Figure 7 shows the percent change in average real rates for those state-to-state ... Estimated transportation rates for coal delivered to electric ...

242

Effective Rate Period  

NLE Websites -- All DOE Office Websites (Extended Search)

10012012 - 09302013 Mid-Year Changes (if applicable) 10012012 - 09302013 Power Rates Annual Revenue Requirement Rate Schedule Power Revenue Requirement 73,381,487...

243

Constraining msugra parameters with mu->e gamma and mu-e conversion in nuclei  

E-Print Network (OSTI)

We show that, in the MSSM with msugra boundary conditions and seesaw induced neutrino masses, the values of BR(mu->e gamma) and the mu-e conversion rate in a nucleus determine the sign of mu and constrain tan beta in a model independent way.

Carlos E. Yaguna

2005-02-02T23:59:59.000Z

244

Xenon diffusion studies with prompt gamma activation analysis Carlos A. Rios Perez Justin D. Lowrey  

E-Print Network (OSTI)

rates of xenon and argon gases through a porous medium. The University of Texas at Austin maintains at thermal and sub-thermal neutron energies, prompt gamma activation analysis is a suitable technique is anticipated to be well suited for this purpose as the energy spectrum of every xenon isotope is unique

Deinert, Mark

245

ANALYSIS OF FUEL ELEMENT CORE BLANKS FOR ARGONNE LOW POWER REACTOR BY GAMMA COUNTING  

SciTech Connect

A technique based on a determinaiion of the differential counting rate exhibited by the 184-kev gamma radiation associated with the decay of U/sup 235/ was developed for the determination of the U/sup 235/ content in Argonne Low Power Reactor fuel element core blanks. The Argonne Low Power Reactor core blanks were an aluminum-highly enriched uranium alloy containing 17.5 weight per cent uranium (approximately 4 g U/sup 235/) having the following dimensions: length, 6.875 inches, width, 3.31 inches, and thickness, 0.200 inch. The gamma- ray spectrum emitied by uranium is rather complex. Using a scintillation spectrometer and scanning the spectrum, the energy is found to be concentrated primarily in two regions, at 184 and 90 kev. The 184-kev gamma rays result primarily from the decay of U/sup 235/ The gammas in the 90-kev region result from the U/sup 235/ decay and daughter products of U/sup 238/ and U/sup 235/. Using a pulse-height analyzer, it is possibie to select the desired radiation emitted from the source and determine the counting rate for a given source. In this work the 184-kev gamma radiation was counted to determine the amount of U/ sup 235/ present in the individual core blanks. (auth)

McGonnagle, W.J.; Perry, R.B.

1959-12-01T23:59:59.000Z

246

Gamma-Ray Burst Physics with GLAST  

SciTech Connect

The Gamma-ray Large Area Space Telescope (GLAST) is an international space mission that will study the cosmos in the energy range 10 keV-300 GeV, the upper end of which is one of the last poorly observed region of the celestial electromagnetic spectrum. The ancestor of the GLAST/LAT was the Energetic Gamma Ray Experiment Telescope (EGRET) detector, which flew onboard the Compton Gamma Ray Observatory (CGRO). The amount of information and the step forward that the high energy astrophysics made thanks to its 9 years of observations are impressive. Nevertheless, EGRET uncovered the tip of the iceberg, raising many questions, and it is in the light of EGRET's results that the great potential of the next generation gamma-ray telescope can be appreciated. GLAST will have an imaging gamma-ray telescope, the Large Area Telescope (LAT) vastly more capable than instruments own previously, as well as a secondary instrument, the GLAST Bursts Monitor, or GBM, to augment the study of gamma-ray bursts. Gamma-Ray Bursts (GRBs) science is one of the most exciting challenges for the GLAST mission, exploring the high energy emission of one of the most intense phenomena in the sky, shading light on various problems: from the acceleration of particles to the emission processes, to more exotic physics like Quantum Gravity effect. In this paper we report the work done so far in the simulation development as well as the study of the LAT sensitivity to GRB.

Omodei, N.; /INFN, Pisa

2006-10-06T23:59:59.000Z

247

Jankovic setting operational exposure limit.ppt  

NLE Websites -- All DOE Office Websites (Extended Search)

Exposure Guides for the Operational Exposure Guides for the Assessment and Control of Nano Assessment and Control of Nano Materials at CNMS Materials at CNMS NSRC Symposium NSRC...

248

Evaluation of Electric Field Exposure Assessment Methods  

Science Conference Proceedings (OSTI)

This evaluation of electric field exposure assessment methods highlights a renewed interest in characterizing electric field exposures and their attendant perceptible nuisance shocks.

2008-09-26T23:59:59.000Z

249

Gamma-Ray Bursts and Particle Astrophysics  

E-Print Network (OSTI)

Gamma-ray bursts are violent events occurring randomly in the sky. In this review, I will present the fireball model, proposed to explain the phenomenon of gamma-ray bursts. This model has important consequences for the production and observation at Earth of gravitational waves, high energy neutrinos, cosmic rays and high energy photons, and the second part of this review will be focused on these aspects. A last section will briefly discuss the topic of the use of gamma-ray bursts as standard candles and possible cosmological studies.

B. Gendre

2008-07-24T23:59:59.000Z

250

Use-Exposure Relationships of Pesticides for Aquatic Risk Assessment  

E-Print Network (OSTI)

Field-scale environmental models have been widely used in aquatic exposure assessments of pesticides. Those models usually require a large set of input parameters and separate simulations for each pesticide in evaluation. In this study, a simple use-exposure relationship is developed based on regression analysis of stochastic simulation results generated from the Pesticide Root-Zone Model (PRZM). The developed mathematical relationship estimates edge-of-field peak concentrations of pesticides from aerobic soil metabolism half-life (AERO), organic carbon-normalized soil sorption coefficient (KOC), and application rate (RATE). In a case study of California crop scenarios, the relationships explained 90– 95 % of the variances in the peak concentrations of dissolved pesticides as predicted by PRZM simulations for a 30-year period. KOC was identified as the governing parameter in determining the relative magnitudes of pesticide exposures in a given crop scenario. The results of model application also indicated that the effects of chemical fate processes such as partitioning and degradation on pesticide exposure were similar among crop scenarios, while the cross-scenario variations were mainly associated with the landscape characteristics, such as organic carbon contents and curve numbers. With a minimum set of input data, the use-exposure relationships proposed in this study could be used in screening procedures for potential water quality impacts from the off-site movement of pesticides.

Yuzhou Luo; Frank Spurlock; Xin Deng; Sheryl Gill; Kean Goh

2010-01-01T23:59:59.000Z

251

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

SciTech Connect

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

252

Pulsed Gamma-Rays From the Millisecond Pulsar J0030+0451 with the Fermi Large Area Telescope  

SciTech Connect

We report the discovery of gamma-ray pulsations from the nearby isolated millisecond pulsar PSR J0030+0451 with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). This discovery makes PSR J0030+0451 the second millisecond pulsar to be detected in gamma-rays after PSR J0218+4232, observed by the EGRET instrument on the Compton Gamma Ray Observatory. The spin-down power {dot E} = 3.5 x 10{sup 33} ergs s{sup -1} is an order of magnitude lower than the empirical lower bound of previously known gamma-ray pulsars. The emission profile is characterized by two narrow peaks, respectively 0.07 {+-} 0.01 and 0.08 {+-} 0.02 wide, separated by 0.44 {+-} 0.02 in phase. The first gamma-ray peak falls 0.15 {+-} 0.01 after the main radio peak. The pulse shape is similar to that of the 'normal' gamma-ray pulsars. An exponentially cut-off power-law fit of the emission spectrum leads to an integral photon flux above 100 MeV of (6.76 {+-} 1.05 {+-} 1.35) x 10{sup -8} cm{sup -2} s{sup -1} with cut-off energy (1.7 {+-} 0.4 {+-} 0.5) GeV. Based on its parallax distance of (300 {+-} 90) pc, we obtain a gamma-ray efficiency L{sub {gamma}}/{dot E} {approx_equal} 15% for the conversion of spin-down energy rate into gamma-ray radiation, assuming isotropic emission.

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M. /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Battelino, M.; /Stockholm U., OKC /Royal Inst. Tech., Stockholm; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /LPCE, Orleans /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /ASDC, Frascati /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Trieste /Hiroshima U.; /more authors..

2011-11-17T23:59:59.000Z

253

Results from the Milagro Gamma-Ray Observatory  

E-Print Network (OSTI)

V energies, and a search for transient emission above 100 GeV from gamma-ray bursts. 1 Introduction remnants and gamma-ray bursts (GRB). Gamma rays are also produced when high-energy cosmic rays interactResults from the Milagro Gamma-Ray Observatory E. Blaufuss for the Milagro Collaboration a,1 , a

California at Santa Cruz, University of

254

The Biggest Bangs The Mystery of Gamma-Ray Bursts,  

E-Print Network (OSTI)

Physique www.sciencedirect.com Gamma-ray burst studies in the SVOM era / �tude des sursauts gamma à l s t r a c t Article history: Available online 13 April 2011 Keywords: Gamma-rays, bursts Stars Black by Elsevier Masson SAS. All rights reserved. 1. Introduction The field of gamma-ray bursts (GRBs) has rapidly

Katz, Jonathan I.

255

Fission neutron/gamma irradiation of Bacillus thuringiensis bacteria at the Texas A&M University Nuclear Science Center Reactor  

E-Print Network (OSTI)

The objective of this research is to fully characterize the effectiveness of the Texas A&M University Nuclear Science Center Reactor (TAMU NSCR) neutrons for bacterial sterilization, and to assess the secondary gamma flux produced when neutrons collide with nuclei in biological materials. Sterilization of bacteria by exposure to gamma rays and charged particles is fairly well understood. Exposure to neutrons and gamma rays from fission as a means of sterilization has not to date been adequately characterized. The lack of data on the relationship between biological detriment resulting from thermal or fast neutron exposures and absorbed doses as applied in countermeasures to weapons of mass destruction (WMD) is the primary motivation for this investigation of neutron doses to endospores. Bacillus thuringiensis (Bt) spores were irradiated after producing and sampling them using standard microbiological procedures. Irradiation was accomplished using neutrons and gamma rays from the 1-MW TRIGA reactor at the TAMU NSCR using a reactor power of 100 kilowatts (kW). The combination of neutron and gamma-ray absorbed dose provided an effective means of sterilization of these types of spores; it yielded a 100-percent kill for the first study. Survival curves have been developed, from subsequent experiments, for these energy dependent neutron interactions with biological materials using a combination of radiation dosimetry, microbiological culture techniques, and computer modeling (Monte Carlo Neutral Particle history modeling - MCNP). Survival curves indicate a D?? value of 321.08 Gy. Additional work is needed to investigate the specific bacteria used in biological weapons in order to understand agent-specific radiation sensitivity. Once this is done, more effective and meaningful experiments can be conducted in order to tailor the neutron source strength to the robustness of the threat.

Hearnsberger, David Wayne

2001-01-01T23:59:59.000Z

256

On the Bimodal Distribution of Gamma-Ray Bursts  

E-Print Network (OSTI)

Kouveliotou et al. (1993) recently confirmed that gamma-ray bursts are bimodal in duration. In this paper we compute the statistical properties of the short ($\\le 2$~s) and long ($>2$~s) bursts using a method of analysis that makes no assumption regarding the location of the bursts, whether in the Galaxy or at a cosmological distance. We find the 64 ms channel on BATSE to be more sensitive to short bursts and the 1024 ms channel is more sensitive to long bursts. We show that all the currently available data are consistent with the simple hypothesis that both short and long bursts have the same spatial distribution and that within each population the sources are standard candles. The rate of short bursts is $\\sim 0.4$ of the rate of long bursts. Although the durations of short and long gamma-ray bursts span several orders of magnitude and the total energy of a typical short burst is smaller than that of a typical long burst by a factor of $\\sim 20$, surprisingly the peak luminosities of the two kinds of bursts are equal to within a factor of $\\sim 2$.

Shude Mao; Ramesh Narayan; Tsvi Piran

1993-04-16T23:59:59.000Z

257

Mining Gamma-Ray Burst Data  

E-Print Network (OSTI)

Gamma-ray bursts provide what is probably one of the messiest of all astrophysical data sets. Burst class properties are indistinct, as overlapping characteristics of individual bursts are convolved with effects of instrumental and sampling biases. Despite these complexities, data mining techniques have allowed new insights to be made about gamma-ray burst data. We demonstrate how data mining techniques have simultaneously allowed us to learn about gamma-ray burst detectors and data collection, cosmological effects in burst data, and properties of burst subclasses. We discuss the exciting future of this field, and the web-based tool we are developing (with support from the NASA AISR Program). We invite others to join us in AI-guided gamma-ray burst classification (http://grb.mnsu.edu/grb/).

Jon Hakkila; Richard J. Roiger; David J. Haglin; Robert S. Mallozzi; Geoffrey N. Pendleton; Charles A. Meegan

2000-11-30T23:59:59.000Z

258

Gravitational waves and gamma-ray bursts  

E-Print Network (OSTI)

Gamma-Ray Bursts are likely associated with a catastrophic energy release in stellar mass objects. Electromagnetic observations provide important, but indirect information on the progenitor. On the other hand, gravitational waves emitted from the central source, carry direct information on its nature. In this context, I give an overview of the multi-messenger study of gamma-ray bursts that can be carried out by using electromagnetic and gravitational wave observations. I also underline the importance of joint electromagnetic and gravitational wave searches, in the absence of a gamma-ray trigger. Finally, I discuss how multi-messenger observations may probe alternative gamma-ray burst progenitor models, such as the magnetar scenario.

Alessandra Corsi; for the LIGO Scientific Collaboration; for the Virgo Collaboration

2012-04-18T23:59:59.000Z

259

Gamma-Ray Pulsar Studies with GLAST  

E-Print Network (OSTI)

Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an extended hiatus between satellite missions, the recently-launched AGILE mission and the upcoming Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) will allow gamma-ray tests of the theoretical models developed based on past discoveries. With its greatly improved sensitivity, better angular resolution, and larger energy reach than older instruments, GLAST LAT should detect dozens to hundreds of new gamma-ray pulsars and measure luminosities, light curves, and phase-resolved spectra with unprecedented resolution. It will also have the potential to find radio-quiet pulsars like Geminga, using blind search techniques. Cooperation with radio and X-ray pulsar astronomers is an important aspect of the LAT team's planning for pulsar studies.

D. J. Thompson

2007-11-27T23:59:59.000Z

260

Current Topics in Gamma-Ray Astrophysics  

Science Conference Proceedings (OSTI)

... into e+–e– pairs ends up as rays. Figure 1 shows a calculation of -ray burst luminosity as ... The integrated energy in gamma-rays from the calculated ...

2000-03-14T23:59:59.000Z

Note: This page contains sample records for the topic "gamma exposure rates" 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 Size Distribution and Stochastic Sampling Errors  

Science Conference Proceedings (OSTI)

A maximum likelihood approach to the application of the gamma size distribution is described and compared with the method of moments approach suggested by Ulbrich. Estimation of distribution parameters based on the maximum likelihood principle ...

Raymond K. W. Wong; Norman Chidambaram

1985-06-01T23:59:59.000Z

262

Gamma-Ray Pulsar Studies With GLAST  

SciTech Connect

Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an extended hiatus between satellite missions, the recently-launched AGILE mission and the upcoming Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) will allow gamma-ray tests of the theoretical models developed based on past discoveries. With its greatly improved sensitivity, better angular resolution, and larger energy reach than older instruments, GLAST LAT should detect dozens to hundreds of new gamma-ray pulsars and measure luminosities, light curves, and phase-resolved spectra with unprecedented resolution. It will also have the potential to find radio-quiet pulsars like Geminga, using blind search techniques. Cooperation with radio and X-ray pulsar astronomers is an important aspect of the LAT team's planning for pulsar studies.

Thompson, D.J.; /NASA, Goddard

2011-11-23T23:59:59.000Z

263

Gravitational waves and short gamma ray bursts.  

E-Print Network (OSTI)

??Short hard gamma-ray bursts (GRB) are believed to be produced by compact binary coalescences (CBC) { either double neutron stars or neutron star{black hole binaries.… (more)

Predoi, Valeriu

2012-01-01T23:59:59.000Z

264

Studying Gamma Ray Bursts from a  

E-Print Network (OSTI)

Studying Gamma Ray Bursts from a new perspective! {... Unraveling some mysteries and adding new Radio Op0cal X-ray Short ( energy -ray photons... ... accompained by a considerable long las0ng emission

Â?umer, Slobodan

265

Diffuse gamma-rays from galactic halos  

E-Print Network (OSTI)

Here we review our current knowledge on diffuse gamma-rays from galactic halos. Estimates of the relative contribution of the various emission processes at low and high latitudes are compared to the data over 6 decades in energy. The observed spectral shape differs from what was expected, especially at ver low and very high energies. In the latter case, above 1 GeV, the sky emission related to gas exceeds the expected pi^0 decay spectrum. At energies below 1 MeV the relatively high gamma-ray intensity indicates at high density of nearly relativistic electrons which would have a strong influence on the energy and ionisation balance of the interstellar medium. Given the EGRET results for the Magellanic Clouds the gamma-ray emissivity in the outer halo is probably small, so that a substantial amount of baryonic dark matter may be hidden at 20-50 kpc radius without inducing observable gamma-ray emission.

M. Pohl

1996-03-12T23:59:59.000Z

266

Can gamma-ray bursts constrain quintessence?  

E-Print Network (OSTI)

Using the narrow clustering of the geometrically corrected gamma-ray energies released by gamma-ray bursts, we investigate the possibility of using these sources as standard candles to probe cosmological parameters such as the matter density Omega_m and the cosmological constant energy density Omega_Lambda. By simulating different samples of gamma-ray bursts, we find that Omega_m can be determined with accuracy ~7% with data from 300 sources. We also show that, if Omega = 1 is due to a quintessence field, some of the models proposed in the literature may be discriminated from a Universe with cosmological constant, by a similar-sized sample of gamma-ray bursts.

T. Di Girolamo; R. Catena; M. Vietri; G. Di Sciascio

2005-04-27T23:59:59.000Z

267

rates | OpenEI  

Open Energy Info (EERE)

rates rates Dataset Summary Description This dataset, compiled by NREL and Ventyx, provides average residential, commercial and industrial electricity rates by zip code for both investor owned utilities (IOU) and non-investor owned utilities. Note: the file includes average rates for each utility, but not the detailed rate structure data found in the database available via the zip-code look-up feature on the OpenEI Utilities page (http://en.openei.org/wiki/Gateway:Utilities). The data was released by NREL/Ventyx in February 2011. Source NREL and Ventyx Date Released February 24th, 2012 (2 years ago) Date Updated Unknown Keywords electric rates rates US utilities Data text/csv icon IOU rates by zipcode (csv, 1.7 MiB) text/csv icon Non-IOU rates by zipcode (csv, 2.1 MiB)

268

Gamma Ray Bursts from Ordinary Cosmic Strings  

E-Print Network (OSTI)

We give an upper estimate for the number of gamma ray bursts from ordinary (non-superconducting) cosmic strings expected to be observed at terrestrial detectors. Assuming that cusp annihilation is the mechanism responsible for the bursts we consider strings arising at a GUT phase transition and compare our estimate with the recent BATSE results. Further we give a lower limit for the effective area of future detectors designed to detect the cosmic string induced flux of gamma ray bursts.

R. H. Brandenberger; A. T. Sornborger; M. Trodden

1993-02-12T23:59:59.000Z

269

Unidentified Gamma-Ray Sources and Microquasars  

E-Print Network (OSTI)

Some phenomenological properties of the unidentified EGRET detections suggest that there are two distinct groups of galactic gamma-ray sources that might be associated with compact objects endowed with relativistic jets. We discuss different models for gamma-ray production in both microquasars with low- and high-mass stellar companions. We conclude that the parent population of low-latitude and halo variable sources might be formed by yet undetected microquasars and microblazars.

G. E. Romero; I. A Grenier; M. M. Kaufman Bernado; I. F. Mirabel; D. F. Torres

2004-02-12T23:59:59.000Z

270

Theoretical Models of Gamma-Ray Bursts  

E-Print Network (OSTI)

Models of gamma ray bursts are reviewed in the light of recent observations of afterglows which point towards a cosmological origin. The physics of fireball shock models is discussed, with attention to the type of light histories and spectra during the gamma-ray phase. The evolution of the remnants and their afterglows is considered, as well as their implications for our current understanding of the mechanisms giving rise to the bursts.

P. Meszaros

1997-11-28T23:59:59.000Z

271

Production of 26Al, 44Ti and 60Fe in Supernovae-sensitivity to the helium burning rates  

E-Print Network (OSTI)

We have studied the sensitivity of supernova production of the gamma emitting nuclei 26Al, 44Ti and 60Fe to variations of the rates of the triple alpha and 12C(alpha, gamma) reactions. Over a range of twice their experimental uncertainties we find variations in the production of 60Fe by more than a factor of five. Smaller variations, about a factor of two to three, were observed for 26Al and 44Ti. The yields of these isotopes change significantly when the abundances of Lodders (2003) are used instead of those of Anders and Grevesse (1989). These sensitivities will limit conclusions based on a comparison of observed gamma ray intensities and stellar models until the helium burning rates are better known. Prospects for improving the helium burning rates are discussed and a new version of the Boyes rate for 12C(alpha, gamma} is presented.

Clarisse Tur; Alexander Heger; Sam M. Austin

2010-12-21T23:59:59.000Z

272

EFFECTS OF TRITIUM GAS EXPOSURE ON THE GLASS TRANSITION TEMPERATURE OF EPDM ELASTOMER AND ON THE CONDUCTIVITY OF POLYANILINE  

Science Conference Proceedings (OSTI)

Four formulations of EPDM (ethylene-propylene diene monomer) elastomer were exposed to tritium gas initially at one atmosphere and ambient temperature for between three and four months in closed containers. Material properties that were characterized include density, volume, mass, appearance, flexibility, and dynamic mechanical properties. The glass transition temperature was determined by analysis of the dynamic mechanical property data per ASTM standards. EPDM samples released significant amounts of gas when exposed to tritium, and the glass transition temperature increased by about 3 C. during the exposure. Effects of ultraviolet and gamma irradiation on the surface electrical conductivity of two types of polyaniline films are also documented as complementary results to planned tritium exposures. Future work will determine the effects of tritium gas exposure on the electrical conductivity of polyaniline films, to demonstrate whether such films can be used as a sensor to detect tritium. Surface conductivity was significantly reduced by irradiation with both gamma rays and ultraviolet light. The results of the gamma and UV experiments will be correlated with the tritium exposure results.

Clark, E; Marie Kane, M

2008-12-12T23:59:59.000Z

273

Buildings Operations and ETS Exposure  

E-Print Network (OSTI)

Mechanical systems are used in buildings to provide conditioned air, dissipate thermal loads, dilute contaminants, and maintain pressure differences. The characteristics of these systems and their operations have implications for the exposures of workers to environmental tobacco smoke (ETS) and for the control of these exposures. This review describes the general features of building ventilation systems and the efficacy of ventilation for controlling contaminant concentrations. Ventilation can reduce the concentration of ETS through dilution, but central heating, ventilating, and air conditioning (HVAC) can also move air throughout a building that has been contaminated by ETS. An understanding of HVAC systems is needed to develop models for exposures of workers to ETS.- Environ Health Perspect 107(Suppl 2):313-317 (1999).

John D. Spengler

1998-01-01T23:59:59.000Z

274

Gamma-ray albedo of the moon  

E-Print Network (OSTI)

We use the GEANT4 Monte Carlo framework to calculate the gamma-ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees with the EGRET data. We show that the spectrum of gamma rays from the Moon is very steep with an effective cutoff around 4 GeV (600 MeV for the inner part of the Moon disc). Apart from other astrophysical sources, the albedo spectrum of the Moon is well understood, including its absolute normalisation; this makes it a useful "standard candle" for gamma-ray telescopes, such as the forthcoming Gamma Ray Large Area Space Telescope (GLAST). The albedo flux depends on the incident CR spectrum which changes over the solar cycle. Therefore, it is possible to monitor the CR spectrum using the albedo gamma-ray flux. Simultaneous measurements of CR proton and helium spectra by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA), and observations of the albedo gamma rays by the GLAST Large Area Telescope (LAT), can be used to test the model predictions and will enable the GLAST LAT to monitor the CR spectrum near the Earth beyond the lifetime of PAMELA.

Igor V. Moskalenko; Troy A. Porter

2007-05-25T23:59:59.000Z

275

{sup 125}I Measurements for Occupational Exposure Assessment  

SciTech Connect

Whenever there is a risk of occupational exposure to dispersible radioactive material, it is necessary to have a monitoring program to assess the effective dose arising from the intake of radionuclides by workers. In this paper we present our experience in bioassay measurements of {sup 125}I in urine samples of workers using high resolution gamma spectrometry. For a 24-hour excretion period, we found activity values of the order of one Bq and estimated the committed effective doses to be less than one {mu}Sv. Although very small, these values led to a re-evaluation and improvement of the laboratory safety conditions. We discuss the calibration procedure followed for the activity measurements, the estimation of the uncertainty in the excreted activity, the calculation of detection and quantification limits and estimation of performance indicators. Aspects regarding the spectral analysis, true coincidence summing and matrix effects are also considered.

Silva, L.; Pinhao, N. R. [Department of Radiological Protection and Nuclear Safety, ITN-Nuclear and Technological Institute, Estrada Nacional N 10, 2686-953 Sacavem (Portugal)

2008-08-14T23:59:59.000Z

276

Occupational Radiation Exposure Analysis of US ITER DCLL TBM  

Science Conference Proceedings (OSTI)

This report documents an Occupational Radiation Exposure (ORE) analysis that was performed for the US International Thermonuclear Experimental Reactor (ITER) Dual Coolant Lead Lithium (DCLL) Test Blanket Module (TBM). This analysis was performed with the QADMOD dose code for anticipated maintenance activities for this TBM concept and its ancillary systems. The QADMOD code was used to model the PbLi cooling loop of this TBM concept by specifying gamma ray source terms that simulated radioactive material within the piping, valves, heat exchanger, permeator, pump, drain tank, and cold trap of this cooling system. Estimates of the maintenance tasks that will have to be performed and the time required to perform these tasks where developed based on either expert opinion or on industrial maintenance experience for similar technologies. This report details the modeling activity and the calculated doses for the maintenance activities envisioned for the US DCLL TBM.

Merrill, Brad J; Cadwallader, Lee C; Dagher, Mohamad

2007-08-01T23:59:59.000Z

277

Fireball/Blastwave Model and Soft Gamma-ray Repeaters  

E-Print Network (OSTI)

Soft gamma-ray repeaters are at determined distances and their positions are known accurately. If observed, afterglows from their soft gamma-ray bursts will provide important clues to the study of the so called "classical gamma-ray bursts". On applying the popular fireball/blastwave model of classical gamma-ray bursts to soft gamma-ray repeaters, it is found that their X-ray and optical afterglows are detectable. Monitoring of the three repeaters is solicited.

Y. F. Huang; Z. G. Dai; T. Lu

1998-10-28T23:59:59.000Z

278

Historical Interest Rates  

NLE Websites -- All DOE Office Websites (Extended Search)

Current and Historical Interest Rates Current and Historical Interest Rates The table lists interest rates, from the project's inception through the present, for all projects with repayment supervised by the CRSP MC. The latest available interest rate is used for all future interest rate calculations. The Amistad-Falcon, Collbran, Provo River, and Rio Grande Projects are all assigned the average daily "Yield Rate" calculated by the U.S. Treasury, on an annual basis, for Treasury bonds having terms of 15 years or more remaining to maturity. The calculated yield rate is rounded to the nearest one-eighth of one percent. The yield rate is based upon the bond's interest rate, as well as its market value. The Colorado River Storage Project and its participating projects, Dolores and Seedskadee, are assigned the average daily "Coupon Rate," annualized for the same U.S. Treasury bonds used in "Yield Rate" calculations. The coupon rate is the interest rate that the bond carries upon its face.

279

Gamma Log At Fort Bliss Area (Combs, Et Al., 1999) | Open Energy  

Open Energy Info (EERE)

Fort Bliss Area (Combs, Et Al., 1999) Fort Bliss Area (Combs, Et Al., 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Gamma Log At Fort Bliss Area (Combs, Et Al., 1999) Exploration Activity Details Location Fort Bliss Area Exploration Technique Gamma Log Activity Date Usefulness not indicated DOE-funding Unknown Notes Three principal types of data were obtained from this drilling project: core samples of the lithology penetrated by the holes, records of drilling behavior (such as water level in the hole, changes in rate of penetration etc.), and multiple temperature logs (both during and after drilling) in each well. A suite of geophysical logs (gamma ray, neutron, sonic, and resistivity) was also run after completion of drilling. References Jim Combs, John T. Finger, Colin Goranson, Charles E. Hockox Jr.,

280

Tracking the Libor Rate  

E-Print Network (OSTI)

Paper 1108R2 Paper 1108R) Tracking the Libor Rate Rosa M.revision 2013 by author(s). Tracking the Libor Rate Rosa M.providing a methodology for tracking the dynamic integrity

Abrantes-Metz, Rosa; Villas-Boas, Sofia B.; Judge, George G.

2013-01-01T23:59:59.000Z

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281

2009 Rate Adjustments  

NLE Websites -- All DOE Office Websites (Extended Search)

provisional rates will be in effect until the Federal Energy Regulatory Commission (FERC) confirms and approves them on a final basis or until they are replaced by other rates....

282

Mouse heart rate  

NLE Websites -- All DOE Office Websites (Extended Search)

Mouse heart rate Name: amj Status: NA Age: NA Location: NA Country: NA Date: Around 1993 Question: Is it possible to get the heart rate of a mouse without special equipment?...

283

Dynamics of heart rate  

Science Conference Proceedings (OSTI)

Heart rate oscillates on several different time scales and has long?term variability in the form of 1/fnoise. The physiological control of heart rate is briefly reviewed

Daniel T. Kaplan; Mario Talajic

1991-01-01T23:59:59.000Z

284

SENSITIVITY OF ASTROPHYSICAL REACTION RATES TO NUCLEAR UNCERTAINTIES  

Science Conference Proceedings (OSTI)

Sensitivities of nuclear reaction rates to a variation of nuclear properties are studied. Target nuclei range from proton- to neutron dripline for 10 {<=} Z {<=} 83. Reactions considered are nucleon- and {alpha}-induced reactions mediated by strong interaction. The contribution of reactions occurring on the target ground state to the total stellar rate is also given. General dependencies on various input quantities are discussed. Additionally, sensitivities of laboratory cross-sections of nucleon-, {alpha}-, and {gamma}-induced reactions are shown, allowing us to estimate the impact of cross-section measurements. Finally, recommended procedures to explore and improve reaction rate uncertainties using the present sensitivity data are outlined.

Rauscher, T. [Department of Physics, University of Basel, CH-4056 Basel (Switzerland)

2012-08-01T23:59:59.000Z

285

EMDEX (Electric and Magnetic Field Digital EXposure) system manuals  

Science Conference Proceedings (OSTI)

The EPRI Electric and Magnetic Field Digital EXposure (EMDEX) system consists of hardware and software for characterizing electric and magnetic field exposures. The EMDEX meter is a computer-based portable unit that samples, at a user-programmable rate, the three vector components of magnetic flux density, a measure of the average electric field acting on the torso of the wearer (if an optional sensor is worn) and a measure of rotational motion of the meter in the earth's magnetic field. Modules of the DATACALC software package are used to program the EMDEX, retrieve data at the end of a measurement session, analyze EMDEX data, and prepare tabular and graphical data summaries. The User Manual is designed to provide instruction on the use of the exposure system hardware and software. The Technical Reference Manual provides additional, detailed descriptions of the hardware, software and methodologies used in the EMDEX system.

Not Available

1989-10-01T23:59:59.000Z

286

THE NEW CANGAROO TELESCOPE AND THE PROSPECT OF VHE GAMMA RAY OBSERVATION AT  

E-Print Network (OSTI)

GammaWhat about Gamma--Ray Bursts?Ray Bursts? Extremely powerful explosions happen in galaxies The Quest for Gamma Rays:The Quest for Gamma Rays: Exploring the Most Violent PlacesExploring the Most is gammaWhat is gamma--ray background light like?ray background light like? How diffuse is the gamma

Enomoto, Ryoji

287

Gamma-Ray Bursts as a Cosmic Window for Galaxy Evolution  

E-Print Network (OSTI)

Present knowledge indicates that gamma-ray bursts are linked with massive stars. They will become invaluable probes of the early universe and galaxy formation. In the future, it will be possible to use gamma-ray bursts for two purposes: 1) to probe the history of massive star formation in the Universe by the rate of occurence of gamma-ray bursts, and 2) for the study of galaxy evolution at all lookback times by determining the nature of the galaxy hosts. Because gamma-rays are not attenuated by intervening dust and gas, the selection of the cosmic sites of massive star formation by this method is less affected by the biases associated with optical-uv surveys (e.g. UV-dropout techniques). Infrared and sub-millimeter follow up studies of the hosts of gamma-ray bursts may: 1) reveal a putative population of reddened ($R-K \\geq 4$) galaxies at high redshifts, and 2) detect very massive stars (population III) formed at $z \\geq$ 5.

I. F. Mirabel; D. B. Sanders; E. Le Floc'h

2000-04-03T23:59:59.000Z

288

Human exposure through food chains:  

Science Conference Proceedings (OSTI)

Using information collected under the community right to know'' provision of the Superfund reauthorization act, the US Environmental Protection Agency has revealed that some two to three billion pounds of toxic chemicals are released annually to the atmosphere from industries in the US. Human populations can contact these environmental pollutants through food, water, and air in varying amounts each day throughout a lifetime. A realistic strategy for managing the potential health risks of industrial emissions requires a comprehensive approach with adequate attention to uncertainties. Using contaminant transfers from air to milk and as a case study, I consider here two important issues in exposure assessment --- (1) estimation of and (2) reduction of uncertainty in exposure estimates. This case study provides a distinction between variability, ignorance and uncertainty. For the air/milk pathways, I explore the use of exposure models that combine information on environmental partitioning with data on human diet, behavior patterns, and physiology into a numerical expression that links ambient air concentrations with chronic daily intake. I examine how uncertainty limits current exposure modeling efforts and suggest research to reduce these uncertainty. 17 refs., 12 figs., 1 tab.

McKone, T.E.

1990-02-01T23:59:59.000Z

289

Verification of the content, isotopic composition and age of plutonium in Pu-Be neutron sources by gamma-spectrometry  

E-Print Network (OSTI)

A non-destructive, gamma-spectrometric method for verifying the plutonium content of Pu-Be neutron sources has been developed. It is also shown that the isotopic composition and the age of plutonium (Pu) can be determined in the intensive neutron field of these sources by the ``Multi-Group Analysis'' method. Gamma spectra were taken in the far-field of the sample, which was assumed to be cylindrical. The isotopic composition and the age of Pu were determined using a commercial implementation of the Multi-Group Analysis algorithm. The Pu content of the sources was evaluated from the count rates of the gamma-peaks of 239Pu, relying on the assumption that the gamma-rays are coming to the detector parallel to each other. The determination of the specific neutron yields and the problem of neutron damage to the detector are also discussed.

Nguyen, C T

2006-01-01T23:59:59.000Z

290

Verification of the content, isotopic composition and age of plutonium in Pu-Be neutron sources by gamma-spectrometry  

E-Print Network (OSTI)

A non-destructive, gamma-spectrometric method for verifying the plutonium content of Pu-Be neutron sources has been developed. It is also shown that the isotopic composition and the age of plutonium (Pu) can be determined in the intensive neutron field of these sources by the ``Multi-Group Analysis'' method. Gamma spectra were taken in the far-field of the sample, which was assumed to be cylindrical. The isotopic composition and the age of Pu were determined using a commercial implementation of the Multi-Group Analysis algorithm. The Pu content of the sources was evaluated from the count rates of the gamma-peaks of 239Pu, relying on the assumption that the gamma-rays are coming to the detector parallel to each other. The determination of the specific neutron yields and the problem of neutron damage to the detector are also discussed.

Cong Tam Nguyen

2005-08-29T23:59:59.000Z

291

Exclusive search for Higgs boson to gamma-gamma decay via vector boson fusion production mechanism  

E-Print Network (OSTI)

We perform an exclusive search for the Higgs boson to gamma-gamma decay via vector boson fusion. We utilize the characteristic features of vector boson fusion, such as the di-jet [Delta][eta] and mass, as well as the ...

Rankin, Dylan Sheldon

2012-01-01T23:59:59.000Z

292

Characterization of the unfolding, refolding, and aggregation pathways of two protein implicated in cataractogenesis : human gamma D and human gamma S crystallin  

E-Print Network (OSTI)

Human [gamma]D crystallin (H[gamma]D-Crys) and human [gamma]S crystallin (H[gamma]S-Crys), are major proteins of the human eye lens and are components of cataracts. H[gamma]D-Crys is expressed early in life in the lens ...

Kosinski-Collins, Melissa Sue, 1978-

2005-01-01T23:59:59.000Z

293

Observation of the Crab Nebula in Soft Gamma Rays with the Nuclear Compton Telescope  

E-Print Network (OSTI)

Gamma-ray bursts . . . . . . . . . . . . . . . . . . . 1.268] G. J. Fishman. The gamma-ray burst capabilities of BATSEOlson. Observations of Gamma- Ray Bursts of Cosmic Origin.

Bandstra, Mark ShenYu

2010-01-01T23:59:59.000Z

294

Bremsstrahlung gamma rays from light Dark Matter  

E-Print Network (OSTI)

We discuss the often-neglected role of bremsstrahlung processes on the interstellar gas in computing indirect signatures of Dark Matter (DM) annihilation in the Galaxy, particularly for light DM candidates in the phenomenologically interesting O(10) GeV mass range. Especially from directions close to the Galactic Plane, the expected gamma-ray spectrum is altered via two effects: directly, by the photons emitted in the bremsstrahlung process on the interstellar gas by energetic electrons which are among the DM annihilation byproducts; indirectly, by the modification of the same electron spectrum, due to the additional energy loss process in the diffusion-loss equation (e.g. the resulting inverse Compton emission is altered). We quantify the importance of the bremsstrahlung emission in the GeV energy range, showing that it is the dominant component of the gamma-ray spectrum for some cases. We also find that, in regions in which bremsstrahlung dominates energy losses, the related gamma-ray emission is only moderately sensitive to possible large variations in the gas density. Still, we stress that, for computing precise spectra in the (sub-)GeV range, it is important to obtain a reliable description of the inner Galaxy gas distribution as well as to compute self-consistently the gamma emission and the solution to the diffusion-loss equation. For example, these are crucial issues to quantify and interpret meaningfully gamma-ray map `residuals' in terms of (light) DM annihilations.

Marco Cirelli; Pasquale D. Serpico; Gabrijela Zaharijas

2013-07-26T23:59:59.000Z

295

About the Ratings  

NLE Websites -- All DOE Office Websites (Extended Search)

2008 Ratings Changes 2008 Ratings Changes EPA's "New" Fuel Economy Ratings Video about EPA's New Fuel Economy Ratings Windows Media Video (6.8 MB) Quicktime Video (7.8 MB) Text Version EPA changed the way it estimates fuel economy starting with the 2008 model year. This "new" way of estimating fuel economy supplements the previous method by incorporating the effects of Faster speeds and acceleration Air conditioner use Colder outside temperatures What else do I need to know about the "new" ratings? The tests lower MPG estimates for most vehicles. View old/new MPG ratings for a specific vehicle The actual mileage you get will still vary based on your driving habits, traffic conditions, and other factors. All MPG estimates in Find-a-Car have been converted to the new

296

FIGARO : detecting nuclear materials using high-energy gamma rays for oxygen.  

SciTech Connect

Potential diversion of nuclear materials is a major international concern. Fissile (e.g., U, Pu) and other nuclear materials (e.g., D, Be) can be detected using 6-7 MeV gamma rays produced in the {sup 19}F(p,{alpha}{gamma}){sup 16}O reaction. These gamma rays will induce neutron emission via the photoneutron and photofission processes in nuclear materials. However, they are not energetic enough to generate significant numbers of neutrons from most common benign materials, thereby reducing the false alarm rate. Neutrons are counted using an array of BF3 counters in a polyethylene moderator. Experiments have shown a strong increase in neutron count rates for depleted uranium, Be, D{sub 2}O, and {sup 6}Li, and little or no increase for other materials (e.g., H{sub 2}O, SS, Cu, Al, C, {sup 7}Li). Gamma source measurements using solid targets of CaF{sub 2} and MgF{sub 2} and a SF{sub 6} gas target show that proton accelerator of 3 MeV and 10-100 microampere average current could lead to acceptable detection sensitivity.

Michlich, B. J.; Smith, D. L.; Massey, T. N.; Ingram, D.; Fessler, A.

2000-10-10T23:59:59.000Z

297

Effective Rate Period  

NLE Websites -- All DOE Office Websites (Extended Search)

Fiscal Year 2014 Fiscal Year 2014 Effective Rate Period As of Beginning of the FY 10/01/2013 - 09/30/2014 Mid-Year Changes (if applicable) 10/01/2013 - 09/30/2014 Power Rates Annual Revenue Requirement Rate Schedule Power Revenue Requirement $73,441,557 CV-F13 Base Resource Revenue Requirement $69,585,875 First Preference Revenue Requirement $3,855,682

298

High Redshift Supernova Rates  

E-Print Network (OSTI)

We use a sample of 42 supernovae detected with the Advanced Camera for Surveys on-board the Hubble Space Telescope as part of the Great Observatories Origins Deep Survey to measure the rate of core collapse supernovae to z~0.7 and type Ia supernovae to z~1.6. This significantly increases the redshift range where supernova rates have been estimated from observations. The rate of core collapse supernovae can be used as an independent probe of the cosmic star formation rate. Based on the observations of 17 core collapse supernovae, we measure an increase in the core collapse supernova rate by a factor of 1.6 in the range 0.3rate. The increase in the rate in this redshift range in consistent with recent measurements of the star formation rate derived from UV-luminosity densities and IR datasets. Based on 25 type Ia supernovae, we find a SN Ia rate that is a factor 3-5 higher at z~1 compared to earlier estimates at lower redshifts (zrate traces a higher star formation rate at redshifts z>1 compared to low redshift. At higher redshift (z>1), we find a suggested decrease in the type Ia rate with redshift. This evolution of the Ia rate with redshift is consistent with a type Ia progenitor model where there is a substantial delay between the formation of the progenitor star and the explosion of the supernova. Assuming that the type Ia progenitor stars have initial main sequence masses 3-8 M_Sun, we find that 5-7% of the available progenitors explode as type Ia supernovae.

Tomas Dahlen; Louis-Gregory Strolger; Adam G. Riess; Bahram Mobasher; Ranga-Ram Chary; Christopher J. Conselice; Henry C. Ferguson; Andrew S. Fruchter; Mauro Giavalisco; Mario Livio; Piero Madau; Nino Panagia; John L. Tonry

2004-06-24T23:59:59.000Z

299

Estimating the exposure to first receivers from a contaminated victim of a radiological dispersal device detonation  

E-Print Network (OSTI)

The threat of a Radiological Dispersal Device (RDD) detonation arouses the concern of contaminated victims of all ages. The purpose of this study was to investigate the dose to a uniformly contaminated five-year old male. It also explores the exposure rates surrounding the victim to be used by first receivers to estimate their exposure from the victim. The victim was modeled as an anthropomorphic phantom using the BodyBuilder program. A thin layer of source material was added to the surface of the phantom’s skin to simulate whole-body contamination. The computer code MCNP5 was used to tally the doses to the individual organs of the phantom and create a mesh to generate contour exposure rate lines. Using an activity of 37 GBq m-2, the five-year-old victim received an effective dose 158.23 mSv in one hour. Contour lines were produced that showed the exposure rates around the victims ranging from 0.5 to 10 R/h. The contour exposure-rate contour lines were also generated after the removal of contaminated clothing. Removing the victim’s clothing reduced the exposure rates by eighty percent.

Phillips, Holly Anne

2008-08-01T23:59:59.000Z

300

Rate Schedule CPP-2  

NLE Websites -- All DOE Office Websites (Extended Search)

or rate schedule accepted or approved by the Federal Energy Regulatory Commission (FERC) or other regulatory bodies will be passed on to each relevant customer. The FERC's or...

Note: This page contains sample records for the topic "gamma exposure rates" 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.


301

Fermi Observations of Gamma-ray Bursts  

SciTech Connect

The gamma-ray emission mechanism of Gamma-ray bursts (GRBs) are still unknown. Fermi Gamma-ray Space Telescope successfully detected high-energy (> 100 MeV) emission from 17 GRBs since its launch. Fermi revealed the distinct temporal behaviors and extra spectral component from high-energy emission. These new observational results are driving many theoretical implications, such as leptonic, hadronic and afterglow origin. The highest energy photon detected by Fermi gives a constraint on the bulk Lorentz factor of the ultra-relativistic jets of GRBs. The impact of the Fermi GRB observations extends not only to the GRB-related issues but also to the outside GRB physics, such as quantum gravity and model of the extra galactic background light.

Ohno, Masanori [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

2010-10-15T23:59:59.000Z

302

Apparatus and method for detecting gamma radiation  

DOE Patents (OSTI)

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

Sigg, Raymond A. (Martinez, GA)

1994-01-01T23:59:59.000Z

303

Gamma-Ray Bursts: Jets and Energetics  

E-Print Network (OSTI)

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

D. A. Frail

2003-11-12T23:59:59.000Z

304

VHE Gamma-ray Supernova Remnants  

SciTech Connect

Increasing observational evidence gathered especially in X-rays and {gamma}-rays during the course of the last few years support the notion that Supernova remnants (SNRs) are Galactic particle accelerators up to energies close to the ''knee'' in the energy spectrum of Cosmic rays. This review summarizes the current status of {gamma}-ray observations of SNRs. Shell-type as well as plerionic type SNRs are addressed and prospect for observations of these two source classes with the upcoming GLAST satellite in the energy regime above 100 MeV are given.

Funk, Stefan; /KIPAC, Menlo Park

2007-01-22T23:59:59.000Z

305

A Shotgun Model for Gamma Ray Bursts  

E-Print Network (OSTI)

We propose that gamma ray bursts (GRBs) are produced by a shower of heavy blobs running into circumstellar material at highly relativistic speeds. The gamma ray emission is produced in the shocks these bullets drive into the surrounding medium. The short term variability seen in GRBs is set by the slowing-down time of the bullets while the overall duration of the burst is set by the lifetime of the central engine. A requirement of this model is that the ambient medium be dense, consistent with a strong stellar wind. The efficiency of the burst can be relatively high.

S. Heinz; M. C. Begelman

1999-08-03T23:59:59.000Z

306

Redshift indicators for gamma-ray bursts  

E-Print Network (OSTI)

The measure of the distances and luminosities of gamma-ray bursts (GRBs) led to the discovery that many GRB properties are strongly correlated with their intrinsic luminosity, leading to the construction of reliable luminosity indicators. These GRB luminosity indicators have quickly found applications, like the construction of 'pseudo-redshifts', or the measure of luminosity distances, which can be computed independently of the measure of the redshift. In this contribution I discuss various issues connected with the construction of luminosity-redshift indicators for gamma-ray bursts.

J-L. Atteia

2005-05-04T23:59:59.000Z

307

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

2004-03-22T23:59:59.000Z

308

Status of the Milagro $\\gamma$ Ray Observatory  

E-Print Network (OSTI)

The Milagro Gamma Ray Observatory is the world's first large-area water Cherenkov detector capable of continuously monitoring the sky at TeV energies. Located in northern New Mexico, Milagro will perform an all sky survey of the Northern Hemisphere at energies between ~250 GeV and 50 TeV. With a high duty cycle, large detector area (~5000 square meters), and a wide field-of-view (~1 sr), Milagro is uniquely capable of searching for transient and DC sources of high-energy gamma-ray emission. Milagro has been operating since February, 1999. The current status of the Milagro Observatory and initial results will be discussed.

Atkins, R; Berley, D; Chen, M L; Coyne, D G; Delay, R S; Dingus, B L; Dorfan, D E; Ellsworth, R W; Evans, D; Falcone, A D; Fleysher, L; Fleysher, R; Gisler, G; Goodman, J A; Haines, T J; Hoffman, C M; Hugenberger, S; Kelley, L A; Leonor, I; Macri, J R; McConnell, M; McCullough, J F; McEnery, J E; Miller, R S; Mincer, A I; Morales, M F; Némethy, P; Ryan, J M; Schneider, M; Shen, B; Shoup, A L; Sinnis, G; Smith, A J; Sullivan, G W; Thompson, T N; Tümer, T O; Wang, K; Wascko, M O; Westerhoff, S; Williams, D A; Yang, T; Yodh, G B

2001-01-01T23:59:59.000Z

309

Exchange Rates and Fundamentals  

E-Print Network (OSTI)

We show analytically that in a rational expectations present-value model, an asset price manifests near–random walk behavior if fundamentals are I(1) and the factor for discounting future fundamentals is near one. We argue that this result helps explain the well-known puzzle that fundamental variables such as relative money supplies, outputs, inflation, and interest rates provide little help in predicting changes in floating exchange rates. As well, we show that the data do exhibit a related link suggested by standard models—that the exchange rate helps predict these fundamentals. The implication is that exchange rates and fundamentals are linked in a way that is broadly consistent with asset-pricing models of the exchange rate. I.

Charles Engel; Kenneth D. West

2005-01-01T23:59:59.000Z

310

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

311

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

E-Print Network (OSTI)

The dissolution of the Soviet Union coupled with the growing sophistication of international terror organizations has brought about a desire to ensure that a sound infrastructure exists to interdict smuggled nuclear material prior to leaving its country of origin. To combat the threat of nuclear trafficking, radiation portal monitors (RPMs) are deployed around the world to intercept illicit material while in transit by passively detecting gamma and neutron radiation. Portal monitors in some 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 undetected. This work is focused on understanding the influence of the concrete surrounding the monitors on the total gamma ray background for the system. This research employed a combination of destructive and nondestructive analytical techniques with computer simulations to form a model that may be adapted to any RPM configuration. Six samples were taken from three different composition concrete slabs. The natural radiologcal background of these samples was determined using a high-purity germanium (HPGe) detector in conjunction with the Canberra In-Situ Object Counting System (ISOCS™) and Genie™ 2000 software packages. The composition of each sample was determined using thermal and fast neutron activation analysis (NAA) techniques. The results from these experiments were incorporated into a Monte Carlo N-Particle (MNCP) photon transport simulation to determine the expected gamma ray count rate in the RPM due to the concrete. The results indicate that a quantitative estimate may be possible if the experimental conditions are optimized to eliminate sources of uncertainty. Comparisons of actual and simulated count rate data for 137Cs check sources showed that the model was accurate to within 15%. A comparison of estimated and simulated count rates in one concrete slab showed that the model was accurate to within 4%. Subsequent sensitivity analysis showed that if the elemental concentrations are well known, the carbon and hydrogen content could be easily estimated. Another sensitivity analysis revealed that the small fluctuations in density have a minimal impact on the gamma count rate. The research described by this thesis provides a method by which RPM end users may quantitatively estimate the expected gamma background from concrete foundations beneath the systems. This allows customers to adjust alarm thresholds to compensate for the elevated background due to the concrete, thereby increasing the probability of intercepting illicit radiological and nuclear material.

Ryan, Christopher Michael

2011-05-01T23:59:59.000Z

312

NREL: Technology Transfer - Materials Exposure Testing Market ...  

National Renewable Energy Laboratory Technology Transfer Materials Exposure Testing Market Expands with Ultra-Accelerated Weathering System

313

SLAC National Accelerator Laboratory - Fermi Sees Record Gamma...  

NLE Websites -- All DOE Office Websites (Extended Search)

Fermi Sees Record Gamma-ray Burst May 3, 2013 A record-setting blast of gamma rays from a dying star in a distant galaxy has wowed astronomers around the world. The eruption, which...

314

Evaluation of Occupational Magnetic Field Exposure Guidelines  

Science Conference Proceedings (OSTI)

As a first step in assessing potential effects of EMF exposure guidelines on utility operations, EPRI sponsored a technical evaluation of the major occupational EMF exposure guidelines and an analysis of existing magnetic-field exposure databases. The research reported herein is a comprehensive extension of that work, that includes studies by several research groups on diverse topics related to guidelines.

1998-12-15T23:59:59.000Z

315

Mechanism of the efficient quenching of tryptophan fluorescence in human gamma crystallin  

E-Print Network (OSTI)

Quenching of the fluorescence of buried tryptophans (Trps) is an important reporter of protein conformation. Human [gamma]D-crystallin (H[gamma]D-Crys) and human [gamma]S-crystallin (H[gamma]S-Crys) are both very stable ...

Chen, Jiejin, Ph. D. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

316

Quantifying the Luminosity Evolution in Gamma-ray Bursts  

E-Print Network (OSTI)

We estimate the luminosity evolution and formation rate for over 900 GRBs by using redshift and luminosity data calculated by Band, Norris, $&$ Bonnell (2004) via the lag-luminosity correlation. By applying maximum likelihood techniques, we are able to infer the true distribution of the parent GRB population's luminosity function and density distributions in a way that accounts for detector selection effects. We find that after accounting for data truncation, there still exists a significant correlation between the average luminosity and redshift, indicating that distant GRBs are on average more luminous than nearby counterparts. This is consistent with previous studies showing strong source evolution and also recent observations of under luminous nearby GRBs. We find no evidence for beaming angle evolution in the current sample of GRBs with known redshift, suggesting that this increase in luminosity can not be due to an evolution of the collimation of gamma-ray emission. The resulting luminosity function...

Kocevski, D; Kocevski, Daniel; Liang, Edison

2006-01-01T23:59:59.000Z

317

Polarized Gravitational Waves from Gamma-Ray Bursts  

E-Print Network (OSTI)

Significant gravitational wave emission is expected from gamma-ray bursts arising from compact stellar mergers, and possibly also from bursts associated with fast-rotating massive stellar core collapses. These models have in common a high angular rotation rate, and observations provide evidence for jet collimation of the photon emission, with properties depending on the polar angle, which may also be of relevance for X-ray flashes. Here we consider the gravitational wave emission and its polarization as a function of angle which is expected from such sources. We discuss possible correlations between the burst photon luminosity, or the delay between gravitational wave bursts and X-ray flashes, and the polarization degree of the gravitational waves.

Shiho Kobayashi; Peter Meszaros

2002-12-25T23:59:59.000Z

318

General Relativistic Binary Merger Simulations and Short Gamma Ray Bursts  

E-Print Network (OSTI)

The recent localization of some short-hard gamma ray bursts (GRBs) in galaxies with low star formation rates has lent support to the suggestion that these events result from compact object binary mergers. We discuss how new simulations in general relativity are helping to identify the central engine of short-hard GRBs. Motivated by our latest relativistic black hole-neutron star merger calculations, we discuss a scenario in which these events may trigger short-hard GRBs, and compare this model to competing relativistic models involving binary neutron star mergers and the delayed collapse of hypermassive neutron stars. Distinguishing features of these models may help guide future GRB and gravitational wave observations to identify the nature of the sources.

Joshua A. Faber; Thomas W. Baumgarte; Stuart L. Shapiro; Keisuke Taniguchi

2006-03-10T23:59:59.000Z

319

Influence of new reaction rates on 18F production in novae  

E-Print Network (OSTI)

Gamma-ray emission from classical novae is dominated, during the first hours, by positron annihilation resulting from the beta decay of radioactive nuclei. The main contribution comes from the decay of 18F and hence is directly related to 18F formation during the outburst. A good knowledge of the nuclear reaction rates of production and destruction of 18F is required to study 18F synthesis in novae and the resulting gamma-ray emission. The rates relevant for the main mode of 18F destruction (i.e, through proton captures) have been the object of many recent experiments. However, subsequent analyses were focused on providing rates for X-ray burst nucleosynthesis not valid at nova temperatures (lower than 3.5 10^8 K). Accordingly, it is crucial to propose and discuss new reaction rates, incorporating all new experimental results, down to the domain of nova nucleosynthesis. We show that in this temperature regime, the 18F(p,gamma) and (p,alpha) reaction rates remain uncertain and deserve further experimental and theoretical efforts. Our hydrodynamic calculations including the new nuclear rates demonstrate that their impact on 18F synthesis in nova explosions is quite large and, consequently, the early gamma-ray emission from classical novae is also affected.

Alain Coc; Margarita Hernanz; Jordi Jose; Jean-Pierre Thibaud

2000-03-13T23:59:59.000Z

320

2003 TMS Annual Meeting: 3rd International Symposium on Gamma ...  

Science Conference Proceedings (OSTI)

Mar 5, 2003 ... 2003 TMS Annual Meeting & Exhibition: 3rd International Symposium on Gamma Titanium Aluminides (ISGTA-3) Banquet ...

Note: This page contains sample records for the topic "gamma exposure rates" 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

Chance Estimations for Detecting Gravitational Waves with LIGO/Virgo Associated with Gamma Ray Bursts  

E-Print Network (OSTI)

Short Gamma Ray Bursts (SGRB) are believed to originate from the merger of two compact objects. If this scenario is correct, SGRB will be accompanied by the emission of strong gravitational waves, detectable by current or planned GW detectors, such as LIGO and Virgo. No detection of a gravitational wave has been made up to date. In this paper I will use a set of SGRB with observed redshifts to fit a model describing the cumulative number of SGRB as a function of redshift, to determine the rate of such merger events in the nearby universe. These estimations will be used to make probability statements about detecting a gravitational wave associated with a short gamma ray burst during the latest science run of LIGO/Virgo. Chance estimations for the enhanced and advanced detectors will also be made, and a comparison between the rates deduced from this work will be compared to the existing literature.

Alexander Dietz

2009-04-02T23:59:59.000Z

322

Filters for High Rate Pulse Processing  

E-Print Network (OSTI)

We introduce a filter-construction method for pulse processing that differs in two respects from that in standard optimal filtering, in which the average pulse shape and noise-power spectral density are combined to create a convolution filter for estimating pulse heights. First, the proposed filters are computed in the time domain, to avoid periodicity artifacts of the discrete Fourier transform, and second, orthogonality constraints are imposed on the filters, to reduce the filtering procedure's sensitivity to unknown baseline height and pulse tails. We analyze the proposed filters, predicting energy resolution under several scenarios, and apply the filters to high-rate pulse data from gamma-rays measured by a transition-edge-sensor microcalorimeter.

B. K. Alpert; R. D. Horansky; D. A. Bennett; W. B. Doriese; J. W. Fowler; A. S. Hoover; M. W. Rabin; J. N. Ullom

2012-12-07T23:59:59.000Z

323

Trigger and data rates expected for the CTA Observatory  

E-Print Network (OSTI)

The Cherenkov Telescope Array (CTA) is an initiative to build a next-generation observatory for very-high energy $\\gamma$-rays. Its expected large effective area ($\\mathcal{O}(10^{7} \\mathrm{m}^2)$) and energy threshold as low as 25 GeV imply a challenge for triggering and data acquisition systems. The analysis of the official CTA Monte Carlo production-1 simulations leads to array trigger rates of $\\mathcal{O}$(10 kHz) and data rates ranging from $\\mathcal{O}$(100 MB/s) to $\\mathcal{O}$(1000 MB/s), depending on the read-out scenario.

Manuel Paz Arribas; Ullrich Schwanke; Ralf Wischnewski; for the CTA Consortium

2012-11-13T23:59:59.000Z

324

Status of PEP and TPC/2/gamma/  

Science Conference Proceedings (OSTI)

The TPC/2/gamma/ program at PEP has been upgraded by increasing the PEP luminosity and by the adding of a vertex chamber to the TPC detector. These improvements will allow a strong program in B and /tau/ physics, and will contribute to ongoing studies in two-photon physics and hadronization. 10 refs., 3 figs.

Zapalac, G.

1989-06-01T23:59:59.000Z

325

Effect of gamma irradiation on optical isolators  

SciTech Connect

The effects of gamma radiation on optical isolators have been investigated. This study has included the simultaneous irradiation and measurement of the individual emitters and detectors making up the isolators. In this manner, the net effect of irradiation on the isolators could be attributed to the degradation of either the emitter or detector, or both. As expected, isolators containing photodiodes are more radiation resistant than those containing phototransistors. In the photodiode isolator the LED is responsible for essentially all the gamma-induced isolator degradation. The performance of phototransistor isolators depends strongly on the phototransistor bias, V/sub CE/ , and the LED input current, I/sub LED/. At high I/sub LED/ and low V/sub CE/ where gamma-induced surface effects in the phototransistor are minimized, the degradation of the isolator is due primarily to the LED which is more sensitive than the LED in the photodiode isolator. In contrast, at low I/sub LED/ and high V/sub CE/, gamma-induced surface damage in the phototransistor is the dominant effect and the isolator is quite sensitive to irradiation. (auth)

Soda, K.J.; Barnes, C.E.; Kiehl, R.A.

1975-12-01T23:59:59.000Z

326

Gamma-ray bursts: a Centauro's cry?  

E-Print Network (OSTI)

A new candidate for the gamma-ray bursts central engine is proposed: if in some energetic cosmic event a macroscopic amount of bubbles of the disoriented chiral condensate can be formed, then their subsequent decays will produce a relativistic fireball without the baryon loading problem. The neutron star to strange star transition is considered as a candidate example of such cosmic event.

Z. K. Silagadze

2003-03-04T23:59:59.000Z

327

Galactic Models of Gamma-Ray Bursts  

E-Print Network (OSTI)

We describe observational evidence and theoretical calculations which support the high velocity neutron star model of gamma-ray bursts. We estimate the energetic requirements in this model, and discuss possible energy sources. we also consider radiative processes involved in the bursts.

Donald Q. Lamb; Tomasz Bulik; Paolo S. Coppi

1995-08-20T23:59:59.000Z

328

Neutrino Balls and Gamma-Ray Bursts  

E-Print Network (OSTI)

We propose a mechanism by which the neutrino emission from a supernova-type explosion can be converted into a gamma-ray burst of total energy $\\sim 10^{50}$ ergs. This occurs naturally if the explosion is situated inside a ball of trapped neutrinos, which in turn may lie at a galactic core. There are possible unique signatures of this scenario.

B. Holdom; R. A. Malaney

1993-06-17T23:59:59.000Z

329

A supersymmetric origin of gamma ray bursts  

E-Print Network (OSTI)

Bright bursts of gamma rays from outer space have been puzzling Astronomers for more than thirty years and there is still no conceptually complete model for the phenomenon within the standard model of particle physics. Is it time to consider a supersymmetric (SUSY) origin for these bursts to add to the astronomical indications of supersymmetry from dark matter?

L. Clavelli

2004-10-01T23:59:59.000Z

330

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

331

On the possible origin of gamma ray bursts as a result of interaction of relativistic jets with the soft photon field in dense stellar regions  

E-Print Network (OSTI)

We examine and develop the model of gamma ray bursts origin proposed by Shaviv and Dar (astro-ph/9606032), according to which the strong gamma ray emission is produced by the interaction of the baryonic relativistic jet (outflow) with the soft photon field in a dense stellar region. It is shown by the simulations of the burst profiles that these profiles are very sensitive to the jet geometry, and the 'clarity' of the GRB profile is (in this model) somehow connected with the gamma rays beaming. Also some event-rate based restrictions are derived and discussed.

Darja N. Drozdova; Ivan E. Panchenko

1997-04-17T23:59:59.000Z

332

The Biggest Bangs The Mystery of Gamma-Ray Bursts,  

E-Print Network (OSTI)

wide field of view and high duty cycle Milagro is uniquely capable of searching for gamma-ray bursts of gamma-ray bursts have come from observa- tions of afterglows over a wide spectral range. This has allowed detailed modeling of gamma-ray burst afterglow properties both as a function of time

Katz, Jonathan I.

333

Gamma-Ray Bursts Nuclear Test Ban Treaty, 1963  

E-Print Network (OSTI)

Lecture 18 Gamma-Ray Bursts #12;Nuclear Test Ban Treaty, 1963 First Vela satellite pair launched and their predecessors, Vela 4, discovered the first gamma-ray bursts. The discovery was announced by Klebesadel, Strong, and Olson (ApJ, 182, 85) in 1973. #12;First Gamma-Ray Burst The Vela 5 satellites functioned from July, 1969

Harrison, Thomas

334

OpenEI - rates  

Open Energy Info (EERE)

U.S. Electric Utility U.S. Electric Utility Companies and Rates: Look-up by Zipcode (Feb 2011) http://en.openei.org/datasets/node/899 This dataset, compiled by NREL and Ventyx, provides average residential, commercial and industrial electricity rates by zip code for both investor owned utilities (IOU) and non-investor owned utilities. Note: the file includes average rates for each utility, but not the detailed rate structure data found in the database available via the zip-code look-up feature on the OpenEI Utilities page (http://en.openei.org/wiki/Gateway:Utilities). The data was released by NREL/Ventyx in February 2011.

335

<RatesMiscInfo>  

NLE Websites -- All DOE Office Websites (Extended Search)

Rates MISCELLANEOUS INFORMATION Power Supply Report June 2013 (53kb pdf) May 2013 (53kb pdf) April 2013 (52kb pdf) March 2013 (54kb pdf) February 2013 (54kb pdf) January 2013 (54kb...

336

Gamma Ray Bursts Cannot Produce the Observed Cosmic Rays Above 10 19 eV  

E-Print Network (OSTI)

Received; accepted – 2 – Using recent results indicating that the redshift distribution of ?-ray bursts most likely follows the redshift evolution of the star formation rate, I show that the energy input from these bursts at low redshifts is insufficient to account for the observed flux of ultrahigh energy cosmic rays with energies above 1019 eV. Subject Headings: gamma-rays: bursts — cosmic rays: theory – 3 – 1.

F. W. Stecker

1999-01-01T23:59:59.000Z

337

B{yields}{gamma}{gamma} in an Appelquist-Cheng-Dobrescu model  

Science Conference Proceedings (OSTI)

We present a full calculation of the amplitudes for B{sub d[s]}{yields}{gamma}{gamma} in a simple Appelquist-Cheng-Dobrescu model that extends an incomplete one in a previous paper. We find cancellations between the contributions from different Kaluza-Klein towers and a small decrease relative to the standard model predictions. It is conjectured that radiative QCD corrections might actually lead to an enhancement in the branching ratios and CP asymmetries, but no more than modest ones.

Bigi, I. I. [Department of Physics, University of Notre Dame du Lac, Notre Dame, Indiana 46556 (United States); Devidze, G. G.; Liparteliani, A. G. [Institute of High Energy Physics and Informatization, Tbilisi State University, 9 University Street, 0186 Tbilisi (Georgia); Meissner, U.-G. [Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Forschungszentrum Juelich, Institut fuer Kernphysik (IKP-3) and Juelich Center for Hadron Physics, D-52425 Juelich (Germany)

2008-11-01T23:59:59.000Z

338

Enhancement of h --> gamma gamma in the Two Higgs Doublet Model Type I  

E-Print Network (OSTI)

We show that in the Two Higgs Doublet Model (THDM) Type I the partial decay width of h --> gamma gamma can be considerably larger than in Type II, due to light charged scalars with a mass about 100 GeV, which are not yet excluded in Type I. A possible enhancement of the width compared to the SM is analyzed for different Higgs potentials, subject to constraints from tree-level unitarity, vacuum stability and electroweak precision tests.

Paul Posch

2010-01-12T23:59:59.000Z

339

The Gamma Transitions, Level Densities and Gamma Strength Function of Isotopes Yb-172 and Sm-153  

E-Print Network (OSTI)

This report is presented the level densities and gamma strength function which is extracted from primary gamma transitions of (n,2g) measurement on the Dalat Nuclear Research Reactor (DNRR). The comparisons with others results and model calculations, there are outside the scope of uncertainty. These research results are showed that having of complement research for deformed nucleus in order to evaluate nuclear structure models.

Vuong Huu Tan; Pham Dinh Khang; Nguyen Xuan Hai; Ho Huu Thang; Dao Manh Trinh; Nguyen An Son

2013-08-22T23:59:59.000Z

340

Heat Rate Program Guidelines  

Science Conference Proceedings (OSTI)

Power plant facilities with performance or heat rate improvement programs perform better than those that do not have those programs. A heat rate improvement program typically provides sufficient information for decision making with respect to timely maintenance actions and/or operational adjustments. Monitoring the performance of any power plant component includes the trending of parameters that also describe the performance of other plant components, providing insight and information on improving ...

2012-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "gamma exposure rates" 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

The Ptolemaic Gamma-Ray Burst Universe  

E-Print Network (OSTI)

The BATSE experiment on GRO has demonstrated the isotropic arrival directions and flat log N vs. log S of cosmic gamma-ray bursts. These data are best explained if the burst sources are distributed throughout an extended spherical Galactic halo, as previously suggested by Jennings. The halo’s radius is at least 40 Kpc, and probably is more than 100 Kpc. I consider possible origins of this halo, including primordial formation and neutron stars recoiling from their birthplaces in the Galactic disc. A simple geometrical model leads to a predicted relation between the dipole and quadrupole anisotropy. I suggest that neutron stars born with low recoil become millisecond pulsars, while those born with high recoil become the sources of gamma-ray bursts; these populations are nearly disjoint. Quiescent counterparts of gamma-ray bursts are predicted to be undetectably faint. 2 The first results from the BATSE on GRO (BATSE Science Team 1991) have revived the question of the distribution of gamma-ray burst sources in space. Their chief results, isotropy of gamma-ray burst directions and a log N vs. log S slope significantly flatter than-1.5, confirm earlier reports (see, for example, Meegan, Fishman and Wilson 1985 and the review by Cline 1984). Questions of relative calibration of different instruments and the paucity of good directional data permitted skepticism in the past. Such skepticism is no longer tenable, and the theoretical questions raised earlier must be faced. An isotropic distribution of sources implies that, out to the maximum distance of observation permitted by instrumental sensitivity, all directions contain equivalent source populations. The source population for an observed flux or fluence S is expressed as the integral N ( ˆ ? ?, S) =

J. I. Katz

1992-01-01T23:59:59.000Z

342

Real-time automatic interpolation of ambient gamma dose rates from the Dutch radioactivity monitoring network  

Science Conference Proceedings (OSTI)

Detection of radiological accidents and monitoring the spread of the contamination is of great importance. Following the Chernobyl accident many European countries have installed monitoring networks to perform this task. Real-time availability of automatically ... Keywords: Automatic interpolation, Interoperability, Kriging, Monitoring networks, Web services

Paul H. Hiemstra; Edzer J. Pebesma; Chris J. W. Twenhöfel; Gerard B. M. Heuvelink

2009-08-01T23:59:59.000Z

343

Cat Heart Rate Monitoring  

NLE Websites -- All DOE Office Websites (Extended Search)

Cat Heart Rate Monitoring Cat Heart Rate Monitoring Name: Shakti Status: student Grade: 9-12 Location: TX Country: USA Date: Summer 2010 Question: What is the best way to find a cat's heart rate using a stethoscope? Because I have tried to hear their heart beat but their purring is all I can hear. If I shouldn't use a stethoscope, then what should I use? Replies: Hi Shakti! If you want to use a stethoscope, the trick is to get your cat to stop purring. Two good ways that I have found to help stop the purring 1. Cover their nose (generally cats don't like this and will stop purring) or 2. Put on the tap to drip or lightly stream water (also, they generally don't like this and will stop purring). Alternatively, you can get their heart rate from feeling their pulse. A good place to try to feel a pulse is right where the leg attaches to the abdomen - in an area called the inguinal region. Now granted there are some heart conditions that will cause an animals pulse and their heart rates don't match up, and it's hard to feel if you have a fat cat, but it's a good place to try if you are really trying to get a heart rate in a healthy kitty!

344

The effect of flight line spacing on radioactivity inventory and spatial feature characteristics of airborne gamma-ray spectrometry data  

Science Conference Proceedings (OSTI)

Airborne Gamma Spectrometry (AGS) is well suited to the mapping of radioactivity in the environment. Flight parameters (e.g. speed and line spacing) directly affect the rate of area coverage, cost, and data quality of any survey. The influences of line ...

D. C. W. Sanderson; A. J. Cresswell; D. C. White

2008-01-01T23:59:59.000Z

345

Radiation Protection at Industrial Radiography in Germany Exposures and Unusual Events  

E-Print Network (OSTI)

Abstract. In the Federal Republic of Germany safety related events in the use and transportation of radioactive materials as well as in the operation of accelerators are registered. The analysis of these events reveals their causation and allows this conclusions on avoidable errors. In this paper, a special insight is given into events in the field of gamma radiography which is a technical application of ionising radiation for non destructive testing of materials. Conclusions from analysis are drawn. In addition, the occupational radiation exposure of workers is presented taking into account that industrial radiography is performed under particular working conditions with different risks. 1.

Renate Czarwinski; Uwe Häusler; Gerhard Frasch; Bundesamt Für; Strahlenschutz Fachbereich Strahlenschutz Und Gesundheit

2006-01-01T23:59:59.000Z

346

Exposure Assessment for Bioaerosols in Health Studies  

NLE Websites -- All DOE Office Websites (Extended Search)

Exposure Assessment for Bioaerosols in Health Studies Exposure Assessment for Bioaerosols in Health Studies Speaker(s): Carol Rao Date: July 9, 2004 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Mark Mendell Exposures to fungi have been linked with asthma, toxicoses, hypersensitivity pneumonitis, and a range of non-specific symptoms. Definitive associations between indoor fungal exposure and health effects in population-based exposure-response studies, however, have not been well established. Issues in exposure assessment methods, both in collection and analysis, are major limitations. Classic methods for assessing airborne fungi rely upon collecting and analyzing whole fungal spores by culture. However, quantifying whole fungal spores may not fully describe fungal exposures, especially for purposes of investigating adverse respiratory

347

The Universe Viewed in Gamma-Rays 1 Toward Ultra Short Gamma Ray Burst Ground Based De-  

E-Print Network (OSTI)

-TIME FERMI LARGE AREA TELESCOPE GAMMA-RAY BURST AFTERGLOWS C. A. Swenson1 , A. Maxham2 , P. W. A. Roming1 2010 June 11; published 2010 June 28 ABSTRACT GRB 090926A was detected by both the Gamma-ray Burst the predicted gamma-ray fluence, as would have been seen by the Burst Alert Telescope (BAT) on board Swift

Enomoto, Ryoji

348

The Chern-Simons Diffusion Rate in Improved Holographic QCD  

E-Print Network (OSTI)

In (3+1)-dimensional SU(Nc) Yang-Mills (YM) theory, the Chern-Simons diffusion rate, Gamma_{CS}, is determined by the zero-momentum, zero-frequency limit of the retarded two-point function of the CP-odd operator tr[F ^ F], with F the YM field strength. The Chern-Simons diffusion rate is a crucial ingredient for many CP-odd phenomena, including the chiral magnetic effect in the quark-gluon plasma. We compute Gamma_{CS} in the high-temperature, deconfined phase of Improved Holographic QCD, a refined holographic model for large-Nc YM theory. Our result for Gamma_{CS}/(sT), where s is entropy density and T is temperature, varies slowly at high T and increases monotonically as T approaches the transition temperature from above. We also study the retarded two-point function of tr[F ^ F] with non-zero frequency and momentum. Our results suggest that the CP-odd phenomena that may potentially occur in heavy ion collisions could be controlled by an excitation with energy on the order of the lightest axial glueball mass.

Umut Gursoy; Ioannis Iatrakis; Elias Kiritsis; Francesco Nitti; Andy O'Bannon

2012-12-17T23:59:59.000Z

349

The Chern-Simons Diffusion Rate in Improved Holographic QCD  

E-Print Network (OSTI)

In (3+1)-dimensional SU(Nc) Yang-Mills (YM) theory, the Chern-Simons diffusion rate, Gamma_{CS}, is determined by the zero-momentum, zero-frequency limit of the retarded two-point function of the CP-odd operator tr[F ^ F], with F the YM field strength. The Chern-Simons diffusion rate is a crucial ingredient for many CP-odd phenomena, including the chiral magnetic effect in the quark-gluon plasma. We compute Gamma_{CS} in the high-temperature, deconfined phase of Improved Holographic QCD, a refined holographic model for large-Nc YM theory. Our result for Gamma_{CS}/(sT), where s is entropy density and T is temperature, varies slowly at high T and increases monotonically as T approaches the transition temperature from above. We also study the retarded two-point function of tr[F ^ F] with non-zero frequency and momentum. Our results suggest that the CP-odd phenomena that may potentially occur in heavy ion collisions could be controlled by an excitation with energy on the order of the lightest axial glueball mass...

Gursoy, Umut; Kiritsis, Elias; Nitti, Francesco; O'Bannon, Andy

2013-01-01T23:59:59.000Z

350

SGARFACE: A Novel Detector For Microsecond Gamma Ray Bursts  

E-Print Network (OSTI)

The Short GAmma Ray Front Air Cherenkov Experiment (SGARFACE) is operated at the Whipple Observatory utilizing the Whipple 10m gamma-ray telescope. SGARFACE is sensitive to gamma-ray bursts of more than 100MeV with durations from 100ns to 35us and provides a fluence sensitivity as low as 0.8 gamma-rays per m^2 above 200MeV (0.05 gamma-rays per m^2 above 2GeV) and allows to record the burst time structure.

S. LeBohec; F. Krennrich; G. Sleege

2005-01-11T23:59:59.000Z

351

Is (d,p{gamma}) a surrogate for neutron capture?  

SciTech Connect

To benchmark the validity of using the (d,p{gamma}) reaction as a surrogate for (n,{gamma}), the {sup 171,173}Yb(d,p{gamma}) reactions were measured and compared with the neutron capture cross sections measured by Wisshak et al. The (d,p{gamma}) ratios were measured using an 18.5 MeV deuteron beam from the 88-Inch Cyclotron at LBNL. Preliminary results comparing the surrogate ratios with the known (n,{gamma}) cross sections are discussed.

Hatarik, R.; Cizewski, J. A.; O'Malley, P. D. [Rutgers University, Department of Physics and Astronomy, New Brunswick, NJ 08901 (United States); Bernstein, L. A.; Burke, J. T.; Lesher, S. R. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Gibelin, J. D.; Phair, L. W. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Swan, T. [Rutgers University, Department of Physics and Astronomy, New Brunswick, NJ 08901 (United States); University of Surrey, Physics Department, Guildford GU2 7XH, Surrey (United Kingdom)

2008-04-17T23:59:59.000Z

352

Mythology of rate design  

SciTech Connect

If power rates are determined by marginal costs with clear signals to the consumer, then the load curve will regulate itself without burdening the public with ethical and patriotic issues. Manipulation of the load factor will only cause hardship and inconvenience, but a choice of rates will allow consumers to determine their own balance between rates and convenience. It makes sense to charge consumers the true cost rather than having the same rate apply during a 24-hour period when costs are not uniform. Discussions of how to determine equitable rate structures flounder because we cannot define equity. Economists, who base their recommendations on the assumption that income distribution is reasonable, believe marginal-cost pricing allows the customer to save whatever the utility is saving. Such a system is economically efficient in that the utility charges 100 percent-load-factor consumers according to a base load plant, while charging peak and offpeak consumers what it costs to add them to the system. Adjustment of prices to cause a minimal distortion of the market is the economists' general rule for handling the balancing of cost increases and regulated profits. (DCK)

Streiter, S.H.

1977-01-01T23:59:59.000Z

353

Lepton flavour violating Higgs Boson decays, tau --> mu gamma and B(s) --> mu+mu- in the constrained MSSM+NR with large tan beta  

E-Print Network (OSTI)

Realistic predictions are made for the rates of lepton flavour violating Higgs boson decays, tau --> mu gamma, mu --> e gamma, Bs --> mu+mu-, Bs --> tau mu and tau --> 3mu, via a top-down analysis of the Minimal Supersymmetric Standard Model(MSSM) constrained by SU(5) unification with right-handed Neutrinos and large tan beta. The third family neutrino Yukawa coupling is chosen to be of order 1, in this way our model bares a significant resemblance to supersymmetric SO(10). In this framework the large PMNS mixings result in potentially large lepton flavour violation. Our analysis predicts tau --> mu gamma and mu --> e gamma rates in the region (10^{-8}-10^{-6}) and (10^{-15}-10^{-14}) respectively. We also show that the rates for lepton flavour violating Higgs decays can be as large as 10^{-7}. The non-decoupling nature of H --> tau mu is observed which leads to its decay rate becoming comparable to that for tau --> mu gamma for large values of m_0 and M_1/2. We also find that the present bound on Bs --> mu+mu- is an important constraint on the rate of lepton flavour violating Higgs decays. The recently measured Bs-Bsbar mixing parameter Delta Ms is also investigated.

J. K. Parry

2005-10-24T23:59:59.000Z

354

Trade, Interdependence and Exchange Rates  

E-Print Network (OSTI)

period is 1971-2000. All inflation rates and predictions areof Goods and Real Exchange Rate Fluc- tuations,” mimeo [5]Between Trade and Exchange Rate Volatility,” mimeo [6

Fitzgerald, Doireann

2004-01-01T23:59:59.000Z

355

Exchange Rates, Information, and Crises  

E-Print Network (OSTI)

3 Intervention and Exchange Rate Misalignment 4 Conclusion 5explain the exchange rate determination puzzle? Americanrisk to defend the exchange rate. Universit¨at Trier Working

Fernholz, Ricardo Turrin

2011-01-01T23:59:59.000Z

356

BCP Annual Rate Process  

NLE Websites -- All DOE Office Websites (Extended Search)

2013 BCP Annual Rate Process 2013 BCP Annual Rate Process Informal Process Rate Activity Schedule (doc) Informal Customer Meeting Thursday March 6, 2013 at 10:30 A.M. Conf Rms 3&4 Informal Customer Meeting Presentation (Pdf) PRS Executive Summary (Mar 07, 2013) (Pdf) FY2014 Final Ten Year Operating Plan PRS Executive Summary (PDF) FORM for Foreign Visits (doc) Formal Process Initial Federal Register Notice (pdf) Public Information Forum March 27,2013 at 10:30 A.M. Conf Rms3&4 Customer Meeting Presentation PIF Presentation (PPT) Presentation Details (pdf) Reclamation Fund Status Report PIF PRS Executive Summary (pdf) PIF Transcripts (PDF) Visitor Center Cost Analysis Questions - Responses Public Comment Forum April 10, 2013 at 10:30 A.M. Conf Rms3&4 PCF Transcripts Customer Letters

357

Multiple System Rate Process  

NLE Websites -- All DOE Office Websites (Extended Search)

DSW Multiple System Transmission Rate Process DSW Multiple System Transmission Rate Process Federal Register Notice Withdrawing Rate Proposal (PDF) Formal Process Extension Federal Register Notice (PDF) Customer Savings Under Various MSTR (XLS) Public Information Forum March 29, 2005 Customer Meeting Overview (Power Point) Customer Meeting Overview (PDF) Customer Meeting Transcript (PDF) Public Comment Forum April 6, 2005 Customer Meeting Transcript (PDF) Response Letter 5-17-05 (PDF) Customer Letters Tonopah ID-5/25/05 (PDF) APS-5/26/05 (PDF) SRP-5/27/05 (PDF) RSLynch-6/1/05 (PDF) KRSaline-6/1/05 (PDF) Formal Process Federal Register Notice (Word) Federal Register Notice (PDF) Brochure (Word) Appendices to Brochure: A B C D E1 E2 F1 F2 GH Public Information Forum July 14, 2004 Customer Meeting Overview (Power Point)

358

Z(gamma) production and limits on anomalous ZZ(gamma) and Z(gamma gamma) couplings in p(p)over-bar collisions at root s 1.96 TeV  

Science Conference Proceedings (OSTI)

We present a measurement of p{bar p} {yields} Z{sub {gamma}} {yields} {ell}{sup +}{ell}{sup -}{sub {gamma}} ({ell} = e, {mu}) production with a data sample corresponding to an integrated luminosity of 6.2 fb{sup -1} collected by the D0 detector at the Fermilab Tevatron p{bar p} Collider. The results of the electron and muon channels are combined, and we measure the total production cross section and the differential cross section d{sigma}/dp{sub T}{sup {gamma}}, where p{sub T}{sup {gamma}} is the momentum of the photon in the plane transverse to the beam line. The results obtained are consistent with the standard model predictions from next-to-leading order use ttransverse momentum spectrum of the photon to place limits on anomalous ZZ{gamma} and Z{gamma}{gamma} couplings.

Abazov, V.M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G. A.; Aoki, M.; Askew, A.; Asman, B.; Atkins, S.; Atramentov, O.; Augsten, K.; Avila, C.; BackusMayes, J.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Belanger-Champagne, C.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besancon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Burnett, T. H.; Buszello, C. P.; Calpas, B.; Camacho-Perez, E.; Carrasco-Lizarraga, M. A.; Casey, B. C. K.; Castilla-Valdez, H.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Thery, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M. -C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; De, K.; de Jong, S. J.; De La Cruz-Burelo, E.; Deliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dorland, T.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; Garcia-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Greenwood, Z. D.; Gregores, E. M.; Grenier, G.; Gris, Ph.; Grivaz, J. -F.; Grohsjean, A.; Gruenendahl, S.; Gruenewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hohlfeld, M.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffre, M.; Jamin, D.; Jayasinghe, A.; Jesik, R.; Johns, K.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kobach, A. C.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kurca, T.; Kuzmin, V. A.; Kvita, J.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, L.; Li, Q. Z.; Lietti, S. M.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; de Sa, R. Lopes; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Mackin, D.; Madar, R.; Magana-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martinez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; et al.

2012-03-01T23:59:59.000Z

359

Redshifts of the Long Gamma-Ray Bursts  

E-Print Network (OSTI)

The low energy spectra of some gamma-ray bursts' show excess components beside the power-law dependence. The consequences of such a feature allows to estimate the gamma photometric redshift of the long gamma-ray bursts in the BATSE Catalog. There is good correlation between the measured optical and the estimated gamma photometric redshifts. The estimated redshift values for the long bright gamma-ray bursts are up to z=4, while for the the faint long bursts - which should be up to z=20 - the redshifts cannot be determined unambiguously with this method. The redshift distribution of all the gamma-ray bursts with known optical redshift agrees quite well with the BATSE based gamma photometric redshift distribution.

Z. Bagoly; I. Csabai; A. Meszaros; P. Meszaros; I. Horvath; L. G. Balazs; R. Vavrek

2007-04-06T23:59:59.000Z

360

Monte-Carlo Simulations of Radiation-Induced Activation in a Fast-Neutron and Gamma- Based Cargo Inspection System  

E-Print Network (OSTI)

An air cargo inspection system combining two nuclear reaction based techniques, namely Fast-Neutron Resonance Radiography and Dual-Discrete-Energy Gamma Radiography is currently being developed. This system is expected to allow detection of standard and improvised explosives as well as special nuclear materials. An important aspect for the applicability of nuclear techniques in an airport inspection facility is the inventory and lifetimes of radioactive isotopes produced by the neutron and gamma radiation inside the cargo, as well as the dose delivered by these isotopes to people in contact with the cargo during and following the interrogation procedure. Using MCNPX and CINDER90 we have calculated the activation levels for several typical inspection scenarios. One example is the activation of various metal samples embedded in a cotton-filled container. To validate the simulation results, a benchmark experiment was performed, in which metal samples were activated by fast-neutrons in a water-filled glass jar. The induced activity was determined by analyzing the gamma spectra. Based on the calculated radioactive inventory in the container, the dose levels due to the induced gamma radiation were calculated at several distances from the container and in relevant time windows after the irradiation, in order to evaluate the radiation exposure of the cargo handling staff, air crew and passengers during flight. The possibility of remanent long-lived radioactive inventory after cargo is delivered to the client is also of concern and was evaluated.

B. Bromberger; D. Bar; M. Brandis; V. Dangendorf; M. B. Goldberg; F. Kaufmann; I. Mor; R. Nolte; M. Schmiedel; K. Tittelmeier; D. Vartsky; H. Wershofen

2012-01-04T23:59:59.000Z

Note: This page contains sample records for the topic "gamma exposure rates" 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.


361

Search for very high energy gamma-rays from WIMP annihilations near the Sun with the Milagro Detector  

E-Print Network (OSTI)

The neutralino, the lightest stable supersymmetric particle, is a strong theoretical candidate for the missing astronomical ``dark matter''. A profusion of such neutralinos can accumulate near the Sun when they lose energy upon scattering and are gravitationally captured. Pair-annihilations of those neutralinos may produce very high energy (VHE, above $100 GeV$) gamma-rays. Milagro is an air shower array which uses the water Cherenkov technique to detect extensive air showers and is capable of observing VHE gamma-rays from the direction of the Sun with an angular resolution of $0.75^{\\circ}$. Analysis of Milagro data with an exposure to the Sun of 1165 hours presents the first attempt to detect TeV gamma-rays produced by annihilating neutralinos captured by the Solar system and shows no statistically significant signal. Resulting limits that can be set on gamma-ray flux due to near-Solar neutralino annihilations and on neutralino cross-section are presented.

Milagro Collaboration

2004-05-14T23:59:59.000Z

362

Chlorobenzylidenemalonitrile Gas Exposure from A Novelty Personal-Protection Gun  

E-Print Network (OSTI)

Chlorobenzylidenemalonitrile Gas Exposure from A Noveltychlorobenzylidenemalonitrile gas, chemical terrorism, toxicbenzylidenemalonitrile (CS) tear-gas exposure from the

Dong, Christopher; Garza, Albert de la

2007-01-01T23:59:59.000Z

363

LAP Transmission Rate  

NLE Websites -- All DOE Office Websites (Extended Search)

LAP Transmission Rate 4.50 4.00 3.82 3.50 3.00 of 2.50 c 0 2.I2 2.68 I 3: 2.00 1.50 1.00 0.50 0.00 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012...

364

Neutron-driven gamma-ray laser  

DOE Patents (OSTI)

A lasing cylinder emits laser radiation at a gamma-ray wavelength of 0.87 {angstrom} when subjected to an intense neutron flux of about 400 eV neutrons. A 250 {angstrom} thick layer of Be is provided between two layers of 100 {angstrom} 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, C.D.

1989-03-28T23:59:59.000Z

365

Factorization in B ---> V gamma decays  

SciTech Connect

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

366

Real time gamma-ray signature identifier  

DOE Patents (OSTI)

A real time gamma-ray signature/source identification method and system using principal components analysis (PCA) for transforming and substantially reducing one or more comprehensive spectral libraries of nuclear materials types and configurations into a corresponding concise representation/signature(s) representing and indexing each individual predetermined spectrum in principal component (PC) space, wherein an unknown gamma-ray signature may be compared against the representative signature to find a match or at least characterize the unknown signature from among all the entries in the library with a single regression or simple projection into the PC space, so as to substantially reduce processing time and computing resources and enable real-time characterization and/or identification.

Rowland, Mark (Alamo, CA); Gosnell, Tom B. (Moraga, CA); Ham, Cheryl (Livermore, CA); Perkins, Dwight (Livermore, CA); Wong, James (Dublin, CA)

2012-05-15T23:59:59.000Z

367

Compositions containing poly (.gamma.-glutamylcysteinyl)glycines  

SciTech Connect

A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly (.gamma.-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly (.gamma.-glutamylcysteinyl)glycines having a particular number of monomer repeat units for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form.

Jackson, Paul J. (Los Alamos, NM); Delhaize, Emmanuel (Los Alamos, NM); Robinson, Nigel J. (Durham, GB2); Unkefer, Clifford J. (Los Alamos, NM); Furlong, Clement (Seattle, WA)

1992-01-01T23:59:59.000Z

368

Compositions containing poly ([gamma]glutamylcysteinyl)glycines  

DOE Patents (OSTI)

A method of removing heavy metals from aqueous solution, a composition of matter used in effecting the removal, and the apparatus used in effecting the removal are described. One or more of the polypeptides, poly ([gamma]glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly ([gamma]glutamylcysteinyl)glycines having a particular number of monomer repeat units for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form. 1 figs.

Jackson, P.J.; Delhaize, E.; Robinson, N.J.; Unkefer, C.J.; Furlong, C.

1992-02-18T23:59:59.000Z

369

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

370

Upper Great Plains Rates information  

NLE Websites -- All DOE Office Websites (Extended Search)

Rates and Repayment Services Rates and Repayment Services Rates 2010 Firm Power Rate (effective January 1, 2010) Rate Adjustments 2010 Firm Power Rate Adjustment 2009 Firm Power Rate Adjustment IS Rate Adjustments Rate Adjustment Process Rate Orders Signed, December 23, 2009 (16kb pdf) Announcements Firm Electric Service Customer Letter - Preliminary Review of Drought Adder Component, June 27, 2013 (74kb pdf) Customer Letter - Final Notice of Drought Adder Component, October 2, 2013 (68kb pdf) Integrated System (IS) Rates 2014 IS Rates Customer Information Meeting Presentation, October 15, 2013 (611kb pdf) Customer Letter - Notification of 2014 Rates, September 13, 2013 (160kb pdf) 2014 Transmission and Ancillary Services Rate Calculation and 2012 Rate True-up Calculation (4.9mb pdf) 2013 IS Rates

371

NO CORRELATION BETWEEN HOST GALAXY METALLICITY AND GAMMA-RAY ENERGY RELEASE FOR LONG-DURATION GAMMA-RAY BURSTS  

Science Conference Proceedings (OSTI)

We compare the redshifts, host galaxy metallicities, and isotropic (E{sub {gamma}},iso) and beaming-corrected (E{sub {gamma}}) gamma-ray energy release of 16 long-duration gamma-ray bursts (LGRBs) at z gamma}},iso, or E{sub {gamma}}. These results are at odds with previous theoretical and observational predictions of an inverse correlation between gamma-ray energy release and host metallicity, as well as the standard predictions of metallicity-driven wind effects in stellar evolutionary models. We consider the implications that these results have for LGRB progenitor scenarios, and discuss our current understanding of the role that metallicity plays in the production of LGRBs.

Levesque, Emily M.; Kewley, Lisa J. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Soderberg, Alicia M.; Berger, Edo, E-mail: emsque@ifa.hawaii.ed, E-mail: kewley@ifa.hawaii.ed, E-mail: asoderbe@cfa.harvard.ed, E-mail: eberger@cfa.harvard.ed [Smithsonian Astrophysical Observatory, 60 Garden St., MS-20, Cambridge, MA 02138 (United States)

2010-12-10T23:59:59.000Z

372

THE GAMMA-RAY BURST MYSTERY  

E-Print Network (OSTI)

Gamma-ray bursts are transient events from beyond the solar system. Besides the allure of their mysterious origin, bursts are physically fascinating because they undoubtedly require exotic physics. Optical transients coincident with burst positions show that some, and probably all, bursts originate at cosmological distances, and not from a large Galactic halo. Observations of these events ’ spectral and temporal behavior will guide and constrain the study of the physical processes producing this extragalactic phenomenon. 1

David L. Band

1997-01-01T23:59:59.000Z

373

Gamma irradiation effects in W films  

Science Conference Proceedings (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

374

Natural Gas Conveyance and Rates  

Reports and Publications (EIA)

Natural gas transportation market; Competition vs. market power; Rate structures Cost-of-service Performance based rates

Information Center

2001-02-01T23:59:59.000Z

375

of Bright, Long Gamma-Ray Bursts  

E-Print Network (OSTI)

The time profiles of many gamma-ray bursts observed by BATSE consist of distinct pulses, which offer the possibility of characterizing the temporal structure of these bursts using a relatively small set of pulse-shape parameters. This pulse analysis has previously been performed on some bright, long bursts using binned data, and on some short bursts using BATSE Time-Tagged Event (TTE) data. The BATSE Time-to-Spill (TTS) burst data records the times required to accumulate a fixed number of photons, giving variable time resolution. The spill times recorded in the TTS data behave as a gamma distribution. We have developed an interactive pulse-fitting program using the pulse model of Norris et al. and a maximum-likelihood fitting algorithm to the gamma distribution of the spill times. We then used this program to analyze a number of bright, long bursts for which TTS data is available. We present statistical information on the attributes of pulses comprising these bursts.

Andrew Lee; Elliott Bloom; Jeffrey Scargle

1996-01-01T23:59:59.000Z

376

Two Classes of Gamma-Ray Bursts  

E-Print Network (OSTI)

If gamma-ray bursts are at cosmological distances, as suggested by their isotropy on the sky and the comparative deficiency of weak bursts, then they represent radiated energies of ? 1051 erg, and imply the release of an even greater energy. Only neutron stars and black holes have binding energies sufficient to power such extraordinarily violent and energetic events. General considerations of neutrino opacity imply1 that the escape of a neutron star’s (or black hole’s) binding energy requires a time of about 10 sec, as shown by the observed duration of neutrino emission from SN1987A. The distribution of durations of gamma-ray bursts is known2 to be bimodal, with one peak between 10 and 100 sec and the other between 0.1 and 1 sec. We hypothesize that the durations of the longer bursts may be explained as the result of the diffusion of energy, by means of neutrinos, from a forming neutron star or black hole, but that the brevity of the shorter bursts requires different physics. An alternative hypothesis supposes that all bursts (excepting soft gamma repeaters, which we do not discuss) represent a single class of events, whose differing durations reflect differences in one or more parameters. These two hypotheses may be tested using data from the recently released 3B Catalogue3.

J. I. Katz; L. M. Canel

1995-01-01T23:59:59.000Z

377

A Link between Prompt Optical and Prompt Gamma-Ray Emission in Gamma-Ray Bursts  

E-Print Network (OSTI)

The prompt optical emission that arrives with gamma-rays from a cosmic gamma-ray burst (GRB) is a signature of the engine powering the burst, the properties of the ultra-relativistic ejecta of the explosion, and the ejecta's interactions with the surroundings. Until now, only GRB 990123 had been detected at optical wavelengths during the burst phase. Its prompt optical emission was variable and uncorrelated with the prompt gamma-ray emission, suggesting that the optical emission was generated by a reverse shock arising from the ejecta's collision with the surrounding material. Here we report prompt optical emission from GRB 041219a. It is variable and correlated with the prompt gamma-rays, indicating a common origin for the optical light and the gamma-rays. Within the context of the standard fireball model of GRBs, we attribute this new optical component to internal shocks driven into the burst ejecta by variations of the inner engine. The correlated optical emission is a direct probe of the jet isolated from the medium. The timing of the uncorrelated optical emission is strongly dependent on the nature of the medium.

W. T. Vestrand; P. R. Wozniak; J. A. Wren; E. E. Fenimore; T. Sakamoto; R. R. White; D. Casperson; H. Davis; S. Evans; M. Galassi; K. E. McGowan; J. A. Schier; J. W. Asa; S. D. Barthelmy; J. R. Cummings; N. Gehrels; D. Hullinger; H. A. Krimm; C. B. Markwardt; K. McLean; D. Palmer; A. Parsons; J. Tueller

2005-03-23T23:59:59.000Z

378

Review and validation of exposure assessment methods  

E-Print Network (OSTI)

The purpose of this research is twofold, to standardize and to validate exposure assessment methods. First, the attempt is made to standardize the manner in which exposure assessment methods are developed. Literature on the subject is reviewed and seven common elements discovered to be common are discussed. The seven elements are causative agents, exposure groups, exposure-modifying parameters, industrial hygiene measurement data, misclassification issues, validation issues, and reliability issues. It is believed that thinking in terms of these elements will yield more consistent and complete exposure assessment models. Three types of exposure estimation methods are reviewed in this form. These methods are selected because they are the most thorough and represent the most frequently used and referenced types of estimation strategies: the statistical model, the deterministic model, and the multiplicative model. Second, the paper reports on an attempt to validate a semiquantitative exposure assessment model against industrial hygiene data collected from employees of one firm in the maritime industry. The set of data contains 440 samples with 75 percent of them censored by the method limit of detection. Methods to calculate an average concentration with nondetectable data are discussed. It is concluded that (1) the model does not predict the data well, (2) the industrial hygiene data does not properly fit the tails of a lognormal distribution, and (3) that average exposure to benzene in the (un)loading of petrochemicals from tankers is decidedly below exposure limits.

Shaw, Eduardo

2001-01-01T23:59:59.000Z

379

2011 DOE Occupational Radiation Exposure Summary poster  

SciTech Connect

This poster graphically presents data pertaining to occupational radiation exposure in terms of total effective dose (TED), primarily, but also collective dose and average measureable dose.

ORAU

2012-12-12T23:59:59.000Z

380

Linking Environmental Exposures to Health Effects  

NLE Websites -- All DOE Office Websites (Extended Search)

studies conducted by his group, including occupational and environmental exposures to benzene and other VOCs and air levels of polycyclic aromatic hydrocarbons following the World...

Note: This page contains sample records for the topic "gamma exposure rates" 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

Adjusted Growth Rates*  

U.S. Energy Information Administration (EIA) Indexed Site

Jan. '99 to Feb. '99: -1.7% Feb. '98 to Feb. '99: +19.8% YTD '98 to YTD '99: +15.0% 4,100 4,400 4,700 5,000 5,300 5,600 5,900 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons U.S. Distillate Fuel Sales 2011 2012 2013 Adjusted Growth Rates* Jul '13 to Aug '13: 2.5% Aug '12 to Aug '13: -1.3% YTD '12 to YTD '13: 1.5% 300 400 500 600 700 800 900 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons U.S. Residual Fuel Sales 2011 2012 2013 Adjusted Growth Rates* Jul '13 to Aug '13: -0.8%

382

Rail Coal Transportation Rates  

U.S. Energy Information Administration (EIA) Indexed Site

reports reports Coal Transportation Rates to the Electric Power Sector With Data through 2010 | Release Date: November 16, 2012 | Next Release Date: December 2013 | Correction Previous editions Year: 2011 2004 Go Figure 1. Deliveries from major coal basins to electric power plants by rail, 2010 Background In this latest release of Coal Transportation Rates to the Electric Power Sector, the U.S. Energy Information Administration (EIA) significantly expands upon prior versions of this report with the incorporation of new EIA survey data. Figure 1. Percent of total U.S. rail shipments represented in data figure data Previously, EIA relied solely on data from the U.S. Surface Transportation Board (STB), specifically their confidential Carload Waybill Sample. While valuable, due to the statistical nature of the Waybill data,

383

Plant Tumor Growth Rates  

NLE Websites -- All DOE Office Websites (Extended Search)

Plant Tumor Growth Rates Plant Tumor Growth Rates Name: Gina and Maria Location: N/A Country: N/A Date: N/A Question: We are doing a science fair project on if B. Carotene, Green tea, and Grape Seed Extract helps plants against the crown gall disease. We injected sunflowers with agrobacterium tum. one week ago (Sun. Feb. 27, 2000). Our questions is how long will it take for the tumors to grow? We scratched the surface of the stems and injected the agrobacterium in the wound. Also which do you think, in your opinion, will do the best, if any? Our science fair is April 13, do you think we'll have growth before then, atleast enough time to do our conclusion and results? Thank you, any information you forward will be very helpful. Replies: Sunflowers form galls relatively quickly. I usually get them in two weeks at least. Good luck.

384

Alpha and gamma radiation effects on air-water systems at high gas/liquid ratios  

SciTech Connect

Radiolysis tests were conducted on air-water systems to examine the effects of radiation on liquid phase chemistry under high gas/liquid volume (G/L) ratios that are characteristic of an unsaturated nuclear waste repository setting. Test parameters included temperatures of 25, 90, and 200{degrees}C; gamma vs. alpha radiation; dose rates of {approximately}3500 and 50,000 rad/h; and G/L ratios of 10 and 100. Formate, oxalate, and total organic carbon contents increased during irradiation of the air-water systems in gamma and alpha tests at low-dose rate ({approximately}3500 rad/h). Increases in organic components were not observed for tests run at 200{degrees}C or high-dose rates (50,000 rad/h). In the tests where increases in organics occurred, the formate and oxalate were preferentially enriched in solutions that were rinsed from the test vessel walls. Nitrate (NO{sub 3}{sup {minus}}) is the dominant anion produced during the radiolysis reactions. Significant nitrite (NO{sub 2}{sup {minus}}) also occurs in some high-dose rate tests, with the reduced form of nitrogen possibly resulting from reactions with the test vessels. These results indicate that nitrogen acids are being produced and concentrated in the limited quantities of solution present in the tests. Nitrate + nitrite production varied inversely with temperature, with the lowest quantities being detected for the higher temperature tests. The G(NO{sub 3}{sup {minus}} + NO{sub 2}{sup {minus}}) values for the 25, 90, and 200{degrees}C experiments with gamma radiation are 3.2 {+-} 0.7, 1.3 {+-} 1.0, and 0.4 {+-} 0.3, respectively. Thus, the elevated temperatures expected early in the life of a repository may counteract pH decreases resulting from nitrogen acid production. Little variation was observed in G values as a function of dose rate or gas/liquid ratio.

Wronkiewicz, D.J.; Bates, J.K.

1993-08-01T23:59:59.000Z

385

Adjusted Growth Rates* Jan.  

U.S. Energy Information Administration (EIA) Indexed Site

Adjusted Adjusted Growth Rates* Jan. '99 to Feb. '99: -1.7% Feb. '98 to Feb. '99: +19.8% YTD '98 to YTD '99: +15.0% U.S. Distillate Fuel Sales 3,000 3,500 4,000 4,500 5,000 5,500 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1998 1999 2000 Adjusted Growth Rates* Dec '99 to Jan '00: -7.4% Jan '99 to Jan '00: -0.1% YTD '99 to YTD '00: -0.1% U.S. Motor Gasoline Sales 8,000 9,000 10,000 11,000 12,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1998 1999 2000 Adjusted Growth Rates* Dec '99 to Jan '00: -16.8% Jan '99 to Jan '00: -3.2% YTD '99 to YTD '00: -3.2% U.S. Kerosene-Type Jet Fuel Sales 1,500 1,600 1,700 1,800 1,900 2,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1998 1999 2000 Adjusted Growth Rates* Dec '99 to Jan '00: -9.3% Jan '99 to Jan '00: +3.5% YTD '99 to YTD '00: +3.5% U.S. Propane Sales 600 800 1,000 1,200 1,400 1,600 1,800 Jan Feb Mar Apr May Jun Jul

386

Toward a better understanding of the gamma index: Investigation of parameters with a surface-based distance method  

SciTech Connect

Purpose: The purpose of this work was to clarify the interactions between the parameters used in the {gamma} index with the surface-based distance method, which itself can be viewed as a generalized version of the {gamma} index. The examined parameters included the distance to agreement (DTA)/dose difference (DD) criteria, the percentage used as a passing criterion, and the passing percentage for given DTA/DD criteria. The specific aims of our work were (1) to understand the relationships between the parameters used in the {gamma} index, (2) to determine the detection limit, or the minimum detectable error, of the {gamma} index with a given set of parameters, and (3) to establish a procedure to determine parameters that are consistent with the capacity of an IMRT QA system. Methods: The surface-based distance technique with dose gradient factor was derived, and then the relationship between surface-based distance and {gamma} index was established. The dose gradient factor for plans and measurements of 10 IMRT patients, 10 spine stereotactic radiosurgery (SRS) patients, and 3 Radiological Physics Center (RPC) head and neck phantom were calculated and evaluated. The detection limits of the surface-based distance and {gamma} index methods were examined by introducing known shifts to the 10 IMRT plans. Results: The means of the dose gradient factors were 0.434 mm/% and 0.956 mm/% for the SRS and IMRT plans, respectively. Key quantities (including the mean and 90th and 99th percentiles of the distance distribution) of the surface-based distance distribution between two dose distributions were linearly proportional to the actual shifts. However, the passing percentage of the {gamma} index for a given set of DTA/DD criteria was not associated with the actual shift. For IMRT, using the standard quality assurance criteria of 3 mm/3% DTA/DD and a 90% passing rate, we found that the detection limit of the {gamma} index in terms of global shift was 4.07 mm/4.07 % without noise. Conclusions: Surface-based distance is a direct measure of the difference between two dose distributions and can be used to evaluate or determine parameters for use in calculating the {gamma} index. The dose gradient factor represents the weighting between spatial and dose shift and should be determined before DTA/DD criteria are set. The authors also present a procedure to determine {gamma} index parameters from measurements.

Li Heng; Dong Lei; Zhang Lifei; Yang, James N.; Gillin, Michael T.; Zhu, X. Ronald [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

2011-12-15T23:59:59.000Z

387

Adjusted Growth Rates*  

U.S. Energy Information Administration (EIA) Indexed Site

July '99 to Aug. '99: +4.7% July '99 to Aug. '99: +4.7% Aug. '98 to Aug. '99: +1.3% YTD '98 to YTD '99: +4.7% U.S. Motor Gasoline Sales 8,000 9,000 10,000 11,000 12,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* July '99 to Aug. '99: -1.9% Aug. '98 to Aug. '99: -0.4% YTD '98 to YTD '99: +0.9% U.S. Kerosene-Type Jet Fuel Sales 1,500 1,600 1,700 1,800 1,900 2,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* July '99 to Aug. '99: -0.1% Aug. '98 to Aug. '99: -1.4% YTD '98 to YTD '99: -0.7% U.S. Propane Sales 600 800 1,000 1,200 1,400 1,600 1,800 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* July '99 to Aug. '99: +22.3% Aug. '98 to Aug. '99: +21.1%

388

Adjusted Growth Rates*  

U.S. Energy Information Administration (EIA) Indexed Site

Aug '99 to Sep '99: +4.9% Aug '99 to Sep '99: +4.9% Sep '98 to Sep '99: +4.7% YTD '98 to YTD '99: +4.7% U.S. Motor Gasoline Sales 8,000 9,000 10,000 11,000 12,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Aug '99 to Sep '99: -2.4% Sep '98 to Sep '99: +0.4% YTD '98 to YTD '99: +1.3% U.S. Kerosene-Type Jet Fuel Sales 1,500 1,600 1,700 1,800 1,900 2,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Aug '99 to Sep '99: -2.1% Sep '98 to Sep '99: +4.6% YTD '98 to YTD '99: 0.0% U.S. Propane Sales 600 800 1,000 1,200 1,400 1,600 1,800 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Aug '99 to Sep '99: +7.3% Sep '98 to Sep '99: +8.4% YTD '98 to YTD '99: +8.3%

389

Adjusted Growth Rates*  

U.S. Energy Information Administration (EIA) Indexed Site

Oct '99 to Nov '99: +0.1% Oct '99 to Nov '99: +0.1% Nov '98 to Nov '99: +5.5% YTD '98 to YTD '99: +4.5% U.S. Motor Gasoline Sales 8,000 9,000 10,000 11,000 12,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Oct '99 to Nov '99: -0.7% Nov '98 to Nov '99: +1.7% YTD '98 to YTD '99: +1.1% U.S. Kerosene-Type Jet Fuel Sales 1,500 1,600 1,700 1,800 1,900 2,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Oct '99 to Nov '99: +2.5% Nov '98 to Nov '99: +6.0% YTD '98 to YTD '99: +0.8% U.S. Propane Sales 600 800 1,000 1,200 1,400 1,600 1,800 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Oct '99 to Nov '99: +9.7% Nov '98 to Nov '99: +2.2% YTD '98 to YTD '99: +6.2%

390

Adjusted Growth Rates*  

U.S. Energy Information Administration (EIA) Indexed Site

Sep '99 to Oct '99: +3.9% Sep '99 to Oct '99: +3.9% Oct '98 to Oct '99: +2.3% YTD '98 to YTD '99: +4.4% U.S. Motor Gasoline Sales 8,000 9,000 10,000 11,000 12,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Sep '99 to Oct '99: -0.2% Oct '98 to Oct '99: -0.9% YTD '98 to YTD '99: +1.0% U.S. Kerosene-Type Jet Fuel Sales 1,500 1,600 1,700 1,800 1,900 2,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Sep '99 to Oct '99: -1.9% Oct '98 to Oct '99: -0.7% YTD '98 to YTD '99: +0.4% U.S. Propane Sales 600 800 1,000 1,200 1,400 1,600 1,800 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Sep '99 to Oct '99: -2.1% Oct '98 to Oct '99: -6.4% YTD '98 to YTD '99: +6.6%

391

Adjusted Growth Rates*  

U.S. Energy Information Administration (EIA) Indexed Site

June '99 to July '99: -5.4% June '99 to July '99: -5.4% July '98 to July '99: +3.3% YTD '98 to YTD '99: +6.3% U.S. Motor Gasoline Sales 8,000 9,000 10,000 11,000 12,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* June '99 to July '99: -0.5% July '98 to July '99: -0.4% YTD '98 to YTD '99: +1.1% U.S. Kerosene-Type Jet Fuel Sales 1,500 1,600 1,700 1,800 1,900 2,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* June '99 to July '99: +0.5% July '98 to July '99: +1.0% YTD '98 to YTD '99: -0.3% U.S. Propane Sales 600 800 1,000 1,200 1,400 1,600 1,800 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* June '99 to July '99: +1.5% July '98 to July '99: +10.2% YTD '98 to YTD '99: +7.2%

392

Adjusted Growth Rates*  

U.S. Energy Information Administration (EIA) Indexed Site

Nov '99 to Dec '99: +5.3% Nov '99 to Dec '99: +5.3% Dec '98 to Dec '99: +8.7% YTD '98 to YTD '99: +5.0% U.S. Motor Gasoline Sales 8,000 9,000 10,000 11,000 12,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Nov '99 to Dec '99: +6.0% Dec '98 to Dec '99: +4.5% YTD '98 to YTD '99: +1.3% U.S. Kerosene-Type Jet Fuel Sales 1,500 1,600 1,700 1,800 1,900 2,000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Nov '99 to Dec '99: +2.4% Dec '98 to Dec '99: +3.0% YTD '98 to YTD '99: +0.9% U.S. Propane Sales 600 800 1,000 1,200 1,400 1,600 1,800 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Millions of Gallons 1997 1998 1999 Adjusted Growth Rates* Nov '99 to Dec '99: +32.3% Dec '98 to Dec '99: +2.0% YTD '98 to YTD '99: +5.5%

393

NEUTRINO-COOLED ACCRETION MODEL WITH MAGNETIC COUPLING FOR X-RAY FLARES IN GAMMA-RAY BURSTS  

Science Conference Proceedings (OSTI)

The neutrino-cooled accretion disk, which was proposed to work as the central engine of gamma-ray bursts, encounters difficulty in interpreting the X-ray flares after the prompt gamma-ray emission. In this paper, the magnetic coupling (MC) between the inner disk and the central black hole (BH) is taken into consideration. For mass accretion rates around 0.001 {approx} 0.1 M{sub Sun} s{sup -1}, our results show that the luminosity of neutrino annihilation can be significantly enhanced due to the coupling effects. As a consequence, after the gamma-ray emission, a remnant disk with mass M{sub disk} {approx}ray flares with the rest frame duration less than 100 s. In addition, a comparison between the MC process and the Blandford-Znajek mechanism is shown on the extraction of BH rotational energy.

Luo Yang; Gu Weimin; Liu Tong; Lu Jufu, E-mail: guwm@xmu.edu.cn [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China)

2013-08-20T23:59:59.000Z

394

Neutron Exposure Parameters for the Dosimetry Capsule in the Heavy-Section Steel Irradiation Program Tenth Irradiation Series  

Science Conference Proceedings (OSTI)

This report describes the computational methodology for the least-squares adjustment of the dosimetry data from the HSSI 10.OD dosimetry capsule with neutronics calculations. It presents exposure rates at each dosimetry location for the neutron fluence greater than 1.0 MeV, fluence greater than 0.1 MeV, and displacements per atom. Exposure parameter distributions are also described in terms of three- dimensional fitting functions. When fitting functions are used it is suggested that an uncertainty of 6% (1 o) should be associated with the exposure rate values. The specific activity of each dosimeter at the end of irradiation is listed in the Appendix.

C.A. Baldwin; F.B.K. Kam; I. Remec

1998-10-01T23:59:59.000Z

395

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

SciTech Connect

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

396

All-Sky Earth Occultation Observations with the Fermi Gamma Ray Burst Monitor  

E-Print Network (OSTI)

Using the Gamma Ray Burst Monitor (GBM) on-board Fermi, we are monitoring the hard X-ray/soft gamma ray sky using the Earth occultation technique. Each time a source in our catalog enters or exits occultation by the Earth, we measure its flux using the change in count rates due to the occultation. Currently we are using CTIME data with 8 energy channels spanning 8 keV to 1 MeV for the GBM NaI detectors and spanning 150 keV to 40 MeV for the GBM BGO detectors. Our preliminary catalog consists of galactic X-ray binaries, the Crab Nebula, and active galactic nuclei. In addition, to Earth occultations, we have observed numerous occultations with Fermi's solar panels. We will present early results. Regularly updated results can be found on our website http://gammaray.nsstc.nasa.gov/gbm/science/occultation

Wilson-Hodge, Colleen A; Bhat, P N; Briggs, M S; Chaplin, V; Connaughton, V; Camero-Arranz, A; Case, G; Cherry, M; Rodi, J; Finger, M H; Jenke, P; Haynes, R H

2009-01-01T23:59:59.000Z

397

DEVELOPMENT OF DEPOSIT DETECTION SYSTEM IN PIPELINES OF THE STEELWORKS USING CS-137 GAMMA-RAY  

SciTech Connect

The deposit is built up in the pipeline of the steelworks by the chemical reaction among COG (coke oven gas), BFG (blast furnace gas), moisture, and steel in the high temperature environment and obstructs the smooth gas flow. In this study a gamma-ray system is developed to detect the deposit accumulated in pipelines and calculate the accumulation rate with respect to the cross section area of pipes. Cs-137 is used as the gamma-ray source and the system is designed to apply to pipes of various diameters. This system also includes the DB for storage and display of the measurement results so that it can be used for the efficient management of the pipelines.

Song, Won-Joon; Lee, Seung-Hee; Jeong, Hee-Dong [Research Institute of Industrial Science and Technology, 32 Hyoja-Dong, Nam-Ku, Pohang, 790-330 (Korea, Republic of)

2008-02-28T23:59:59.000Z

398

THE EXTRAGALACTIC BACKGROUND LIGHT FROM THE MEASUREMENTS OF THE ATTENUATION OF HIGH-ENERGY GAMMA-RAY SPECTRUM  

SciTech Connect

The attenuation of high-energy gamma-ray spectrum due to the electron-positron pair production against the extragalactic background light (EBL) provides an indirect method to measure the EBL of the universe. We use the measurements of the absorption features of the gamma-rays from blazars as seen by the Fermi Gamma-ray Space Telescope to explore the EBL flux density and constrain the EBL spectrum, star formation rate density (SFRD), and photon escape fraction from galaxies out to z = 6. Our results are basically consistent with the existing determinations of the quantities. We find a larger photon escape fraction at high redshifts, especially at z = 3, compared to the result from recent Ly{alpha} measurements. Our SFRD result is consistent with the data from both gamma-ray burst and ultraviolet (UV) observations in the 1{sigma} level. However, the average SFRD we obtain at z {approx}> 3 matches the gamma-ray data better than the UV data. Thus our SFRD result at z {approx}> 6 favors the fact that star formation alone is sufficiently high enough to reionize the universe.

Gong Yan; Cooray, Asantha [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)

2013-07-20T23:59:59.000Z

399

Cross sections for proton-induced reactions on Pd isotopes at energies relevant for the {gamma} process  

Science Conference Proceedings (OSTI)

Proton-activation reactions on natural and enriched palladium samples were investigated via the activation technique in the energy range of E{sub p}=2.75-9 MeV, close to the upper end of the respective Gamow window of the {gamma} process. We have determined cross sections for {sup 102}Pd(p, {gamma}){sup 103}Ag, {sup 104}Pd(p, {gamma}){sup 105}Ag, and {sup 105}Pd(p, n){sup 105}Ag, as well as partial cross sections of {sup 104}Pd(p, n){sup 104}Ag{sup g}, {sup 105}Pd(p, {gamma}){sup 106}Ag{sup m}, {sup 106}Pd(p, n){sup 106}Ag{sup m}, and {sup 110}Pd(p, n){sup 110}Ag{sup m} with uncertainties between 3% and 15% for constraining theoretical Hauser-Feshbach rates and for direct use in {gamma}-process calculations.

Dillmann, I.; Coquard, L.; Domingo-Pardo, C.; Kaeppeler, F.; Marganiec, J.; Uberseder, E.; Giesen, U.; Heiske, A.; Feinberg, G.; Hentschel, D.; Hilpp, S.; Leiste, H.; Rauscher, T.; Thielemann, F.-K. [Karlsruher Institut fuer Technologie (KIT), Campus Nord, Institut fuer Kernphysik, Postfach 3640, D-76021 Karlsruhe (Germany); Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, D-38116 Braunschweig (Germany); Soreq Nuclear Research Center, Yavne (Israel); Karlsruher Institut fuer Technologie (KIT), Campus Nord, Institut fuer Nukleare Entsorgung, Postfach 3640, D-76021 Karlsruhe (Germany); Karlsruher Institut fuer Technologie (KIT), Campus Nord, Institut fuer Angewandte Materialien, Postfach 3640, D-76021 Karlsruhe (Germany); Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

2011-07-15T23:59:59.000Z

400

GAMQUEST, a Computer Program to Identify Gamma Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

GAMQUEST GAMQUEST A Computer Program to Identify Gamma Rays Edgardo Browne, Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 EBROWNE@LBL.Gov Table of Contents Introduction. Program Access and Output Files. How to Run GAMQUEST. From Individual Accounts. From Guest Account. Gamma-Ray Data. GAMQUEST, a Tool for Applied Research. Searching Strategies. Examples. Neutron Activation Analysis. Gamma-Ray Spectrum Between 100 and 800 keV. Gamma-Ray Spectrum Between 800 and 1600 keV. A List of X Rays and Gamma Rays from the Decay of 192Ir (74 hr). Run GAMQUEST from Guest Account Acknowledgments. References. 1. Introduction. The characteristic energies and intensities of gamma rays emitted by radioactive isotopes are commonly used as fingerprints for isotope

Note: This page contains sample records for the topic "gamma exposure rates" 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

Gamma Log At Coso Geothermal Area (1977) | Open Energy Information  

Open Energy Info (EERE)

Gamma Log At Coso Geothermal Area (1977) Gamma Log At Coso Geothermal Area (1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Gamma Log At Coso Geothermal Area (1977) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Gamma Log Activity Date 1977 Usefulness not indicated DOE-funding Unknown Notes extensive geophysical logging surveys were conducted: natural gamma and neutron porosity logs indicate gross rock type References Galbraith, R. M. (1 May 1978) Geological and geophysical analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California Goranson, C.; Schroeder, R. (1 June 1978) Static downhole characteristics of well CGEH-1 at Coso Hot Springs, China Lake, California Retrieved from "http://en.openei.org/w/index.php?title=Gamma_Log_At_Coso_Geothermal_Area_(1977)&oldid=510780"

402

Gamma-ray burst interaction with dense interstellar medium  

E-Print Network (OSTI)

Interaction of cosmological gamma ray burst radiation with the dense interstellar medium of host galaxy is considered. Gas dynamical motion of interstellar medium driven by gamma ray burst is investigated in 2D approximation for different initial density distributions of host galaxy matter and different total energy of gamma ray burst. The maximum velocity of motion of interstellar medium is $1.8\\cdot10^4$ km/s. Light curves of gamma ray burst afterglow are calculated for set of non homogeneous density, distribution gamma ray burst total energy, and different viewing angles. Spectra of gamma ray burst afterglow are modeled taking into account conversion of hard photons (soft X-ray, hard UV) to soft UV and optics photons.

Maxim Barkov; Gennady Bisnovatyi-Kogan

2004-10-07T23:59:59.000Z

403

Estimation of Dynamic Rate Parameters in Insect Populations Undergoing Sublethal Exposure to  

E-Print Network (OSTI)

. This was partly because matrix algebra was perceived as an advanced and esoteric branch of mathematics

404

Common Indoor Sources of volatile organic compounds: emission rates and techniques for reducing consumer exposures  

E-Print Network (OSTI)

of 1.3-cm thick, smooth plywood. These paints were appliedlatex paint combination. The plywood floor was covered withpaint consisted of two plywood panels each with surface

Hodgson, A.T.

2011-01-01T23:59:59.000Z

405

EFFECTS OF TRITIUM EXPOSURE ON UHMW-PE, PTFE, AND VESPEL  

DOE Green Energy (OSTI)

Samples of three polymers, Ultra-High Molecular Weight Polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, also known as Teflon{reg_sign}), and Vespel{reg_sign} polyimide were exposed to 1 atmosphere of tritium gas at ambient temperature for varying times up to 2.3 years in closed containers. Sample mass and size measurements (to calculate density), spectra-colorimetry, dynamic mechanical analysis (DMA), and Fourier-transform infrared spectroscopy (FT-IR) were employed to characterize the effects of tritium exposure on these samples. Changes of the tritium exposure gas itself were characterized at the end of exposure by measuring total pressure and by mass spectroscopic analysis of the gas composition. None of the polymers exhibited significant changes of density. The color of initially white UHMW-PE and PTFE dramatically darkened to the eye and the color also significantly changed as measured by colorimetry. The bulk of UHMW-PE darkened just like the external surfaces, however the fracture surface of PTFE appeared white compared to the PTFE external surfaces. The white interior could have been formed while the sample was breaking or could reflect the extra tritium dose at the surface directly from the gas. The dynamic mechanical response of UHMW-PE was typical of radiation effects on polymers- an initial stiffening (increased storage modulus) and reduction of viscous behavior after three months exposure, followed by lowering of the storage modulus after one year exposure and longer. The storage modulus of PTFE increased through about nine months tritium exposure, then the samples became too weak to handle or test using DMA. Characterization of Vespel{reg_sign} using DMA was problematic--sample-to-sample variations were significant and no systematic change with tritium exposure could be discerned. Isotopic exchange and incorporation of tritium into UHMW-PE (exchanging for protium) and into PTFE (exchanging for fluorine) was observed by FT-IR using an attenuated total reflectance method. No significant change in the Vespel{reg_sign} infrared spectrum was observed after three months exposure. Protium significantly pressurized the UHMW-PE containers during exposure to about nine atmospheres (the initial pressure was one atmosphere of tritium). This is consistent with the well-known production of hydrogen by irradiation of polyethylene by ionizing radiation. The total pressure in the PTFE containers decreased, and a mass balance reveals that the observed decrease is consistent with the formation of small amounts of {sup 3}HF, which is condensed at ambient temperature. No significant change of pressure occurred in the Vespel{reg_sign} containers; however the composition of the gas became about 50% protium, showing that Vespel{reg_sign} interacted with the tritium gas atmosphere to some degree. The relative resistance to degradation from tritium exposure is least for PTFE, more for UHMW-PE, and the most for Vespel{reg_sign}, which is consistent with the known relative resistance of these polymers to gamma irradiation. This qualitatively agrees with the concept of equivalent effects for equivalent absorbed doses of radiation damage of polymers. Some of the changes of different polymers are qualitatively similar; however each polymer exhibited unique property changes when exposed to tritium. Information from this study that can be applied to a tritium facility is: (1) the relative resistance to tritium degradation of the three polymers studied is the same as the relative resistance to gamma irradiation in air (so relative rankings of polymer resistance to ionizing radiation can be used as a relative ranking for assessing tritium compatibility and polymer selection); and (2) all three polymers changed the gas atmosphere during tritium exposure--UHMW-PE and Vespel{reg_sign} exposed to tritium formed H{sub 2} gas (UHMW-PE much more so), and PTFE exposed to tritium formed {sup 3}HF. This observation of forming {sup 3}HF supports the general concept of minimizing chlorofluorocarbon polymers in tritium systems.

Clark, E; Kirk Shanahan, K

2006-05-31T23:59:59.000Z

406

Rate Adjustments and Public Involvement  

NLE Websites -- All DOE Office Websites (Extended Search)

Rate Adjustments and Public Involvement Documents Rate Adjustments and Public Involvement Documents CRSP Transmission 9/16/2013 WAPA-161 FRN, CRSP transmission and ancillary services rates extension Letter announcing two-year extension to CRSP transmission and ancillary services rates Letter announcing revised CRSP transmission rates for FY 2014 Accompanying calculation table for FY 2014 CRSP transmission rate letter Letter announcing revised CRSP transmission rates for FY 2013 Letter announcing revised CRSP transmission rates for FY 2012 Letter announcing revised CRSP transmission rates for FY 2011 Letter announcing revised CRSP transmission rates for FY 2010 SLCA/IP 9/16/2013 WAPA-161 FRN, SLCA/IP firm power rate extension Letter announcing two-year extension to SLCA/IP firm power rate SLCA/IP Tentative Rate Adjustment Schedule

407

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

408

The Multiwavelength Approach to Unidentified Gamma-Ray Sources  

E-Print Network (OSTI)

As the highest-energy photons, gamma rays have an inherent interest to astrophysicists and particle physicists studying high-energy, nonthermal processes. Gamma-ray telescopes complement those at other wavelengths, especially radio, optical, and X-ray, providing the broad, mutiwavelength coverage that has become such a powerful aspect of modern astrophysics. Multiwavelength techniques of various types have been developed to help identify and explore unidentified gamma-ray sources. This overview summarizes the ideas behind several of these methods.

David J. Thompson

2004-07-20T23:59:59.000Z

409

Gamma Ray Bursts, Neutron Star Quakes, and the Casimir Effect  

E-Print Network (OSTI)

We propose that the dynamic Casimir effect is a mechanism that converts the energy of neutron starquakes into $\\gamma$--rays. This mechanism efficiently produces photons from electromagnetic Casimir energy released by the rapid motion of a dielectric medium into a vacuum. Estimates based on the cutoff energy of the gamma ray bursts and the volume involved in a starquake indicate that the total gamma ray energy emission is consonant with observational requirements.

C. Carlson; T. Goldman; J. Perez-Mercader

1994-11-25T23:59:59.000Z

410

Nuclear Criticality as a Contributor to Gamma Ray Burst Events  

E-Print Network (OSTI)

Most gamma ray bursts are able to be explained using supernovae related phenomenon. Some measured results still lack compelling explanations and a contributory cause from nuclear criticality is proposed. This is shown to have general properties consistent with various known gamma ray burst properties. The galactic origin of fast rise exponential decay gamma ray bursts is considered a strong candidate for these types of events.

Robert Bruce Hayes

2013-01-15T23:59:59.000Z

411

Integrated Job Exposure Matrix for Electric Utility Workers  

Science Conference Proceedings (OSTI)

This report identifies and includes all exposure factors in a prototype job-exposure matrix (JEM) to inform utility professionals, exposure assessment experts, and epidemiologists about exposures other than electric and magnetic fields that should be considered when assessing health and safety issues related to work near electric facilities. The nature of exposures to these factors, the ordinal exposure ranking for most of the factors, and the methodology for establishing such determining ordinal exposur...

2009-07-14T23:59:59.000Z

412

PULSE RATE DIVIDER  

DOE Patents (OSTI)

A compact pulse-rate divider circuit affording low impedance output and high input pulse repetition rates is described. The circuit features a single secondary emission tube having a capacitor interposed between its dynode and its control grid. An output pulse is produced at the anode of the tube each time an incoming pulse at the control grid drives the tube above cutoff and the duration of each output pulse corresponds to the charging time of the capacitor. Pulses incoming during the time the grid bias established by the discharging capacitor is sufficiently negative that the pulses are unable to drive the tube above cutoff do not produce output pulses at the anode; these pulses are lost and a dividing action is thus produced by the circuit. The time constant of the discharge path may be vanied to vary in turn the division ratio of the circuit; the time constant of the charging circuit may be varied to vary the width of the output pulses. (AEC)

McDonald, H.C. Jr.

1962-12-18T23:59:59.000Z

413

Inelastic cross sections from gamma-ray measurements  

Science Conference Proceedings (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

414

Future Facilities for Gamma-Ray Pulsar Studies  

E-Print Network (OSTI)

Pulsars seen at gamma-ray energies offer insight into particle acceleration to very high energies, along with information about the geometry and interaction processes in the magnetospheres of these rotating neutron stars. During the next decade, a number of new gamma-ray facilities will become available for pulsar studies. This brief review describes the motivation for gamma-ray pulsar studies, the opportunities for such studies, and some specific discussion of the capabilities of the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) for pulsar measurements.

D. J. Thompson

2003-10-17T23:59:59.000Z

415

Available Technologies: Plasma-Driven Neutron/Gamma Generators  

Biofuels; Biotechnology & Medicine. ... with changes in appropriate source gases and target materials, for creating either a neutron beam or a gamma ray beam, ...

416

The Diverse Environments of Gamma-Ray Bursts.  

E-Print Network (OSTI)

??I present results from several years of concerted observations of the afterglows and host galaxies of gamma-ray bursts (GRBs), the most energetic explosions in the… (more)

Perley, Daniel Alan

2011-01-01T23:59:59.000Z

417

X-ray Flares in Gamma-Ray Bursts.  

E-Print Network (OSTI)

??Data from the Swift mission have now shown that flares are a common component of Gamma-Ray Burst afterglows, appearing in roughly 50% of GRBs to… (more)

Morris, David

2008-01-01T23:59:59.000Z

418

JOM 0601: Recent Progress in the Coating Protection of Gamma ...  

Science Conference Proceedings (OSTI)

Recent Progress in the Coating Protection of Gamma Titanium-Aluminides. C. LEYENS, R. BRAUN, M. FRÖHLICH, and P. EH. HOVSEPIAN ...

419

Emerging Robust Beta Gamma TiAl Alloys  

Science Conference Proceedings (OSTI)

Recently a new class of TiAl based alloy system, called beta gamma, that ... Phase-Field Simulation on Phase Transformation during Creep Deformation in Type ...

420

Additive Manufacturing of Gamma Titanium Aluminide Parts by ...  

Science Conference Proceedings (OSTI)

Feb 1, 2010 ... Additive Manufacturing of Gamma Titanium Aluminide Parts by Electron Beam Melting by Silvia Sabbadini, Oriana Tassa, P. Gennaro, and Ulf ...

Note: This page contains sample records for the topic "gamma exposure rates" 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

Astrophysical and Astrobiological effects of Gamma-Ray Bursts.  

E-Print Network (OSTI)

??O presente trabalho tem o objetivo principal de compreender os possíveis efeitos da radiação energética de um evento de Gamma-Ray Burst (GRB) sobre o meio… (more)

Douglas Galante

2009-01-01T23:59:59.000Z

422

Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture  

SciTech Connect

The countrate response of a gamma spectrometry system from a neutron radiation source behind a plane of moderating material doped with a nuclide of a large radiative neutron capture cross-section exhibits a countrate response analogous to a gamma radiation source at the same position from the detector. Using a planar, surface area of the neutron moderating material exposed to the neutron radiation produces a larger area under the prompt gamma ray peak in the detector than a smaller area of dimensions relative to the active volume of the gamma detection system.

Scott Wilde, Raymond Keegan

2008-07-01T23:59:59.000Z

423

THE NEW CANGAROO TELESCOPE AND THE PROSPECT OF VHE GAMMA RAY OBSERVATION AT  

E-Print Network (OSTI)

), the doppler boosting of secondary gamma-rays is sufficient to produce TeV gamma-rays. Gamma-ray bursts: Fireballs expanding with relativistic speed explain gamma-ray bursts at cosmological distancesStudy of Celestial Objects with Very High Energy Gamma Rays CANGAROO III Project Description

Enomoto, Ryoji

424

Compton scattering effects on the duration of terrestrial gamma-ray flashes  

E-Print Network (OSTI)

; published 18 January 2012. [1] Terrestrial gamma-ray flashes (TGFs) are gamma-ray bursts detected from space) recently discovered by the gamma-ray burst monitor (GBM) aboard the Fermi Gamma-Ray Space Telescope. Introduction [2] Terrestrial gamma-ray flashes (TGFs) are bursts of high-energy photons originating from

Pasko, Victor

425

Study of Celestial Objects with Very High Energy Gamma Rays CANGAROO III  

E-Print Network (OSTI)

), the doppler boosting of secondary gamma-rays is sufficient to produce TeV gamma-rays. Gamma-ray bursts: Fireballs expanding with relativistic speed explain gamma-ray bursts at cosmological distancesStudy of Celestial Objects with Very High Energy Gamma Rays CANGAROO III Project Description

Enomoto, Ryoji

426

OBSERVATIONS OF THE PROMPT GAMMA-RAY EMISSION OF GRB 070125 Eric C. Bellm,1  

E-Print Network (OSTI)

2007 November 13; accepted 2008 July 25 ABSTRACT The long, bright gamma-ray burst GRB 070125: gamma rays: bursts 1. INTRODUCTION The prompt gamma-ray emission of gamma-ray bursts (GRBs) is the mostOBSERVATIONS OF THE PROMPT GAMMA-RAY EMISSION OF GRB 070125 Eric C. Bellm,1 Kevin Hurley,1 Valentin

California at Berkeley, University of

427

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

428

Gamma-Ray Bursts observed by INTEGRAL  

E-Print Network (OSTI)

During the first six months of operations, six Gamma Ray Bursts (GRBs) have been detected in the field of view of the INTEGRAL instruments and localized by the INTEGRAL Burst Alert System (IBAS): a software for the automatic search of GRBs and the rapid distribution of their coordinates. I describe the current performances of IBAS and review the main results obtained so far. The coordinates of the latest burst localized by IBAS, GRB 031203, have been distributed within 20 s from the burst onset and with an uncertainty radius of only 2.7 arcmin.

S. Mereghetti

2003-12-12T23:59:59.000Z

429

Higgs boson decay to mu mubar gamma  

E-Print Network (OSTI)

The Higgs boson decay, H -> mu mubar gamma, is studied in the Standard Model at the tree and one-loop levels. It is shown that for Higgs boson masses above 110 GeV, the contribution to the radiative width from the one-loop level exceeds the contribution from the tree level, and for Higgs boson masses above 140 GeV, it even exceeds the contribution from the tree level decay H -> mu mubar. We also show that the contributions to the radiative decay width from the interference terms between the tree and one-loop diagrams are negligible.

Ali Abbasabadi; Wayne W. Repko

2000-04-17T23:59:59.000Z

430

Radicals in {gamma}-irradiated wool  

SciTech Connect

Radicals were identified in wool fiber {gamma}-irradiated at 77 K by EPR: products of reaction of an electron e and H atom with amino acid residues and a polypeptide chain, and their partial yields at 77 K and the reactivity scale of e with respect to the individual fragments of the protein molecule were determined: [RSSR]: [>C=O{sub p.b.}]:[NH{sub 3}{sup +}-R]:[aromatic ring] = 4:3: > 1:1. 10 refs., 1 fig., 1 tab.

Baeva, N.N.; Sadova, S.F.; Sharpatyi, V.A.

1992-01-01T23:59:59.000Z

431

Can Naked Singularities Yield Gamma Ray Bursts?  

E-Print Network (OSTI)

Gamma-ray bursts are believed to be the most luminous objects in the Universe. There has been some suggestion that these arise from quantum processes around naked singularities. The main problem with this suggestion is that all known examples of naked singularities are massless and hence there is effectively no source of energy. It is argued that a globally naked singularity coupled with quantum processes operating within a distance of the order of Planck length of the singularity will probably yield energy burst of the order of M_pc^2\\approx2\\times 10^{16} ergs, where M_p is the Planck mass.

H. M. Antia

1998-07-09T23:59:59.000Z

432

Gamma Ray Burst Neutrinos Probing Quantum Gravity  

E-Print Network (OSTI)

Very high energy, short wavelength, neutrinos may interact with the space-time foam predicted by theories of quantum gravity. They would propagate like light through a crystal lattice and be delayed, with the delay depending on the energy. This will appear to the observer as a violation of Lorenz invariance. Back of the envelope calculations imply that observations of neutrinos produced by gamma ray bursts may reach Planck-scale sensitivity. We revisit the problem considering two essential complications: the imprecise timing of the neutrinos associated with their poorly understood production mechanism in the source and the indirect nature of their energy measurement made by high energy neutrino telescopes.

M. C. Gonzalez-Garcia; F. Halzen

2006-11-28T23:59:59.000Z

433

Image Recognition Techniques for Gamma Spectroscopy  

SciTech Connect

Photons, after generated from a radioactive source and before they deposit their energy in a photo detector, are subsequent to multiple scattering mechanisms. As a result, the measured energy from the photo detector is different from the energy the photon had when generated. This is known as folding of the photon energy. Moreover, statistical fluctuation inside the detector contribute to energy folding. In this work, a new method is presented for unfolding the gamma ray spectrum. The method uses a 2-dimensional representation of the measured spectrum (image) and then uses image recognition techniques, and especially differential edge detection, to generate the original spectrum.

Vlachos, D. S. [University of Peloponnese, 22100 Tripoli (Greece); Tsabaris, C. G. [Hellenic Center for Marine Research, 19013 Athens (Greece)

2007-12-26T23:59:59.000Z

434

The Animated Gamma-ray Sky Revealed by the Fermi Gamma-ray Space Telescope  

SciTech Connect

The Fermi Gamma-ray Space Telescope has been observing the sky in gamma-rays since August 2008. In addition to breakthrough capabilities in energy coverage (20 MeV-300 GeV) and angular resolution, the wide field of view of the Large Area Telescope enables observations of 20% of the sky at any instant, and of the whole sky every three hours. It has revealed a very animated sky with bright gamma-ray bursts flashing and vanishing in minutes, powerful active galactic nuclei flaring over hours and days, many pulsars twinkling in the Milky Way, and X-ray binaries shimmering along their orbit. Most of these variable sources had not been seen by the Fermi predecessor, EGRET, and the wealth of new data already brings important clues to the origin of the high-energy emission and particles powered by the compact objects. The telescope also brings crisp images of the bright gamma-ray emission produced by cosmic-ray interactions in the interstellar medium, thus allowing to measure the cosmic nuclei and electron spectra across the Galaxy, to weigh interstellar clouds, in particular in the dark-gas phase. The telescope sensitivity at high energy will soon provide useful constraints on dark-matter annihilations in a variety of environments. I will review the current results and future prospects of the Fermi mission.

Grenier, Isabelle (University Paris Diderot and CEA Saclay, France)

2009-04-01T23:59:59.000Z

435

No Evidence for Gamma-Ray Burst/Abell Cluster or Gamma- Ray Burst/Radio-Quiet Quasar Correlations  

E-Print Network (OSTI)

We examine the recent claims that cosmic gamma-ray bursts are associated with either radio-quiet quasars or Abell clusters. These associations were based on positional coincidences between cataloged quasars or Abell clusters, and selected events from the BATSE 3B catalog of gamma-ray bursts. We use a larger sample of gamma-ray bursts with more accurate positions, obtained by the 3rd Interplanetary Network, to re-evaluate these possible associations. We find no evidence for either.

K. Hurley; D. H. Hartmann; C. Kouveliotou; R. M. Kippen; J. Laros; T. Cline; M. Boer

1998-11-28T23:59:59.000Z

436

AC field exposure study: human exposure to 60-Hz electric fields  

SciTech Connect

The objective of this study was to develop a method of estimating human exposure to the 60 Hz electric fields created by transmission lines. The Activity Systems Model simulates human activities in a variety of situations where exposure to electric fields is possible. The model combines maps of electric fields, activity maps, and experimentally determined activity factors to provide histograms of time spent in electric fields of various strengths in the course of agricultural, recreational, and domestic activities. For corroboration, the study team measured actual human exposure at locations across the United States near transmission lines ranging in voltage from 115 to 1200 kV. The data were collected with a specially designed vest that measures exposure. These data demonstrate the accuracy of the exposure model presented in this report and revealed that most exposure time is spent in fields of magnitudes similar to many household situations. The report provides annual exposure estimates for human activities near transmission lines and in the home and compares them with exposure data from typical laboratory animal experiments. For one exposure index, the cumulative product of time and electric field, exposure during some of the laboratory animal experiments is two to four orders of magnitude greater than cumulative exposure for a human during one year of outdoor work on a farm crossed by a transmission line.

Silva, J.M.

1985-04-01T23:59:59.000Z

437

Survey of innovative rates, 1991  

SciTech Connect

Current innovative rate data from 135 major utilities throughout the United States were gathered and analyzed. Over 1000 innovative rates that were in use by the utilities in 1990 and 1991 were identified, abstracted and entered into a database. Survey results indicate that over 616 million MWh were sold to the nearly five million customers using the innovative rates offered. From an annual sales perspective, the most widely used rates are demand-side management rates -- rates intended to change customer energy use -- and rates that are market-driven.'' The survey identified 525 demand-side management rates serving our four million customers with reported sales of approximately 520 million MWh. These rates serve over 80% of the total innovative rate customers and account for 84% of the total MWh sales. Also important in terms of MWh sales they represent are market-driven rates, which accounted for sales of 48 million MWh in 1990. Both demand-side management and market-driven rates show a 20% customer growth rate between 1988 and 1990. Other innovative rates examined in the survey included: prepaid service; load retention incentive rates; technology specific rates; and those rates related expressly to non-utility generators -- namely buy-back and standby rates.

White, L.J.; Wakefield, R.A.; McVicker, C.M.

1992-04-01T23:59:59.000Z

438

Survey of innovative rates, 1991  

Science Conference Proceedings (OSTI)

Current innovative rate data from 135 major utilities throughout the United States were gathered and analyzed. Over 1000 innovative rates that were in use by the utilities in 1990 and 1991 were identified, abstracted and entered into a database. Survey results indicate that over 616 million MWh were sold to the nearly five million customers using the innovative rates offered. From an annual sales perspective, the most widely used rates are demand-side management rates -- rates intended to change customer energy use -- and rates that are market-driven.'' The survey identified 525 demand-side management rates serving our four million customers with reported sales of approximately 520 million MWh. These rates serve over 80% of the total innovative rate customers and account for 84% of the total MWh sales. Also important in terms of the MWh sales they represent are market-driven rates, which accounted for sales of 48 million MWh in 1990. Both demand-side management and market-driven rates show a 20% customer growth rate between 1988 and 1990. Other innovative rates examined in the survey included: prepaid service; load retention incentive rates; technology specific rates; and those rates related expressly to non-utility generators -- namely buy-back and standby rates.

White, L.J.; Wakefield, R.A.; McVicker, C.M.

1992-04-01T23:59:59.000Z

439

Ambient air pollution exposure and the incidence of related health effects among racial/ethnic minorities  

Science Conference Proceedings (OSTI)

Differences among racial and ethnic groups in morbidity and mortality rates for diseases, including diseases with environmental causes, have been extensively documented. However, documenting the linkages between environmental contaminants, individual exposures, and disease incidence has been hindered by difficulties in measuring exposure for the population in general and for minority populations in particular. After briefly discussing research findings on associations of common air pollutants with disease incidence, the authors summarize recent studies of radial/ethnic subgroup differences in incidence of these diseases in the US. They then present evidence of both historic and current patterns of disproportionate minority group exposure to air pollution as measured by residence in areas where ambient air quality standards are violated. The current indications of disproportionate potential exposures of minority and low-income populations to air pollutants represent the continuation of a historical trend. The evidence of linkage between disproportionate exposure to air pollution of racial/ethnic minorities and low-income groups and their higher rates of some air pollution-related diseases is largely circumstantial. Differences in disease incidence and mortality rates among racial/ethnic groups are discussed for respiratory diseases, cancers, and lead poisoning. Pollutants of concern include CO, Pb, SO{sub 2}, O{sub 3}, and particulates.

Nieves, L.A.; Wernette, D.R.

1997-02-01T23:59:59.000Z

440

NNLL QCD Contribution of the Electromagnetic Dipole Operator to Gamma(anti-B -> X(s) gamma)  

E-Print Network (OSTI)

We present an independent calculation of that part of the O(\\alpha_s^2) contribution to the decay width \\Gamma(\\bar B -> X_s \\gamma) which arises from the self-interference term of the electromagnetic dipole operator O_7. Using a different method, we find complete agreement with a previous calculation. This NNLL contribution is an important ingredient for the complete NNLL prediction of \\Gamma(\\bar B -> X_s \\gamma) which will resolve the charm quark mass ambiguity appearing at NLL accuracy.

H. M. Asatrian; A. Hovhannisyan; V. Poghosyan; T. Ewerth; C. Greub; T. Hurth

2006-04-30T23:59:59.000Z

Note: This page contains sample records for the topic "gamma exposure rates" 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

Supermassive Objects as Gamma-Ray Bursters  

E-Print Network (OSTI)

We propose that the gravitational collapse of supermassive objects ($ M\\ga 10^4 M_\\odot$), either as relativistic star clusters or as single supermassive stars (which may result from stellar mergers in dense star clusters), could be a cosmological source of $\\gamma$-ray bursts. These events could provide the seeds of the supermassive black holes observed at the center of many galaxies. Collapsing supermassive objects will release a fraction of their huge gravitational binding energy as thermal neutrino pairs. We show that the accompanying neutrino/antineutrino annihilation-induced heating could drive electron/positron ``fireball'' formation, relativistic expansion, and associated $\\gamma$-ray emission. The major advantage of this model is its energetics: supermassive object collapses are far more energetic than solar mass-scale compact object mergers; therefore, the conversion of gravitational energy to fireball kinetic energy in the supermassive object scenario need not be highly efficient, nor is it necessary to invoke directional beaming. The major weakness of this model is difficulty in avoiding a baryon loading problem for one dimensional collapse scenarios.

George M. Fuller; Xiangdong Shi

1997-11-04T23:59:59.000Z

442

A Theory of Gamma-Ray Bursts  

E-Print Network (OSTI)

We present a specific scenario for the link between GRB and hypernovae, based on Blandford-Znajek extraction of black-hole spin energy. Such a mechanism requires a high angular momentum in the progenitor object. The observed association of gamma-ray bursts with type Ibc supernovae leads us to consider massive helium stars that form black holes at the end of their lives as progenitors. We combine the numerical work of MacFadyen & Woosley with analytic calculations, to show that about 1E53 erg each are available to drive the fast GRB ejecta and the supernova. The GRB ejecta are driven by the power output through the open field lines, whereas the supernova is powered by closed filed lines and jet shocks. We also present a much simplified approximate derivation of these energetics. Helium stars that leave massive black-hole remnants in special ways, namely via soft X-ray transients or very massive WNL stars. Since binaries naturally have high angular momentum, we propose a link between black-hole transients and gamma-ray bursts. Recent observations of one such transient, GRO J1655-40/Nova Scorpii 1994, explicitly support this connection: its high space velocity indicates that substantial mass was ejected in the formation of the black hole, and the overabundance of alpha-nuclei, especially sulphur, indicates that the explosion energy was extreme, as in SN 1998bw/GRB 980425. (abstract shortened)

G. E. Brown; C. -H. Lee; R. A. M. J. Wijers; H. K. Lee; G. Israelian; H. A. Bethe

2000-03-23T23:59:59.000Z

443

Gamma neutron assay method and apparatus  

DOE Patents (OSTI)

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

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

1995-01-03T23:59:59.000Z

444

Gamma neutron assay method and apparatus  

DOE Patents (OSTI)

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

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

1995-01-01T23:59:59.000Z

445

Composition and apparatus for detecting gamma radiation  

DOE Patents (OSTI)

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

Hofstetter, Kenneth J. (Aiken, SC)

1994-01-01T23:59:59.000Z

446

Composition and apparatus for detecting gamma radiation  

DOE Patents (OSTI)

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

Hofstetter, K.J.

1994-08-09T23:59:59.000Z

447

Two-photon widths of the $\\chi_{c0, 2}$ states and helicity analysis for $\\chi_{c2}\\ar\\gamma\\gamma$}  

E-Print Network (OSTI)

Based on a data sample of 106 M $\\psi^{\\prime}$ events collected with the BESIII detector, the decays $\\psi^{\\prime}\\ar\\gamma\\chi_{c0, 2}$,$\\chi_{c0, 2}\\ar\\gamma\\gamma$ are studied to determine the two-photon widths of the $\\chi_{c0, 2}$ states. The two-photon decay branching fractions are determined to be ${\\cal B}(\\chi_{c0}\\ar\\gamma\\gamma) = (2.24\\pm 0.19\\pm 0.12\\pm 0.08)\\times 10^{-4}$ and ${\\cal B}(\\chi_{c2}\\ar\\gamma\\gamma) = (3.21\\pm 0.18\\pm 0.17\\pm 0.13)\\times 10^{-4}$. From these, the two-photon widths are determined to be $\\Gamma_{\\gamma \\gamma}(\\chi_{c0}) = (2.33\\pm0.20\\pm0.13\\pm0.17)$ keV, $\\Gamma_{\\gamma \\gamma}(\\chi_{c2}) = (0.63\\pm0.04\\pm0.04\\pm0.04)$ keV, and $\\cal R$ $=\\Gamma_{\\gamma \\gamma}(\\chi_{c2})/\\Gamma_{\\gamma \\gamma}(\\chi_{c0})=0.271\\pm 0.029\\pm 0.013\\pm 0.027$, where the uncertainties are statistical, systematic, and those from the PDG ${\\cal B}(\\psi^{\\prime}\\ar\\gamma\\chi_{c0,2})$ and $\\Gamma(\\chi_{c0,2})$ errors, respectively. The ratio of the two-photon widths for helicity $\\lambda=0...

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2012-01-01T23:59:59.000Z

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