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1

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

2

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...

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

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

5

Gamma radiation field intensity meter  

DOE Patents (OSTI)

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

Thacker, L.H.

1995-10-17T23:59:59.000Z

6

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

7

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

8

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

9

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

10

Types of Radiation Exposure  

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

External Irradiation Contamination Incorporation Biological Effects of Acute, Total Body Irradiation Managing Radiation Emergencies Procedure Demonstration Types of radiation...

11

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

12

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

13

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

14

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

15

ORISE: DOE's Radiation Exposure Monitoring System (REMS)  

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

Monitoring System (REMS) Monitoring System (REMS) ORISE maintains large database of radition exposure records for the U.S. Department of Energy ORISE staff monitoring radiation data for DOE Rule 10 CFR 835 establishes the U.S. Department of Energy's (DOE) occupational protection rule and requires assessment and recording of radiation doses to individuals who are exposed to sources of radiation or contamination. The Radiation Exposure Monitoring System (REMS) database is the radiation exposure data repository for all monitored DOE employees, contractors, subcontractors and members of the public. REMS maintains dose records for all monitored individuals dating back to 1969. Aggregated, site-specific data are available on the Radiation Exposure Monitoring System website for all years since 1986. Currently,

16

Sources Of Average Individual Radiation Exposure  

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

Of Average Individual Radiation Exposure Of Average Individual Radiation Exposure Natural background Medical Consumer products Industrial, security, educational and research Occupational 0.311 rem 0.300 rem 0.013 rem 0.0003 rem 0.0005 rem Savannah River Nuclear Solutions, LLC, provides radiological protection services and oversight at the Savannah River Site (SRS). These services include radiation dose measurements for persons who enter areas where they may be exposed to radiation or radioactive material. The results are periodically reported to monitored individuals. The results listed are based on a radiation dose system developed by the International Commission on Radiation Protection. The system uses the terms "effective dose," "equivalent dose" and units of rem. You may be more familiar with the term "millirem" (mrem), which is 1/1000 of a rem.

17

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

18

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

19

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

20

DOE occupational radiation exposure 1996 report  

SciTech Connect

The goal of the US Department of Energy (DOE) is to conduct its radiological operations to ensure the health and safety of all DOE employees including contractors and subcontractors. The DOE strives to maintain radiation exposures to its workers below administrative control levels and DOE limits and to further reduce these exposures and releases to levels that are ``As Low As Reasonably Achievable`` (ALARA). The DOE Occupational Radiation Exposure Report, 1996 provides summary and analysis of the occupational radiation exposure received by individuals associated with DOE activities. The DOE mission includes stewardship of the nuclear weapons stockpile and the associated facilities, environmental restoration of DOE and precursor agency sites, and energy research. Collective exposure at DOE has declined by 80% over the past decade due to a cessation in opportunities for exposure during the transition in DOE mission from weapons production to cleanup, deactivation and decommissioning, and changes in reporting requirements and dose calculation methodology. In 1996, the collective dose decreased by 10% from the 1995 value due to decreased doses at five of the seven highest-dose DOE sites. For 1996, these sites attributed the reduction in collective dose to the completion of several decontamination and decommissioning projects, reduced spent fuel storage activities, and effective ALARA practices. This report is intended to be a valuable tool for managers in their management of radiological safety programs and commitment of resources.

NONE

1996-12-31T23:59:59.000Z

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

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

22

Effects of prenatal exposure to ionizing radiation  

SciTech Connect

Prenatal exposure to ionizing radiation induces some effects that are seen at birth and others that cannot be detected until later in life. Data from A-bomb survivors in Hiroshima and Nagasaki show a diminished number of births after exposure under 4 wk of gestational age. Although a wide array of congenital malformations has been found in animal experimentation after such exposure to x rays, in humans only small head size (exposure at 4-17 wk) and mental retardation (exposure primarily at 8-15 wk) have been observed. In Hiroshima, small head size occurred after doses of 0.10-0.19 Gy or more, and an excess of mental retardation at 0.2-0.4 Gy or more. Intelligence test scores were reduced among A-bomb survivors exposed at 8-15 wk of gestational age by 21-29 IQ points per Gy. Other effects of in-utero exposure to atomic radiation include long-lasting complex chromosome abnormalities.

Miller, R.W. (National Cancer Institute, Bethesda, MD (USA))

1990-07-01T23:59:59.000Z

23

DOE 2008 Occupational Radiation Exposure October 2009  

Science Conference Proceedings (OSTI)

A major priority of the U.S. Department of Energy (DOE) is to ensure the health, safety, and security of DOE employees, contractors, and subcontractors. The Office of Health, Safety and Security (HSS) provides the corporate-level leadership and strategic vision necessary to better coordinate and integrate health, safety, environment, security, enforcement, and independent oversight programs. One function that supports this mission is the DOE Corporate Operating Experience Program that provides collection, analysis, and dissemination of performance indicators, such as occupational radiation exposure information. This analysis supports corporate decision-making and synthesizes operational information to support continuous environment, safety, and health improvement across the DOE complex.

U.S. Department of Energy, Office of Health, Safety and Security

2009-10-01T23:59:59.000Z

24

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

25

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

Science Conference Proceedings (OSTI)

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

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

2005-08-08T23:59:59.000Z

26

A Basic Overview of the Occupational Radiation Exposure Monitoring...  

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

and dissemination of occupational radiation exposure information. The annual REMS report is a valuable tool for managing radiological safety programs and for developing...

27

ORISE: Worker Health Studies - Radiation Exposure Data Collection  

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

Overview Argonne Electronic Medical Records System Beryllium Testing and Surveillance Radiation Exposure Information and Reporting System (REIRS) U.S. Department of Energy...

28

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

29

DOE occupational radiation exposure. Report 1992--1994  

Science Conference Proceedings (OSTI)

The DOE Occupational Radiation Exposure Report, 1992-1994 reports occupational radiation exposures incurred by individuals at US Department of Energy (DOE) facilities from 1992 through 1994. This report includes occupational radiation exposure information for all DOE employees, contractors, subcontractors, and visitors. This information is analyzed and trended over time to provide a measure of the DOE`s performance in protecting its workers from radiation. Occupational radiation exposure at DOE has been decreasing over the past 5 years. In particular, doses in the higher dose ranges are decreasing, including the number of doses in excess of the DOE limits and doses in excess of the 2 rem Administrative Control Level (ACL). This is an indication of greater attention being given to protecting these individuals from radiation in the workplace.

NONE

1997-05-01T23:59:59.000Z

30

DOE Basic Overview of Occupational Radiation Exposure_2011 pamphlet  

SciTech Connect

This pamphlet focusses on two HSS activities that help ensure radiation exposures are accurately assessed and recorded, namely: 1) the quality and accuracy of occupational radiation exposure monitoring, and 2) the recording, reporting, analysis, and dissemination of the monitoring results. It is intended to provide a short summary of two specific HSS programs that aid in the oversight of radiation protection activities at DOE. The Department of Energy Laboratory Accreditation Program (DOELAP) is in place to ensure that radiation exposure monitoring at all DOE sites is precise and accurate, and conforms to national and international performance and quality assurance standards. The DOE Radiation Exposure Monitoring Systems (REMS) program provides for the collection, analysis, and dissemination of occupational radiation exposure information. The annual REMS report is a valuable tool for managing radiological safety programs and for developing policies to protect individuals from occupational exposure to radiation. In tandem, these programs provide DOE management and workers an assurance that occupational radiation exposures are accurately measured, analyzed, and reported.

ORAU

2012-08-08T23:59:59.000Z

31

ORISE: U.S. Nuclear Regulatory Commission Radiation Exposure Information  

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

Information and Reporting System (REIRS) Information and Reporting System (REIRS) ORISE maintains large database of radiation exposure records for the U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission Radiation Exposure Information and Reporting System (REIRS) The U.S. Nuclear Regulatory Commission (NRC) is required by federal mandate to maintain and evaluate radiation protection data for workers at facilities that it licenses. As part of its mission of safety, the NRC operates the Radiation Exposure Information and Reporting System (REIRS), a database system containing all occupational radiation exposure records that have been submitted to the NRC under 10 CFR Part 20. REIRS encompasses 1,800-plus NRC licensees and contains more than five million records for more than one million monitored individuals.

32

Global methylation responses to low dose radiation exposure  

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

methylation responses to low dose radiation exposure methylation responses to low dose radiation exposure Pamela J Sykes, Michelle R Newman, Benjamin J Blyth and Rebecca J Ormsby Haematology and Genetic Pathology, Flinders University and Medical Centre, Flinders Centre for Cancer Prevention and Control, Bedford Park, Adelaide, South Australia 5042 Australia. (pam.sykes@flinders.edu.au). Our goal is to study the mechanisms involved in biological responses to low doses of radiation in vivo in the dose range that is relevant to population and occupational exposures. At high radiation doses, DNA double-strand breaks are considered the critical lesion underlying the initiation of radiation-induced carcinogenesis. However, at the very low radiation doses relevant for the general public, the induction of DNA double-strand breaks

33

DOE 2010 Occupational Radiation Exposure November 2011  

Science Conference Proceedings (OSTI)

This report discusses radiation protection and dose reporting requirements, presents the 2010 occupational radiation dose data trended over the past 5 years, and includes instructions to submit successful ALARA projects.

U.S. Department of Energy, Office of Health, Safety and Security, Office of Analysis

2011-11-11T23:59:59.000Z

34

EPIDEMIOLOGICAL STUDIES ON RADIATION CARCINOGENESIS IN HUMAN POPULATIONS FOLLOWING ACUTE EXPOSURE: NUCLEAR EXPLOSIONS AND MEDICAL RADIATION  

E-Print Network (OSTI)

exposure to radioactive fallout in Radiation-Associated inIslanders, who were exposed to fallout H-bomb test explosion

Fabrikant, J.I.

2010-01-01T23:59:59.000Z

35

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

36

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

37

Gamma Radiation from PSR B1055-52  

E-Print Network (OSTI)

The telescopes on the Compton Gamma Ray Observatory (CGRO) have observed PSR B1055-52 a number of times between 1991 and 1998. From these data, a more detailed picture of the gamma radiation from this source has been developed, showing several characteristics which distinguish this pulsar: the light curve is complex; there is no detectable unpulsed emission; the energy spectrum is flat, with no evidence of a sharp high-energy cutoff up to >4 GeV. Comparisons of the gamma-ray data with observations at longer wavelengths show that no two of the known gamma-ray pulsars have quite the same characteristics; this diversity make s interpretation in terms of theoretical models difficult.

D. J. Thompson

1998-11-13T23:59:59.000Z

38

Low Dose Radiation Exposure: Exploring Bystander Effects In Vivo.  

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

Exposure: Exploring Bystander Effects Exposure: Exploring Bystander Effects In Vivo. 1 Blyth, B.J., 1 Sykes, P.J. 1 Department of Haematology and Genetic Pathology, Flinders University and Medical Centre, Bedford Park, South Australia, 5042, The general population is daily exposed to chronic, low doses of ionizing radiation from both natural and artificial sources. The shape of the radiation dose-response curve at these low doses is currently linearly extrapolated from data obtained after high dose exposure due to the low sensitivity of traditional biological assays after near-background exposures. At odds with this Linear No-Threshold model, are the phenomena collectively referred to as the radiation-induced bystander effect. The bystander effect describes a collection of in vitro

39

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

40

Health Impacts from Acute Radiation Exposure  

SciTech Connect

Absorbed doses above1-2 Gy (100-200 rads) received over a period of a day or less lead to one or another of the acute radiation syndromes. These are the hematopoietic syndrome, the gastrointestinal (GI) syndrome, the cerebrovascular (CV) syndrome, the pulmonary syndrome, or the cutaneous syndrome. The dose that will kill about 50% of the exposed people within 60 days with minimal medical care, LD50-60, is around 4.5 Gy (450 rads) of low-LET radiation measured free in air. The GI syndrome may not be fatal with supportive medical care and growth factors below about 10 Gy (1000 rads), but above this is likely to be fatal. Pulmonary and cutaneous syndromes may or may not be fatal, depending on many factors. The CV syndrome is invariably fatal. Lower acute doses, or protracted doses delivered over days or weeks, may lead to many other health outcomes than death. These include loss of pregnancy, cataract, impaired fertility or temporary or permanent sterility, hair loss, skin ulceration, local tissue necrosis, developmental abnormalities including mental and growth retardation in persons irradiated as children or fetuses, radiation dermatitis, and other symptoms listed in Table 2 on page 12. Children of parents irradiated prior to conception may experience heritable ill-health, that is, genetic changes from their parents. These effects are less strongly expressed than previously thought. Populations irradiated to high doses at high dose rates have increased risk of cancer incidence and mortality, taken as about 10-20% incidence and perhaps 5-10% mortality per sievert of effective dose of any radiation or per gray of whole-body absorbed dose low-LET radiation. Cancer risks for non-uniform irradiation will be less.

Strom, Daniel J.

2003-09-30T23:59:59.000Z

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


41

Radiation from Poynting Flux Acceleration and Gamma-Ray Bursts  

E-Print Network (OSTI)

We compute the radiation output of electrons accelerated by Poynting flux numerically from Particle-In-Cell simulations, and derive an analytic formula to explain these numerical results. We show that the in-situ power output and critical frequency are much below those predicted by the classical synchrotron formulae. We then apply these results to a model of long gamma-ray bursts. This model predicts spectral break energies remarkably consistent with the observed values.

Liang, Edison

2007-01-01T23:59:59.000Z

42

Radiation exposure in X-ray-based imaging techniques used in osteoporosis  

E-Print Network (OSTI)

to low levels of ionizing radiation: BEIR VII Phase 2. TheBlake G, Genant HK (1999) Radiation exposure in bone mineralGuglielmi Thomas M. Link Radiation exposure in X-ray-based

Damilakis, John; Adams, Judith E.; Guglielmi, Giuseppe; Link, Thomas M.

2010-01-01T23:59:59.000Z

43

RIS-M-2339 SHIELDING FACTORS FOR VEHICLES TO GAMMA RADIATION FROM  

E-Print Network (OSTI)

fallout has been approximated by a point source that has been placed in a matrix around and above descriptors: REACTORS ACCIDENTS; EXTERNAL RADIATION; GAMMA RADIATION; RADIATION DOSES; FALLOUT DEPOSITS

44

Environmental radiation exposure: Regulation, monitoring, and assessment  

Science Conference Proceedings (OSTI)

Radioactive releases to the environment from nuclear facilities constitute a public health concern. Protecting the public from such releases can be achieved through the establishment and enforcement of regulatory standards. In the United States, numerous standards have been promulgated to regulate release control at nuclear facilities. Most recent standards are more restrictive than those in the past and require that radioactivity levels be as low as reasonably achievable (ALARA). Environmental monitoring programs and radiological dose assessment are means of ensuring compliance with regulations. Environmental monitoring programs provide empirical information on releases, such as the concentrations of released radioactivity in environmental media, while radiological dose assessment provides the analytical means of quantifying dose exposures for demonstrating compliance.

Chen, S.Y.; Yu, C.; Hong, K.J.

1991-01-01T23:59:59.000Z

45

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

46

Current Trends in Gamma Radiation Detection for Radiological Emergency Response  

SciTech Connect

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

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

2011-09-01T23:59:59.000Z

47

EPIDEMIOLOGICAL STUDIES ON RADIATION CARCINOGENESIS IN HUMAN POPULATIONS FOLLOWING ACUTE EXPOSURE: NUCLEAR EXPLOSIONS AND MEDICAL RADIATION  

E-Print Network (OSTI)

Atomic Bomb by Radiation Dose, Years Research Research after Survivors, Hiroshima and Nagasaki, 1950-71 Exposure, Age,atomic bomb survivors in Hiroshima and Nagasaki (36), and the Japanese Here, 'here is an The latent age-

Fabrikant, J.I.

2010-01-01T23:59:59.000Z

48

DOE Radiation Exposure Monitoring System (REMS) Data Update  

SciTech Connect

This slide show presents the 2011 draft data for DOE occupational radiation exposure.Clarification is given on Reporting Data regarding: reporting Total Organ Dose (TOD); reporting Total Skin Dose (TSD), and Total Extremity Dose (TExD) ; and Special individuals reporting.

Rao, Nimi; Hagemeyer, Derek

2012-05-05T23:59:59.000Z

49

Reducing waste generation and radiation exposure by analytical method modification  

SciTech Connect

The primary goal of an analytical support laboratory has traditionally been to provide accurate data in a timely and cost effective fashion. Added to this goal is now the need to provide the same high quality data while generating as little waste as possible. At the Savannah River Technology Center (SRTC), we have modified and reengineered several methods to decrease generated waste and hence reduce radiation exposure. These method changes involved improving detection limits (which decreased the amount of sample required for analysis), decreasing reaction and analysis time, decreasing the size of experimental set-ups, recycling spent solvent and reagents, and replacing some methods. These changes had the additional benefits of reducing employee radiation exposure and exposure to hazardous chemicals. In all cases, the precision, accuracy, and detection limits were equal to or better than the replaced method. Most of the changes required little or no expenditure of funds. This paper describes these changes and discusses some of their applications.

Ekechukwu, A.A.

1996-10-01T23:59:59.000Z

50

Gravitational radiation from long gamma-ray bursts  

E-Print Network (OSTI)

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

Maurice H. P. M. van Putten

2001-02-11T23:59:59.000Z

51

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

52

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

53

ASSESSMENT OF THE PROTECTION AFFORDED BY BUILDINGS AGAINST GAMMA RADIATION FROM FALLOUT  

SciTech Connect

A method is described for estimating the protection against gamma radiation from radioactive fall-out afforded by buildings. A sample calculation is included. (C.H.)

1957-07-01T23:59:59.000Z

54

Occupational radiation Exposure at Agreement State-Licensed Materials Facilities, 1997-2010  

SciTech Connect

The purpose of this report is to examine occupational radiation exposures received under Agreement State licensees. As such, this report reflects the occupational radiation exposure data contained in the Radiation Exposure Information and Reporting System (REIRS) database, for 1997 through 2010, from Agreement State-licensed materials facilities.

U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research

2012-07-07T23:59:59.000Z

55

Closed-Form E1 Radiative Strength Functions for Gamma-Decay and Photoabsorption  

SciTech Connect

Photoabsorption cross sections and {gamma}-decay strength functions are calculated and compared with experimental data to test simple phenomenological models of E1 gamma-strength description in the middle-weight and heavy atomic nuclei. Radiative strength functions with energy asymmetric shape are recommended for overall estimation of averaged gamma-strengths. Systematics for giant dipole resonance (GDR) parameters are given.

Plujko, Vladimir A.; Kadenko, Igor M.; Kulich, Elizaveta V.; Gorbachenko, Oleksandr M. [Nuclear Physics Department, Taras Shevchenko National University, Pr. Acad. Glushkova, 2, bldg. 11, 03022 Kyiv (Ukraine)

2009-01-28T23:59:59.000Z

56

Architecture and 3D device simulation of a PIN diode-based Gamma radiation detector  

Science Conference Proceedings (OSTI)

In this paper, we present a new IC-based gamma radiation detector. We report 3D simulation results for the PIN diode structure which is used in this detector, along with a discussion of the architecture of the readout electronics for this detector. Gamma ... Keywords: pin diode, radiation detection, solid-state

Amr Elshennawy; Craig M. Marianno; Sunil P. Khatri

2013-05-01T23:59:59.000Z

57

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

DOE Patents (OSTI)

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

Hondorp, H.L.

1981-07-06T23:59:59.000Z

58

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

DOE Patents (OSTI)

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

Hondorp, Hugh L. (Princeton Junction, NJ)

1984-01-01T23:59:59.000Z

59

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

60

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 radiation exposure" 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

Workshop Report on Atomic Bomb Dosimetry--Residual Radiation Exposure: Recent Research and Suggestions for Future Studies  

SciTech Connect

There is a need for accurate dosimetry for studies of health effects in the Japanese atomic bomb survivors because of the important role that these studies play in worldwide radiation protection standards. International experts have developed dosimetry systems, such as the Dosimetry System 2002 (DS02), which assess the initial radiation exposure to gamma rays and neutrons but only briefly consider the possibility of some minimal contribution to the total body dose by residual radiation exposure. In recognition of the need for an up-to-date review of the topic of residual radiation exposure in Hiroshima and Nagasaki, recently reported studies were reviewed at a technical session at the 57th Annual Meeting of the Health Physics Society in Sacramento, California, 22-26 July 2012. A one-day workshop was also held to provide time for detailed discussion of these newer studies and to evaluate their potential use in clarifying the residual radiation exposures to the atomic-bomb survivors at Hiroshima and Nagasaki. Suggestions for possible future studies are also included in this workshop report.

none,

2013-06-06T23:59:59.000Z

62

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

E-Print Network (OSTI)

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

Zhang, Bing

63

15TH INTERNATIONAL SYMPOSIUM ON TOXICITY ASSESSMENT Alpha radiation exposure decreases apoptotic cells in zebrafish  

E-Print Network (OSTI)

15TH INTERNATIONAL SYMPOSIUM ON TOXICITY ASSESSMENT Alpha radiation exposure decreases apoptotic of an adaptive response by the ionizing radiation against sub- sequent exposures to Cd. Keywords Multiple embryos subjected to a priming exposure provided by one environmental stressor (low-dose alpha particles

Yu, K.N.

64

Health Physics Society Specialists in Radiation Safety Radiation Exposure and Pregnancy  

E-Print Network (OSTI)

Everyone is exposed to radiation every day. People are continuously exposed to low-level radiation found in food, soils, building materials, and the air and from outer space. All of this radiation originates from naturally occurring sources. For example, bananas contain naturally occurring radioactive potassium-40 and air contains radon, a radioactive gas. Your average natural background radiation dose * is about 3.0 mSv (300 mrem) each year (millisieverts and millirem are units of radiation dose, much like a gram or an ounce is a unit of weight). In addition to natural background radiation, you may be exposed to radiation from medical x rays and medical radiation tests or treatments. If you think, or there is a possibility, that you may be pregnant and need a medical x-ray or radiation procedure, the information below will help answer your question “Does a medical procedure involving radiation increase my baby’s health risks?” What are the health risks from medical x rays or radionuclide medical tests performed during pregnancy? There is a lot of reliable information about the effects of radiation exposure during pregnancy. Potential radiation effects vary depending on the fetal stage of development and the magnitude of the doses. Our best knowledge indicates that there is a threshold below which negative effects are not observed. According to the American College of Radiology, routine x rays of a mother’s abdomen, back, hips, and pelvis are not likely to pose a serious risk to the child (ACR/RSNA 2010). However, certain procedures (such as a computerized tomography [CT scan] or a lower GI fluoroscope exam) to the mother’s stomach or hips may give higher doses. If you are administered a radioactive drug (nuclear medicine), radioactivity in your urine or intestines could give a moderate dose to the fetus, and some compounds can cross the placenta *Words in italics are defined in the Glossary on page 3.

Melissa Arch; At Immanuel St. Joseph’s

2010-01-01T23:59:59.000Z

65

Low dose diagnostic radiation exposure and cancer risk in Trp53...  

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

University Abstract The cancer risk associated with exposure to low doses of ionizing radiation has traditionally been extrapolated from effects observed at high doses and high...

66

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

67

Alpha Radiation  

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

Basics of Radiation Basics of Radiation Gamma Radiation and X-Rays Beta Radiation Alpha Radiation Irradiation Radioactive Contamination Definitions Detection Measurement Safety Around Radiation Sources Types of Radiation Exposure Managing Radiation Emergencies Basics of Radiation Characteristics of Alpha Radiation 1. Alpha radiation is not able to penetrate skin. 2. Alpha-emitting materials can be harmful to humans if the materials are inhaled, swallowed, or absorbed through open wounds. 3. A variety of instruments have been designed to measure alpha radiation. Special training in use of these instruments is essential for making accurate measurements. 4. A civil defense instrument (CD V-700) cannot detect the presence of radioactive materials that produce alpha radiation unless the radioactive materials also produce beta and/or gamma radiation.

68

Monitoring exposure to atomic bomb radiation by somatic mutation  

SciTech Connect

Atomic bomb survivors are a population suitable for studying the relationship between somatic mutation and cancer risk because their exposure doses are relatively well known and their dose responses in terms of cancer risk have also been thoroughly studied. An analysis has been made of erythrocyte glycophorin A (GPA) gene mutations in 1,226 atomic bomb survivors in Hiroshima and Nagasaki. The GPA mutation frequency (Mf) increased slightly but significantly with age at the time of measurement and with the number of cigarettes smoked. After adjustment for the effect of smoking, the Mf was significantly higher in males than in females and higher in Hiroshima than in Nagasaki. All of these characteristics of the background GPA Mf were in accord with those of solid tumor incidence obtained from an earlier epidemiological study of A-bomb survivors. Analysis of the dose effect on Mf revealed the doubling dose to be about 1.20 Sv and the minimum dose for detection of a significant increase to be about 0.24 Sv. No significant dose effect for difference in sex, city, or age at the time of bombing was observed. Interestingly, the doubling dose for the GPA Mf approximated that for solid cancer incidence (1.59 Sv). And the minimum dose for detection was not inconsistent with the data for solid cancer incidence. The dose effect was significantly higher in those diagnosed with cancer before or after measurement than in those without a history of cancer. These findings are consistent with the hypothesis that somatic mutations are the main cause of excess cancer risk from radiation exposure. 27 refs., 2 figs.

Akiyama, Mitoshi; Kyoizumi, Seishi; Kusunoki, Yoichiro [Radiation Effects Research Foundation, Hiroshima (Japan)] [and others

1996-05-01T23:59:59.000Z

69

Radiation chemistry of salt-mine brines and hydrates. [Gamma radiation  

Science Conference Proceedings (OSTI)

Certain aspects of the radiation chemistry of NaCl-saturated MgCl/sub 2/ solutions and MgCl/sub 2/ hydrates at temperatures in the range of 30 to 180/sup 0/C were investigated through experiments. A principal objective was to establish the values for the yields of H/sub 2/ (G(H/sub 2/)) and accompanying oxidants in the gamma-ray radiolysis of concentrated brines that might occur in waste repositories in salt. We concluded that G(H/sub 2/) from gamma-irradiated brine solution into a simultaneously irradiated, deaerated atmosphere above the solution is between 0.48 and 0.49 over most of the range 30 to 143/sup 0/C. The yield is probably somewhat lower at the lower end of this range, averaging 0.44 at 30 to 45/sup 0/C. Changes in the relative amounts of MgCl/sub 2/ and NaCl in the NaCl-saturated solutions have negligible effects on the yield. The yield of O/sub 2/ into the same atmosphere averages 0.13, independent of the temperature and brine composition, showing that only about 50% of the radiolytic oxidant that was formed along with the H/sub 2/ was present as O/sub 2/. We did not identify the species that compose the remainder of the oxidant. We concluded that the yield of H/sub 2/ from a gamma-irradiated brine solution into a simultaneously irradiated atmosphere containing 5 to 8% air in He may be greater than the yield in deaerated systems by amounts ranging from 0% for temperatures of 73 to 85/sup 0/C, to about 30 and 40% for temperatures in the ranges 100 to 143/sup 0/C and 30 to 45/sup 0/C, respectively. We did not establish the mechanism whereby the air affected the yields of H/sub 2/ and O/sub 2/. The values found in this work for G(H/sub 2/) in deaerated systems are in approximate agreement with the value of 0.44 for the gamma-irradiation yield of H/sub 2/ in pure H/sub 2/O at room temperature. They are also in agreement with the values predicted by extrapolation from the findings of previous researchers for the value for G(H/sub 2/) in 2 M NaCl solutions at room temperature.

Jenks, G.H.; Walton, J.R.; Bronstein, H.R.; Baes, C.F. Jr.

1981-07-01T23:59:59.000Z

70

Coherent Radiation in Gamma-Ray Bursts and Relativistic Collisionless Shocks  

E-Print Network (OSTI)

We suggest that coherent radiation may occur in relativistic collisionless shocks via two-stream Weibel instabilities. The coherence amplifies the radiation power by many orders [$\\sim 10^{12}$ in Gamma-Ray Bursts (GRBs)] and particles cool very fast before being randomized. We imply (1) GRBs accompany strong infrared emission, (2) protons efficiently transfer energy to electrons and (3) prompt GRBs might be the upscattered coherent radiation.

Kunihito Ioka

2005-08-23T23:59:59.000Z

71

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

SciTech Connect

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

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

2010-07-15T23:59:59.000Z

72

Gamma radiation induced degradation in PE-PP block copolymer  

SciTech Connect

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

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

2012-06-05T23:59:59.000Z

73

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

Science Conference Proceedings (OSTI)

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

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

2013-02-12T23:59:59.000Z

74

RADIATION SAFETY POLICY Effective Date: April 4, 2012 Originating Office: Office of the  

E-Print Network (OSTI)

radiation exposure "As Low as Reasonably Achievable" "Internal Radiation Permit" ("IRP") means and the general public from unnecessary or potentially harmful levels of radiation exposure. PURPOSE capable of generating X or Gamma radiation "Radiology" involves external exposure of humans to Radiation

Doedel, Eusebius

75

Radiation detection system for portable gamma-ray spectroscopy  

DOE Patents (OSTI)

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

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

2006-06-20T23:59:59.000Z

76

EPIDEMIOLOGICAL STUDIES ON RADIATION CARCINOGENESIS IN HUMAN POPULATIONS FOLLOWING ACUTE EXPOSURE: NUCLEAR EXPLOSIONS AND MEDICAL RADIATION  

E-Print Network (OSTI)

EPIDEMIOLOGICAL STUDIES ON RADIATION CARCINOGENESIS IN HUMANEXPLOSIONS AND MEDICAL RADIATION . Jacob I. Fabrikant, MD,Low Levels of Ionizing Radiation, Yale University School of

Fabrikant, J.I.

2010-01-01T23:59:59.000Z

77

EPIDEMIOLOGICAL STUDIES ON RADIATION CARCINOGENESIS IN HUMAN POPULATIONS FOLLOWING ACUTE EXPOSURE: NUCLEAR EXPLOSIONS AND MEDICAL RADIATION  

E-Print Network (OSTI)

of the Current State of Radiation Protection Philosophy.Against Pergamon Ionizing Radiation from External Sources,for Protection Against Ionizing Radiation from Supplement to

Fabrikant, J.I.

2010-01-01T23:59:59.000Z

78

REGULATORY GUIDE 8.13 (Draft was issued as DG-8014) INSTRUCTION CONCERNING PRENATAL RADIATION EXPOSURE  

E-Print Network (OSTI)

Inspection and Investigations, ” in Section 19.12, “Instructions to Workers, ” requires instruction in “the health protection problems associated with exposure to radiation and/or radioactive material, in precautions or procedures to minimize exposure, and in the purposes and functions of protective devices employed. ” The

unknown authors

1999-01-01T23:59:59.000Z

79

ORISE: Illness and Injury Surveillance, Radiation Exposure, and...  

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

Surveillance Data, December 2012 (PDF) Technical Report: Health Surveillance of Rocky Flats Radiation Workers, April 2006 (PDF) Technical Basis Document for the Neutron Dose...

80

Video Camera Use at Nuclear Power Plants: Tools for Increasing Productivity and Reducing Radiation Exposure: Tools for Increasing Pr oductivity and Reducing Radiation Exposure  

Science Conference Proceedings (OSTI)

Nuclear power plants have increased the use of industrial video cameras as support tools for a variety of plant operations and outage tasks. This survey on utility use of video cameras, the equipment being used, and the benefits derived found that the video camera is an important tool for reducing radiation exposure and improving productivity through more efficient use of personnel.

1990-08-14T23:59:59.000Z

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


81

Literature Highlight: Radiation Exposure to the Heart and the Risk of Ischemic Heart Disease  

E-Print Network (OSTI)

, fish, and olive oil.1-4 This diet discourages dairy products, saturated fats, and red meats.1-4 Older have helped to limit radiation exposure to unaffected tissues, radiation expo- sure to the heart may benefit from an -linolenic acid-rich Mediterranean diet which emphasizes bread, fruits, nuts, vegetables

Vonessen, Nikolaus

82

Method and Apparatus for Measuring Radiation Quantities  

DOE Patents (OSTI)

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

Roberts, N.O.

1950-07-31T23:59:59.000Z

83

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

E-Print Network (OSTI)

Astronauts in space flight missions are exposed to increased iron (Fe) stores and galactic cosmic radiation, both of which independently induce oxidative stress. Oxidative stress can result in protein, lipid, and DNA oxidation. Recent evidence has linked oxidative stress to bone loss with aging and estrogen deficiency. Whether the increased iron stores and radiation that astronauts face are exacerbating their extreme bone loss while in space is unclear. We hypothesized that elevated iron levels (induced by feeding a high iron diet) and gamma radiation exposure would independently increase markers of oxidative stress and markers of oxidative damage and result in loss of bone mass, with the combined treatment having additive or synergistic effects. Male Sprague-Dawley rats (15-weeks old, n=32) were randomized to receive an adequate (45 mg Fe/kg diet) or high (650 mg Fe/kg diet) Fe diet for 4 weeks and either 3 Gy (8 fractions, 0.375 Gy each) of 137Cs radiation (?RAD) or sham exposure every other day over 16 days starting on day 14. Serum Fe and catalase and liver Fe and glutathione peroxidase (GPX) were assessed by standard techniques. Immunostaining for 8-hydroxy-2-deoxyguanosine (8-OHdG, marker of DNA adducts) quantified the number of cells with oxidative damage in cortical bone. Bone histomorphometry assessed bone cell activity and cancellous bone microarchitecture in the metaphyseal region. Ex vivo pQCT quantified volumetric bone mineral density (vBMD); bone mechanical strength was assessed by 3-pt bending at the midshaft tibia and compression of the femoral neck. High Fe diet increased liver Fe and decreased volume per total volume (BV/TV). ?RAD decreased osteoid surface per bone surface (OS/BS) and osteocyte density. The combined treatment increased serum catalase, liver GPX, and serum iron and decreased cancellous vBMD and trabecular number (Tb.N). High Fe diet and ?RAD independently increased number of osteocytes stained positive for 8-OHdG, with the combined treatment exhibiting twice as many osteocytes positively stained compared to the control. Higher serum Fe levels were associated with higher oxidative damage (r =0.38) and lower proximal tibial cancellous vBMD (r =–0.38). Higher serum catalase levels were associated with higher oxidative damage (r =0.48), lower BV/TV (r =–0.40) and lower cancellous vBMD (r =–0.39). High dietary iron and fractionated 137Cs ?RAD leads to a moderate elevation in iron stores and results in oxidative damage in bone and are associated with decreased cancellous bone density. Moderate elevations in iron stores are not only found in astronauts, but also naturally occur in healthy human populations. This healthy population with elevated iron stores may also have increased levels of oxidative stress in the body. Elevated levels of oxidative stress not only increase one’s risk for accelerated bone loss, but also the risk of developing other chronic diseases such as insulin resistance, hypertension, dyslipidemia, and metabolic syndrome.

Yuen, Evelyn P

2013-05-01T23:59:59.000Z

84

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

Science Conference Proceedings (OSTI)

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

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

2012-08-10T23:59:59.000Z

85

POSITION STATEMENT DOCUMENTING IONIZING RADIATION EXPOSURE IN THE ELECTRONIC HEALTH RECORD  

E-Print Network (OSTI)

IEEE-USA believes that maintaining an accurate record of a patient’s cumulative exposure to ionizing radiation can be of substantial value for clinical, health services management and research purposes. Excessive radiation can cause cancer, skin and bone marrow disease and a variety of other diseases. Radiation exposure can come from a number of sources, both natural and manmade. Over the lifetime of the individual, medical procedures, such as X-rays, Computed Tomography (CT) scans, and isotope radiation therapy, contribute significant radiation dosages. Monitoring the use of radiological procedures, measuring the radiation dose directly, and recording the dose in the Electronic Health Record (EHR) can help assess and reduce the risk posed by excessive radiation while optimizing the diagnostic value of these procedures. With these risks and benefits in mind, IEEE-USA recommends the following: 1. Health Level Seven International (HL7), the global authority responsible for standards for interoperability of health information technology, should add the appropriate "dose object " radiation parameters, as defined in the IHE Radiology Technical Framework Supplement, Radiation Exposure Monitoring (REM), to HL7/CDA format longitudinal electronic health records (EHRs), to create a longitudinal record of a patient's exposure to radiation resulting from medical procedures. These records should note both the procedure and estimated radiation dose from each procedure. 2. The Office of the National Coordinator for Health Information Technology (ONCHIT) should make radiation dose monitoring a part of meaningful use criteria for EHRs. 3. Healthcare accreditation organizations (JCAHO, NCQA and URAC), in collaboration with the American College of Radiologists (ACR), should continue

Adopted The Ieee-usa

2011-01-01T23:59:59.000Z

86

Radiation and Uranium Resources Exposure Control (South Dakota)  

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

The public policy of South Dakota is to encourage the constructive uses of radiation, the proper development of uranium resources, and the control of any associated harmful effects. The disposal of...

87

Risk equivalent of exposure versus dose of radiation  

SciTech Connect

This report describes a risk analysis study of low-dose irradiation and the resulting biological effects on a cell. The author describes fundamental differences between the effects of high-level exposure (HLE) and low-level exposure (LLE). He stresses that the concept of absorbed dose to an organ is not a dose but a level of effect produced by a particular number of particles. He discusses the confusion between a linear-proportional representation of dose limits and a threshold-curvilinear representation, suggesting that a LLE is a composite of both systems. (TEM)

Bond, V.P.

1986-01-01T23:59:59.000Z

88

Assessment of potential radiation exposures by uncontrolled recycle or reuse of radioactive scrap metals  

Science Conference Proceedings (OSTI)

With current waste monitoring technology it is reasonable to assume that much of the material designated as low-level waste, generated within nuclear facilities, is in fact uncontaminated. A criterion for uncontrolled disposal of low-level radioactive contaminated waste is that the radiation exposure of the public and of each individual caused by this disposal is so low that radiation protection measures need not be taken. The International Atomic Energy Agency (IAEA) suggests an annual effective dose of 10 {micro}Sv as a limit for the individual radiation dose and derived the initial control levels of residual radioactivity based on the Publication 30 of the International Commission on Radiological Protection (ICRP). In 1990, new recommendations on radiation protection standards were developed by ICRP to take into account new biological information related to the detriment associated with radiation exposure. Adoption of these recommendations necessitated a revision of the Commission's secondary limits contained in Publication 30. This study summarizes the potential radiation exposure from valuable scrap metal considered for uncontrolled recycle by new ICRP recommendations. Potential exposure pathways to people were analyzed and concentrations leading to an individual dose of 10 {micro}Sv/year were calculated for 14 key radionuclides. These potential radiation doses are compared with the results of previous study.

Lee, S.Y.; Lee, K.J.

1999-07-01T23:59:59.000Z

89

Body radiation exposure in breast cancer radiotherapy: Impact of breast IMRT and virtual wedge compensation techniques  

Science Conference Proceedings (OSTI)

Purpose: Recent reports demonstrate a dramatically increased rate of secondary leukemia for breast cancer patients receiving adjuvant high-dose anthracycline and radiotherapy, and that radiation is an independent factor for the development of leukemia. This study aimed to evaluate the radiation body exposure during breast radiotherapy and to characterize the factors associated with an increased exposure. Patients and Methods: In a prospective cohort of 120 women, radiation measurements were taken from four sites on the body at the time of adjuvant breast radiotherapy. Multiple regression analysis was performed to analyze patient and treatment factors associated with the amount of scattered radiation. Results: For standard 50 Gy breast radiotherapy, the minimal dose received by abdominal organs is on average 0.45 Gy, ranging from 0.06 to 1.55 Gy. The use of physical wedges as a compensation technique was the most significant factor associated with increased scattered dose (p < 0.001), resulting in approximately three times more exposure compared with breast intensity-modulated radiation therapy (IMRT) and dynamic wedge. Conclusions: The amount of radiation that is scattered to a patient's body is consistent with exposure reported to be associated with excess of leukemia. In accordance with the As Low As Reasonably Achievable (ALARA) principle, we recommend using breast IMRT or virtual wedging for the radiotherapy of breast cancer receiving high-dose anthracycline chemotherapy.

Woo, Tony [Department of Radiation Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada); Pignol, Jean-Philippe [Department of Radiation Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada)]. E-mail: Jean-Philippe.Pignol@sw.ca; Rakovitch, Eileen [Department of Radiation Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada); Vu, Toni [Department of Radiation Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada); Hicks, Deanna [Department of Radiation Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada); O'Brien, Peter [Department of Medical Physics, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada); Pritchard, Kathleen [Department of Medical Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada)

2006-05-01T23:59:59.000Z

90

Light scattering apparatus and method for determining radiation exposure to plastic detectors  

DOE Patents (OSTI)

An improved system and method of analyzing cumulative radiation exposure registered as pits on track etch foils of radiation dosimeters. The light scattering apparatus and method of the present invention increases the speed of analysis while it also provides the ability to analyze exposure levels beyond that which may be properly measured with conventional techniques. Dosimeters often contain small plastic sheets that register accumulated damage when exposed to a radiation source. When the plastic sheet from the dosimeter is chemically etched, a track etch foil is produced wherein pits or holes are created in the plastic. The number of these pits, or holes, per unit of area (pit density) correspond to the amount of cumulative radiation exposure which is being optically measured by the apparatus. To measure the cumulative radiation exposure of a track etch foil a high intensity collimated beam is passed through foil such that the pits and holes within the track etch foil cause a portion of the impinging light beam to become scattered upon exit. The scattered light is focused with a lens, while the primary collimated light beam (unscattered light) is blocked. The scattered light is focused by the lens onto an optical detector capable of registering the optical power of the scattered light which corresponds to the cumulative radiation to which the track etch foil has been exposed.

Hermes, Robert E. (White Rock, NM)

2002-01-01T23:59:59.000Z

91

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

E-Print Network (OSTI)

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

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

2010-01-01T23:59:59.000Z

92

Increased radiation dose at mammography due to prolonged exposure, delayed processing, and increased film darkening  

SciTech Connect

Four single-emulsion films introduced over the past 2 years--Du Pont Microvision, Fuji MiMa, Konica CM, and Eastman Kodak OM--were compared with Eastman Kodak OM SO-177 (Min-RE) film to evaluate their varying effects on mean glandular dose of reciprocity law failure due to prolonged exposure, delayed processing, and increased film darkening as a result of increased radiation exposure to improve penetration of glandular tissue. Exposures over 1.3 seconds led to increased radiation doses of 20%-30%. Delays in processing of 6 hours decreased processing speed by 11%-32% for all films except Du Pont Microvision. Optical density increases of 0.40 required 20%-30% more skin exposure for all five films. Optimal viewing densities were also evaluated and found to be different for each of the five films. Mammographers need to be aware of these differences in mammographic films to achieve maximum contrast at mammography.

Kimme-Smith, C.; Bassett, L.W.; Gold, R.H.; Chow, S. (UCLA Medical Center (USA))

1991-02-01T23:59:59.000Z

93

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

Science Conference Proceedings (OSTI)

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

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

2013-03-10T23:59:59.000Z

94

Occupational radiation exposure history of Idaho Field Office Operations at the INEL  

Science Conference Proceedings (OSTI)

An extensive review has been made of the occupational radiation exposure records of workers at the Idaho National Engineering Laboratory (INEL) over the period of 1951 through 1990. The focus has been on workers employed by contractors and employees of the Idaho Field Operations Office (ID) of the United States Department of Energy (USDOE) and does not include the Naval Reactors Facility (NRF), the Argonne National Laboratory (ANL), or other operations field offices at the INEL. The radiation protection guides have decreased from 15 rem/year to 5 rem/year in 1990 for whole body penetrating radiation exposure. During these 40 years of nuclear operations (in excess of 200,000 man-years of work), a total of twelve individuals involved in four accidents exceeded the annual guidelines for exposure; nine of these exposures were received during life saving efforts on January 3, 1961 following the SL-1 reactor accident which killed three military personnel. These exposures ranged from 8 to 27 rem. Only one individual has exceeded the annual whole body penetrating radiation protection guidelines in the last 29 years.

Horan, J.R.; Braun, J.B.

1993-10-01T23:59:59.000Z

95

Exposure to ionizing radiation in the emergency department from commonly performed portable radiographs  

SciTech Connect

To accurately assess the potential hazard of exposure to ionizing radiation from portable radiographs taken in the emergency department, a study was performed to measure such radiation at different distances from the edge of an irradiated field during portable cervical-spine (pC-S), portable chest radiograph (pCXR), and portable anteroposterior-pelvis (pAP-pelvis) radiographs. For all three types of portable radiographs, radiation exposure is a function of distance from the beam. However, at 40 cm (15 inches) away from the beam during a pC-S or pCXR and at 160 cm (63 inches) from a pAP-pelvis film, exposure is minimal. At these distances one would need to be exposed to more than 1,200 such radiographs to equal background environmental ionizing radiation. Medical personnel should not have to leave a patient care area for fear of undue acute and chronic radiation exposure while portable radiographs are performed in the ED. By using protective garments and standing appropriate distances away from the patient, continuous patient care can be maintained while portable radiographs are taken in the ED.

Grazer, R.E.; Meislin, H.W.; Westerman, B.R.; Criss, E.A.

1987-04-01T23:59:59.000Z

96

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

E-Print Network (OSTI)

A series of experiments were designed to develop a collection of irradiation parameters for polymerizing a variety of molecular weights of polymer siloxanes for the purpose of bulking and conserving waterlogged archaeological organic materials. Waterlogged wooden tongue depressors (Betula spp) were bulked with five different silicone oils of varying molecular weights, denoted as PS340, PS341, PS343, SFD-1, and an equal mix of SFD-1 and SFD-5. The lightest weight oil being PS340 and the heaviest being the SFD-I /SFD-5 mix. These bulked samples were exposed to gamma radiation emitted from a nuclear research reactor and received gamma doses ranging from 30 Gy to 228 Gy with dose rates ranging from 0.6 Gy/min to 5.1 Gy/min. Following irradiation, thin cross sections of each tongue depressor were analyzed and photographed using a photomicroscope. The results of the irradiation indicated that the heavier molecular weights of siloxanes fully bulked the wood cells. For these fully bulked samples, large radiation doses induced polymerization in the oil to such an extent the cells swelled and became extremely distorted. However, for the same fully bulked samples, small radiation doses produced little to moderate polymerization of the oil in the wood cells. For the tongue depressors bulked with the lighter weight siloxanes, low radiation doses produced very little polymerization, whereas the higher doses induced substantially more polymerization within the wood cells but not to the point of distortion. With these lighter weight siloxanes, the wood cells were not as fully bulked nor looked as natural as those cells bulked with the heavier weight oils. The best combination of molecular weight and radiation dose occurred with the samples bulked in PS343 and irradiated with gamma-rays to a dose of 150 Gy.

Gidden, Richmond Paul

1996-01-01T23:59:59.000Z

97

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

98

Occupational Radiation Exposure at Commercial Nuclear Power Reactors and Other Facilities 2008  

Science Conference Proceedings (OSTI)

This report summarizes the occupational exposure data that are maintained in the U.S. Nuclear Regulatory Commission (NRC) Radiation Exposure Information and Reporting System (REIRS). The bulk of the information contained in the report was compiled from the 2008 annual reports submitted by five of the seven categories1 of NRC licensees subject to the reporting requirements of 10 CFR 20.2206. The annual reports submitted by these licensees consist of radiation exposure records for each monitored individual. These records are analyzed for trends and presented in this report in terms of collective dose and the distribution of dose among the monitored individuals. Because there are no geologic repositories for high-level waste currently licensed and no low-level waste disposal facilities in operation, only five categories will be considered in this report.

U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research

2009-12-01T23:59:59.000Z

99

EPIDEMIOLOGICAL STUDIES ON RADIATION CARCINOGENESIS IN HUMAN POPULATIONS FOLLOWING ACUTE EXPOSURE: NUCLEAR EXPLOSIONS AND MEDICAL RADIATION  

E-Print Network (OSTI)

of Atomic Bomb Radiation Effects Life Span Study Report 8.reports derive mainly from the epidemiological studies of the Japanese atomic bomb

Fabrikant, J.I.

2010-01-01T23:59:59.000Z

100

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

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

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

102

On the Use of SRIM/TRIM for Computing Radiation Damage Exposure  

SciTech Connect

The SRIM (formerly TRIM) Monte Carlo simulation code is widely used to compute a number of parameters relevant to ion beam implantation and ion beam processing of materials. It also has the capability to compute a common radiation damage exposure unit known as atomic displacements per atom (dpa). Since dpa is a standard measure of primary radiation damage production, most researchers who employ ion beams as a tool for inducing radiation damage in materials use SRIM to determine the dpa associated with their irradiations. The use of SRIM for this purpose has been evaluated and comparisons with an internationally-recognized standard definition of dpa, as well as more detailed atomistic simulations of atomic displacement cascades have been made. Differences between the standard and SRIM-based dpa are discussed and recommendations for future usage of SRIM in radiation damage studies are made.

Stoller, Roger E [ORNL; Toloczko, M [Pacific Northwest National Laboratory (PNNL); Was, Gary [University of Michigan; Certain, Alicia [Pacific Northwest National Laboratory (PNNL); Dwaraknath, Shyam [University of Michigan

2013-01-01T23:59:59.000Z

103

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

SciTech Connect

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

Burns, H.

2009-11-10T23:59:59.000Z

104

Individual Radiation Exposure Dose Due to Support Activities at Safe Shelters in Fukushima Prefecture  

E-Print Network (OSTI)

Immediately after the accidents in the nuclear power stations in Fukushima on March 11, the Japanese Government ordered the evacuation of the residents within a 20-km radius from the station on March 12, and asked various institutions to monitor the contamination levels of the residents. Hirosaki University, which is located 355 km north of Fukushima City, decided to send support staff to Fukushima. This report summarizes the results of the exposure of 13 individual teams from March 15 to June 20. The support teams surveyed more than 5,000 people during this period. Almost all subjects had external contamination levels of less than 13 kcpm on Geiger-Müller (GM) survey meter, which is categorized as ‘‘no contamination level.’ ’ The 1 st team showed the highest external exposure dose, but the 4 th team onward showed no significant change. Subsequently, the internal radiation exposure was measured using a whole body counter that indicated undetectable levels in all staff members. Although the measured external radiation exposure dose cannot have serious biological effects on the health of an individual, a follow-up study of the residents in Fukushima and other regions where

Satoru Monzen; Masahiro Hosoda; Shinji Tokonami; Minoru Osanai; Hironori Yoshino; Mitsuaki A. Yoshida; Masatoshi Yamada; Yasushi Asari; Kei Satoh; Ikuo Kashiwakura

2011-01-01T23:59:59.000Z

105

Assessing risks from occupational exposure to low-level radiation: The statistician's role  

SciTech Connect

Currently, several epidemiological studies of workers who have been exposed occupationally to radiation are being conducted. These include workers in the United States, Great Britain, and Canada, involved in the production of both defense materials and nuclear power. A major reason for conducting these studies is to evaluate possible adverse health effects that may have resulted because of the radiation exposure received. The general subject of health effects resulting from low levels of radiation, including these worker studies, has attracted the attention of various news media, and has been the subject of considerable controversy. These studies provide a good illustration of certain other aspects of the statistician's role; namely, communication and adequate subject matter knowledge. A competent technical job is not sufficient if these other aspects are not fulfilled.

Gilbert, E.S.

1989-06-01T23:59:59.000Z

106

Relativistic Winds from Compact Gamma-ray Sources: I. Radiative Acceleration in the Klein-Nishina Regime  

E-Print Network (OSTI)

We consider the radiative acceleration to relativistic bulk velocities of a cold, optically thin plasma which is exposed to an external source of gamma-rays. The flow is driven by radiative momentum input to the gas, the accelerating force being due to Compton scattering in the relativistic Klein-Nishina limit. The bulk Lorentz factor of the plasma, Gamma, derived as a function of distance from the radiating source, is compared with the corresponding result in the Thomson limit. Depending on the geometry and spectrum of the radiation field, we find that particles are accelerated to the asymptotic Lorentz factor at infinity much more rapidly in the relativistic regime; and the radiation drag is reduced as blueshifted, aberrated photons experience a decreased relativistic cross section and scatter preferentially in the forward direction. The random energy imparted to the plasma by gamma-rays can be converted into bulk motion if the hot particles execute many Larmor orbits before cooling. This `Compton afterburn' may be a supplementary source of momentum if energetic leptons are injected by pair creation, but can be neglected in the case of pure Klein-Nishina scattering. Compton drag by side-scattered radiation is shown to be more important in limiting the bulk Lorentz factor than the finite inertia of the accelerating medium. The processes discussed here may be relevant to a variety of astrophysical situations where luminous compact sources of hard X- and gamma-ray photons are observed, including active galactic nuclei, galactic black hole candidates, and gamma-ray bursts.

Piero Madau; Christopher Thompson

1999-09-03T23:59:59.000Z

107

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

SciTech Connect

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

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

2007-01-01T23:59:59.000Z

108

Review of exposure limits and experimental data for corneal and lenticular damage from short pulsed UV and IR laser radiation  

E-Print Network (OSTI)

for publication 30 October 2007; published 22 April 2008 Laser exposure limits as promulgated by the International at the international level by ICNIRP the International Commission on Non-Ionizing Radiation Protection.1,2 OtherReview of exposure limits and experimental data for corneal and lenticular damage from short pulsed

109

Limitations and Problems in Deriving Risk Estimates for Low-level Radiation Exposure  

E-Print Network (OSTI)

Some of the problems in determining the cancer risk of low-level radiation from studies of exposed groups are reviewed and applied to the study of Hanford workers by Mancuso, Stewart, and Kneale. Problems considered are statistical limitations, variation of cancer rates with geography and race, the "healthy worker effect, " calendar year and age variation of cancer mortality, choosing from long lists, use of proportional mortality rates, cigarette smoking-cancer correlations, use of averages to represent data distributions, ignoring other data, and correlations between radiation exposure and other factors that may cause cancer. The current status of studies of the Hanford workers is reviewed. There have been several papers in recent years purporting to give evidence that low level radiation (- 10 rad) is more dangerous than indicated by conventional estimates like those of the National Academy of Sciences Committee on Biological Effects of Ionizing Radiation (BEIR) [1], the United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR) [21, and the International Commission on Radiological Protection (ICRP) [3]. The best known of these is the study by Mancuso, Stewart, and Kneale [4] (hereafter referred to as MSK) on workers at the

Bernard L. Cohen; D. Sc

1981-01-01T23:59:59.000Z

110

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

SciTech Connect

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

Tan, Ping; /Wisconsin U., Madison

2006-03-08T23:59:59.000Z

111

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

Science Conference Proceedings (OSTI)

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

Tan, Ping; /Wisconsin U., Madison

2006-03-08T23:59:59.000Z

112

Preprint typeset using L ATEX style emulateapj ON THE KINETIC ENERGY AND RADIATIVE EFFICIENCY OF GAMMA-RAY BURSTS  

E-Print Network (OSTI)

Using measured X-ray luminosities to 17 Gamma-Ray Bursts (GRBs) during the afterglow phase and accounting for radiative losses, we calculate the kinetic energy of these bursts and investigate its relation to other GRB properties. We then use the observed radiated energy during the prompt phase to determine the radiative efficiency of these bursts, and explore how the efficiency relates to other GRB observables. We find that the kinetic energy in the afterglow phase is directly correlated with the radiated energy, total energy as well as possibly the jet opening angle and spectral peak energy. More importantly, we find the intriguing fact that the efficiency is correlated with the radiated energy, and mildly with the total energy, jet opening angle and spectral peak energy. XRF020903 also seems to follow the trends we find for our GRB sample. We discuss the implications of these results for the GRB radiation and jet models. 1.

Nicole M. Lloyd-ronning; Bing Zhang

2008-01-01T23:59:59.000Z

113

Measuring Radiation  

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

Measurement Activity SI Units and Prefixes Conversions Safety Around Radiation Sources Types of Radiation Exposure Managing Radiation Emergencies Procedure Demonstration...

114

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

E-Print Network (OSTI)

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

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

2012-05-01T23:59:59.000Z

115

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

Science Conference Proceedings (OSTI)

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

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

2011-01-15T23:59:59.000Z

116

An Analysis of a Spreader Bar Crane Mounted Gamma-Ray Radiation Detection System  

E-Print Network (OSTI)

Over 95% of imports entering the United States from outside North America arrive via cargo containers by sea at 329 ports of entry. The current layered approach for the detection only scans 5% of cargo bound for the United States. This is inadequate to protect our country. This research involved the building of a gamma-ray radiation detection system used for cargo scanning. The system was mounted on a spreader bar crane (SBC) at the Port of Tacoma (PoT) and the applicability and capabilities of the system were analyzed. The detection system provided continuous count rate and spectroscopic data among three detectors while operating in an extreme environment. In a separate set of experiments, 60Co and 137Cs sources were positioned inside a cargo container and data were recorded for several count times. The Monte Carlo N-Particle (MCNP) code was used to simulate a radioactive source inside an empty cargo container and the results were compared to experimentally recorded data. The detection system demonstrated the ability to detect 60Co, 137Cs, 192Ir, highly-enriched uranium (HEU), and weapons-grade plutonium (WGPu) with minimum detectable activities (MDA) of 5.9 ± 0.4 microcuries (?Ci), 19.3 ± 1.1 ?Ci, 11.7 ± 0.6 ?Ci, 3.5 ± 0.3 kilograms (kg), and 30.6 ± 1.3 grams (g), respectively. This system proved strong gamma-ray detection capabilities, but was limited in the detection of fissile materials Additional details of this system are presented and advantages of this approach to cargo scanning over current approaches are discussed.

Grypp, Matthew D

2013-05-01T23:59:59.000Z

117

Lesson 4 - Ionizing Radiation | Department of Energy  

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

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

118

Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters  

SciTech Connect

Of the important health effects of ionizing radiation, three important late effects - carcinogenesis, teratogenesis and mutagenesis are of greatest concern. This is because any exposure, even at low levels, carries some risk of such deleterious effects. As the dose of radiation increases above very low levels, the risk of health effects increases. Cancer-induction is the most important late somatic effect of low-dose ionizing radiation. Solid cancers, rather than leukemia, are principal late effects in exposed individuals. Tissues vary greatly in their susceptibility to radiation carcinogenesis. The most frequently occurring radiation-induced cancers in man include, in decreasing order of susceptibility: the female breast, the thyroid gland, the blood-forming tissues, the lung, certain organs of the gastrointestinal tract, and the bones. A number of biological and physical factors affect the cancer risk, such as age, sex, life-style, LET, and RBE. Despite uncertainty about low-level radiation risks, regulatory and advisory bodies must set standards for exposure, and individuals need information to be able to make informed judgments for themselves. From the point of view of the policy maker, the overriding concern is the fact that small doses of radiation can cause people to have more cancers than would otherwise be expected. While concern for all radiation effects exists, our human experience is limited to cancer-induction in exposed populations. This discussion is limited to cancer risk estimation and decision-making in relation to the health effects on populations of exposure to low levels of ionizing radiation. Here, low-level radiation will refer to yearly whole-body doses up to 5 rems or 0.05 Sv, or to cumulative doses up to 50 rems or 0.5 Sv from low-LET radiation and from high-LET radiation. (ERB)

Fabrikant, J.I.

1982-04-01T23:59:59.000Z

119

Solar Radiation and Tidal Exposure as Environmental Drivers of Enhalus acoroides Dominated Seagrass  

E-Print Network (OSTI)

There is strong evidence of a global long-term decline in seagrass meadows that is widely attributed to anthropogenic activity. Yet in many regions, attributing these changes to actual activities is difficult, as there exists limited understanding of the natural processes that can influence these valuable ecosystem service providers. Being able to separate natural from anthropogenic causes of seagrass change is important for developing strategies that effectively mitigate and manage anthropogenic impacts on seagrass, and promote coastal ecosystems resilient to future environmental change. The present study investigated the influence of environmental and climate related factors on seagrass biomass in a large solar radiation. This study documents how natural long-term tidal variability can influence long-term seagrass dynamics. Exposure to desiccation, high UV, and daytime temperature regimes are discussed as the likely mechanisms for the action of these factors in causing this decline. The results emphasise the importance of understanding and assessing natural environmentally-driven change when

Richard K. F. Unsworth; Michael A. Rasheed; Kathryn M. Chartr; Anthony J. Roelofs

2012-01-01T23:59:59.000Z

120

Effective Personnel Exposure Control in Shortened Refueling Outages: Final Report: Review of Remote Monitoring Systems in Radiation Protection Applications  

Science Conference Proceedings (OSTI)

Remote monitoring technology (RMT) significantly enhances worker protection and reduces worker radiation exposure, particularly during shortened refueling outages. This report provides a brief description of the hardware and features of remote monitoring systems, then focuses on nuclear plant experiences in applying such systems for enhanced radiation protection. It also discusses EPRI's RMT research program and formation of the RMT Working Group to support research in this area. Such information will gr...

2003-12-02T23:59:59.000Z

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

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

122

Occupational radiation exposure at commercial nuclear power reactors and other facilities 1992; Twenty-fifth annual report, Volume 14  

SciTech Connect

This report summarizes the occupational radiation exposure information that has been reported to the NRC`s Radiation Exposure Information Reporting System (REIRS) by nuclear power facilities and certain other categories of NRC licensees during the years 1969 through 1992. The bulk of the data presented in the report was obtained from annual radiation exposure reports submitted in accordance with the requirements of 10CFR20.407 and the technical specifications of nuclear power plants. Data on workers terminating their employment at certain NRC licensed facilities were obtained from reports submitted pursuant to 10CFR20.408. The 1992 annual reports submitted by about 364 licensees indicated that approximately 204,365 individuals were monitored, 183,927 of whom were monitored by nuclear power facilities. They incurred an average individual dose of 0.16 rem (cSv) and an average measurable dose of about 0.30 (cSv). Termination radiation exposure reports were analyzed to reveal that about 74,566 individuals completed their employment with one or more of the 364 covered licensees during 1992. Some 71,846 of these individuals terminated from power reactor facilities, and about 9,724 of them were considered to be transient workers who received an average dose of 0.50 rem (cSv).

Raddatz, C.T. [US Nuclear Regulatory Commission, Washington, DC (United States). Division of Regulatory Applications; Hagemeyer, D. [Science Applications International Corp., Oak Ridge, TN (United States)

1993-12-01T23:59:59.000Z

123

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

124

Out-of-Field Cell Survival Following Exposure to Intensity-Modulated Radiation Fields  

Science Conference Proceedings (OSTI)

Purpose: To determine the in-field and out-of-field cell survival of cells irradiated with either primary field or scattered radiation in the presence and absence of intercellular communication. Methods and Materials: Cell survival was determined by clonogenic assay in human prostate cancer (DU145) and primary fibroblast (AGO1552) cells following exposure to different field configurations delivered using a 6-MV photon beam produced with a Varian linear accelerator. Results: Nonuniform dose distributions were delivered using a multileaf collimator (MLC) in which half of the cell population was shielded. Clonogenic survival in the shielded region was significantly lower than that predicted from the linear quadratic model. In both cell lines, the out-of-field responses appeared to saturate at 40%-50% survival at a scattered dose of 0.70 Gy in DU-145 cells and 0.24 Gy in AGO1522 cells. There was an approximately eightfold difference in the initial slopes of the out-of-field response compared with the {alpha}-component of the uniform field response. In contrast, cells in the exposed part of the field showed increased survival. These observations were abrogated by direct physical inhibition of cellular communication and by the addition of the inducible nitric oxide synthase inhibitor aminoguanidine known to inhibit intercellular bystander effects. Additional studies showed the proportion of cells irradiated and dose delivered to the shielded and exposed regions of the field to impact on response. Conclusions: These data demonstrate out-of-field effects as important determinants of cell survival following exposure to modulated irradiation fields with cellular communication between differentially irradiated cell populations playing an important role. Validation of these observations in additional cell models may facilitate the refinement of existing radiobiological models and the observations considered important determinants of cell survival.

Butterworth, Karl T., E-mail: k.butterworth@qub.ac.u [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); McGarry, Conor K. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Northern Ireland (United Kingdom); Trainor, Colman [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); O'Sullivan, Joe M. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Clinical Oncology, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland (United Kingdom); Hounsell, Alan R. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Northern Ireland (United Kingdom); Prise, Kevin M. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom)

2011-04-01T23:59:59.000Z

125

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. T...

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

2012-01-01T23:59:59.000Z

126

Shellfish consumption and intertidal occupancy review, Sellafield, 2004. This note describes a review of public radiation exposure pathways due to liquid radioactive  

E-Print Network (OSTI)

a review of public radiation exposure pathways due to liquid radioactive waste discharges from the British limited to adults. The results are shown in Tables 1 to 3. Data analysis Internal exposure In addition and external exposure pathways have also been conducted by the Centre for Environment, Fisheries

127

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

SciTech Connect

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

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

1989-06-01T23:59:59.000Z

128

An evaluation of theories concerning the health effects of low-dose radiation exposures  

E-Print Network (OSTI)

The danger of high, acute doses of radiation is well documented, but the effects of low-dose radiation below 100 mSv is still heavily debated. Four theories concerning the effects of lowdose radiation are presented here: ...

Wei, Elizabeth J. (Elizabeth Jay)

2012-01-01T23:59:59.000Z

129

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

SciTech Connect

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

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

2006-12-04T23:59:59.000Z

130

Definition of Radiation  

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

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

131

Deep diode atomic battery. [Patent: electron-hole pair production by gamma or x radiation  

SciTech Connect

A deep diode atomic battery is made from a bulk semiconductor crystal containing three-dimensional arrays of columnar and lamellar P-N junctions. The battery is powered by gamma rays and x-ray emission from a radioactive source embedded in the interior of the semiconductor crystal.

Anthony, T.R.; Cline, H.E.

1977-05-17T23:59:59.000Z

132

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

SciTech Connect

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

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

2009-02-01T23:59:59.000Z

133

Use of ionizing radiation for fixing textile resins on wool. [Gamma rays  

SciTech Connect

Ambient-temperature treatments with ionizing radiation can be used as an alternative to conventional thermal/catalytic cure methods of fixing textile resins on wool materials. The effectiveness of the radiation-induced fixation of resins on wool has been demonstrated by machine-wash shrinkage tests on fabrics treated with a variety of commercial polymer resins.

McLaren, K.G.

1980-04-01T23:59:59.000Z

134

DOE Radiation Exposure Monitoring System (REMS) Data Update Presented at the 32nd Annual International Dosimetry and Records Symposium, June 3-6, Scottsdale, AZ  

Science Conference Proceedings (OSTI)

This slide-show presents the 2012 draft data for DOE occupational radiation exposure, compares those data with last year and the last five years, and clarifies reporting data.

none,

2013-01-01T23:59:59.000Z

135

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

SciTech Connect

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

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

2012-09-10T23:59:59.000Z

136

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

137

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

138

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

SciTech Connect

The fundamental nature of mass is one of the greatest mysteries in physics. The Higgs mechanism is a theoretically appealing way to account for the different masses of elementary particles and implies the existence of a new, yet unseen particle, the Higgs boson. We search for evidence of a light scalar (e.g. a Higgs boson) in the radiative decays of the narrow {Upsilon}(3S) resonance: {Upsilon}(3S) {yields} {gamma}A{sup 0}, A{sup 0} {yields} {mu}{sup +}{mu}{sup -}. Such an object appears in extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. We find no evidence for such processes in a sample of 122 x 10{sup 6} {Upsilon}(3S) decays collected by the BABAR collaboration at the PEP-II B-factory, and set 90% C.L. upper limits on the branching fraction product {Beta}({Upsilon}(3S) {yields} {gamma}A{sup 0}) x {Beta}(A{sup 0} {yields} {mu}{sup +}{mu}{sup -}) at (0.25 - 5.2) x 10{sup -6} in the mass range 0.212 {<=} m{sub A{sup 0}} {<=} 9.3 GeV. We also set a limit on the dimuon branching fraction of the {eta}{sub b} meson {Beta}({eta}{sub b} {yields} {mu}{sup +}{mu}{sup -}) < 0.8% at 90% C.L. The results are preliminary.

Aubert, B

2009-06-02T23:59:59.000Z

139

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

Science Conference Proceedings (OSTI)

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

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

2011-04-18T23:59:59.000Z

140

Miniaturized radiation chirper  

SciTech Connect

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

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

1980-01-01T23:59:59.000Z

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

Analysis of radiation exposure for additional naval personnel at Operation CASTLE - supplemental report. Technical report, 24 Apr-20 Nov 89  

SciTech Connect

This report supplements DNA-TR-84-6 by analyzing the radiation exposure for typical crewmembers of eight additional ships at Operation CASTLE in 1954: RECLAIMER, SHEA, COCOPA, MENDER, MOLALA, TAWAKONI, PC-1546, and LST-1146. Utilizing the reconstructed radiation environments from deck contamination, water shine, proximate ship shine, and contaminated hulls and piping, equivalent film badge doses are calculated and compared with analyzed film badge dosimetry. Comparisons are hampered by a shortage of badge readings and by cohort badging that may have emphasized non-representative crew activities. Considering this, agreement is good (within a few hundred millirem) when doses were high but less when doses were low. In all cases, overall totals appear to be in excellent agreement.

Thomas, C.; Geotz, J.; Klemm, J.; Ortlieb, E.

1991-10-01T23:59:59.000Z

142

Estimation of Internal Radiation Dose from both Immediate Releases and Continued Exposures to Contaminated Materials  

Science Conference Proceedings (OSTI)

A brief description is provided of the basic concepts related to 'internal dose' and how it differs from doses that result from radioactive materials and direct radiation outside of the body. The principles of radiation dose reconstruction, as applied to both internal and external doses, is discussed based upon a recent publication prepared by the US National Council on Radiation Protection and Measurements. Finally, ideas are introduced related to residual radioactive contamination in the environment that has resulted from the releases from the damaged reactors and also to the management of wastes that may be generated in both regional cleanup and NPP decommissioning.

Napier, Bruce A.

2012-03-26T23:59:59.000Z

143

The risk equivalent of an exposure to-, versus a dose of radiation  

SciTech Connect

The long-term potential carcinogenic effects of low-level exposure (LLE) are addressed. The principal point discussed is linear, no-threshold dose-response curve. That the linear no-threshold, or proportional relationship is widely used is seen in the way in which the values for cancer risk coefficients are expressed - in terms of new cases, per million persons exposed, per year, per unit exposure or dose. This implies that the underlying relationship is proportional, i.e., ''linear, without threshold''. 12 refs., 9 figs., 1 tab.

Bond, V.P.

1986-01-01T23:59:59.000Z

144

A Personal Experience Reducing Radiation Exposures: Protecting Family in Kiev during the First Two Weeks after Chernobyl  

SciTech Connect

The Chernobyl nuclear reactor accident occurred in 1986. The plume from the explosions and fires was highly radioactive and resulted in very high exposure levels in the surrounding regions. This paper describes how the people in Kiev, Ukraine, a city 90 miles (120 km) south of Chernobyl, and in particular one individual in that city, Professor Vitaly Eremenko, became aware of the threat before the official announcement and the steps he took to mitigate potential impacts to his immediate family. The combination of being informed and using available resources led to greatly reduced consequences for his family and, in particular, his newborn granddaughter. He notes how quickly word of some aspects of the hazard spread in the city and how other aspects appear to not have been understood. Although these events are being recalled as the 20th anniversary of the terrible event approaches, the lessons are still pertinent today. Threats of possible terrorist use of radiation dispersal devices makes knowledge of effective individual actions for self-protection from radiation exposures a topic of current interest.

Eremenko, Vitaly A.; Droppo, James G.

2006-08-01T23:59:59.000Z

145

Gamma knife radiosurgery of radiation-induced intracranial tumors: Local control, outcomes, and complications  

Science Conference Proceedings (OSTI)

Purpose: To determine local control (LC) and complication rates for patients who underwent radiosurgery for radiation-induced intracranial tumors. Methods and Materials: Review of a prospectively maintained database (2,714 patients) identified 16 patients (20 tumors) with radiation-induced tumors treated with radiosurgery between 1990 and 2004. Tumor types included typical meningioma (n = 17), atypical meningioma (n = 2), and schwannoma (n 1). Median patient age at radiosurgery was 47.5 years (range, 27-70 years). The median tumor margin dose was 16 Gy (range, 12-20 Gy). Median follow-up was 40.2 months (range, 10.8-146.2 months). Time-to-event outcomes were calculated with Kaplan-Meier estimates. Results: Three-year and 5-year LC rates were 100%. Three-year and 5-year overall survival rates were 92% and 80%, respectively. Cause-specific survival rates at 3 and 5 years were 100%. Three patients died: 1 had in-field progression 65.1 months after radiosurgery and later died of the tumor, 1 died of progression of a preexisting brain malignancy, and 1 died of an unrelated cause. One patient had increased seizure activity that correlated with development of edema seen on neuroimaging. Conclusions: LC, survival, and complication rates in our series are comparable to those in previous reports of radiosurgery for intracranial meningiomas. Also, LC rates with radiosurgery are at least comparable to those of surgical series for radiation-induced meningiomas. Radiosurgery is a safe and effective treatment option for radiation-induced intracranial tumors, most of which are typical meningiomas.

Jensen, Ashley W. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Brown, Paul D. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Pollock, Bruce E. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Department of Neurologic Surgery, Mayo Clinic, Rochester, MN (United States); Stafford, Scott L. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Link, Michael J. [Department of Neurologic Surgery, Mayo Clinic, Rochester, MN (United States); Garces, Yolanda I. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Foote, Robert L. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Gorman, Deborah A. [Department of Neurologic Surgery, Mayo Clinic, Rochester, MN (United States); Schomberg, Paula J. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States)

2005-05-01T23:59:59.000Z

146

Thyroid cancer in the Marshallese: relative risk of short-lived internal emitters and external radiation exposure  

Science Conference Proceedings (OSTI)

In a study of the comparative effects of internal versus external irradiation of the thyroid in young people, we determined that the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times less thyroid cancer than did the same dose of radiation given externally. We determined this finding for a group of 85 Marshall Islands children, who were less than 10 years of age at the time of exposure and who were accidentially exposed to internal and external thyroid radiation at an average level of 1400 rad. The external risk coefficient ranged between 2.5 and 4.9 cancers per million person-rad-years at risk, and thus, from our computations, the internal risk coefficient for the Marshallese children was estimated to range between 1.0 and 1.4 cancers per million person-rad-years at risk. In contrast, for individual more than 10 years of age at the time of exposure, the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times more thyroid cancer than did the same dose of radiation given externally. The external risk coefficients for the older age groups were reported in the literature to be in the range of 1.0 to 3.3 cancers per million person-rad-years-at risk. We computed internal risk coefficients of 3.3 to 8.1 cancers per million person-rad-years at risk for adolescent and adult groups. This higher sensitivity to cancer induction in the exposed adolescents and adults, is different from that seen in other exposed groups. 14 refs., 8 tabs.

Lessard, E.T.; Brill, A.B.; Adams, W.H.

1985-01-01T23:59:59.000Z

147

SRNL Deploys Innovative Radiation Mapping Device | Department of Energy  

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

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

148

How to Detect Radiation  

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

How to Detect Radiation How to Survey Measurement Safety Around Radiation Sources Types of Radiation Exposure Managing Radiation Emergencies Procedure Demonstration Detection How...

149

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

Science Conference Proceedings (OSTI)

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

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

2012-04-15T23:59:59.000Z

150

Energy spectrum and mass composition of primary cosmic radiation in the region above the knee from the GAMMA experiment  

E-Print Network (OSTI)

The energy spectrum of the primary cosmic radiation in the energy range 1 - 100 PeV and the extensive air shower (EAS) characteristics obtained on the basis of the expanded data bank of the GAMMA experiment (Mt. Aragats, Armenia) are presented. With increased statistics we confirm our previous results on the energy spectrum. The spectral index above the knee is about -3.1, but at energies beyond 20 PeV a flattening of the spectrum is observed. The existence of the 'bump' at about 70 PeV is confirmed with a significance of more than 4{\\sigma}. In the energy range of 10 - 100 PeV the shower age becomes energy independent and we observe a direct proportionality of the EAS size to the primary energy. This suggests an approximately constant depth of the EAS maximum in this energy range. This is evidence in favour of an increasing average mass of primary particles at energies above 20 PeV. The additional source scenario, which is a possible explanation of the 'bump' in the spectrum, also leads to the conclusion of ...

Martirosov, R M; Vardanyan, H S; Erlykin, A D; Nikolskaya, N M; Gallant, Y A; Jones, L W; Babayan, H A

2012-01-01T23:59:59.000Z

151

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

E-Print Network (OSTI)

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

Michael A. Ivanov

2006-09-19T23:59:59.000Z

152

REGULATORY GUIDE 8.18 liNJFORMATIOiN RELEVANT TO EiNSURING THAT OCCUPATIONAL RADIATION EXPOSURES AT MEL)ICAL INSTITUTIONS,rILL BE AS LOW AS,IEASONAdLY ACHIEVABLE  

E-Print Network (OSTI)

Paragraph 20.1(c) of 10 CFR Part 20, "Standards for Protection Against Radiation, " states that licensees should make every reasonable effort to keep radiation exposures, as well as releases of radioactive material to unrestricted

unknown authors

1982-01-01T23:59:59.000Z

153

RADIATION SAFETY OFFICE UNIVERSITYOF MARYLAND  

E-Print Network (OSTI)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. RADIATION EXPOSURE CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.2.2. Internal ExposureRADIATION SAFETY OFFICE UNIVERSITYOF MARYLAND RADIATION SAFETY MANUAL UNIVERSITY OF MARYLAND

Rubloff, Gary W.

154

Method and apparatus for reducing radiation exposure through the use of infrared data transmission  

SciTech Connect

A method and apparatus is described for transmitting information, for exae, dosimetry data from a hazardous environment such as a radioactive area to a remote relatively safe location. A radiation detector senses the radiation and generates an electrical signal which is fed as a binary coded decimal signal to an infrared transmitter having a microprocessor. The microprocessor formats the detected information into digits of data and modulates a 40 kHz oscillator, the output of which is fed to and intensity modulates one or more infrared emitting diodes. The infrared signal from the diodes is transmitted to a portable hand-held infrared receiver remote from the hazardous environment. The receiver includes an infrared sensitive diode which decodes the data and generates an electrical signal which is coupled to a microcomputer. The microcomputer synchronizes itself to the transmitter, reads the digits of data as they are received, sums the digits and compares the sum with a checksum signal generated and transmitted from the transmitter. If a match of the checksum signals exists, the received data is displayed, otherwise it is described and the receiver conditions itself for the next transmission of data.

Austin, Frank S. (Schaghticoke, NY); Hance, Albert B. (Schenectady, NY)

1989-01-01T23:59:59.000Z

155

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

E-Print Network (OSTI)

R.B. Mikkelsen, Ionizing radiation-induced, mitochondria-W.K. Rorrer, P.B. Chen, Radiation-induced proliferation ofresponse genes to ionizing radiation in human lymphoblastoid

Wyrobek, A. J.

2011-01-01T23:59:59.000Z

156

Cell Type-dependent Gene Transcription Profile in Three Dimensional Human Skin Tissue Model Exposed to Low Doses of Ionizing Radiation: Implications for Medical Exposures  

SciTech Connect

The concern over possible health risks from exposures to low doses of ionizing radiation has been driven largely by the increase in medical exposures, the routine implementation of X-ray backscatter devices for airport security screening, and, most recently, the nuclear incident in Japan. Due to a paucity of direct epidemiological data at very low doses, cancer risk must be estimated from high dose exposure scenarios. However, there is increasing evidence that low and high dose exposures result in different signaling events and may have different mechanisms of cancer induction. We have examined the radiation induced temporal response of an in vitro three dimensional (3D) human skin tissue model using microarray-based transcriptional profiling. Our data shows that exposure to 100 mGy of X-rays is sufficient to affect gene transcription. Cell type specific analysis showed significant changes in gene expression with the levels of > 1400 genes altered in the dermis and > 400 genes regulated in the epidermis. The two cell types rarely exhibited overlapping responses at the mRNA level. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) measurements validated the microarray data in both regulation direction and value. Key pathways identified relate to cell cycle regulation, immune responses, hypoxia, reactive oxygen signaling, and DNA damage repair. We discuss in particular the role of proliferation and emphasizing how the disregulation of cellular signaling in normal tissue may impact progression towards radiation induced secondary diseases.

Freiin von Neubeck, Claere H.; Shankaran, Harish; Karin, Norman J.; Kauer, Paula M.; Chrisler, William B.; Wang, Xihai; Robinson, Robert J.; Waters, Katrina M.; Tilton, Susan C.; Sowa, Marianne B.

2012-04-17T23:59:59.000Z

157

SHP-2 tyrosine phosphate-dependent focal adhesion kinase mediated cell migration of primary endothelial cells upon low LET radiation exposure  

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

SHP-2 tyrosine phosphate-dependent focal adhesion kinase mediated cell SHP-2 tyrosine phosphate-dependent focal adhesion kinase mediated cell migration of primary endothelial cells upon low LET radiation exposure Xiangpeng Zheng, 1 Sumathy Mohan, 3 and Mohan Natarajan 1,2 Departments of 1 Otolaryngology, 2 Radiation Oncology, and 3 Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229 The influence and mechanism of low LET radiation exposure on wound healing process is not yet fully understood. Based on the vital role of endothelial cells in migration and wound healing, this study investigated the response of endothelial cells to low-dose irradiation and the underlying mechanism. A wound was inflicted in the confluent monolayer of primary vascular endothelial cells exposing a cell-free zone on the plate. The cells were then exposed

158

Occupational radiation exposure at commercial nuclear power reactors and other facilities 1996: Twenty-ninth annual report. Volume 18  

SciTech Connect

This report summarizes the occupational exposure data that are maintained in the US Nuclear Regulatory Commission`s (NRC) Radiation Exposure Information and Reporting System (REIRS). The bulk of the information contained in the report was compiled from the 1996 annual reports submitted by six of the seven categories of NRC licensees subject to the reporting requirements of 10 CFR 20.2206. Since there are no geologic repositories for high level waste currently licensed, only six categories will be considered in this report. Annual reports for 1996 were received from a total of 300 NRC licensees, of which 109 were operators of nuclear power reactors in commercial operation. Compilations of the reports submitted by the 300 licensees indicated that 138,310 individuals were monitored, 75,139 of whom received a measurable dose. The collective dose incurred by these individuals was 21,755 person-cSv (person-rem){sup 2} which represents a 13% decrease from the 1995 value. The number of workers receiving a measurable dose also decreased, resulting in the average measurable dose of 0.29 cSv (rem) for 1996. The average measurable dose is defined to be the total collective dose (TEDE) divided by the number of workers receiving a measurable dose. These figures have been adjusted to account for transient reactor workers. Analyses of transient worker data indicate that 22,348 individuals completed work assignments at two or more licensees during the monitoring year. The dose distributions are adjusted each year to account for the duplicate reporting of transient workers by multiple licensees. In 1996, the average measurable dose calculated from reported was 0.24 cSv (rem). The corrected dose distribution resulted in an average measurable dose of 0.29 cSv (rem).

Thomas, M.L. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Regulatory Applications; Hagemeyer, D. [Science Applications International Corp., Oak Ridge, TN (United States)

1998-02-01T23:59:59.000Z

159

RADIATION EFFECTS ON EPOXY CARBON FIBER COMPOSITE  

SciTech Connect

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

Hoffman, E

2008-05-30T23:59:59.000Z

160

Estimates of Radiation Exposures for Human Crews in Deep Space from the January 15, 2005, Solar Energetic Particle Event Using the Earth-Moon-Mars Radiation Environment Module  

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

Mahmoud PourArsalan; Lawrence W. Townsend; Nathan A. Schwadron; Kamen Kozarev; Maher A. Dayeh; Mihir I. Desai

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

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

162

Early Brain Response to Low-Dose Radiation Exposure Involves Molecular Networks and Pathways Associated with Cognitive Functions, Advanced Aging and Alzheimer's Disease  

SciTech Connect

Understanding the cognitive and behavioral consequences of brain exposures to low-dose ionizing radiation has broad relevance for health risks from medical radiation diagnostic procedures, radiotherapy, environmental nuclear contamination, as well as earth orbit and space missions. Analyses of transcriptome profiles of murine brain tissue after whole-body radiation showed that low-dose exposures (10 cGy) induced genes not affected by high dose (2 Gy), and low-dose genes were associated with unique pathways and functions. The low-dose response had two major components: pathways that are consistently seen across tissues, and pathways that were brain tissue specific. Low-dose genes clustered into a saturated network (p < 10{sup -53}) containing mostly down-regulated genes involving ion channels, long-term potentiation and depression, vascular damage, etc. We identified 9 neural signaling pathways that showed a high degree of concordance in their transcriptional response in mouse brain tissue after low-dose radiation, in the aging human brain (unirradiated), and in brain tissue from patients with Alzheimer's disease. Mice exposed to high-dose radiation did not show these effects and associations. Our findings indicate that the molecular response of the mouse brain within a few hours after low-dose irradiation involves the down-regulation of neural pathways associated with cognitive dysfunctions that are also down regulated in normal human aging and Alzheimer's disease.

Lowe, Xiu R; Bhattacharya, Sanchita; Marchetti, Francesco; Wyrobek, Andrew J.

2008-06-06T23:59:59.000Z

163

Early Brain Response to Low-Dose Radiation Exposure Involves Molecular Networks and Pathways Associated with Cognitive Functions, Advanced Aging and Alzheimer's Disease  

SciTech Connect

Understanding the cognitive and behavioral consequences of brain exposures to low-dose ionizing radiation has broad relevance for health risks from medical radiation diagnostic procedures, radiotherapy, environmental nuclear contamination, as well as earth orbit and space missions. Analyses of transcriptome profiles of murine brain tissue after whole-body radiation showed that low-dose exposures (10 cGy) induced genes not affected by high dose (2 Gy), and low-dose genes were associated with unique pathways and functions. The low-dose response had two major components: pathways that are consistently seen across tissues, and pathways that were brain tissue specific. Low-dose genes clustered into a saturated network (p < 10{sup -53}) containing mostly down-regulated genes involving ion channels, long-term potentiation and depression, vascular damage, etc. We identified 9 neural signaling pathways that showed a high degree of concordance in their transcriptional response in mouse brain tissue after low-dose radiation, in the aging human brain (unirradiated), and in brain tissue from patients with Alzheimer's disease. Mice exposed to high-dose radiation did not show these effects and associations. Our findings indicate that the molecular response of the mouse brain within a few hours after low-dose irradiation involves the down-regulation of neural pathways associated with cognitive dysfunctions that are also down regulated in normal human aging and Alzheimer's disease.

Lowe, Xiu R; Bhattacharya, Sanchita; Marchetti, Francesco; Wyrobek, Andrew J.

2008-06-06T23:59:59.000Z

164

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

Science Conference Proceedings (OSTI)

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

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

2013-09-01T23:59:59.000Z

165

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

E-Print Network (OSTI)

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

Pittori, Carlotta; Colafrancesco, Sergio; Giommi, Paolo

2007-01-01T23:59:59.000Z

166

Cellular and molecular level responses after radiofrequency radiation exposure, alone or in combination with x-rays or chemicals. Final report, 1 April 1991-30 September 1994  

SciTech Connect

This project was initiated to explore the potential bioeffects of microwave radiation, alone or in combination with ionizing radiation and chemicals. Over the time period of the project, an automated thermal control system, to be used for maintaining the temperature in tissue culture medium during microwave exposures, was designed, constructed, and software was created. While this was underway during the project period, numerous positive control biological experiments were performed on two different cell types, the Epstein Barr Virus transformed 244B human lymphoblastoid cell, and the freshly isolated peripheral human lymphocyte. The 244B cells were used to address the question of whether a physical agent, ionizing radiation, at low doses where cells would predominantly remain viable, would induce the DNA binding protein NF-kB, and/or four immediate early genes (IEG) (protooncogenes).

Meltz, M.L.; Natarajan, M.; Prasad, A.V.

1995-02-21T23:59:59.000Z

167

Nuclear radiation-warning detector that measures impedance  

DOE Patents (OSTI)

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

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

2013-06-04T23:59:59.000Z

168

Precise Measurement of the e(+)e(-)->pi(+)pi(-)(gamma) Cross Section with the Initial State Radiation Method at BABAR  

E-Print Network (OSTI)

A precise measurement of the cross section of the process e[superscript +]e[superscript -]??[superscript +]?[superscript -](?) from threshold to an energy of 3 GeV is obtained with the initial state radiation (ISR) method ...

Cowan, Ray Franklin

169

RESRAD-RECYCLE : a computer model for analyzing radiation exposures resulting from recycling radioactively contaminated scrap metals or reusing ratioactively surface-contaminated materials and equipment.  

Science Conference Proceedings (OSTI)

RESRAD-RECYCLE is a computer code designed by Argonne National Laboratory (ANL) to be used in making decisions about the disposition of radioactively contaminated materials and scrap metals. It implements a pathway analysis methodology to evaluate potential radiation exposures resulting from the recycling of contaminated scrap metals and the reuse of surface-contaminated materials and equipment. For modeling purposes, it divides the entire metal recycling process into six steps: (1) scrap delivery, (2) scrap melting, (3) ingot delivery, (4) product fabrication, (5) product distribution, and (6) use of finished product. RESRAD-RECYCLE considers the reuse of surface-contaminated materials in their original forms. It contains representative exposure scenarios for each recycling step and the reuse process; users can also specify scenarios if desired. The model calculates individual and collective population doses for workers involved in the recycling process and for the public using the finished products. The results are then used to derive clearance levels for the contaminated materials on the basis of input dose restrictions. The model accounts for radiological decay and ingrowth, dilution and partitioning during melting, and distribution of refined metal in the various finished products, as well as the varying densities and geometries of the radiation sources during the recycling process. A complete material balance in terms of mass and radioactivity during the recycling process can also be implemented. In an international validation study, the radiation doses calculated by RESRAD-RECYCLE were shown to agree fairly well with actual measurement data.

Cheng, J. J.; Kassas, B.; Yu, C.; Arnish, J. J.; LePoire, D.; Chen, S.-Y.; Williams, W. A.; Wallo, A.; Peterson, H.; Environmental Assessment; DOE; Univ. of Texas

2004-11-01T23:59:59.000Z

170

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

SciTech Connect

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

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

1985-07-01T23:59:59.000Z

171

Historical Evaluation of Film Badge Dosimetry Y-12 Plant: Part 2–Neutron Radiation ORAUT-OTIB-0045  

SciTech Connect

A summary of the major neutron sources involved in radiation exposures to Y-12 workers is presented in this TIB. Graphical methods are used to evaluate available neutron dose data from quarterly exposures to Y-12 workers and to determine how the data could be used to derive neutron-to-gamma dose ratios for dose reconstruction purposes. This TIB provides estimates of neutron-to-gamma dose ratios for specific departments and a default value for the neutron-to-gamma dose ratio based on the pooled neutron dose data for all Y-12 departments.

Kerr GD, Frome EL, Watkins JP, Tankersley WG

2009-12-14T23:59:59.000Z

172

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

173

Technology, safety, and costs of decommissioning reference nuclear research and test reactors: sensitivity of decommissioning radiation exposure and costs to selected parameters  

Science Conference Proceedings (OSTI)

Additional analyses of decommissioning at the reference research and test (R and T) reactors and analyses of five recent reactor decommissionings are made that examine some parameters not covered in the initial study report (NUREG/CR-1756). The parameters examined for decommissioning are: (1) the effect on costs and radiation exposure of plant size and/or type; (2) the effects on costs of increasing disposal charges and of unavailability of waste disposal capacity at licensed waste disposal facilities; and (3) the costs of and the available alternatives for the disposal of nuclear R and T reactor fuel assemblies.

Konzek, G.J.

1983-07-01T23:59:59.000Z

174

Low Dose Radiation Research Program: DOE Lowdose Radiation Program Workshop  

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

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

175

DNA Double-Strand Break Analysis by {gamma}-H2AX Foci: A Useful Method for Determining the Overreactors to Radiation-Induced Acute Reactions Among Head-and-Neck Cancer Patients  

SciTech Connect

Purpose: Interindividual variability in normal tissue toxicity during radiation therapy is a limiting factor for successful treatment. Predicting the risk of developing acute reactions before initiation of radiation therapy may have the benefit of opting for altered radiation therapy regimens to achieve minimal adverse effects with improved tumor cure. Methods and Materials: DNA double-strand break (DSB) induction and its repair kinetics in lymphocytes of head-and-neck cancer patients undergoing chemoradiation therapy was analyzed by counting {gamma}-H2AX foci, neutral comet assay, and a modified version of neutral filter elution assay. Acute normal tissue reactions were assessed by Radiation Therapy Oncology Group criteria. Results: The correlation between residual DSBs and the severity of acute reactions demonstrated that residual {gamma}-H2AX foci in head-and-neck cancer patients increased with the severity of oral mucositis and skin reaction. Conclusions: Our results suggest that {gamma}-H2AX analysis may have predictive implications for identifying the overreactors to mucositis and skin reactions among head-and-neck cancer patients prior to initiation of radiation therapy.

Goutham, Hassan Venkatesh; Mumbrekar, Kamalesh Dattaram [Division of Radiobiology and Toxicology, Manipal Life Sciences Centre, Manipal University, Manipal, Karnataka (India)] [Division of Radiobiology and Toxicology, Manipal Life Sciences Centre, Manipal University, Manipal, Karnataka (India); Vadhiraja, Bejadi Manjunath [Manipal Hospital, Bangalore, Karnataka (India)] [Manipal Hospital, Bangalore, Karnataka (India); Fernandes, Donald Jerard; Sharan, Krishna [Department of Radiotherapy and Oncology, Shiridi Sai Baba Cancer Hospital and Research Centre, Kasturba Hospital, Manipal, Karnataka (India)] [Department of Radiotherapy and Oncology, Shiridi Sai Baba Cancer Hospital and Research Centre, Kasturba Hospital, Manipal, Karnataka (India); Kanive Parashiva, Guruprasad; Kapaettu, Satyamoorthy [Division of Biotechnology, Manipal Life Sciences Centre, Manipal University, Manipal, Karnataka (India)] [Division of Biotechnology, Manipal Life Sciences Centre, Manipal University, Manipal, Karnataka (India); Bola Sadashiva, Satish Rao, E-mail: satishraomlsc@gmail.com [Division of Radiobiology and Toxicology, Manipal Life Sciences Centre, Manipal University, Manipal, Karnataka (India)

2012-12-01T23:59:59.000Z

176

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

177

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

178

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

179

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

180

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

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

Radiators  

SciTech Connect

A heat-exchange radiator is connected to a fluid flow circuit by a connector which provides one member of an interengageable spigot and socket pair for push-fit, fluid-tight, engagement between the connector and the radiator, with latching formations at least one of which is resilient. Preferably the connector carries the spigot which tapers and engages with a socket of corresponding shape, the spigot carrying an O-ring seal and either latching fingers or a resilient latching circlip.

Webster, D. M.

1985-07-30T23:59:59.000Z

182

Discovery of Very High-Energy Gamma-Ray Radiation from the BL Lac 1ES 0806+524  

E-Print Network (OSTI)

The high-frequency-peaked BL-Lacertae object \\objectname{1ES 0806+524}, at redshift z=0.138, was observed in the very-high-energy (VHE) gamma-ray regime by VERITAS between November 2006 and April 2008. These data encompass the two-, and three-telescope commissioning phases, as well as observations with the full four-telescope array. \\objectname{1ES 0806+524} is detected with a statistical significance of 6.3 standard deviations from 245 excess events. Little or no measurable variability on monthly time scales is found. The photon spectrum for the period November 2007 to April 2008 can be characterized by a power law with photon index $3.6 \\pm 1.0_{\\mathrm{stat}} \\pm 0.3_{\\mathrm{sys}}$ between $\\sim$300 GeV and $\\sim$700 GeV. The integral flux above 300 GeV is $(2.2\\pm0.5_{\\mathrm{stat}}\\pm0.4_{\\mathrm{sys}})\\times10^{-12}\\:\\mathrm{cm}^{2}\\:\\mathrm{s}^{-1}$ which corresponds to 1.8% of the Crab Nebula flux. Non contemporaneous multiwavelength observations are combined with the VHE data to produce a broadband spectral energy distribution that can be reasonably described using a synchrotron-self Compton model.

VERITAS Collaboration; V. Acciari; E. Aliu; T. Arlen; M. Bautista; M. Beilicke; W. Benbow; M. Böttcher; S. M. Bradbury; J. H. Buckley; V. Bugaev; Y. Butt; K. Byrum; A. Cannon; O. Celik; A. Cesarini; Y. C. Chow; L. Ciupik; P. Cogan; P. Colin; W. Cui; R. Dickherber; C. Duke; T. Ergin; A. Falcone; S. J. Fegan; J. P. Finley; G. Finnegan; P. Fortin; L. Fortson; A. Furniss; D. Gall; K. Gibbs; G. H. Gillanders; J. Grube; R. Guenette; G. Gyuk; D. Hanna; E. Hays; J. Holder; D. Horan; C. M. Hui; T. B. Humensky; A. Imran; P. Kaaret; N. Karlsson; M. Kertzman; D. Kieda; J. Kildea; A. Konopelko; H. Krawczynski; F. Krennrich; M. J. Lang; S. LeBohec; G. Maier; A. McCann; M. McCutcheon; J. Millis; P. Moriarty; R. Mukherjee; T. Nagai; R. A. Ong; A. N. Otte; D. Pandel; J. S. Perkins; D. Petry; M. Pohl; J. Quinn; K. Ragan; L. C. Reyes; P. T. Reynolds; E. Roache; J. Rose; M. Schroedter; G. H. Sembroski; A. W. Smith; D. Steele; S. P. Swordy; M. Theiling; J. A. Toner; L. Valcarcel; A. Varlotta; V. V. Vassiliev; R. G. Wagner; S. P. Wakely; J. E. Ward; T. C. Weekes; A. Weinstein; R. J. White; D. A. Williams; S. Wissel; M. Wood; B. Zitzer

2008-12-04T23:59:59.000Z

183

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

184

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

SciTech Connect

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

Dubovichenko, S. B., E-mail: sergey@dubovichenko.ru [National Space Agency of the Republic of Kazakhstan, Fessenkov Astrophysical Institute, National Center of Space Research and Technology (Kazakhstan); Burtebaev, N., E-mail: burteb@inp.kz; Zazulin, D. M.; Kerimkulov, Zh. K. [National Nuclear Center of Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Amar, A. S. A. [Al-Farabi Kazakh National University (Kazakhstan)

2011-07-15T23:59:59.000Z

185

Quick Reference Information - Radiation  

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

Gamma and x-rays are photons. Protons: Positively charged elementary particles found in atomic nuclei. Radiation: The propagation of energy through space, or some other medium,...

186

DNA damage produced by exposure of supercoiled plasmid DNA to high- and low-LET ionizing radiation: Effects of hydroxyl radical quenchers. DNA breakage, neutrons, OH radicals  

SciTech Connect

A supercoiled plasmid of 7300 base pairs was isolated and exposed in an aqueous environment to {sup 60}Co {gamma} rays and JANUS 0.85 MeV fission-spectrum neutrons. Dose responses for the production of single-strand breaks (SSBs), double-strand breaks (DSBs) and alkali-labile sites (ALSs) were compared with computations made from the conversion of the supercoil to its relaxed and linear forms. The relative biological effectiveness (RBE) for production of SSBs and DSBs was similar to that previously measured in the cellular environment. The RBE for destruction of genetic transforming activity of M13 viral DNA followed that for DNA damage. This is in contrast to the situation for biological effects such as lethality, mutagenesis, and cellular transformation measured in mammalian cells, where the RBE values are reversed. The role of hydroxyl (OH) radical in DNA damage induction by neutrons was investigated by exposure of plasmid in the presence of known quenchers of this species. Of four quenchers tested, all were able to reduce the yields of both SSBs and DSBs. These findings are consistent with a model for SSB and DSB induction by high linear energy transfer that involves OH radical mediation.

Peak, J.G.; Ito, T.; Peak, M.J. [Argonne National Lab., IL (United States); Robb, F.T. [Univ. of Maryland, Baltimore, MD (United States). Center for Marine Biotechnology

1994-08-01T23:59:59.000Z

187

Evaluation of potential modifications to the SEER (Simplified Estimation of Exposure to Radiation) fallout code. Technical report, 1 August 1982-1 August 1983  

Science Conference Proceedings (OSTI)

This report presents the methodology and results of an attempt to modify and improve the computer code SEER (Simplified Estimation of Exposure to Radiation). SEER, part of the large nuclear weapon damage-assessment code CIVIC, was developed in the early 1970s with the intent that it simulate the fallout exposure-rate contours of DELFIC (Defense Land Fallout Interpretive code) while using a minimal amount of computer time. A problem that surfaced with the development of SEER was the fact that the SEER methodology leads to an overprediction of the total activity deposited on the ground. In order to compensate for this characteristic, SAI has lowered the value of the K-factor in the SEER portion of CIVIC to approximately half of the original value. The K-factor is the amount of weapon fallout activity per unit yield, distributed over unit area. Its value is not precisely known, in part because the percentage of total radioactive debris that constitutes early fallout (as opposed to that which is lofted to high altitudes and carried off beyond local fallout distances) is not well known and varies with height of burst and other conditions. This work effort investigated the possibility of modifying the SEER methodology so that activity is conserved and a good approximation to DELFIC results could be obtained without resort to the adjustment of the K-factor.

Edwards, R.C.

1983-09-01T23:59:59.000Z

188

Development and Validation of a Heart Atlas to Study Cardiac Exposure to Radiation Following Treatment for Breast Cancer  

SciTech Connect

Purpose: Cardiac toxicity is an important sequela of breast radiotherapy. However, the relationship between dose to cardiac structures and subsequent toxicity has not been well defined, partially due to variations in substructure delineation, which can lead to inconsistent dose reporting and the failure to detect potential correlations. Here we have developed a heart atlas and evaluated its effect on contour accuracy and concordance. Methods and Materials: A detailed cardiac computed tomography scan atlas was developed jointly by cardiology, cardiac radiology, and radiation oncology. Seven radiation oncologists were recruited to delineate the whole heart, left main and left anterior descending interventricular branches, and right coronary arteries on four cases before and after studying the atlas. Contour accuracy was assessed by percent overlap with gold standard atlas volumes. The concordance index was also calculated. Standard radiation fields were applied. Doses to observer-contoured cardiac structures were calculated and compared with gold standard contour doses. Pre- and post-atlas values were analyzed using a paired t test. Results: The cardiac atlas significantly improved contour accuracy and concordance. Percent overlap and concordance index of observer-contoured cardiac and gold standard volumes were 2.3-fold improved for all structures (p < 0.002). After application of the atlas, reported mean doses to the whole heart, left main artery, left anterior descending interventricular branch, and right coronary artery were within 0.1, 0.9, 2.6, and 0.6 Gy, respectively, of gold standard doses. Conclusions: This validated University of Michigan cardiac atlas may serve as a useful tool in future studies assessing cardiac toxicity and in clinical trials which include dose volume constraints to the heart.

Feng, Mary, E-mail: maryfeng@umich.ed [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Moran, Jean M. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Koelling, Todd [Department of Internal Medicine, Division of Cardiology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Chughtai, Aamer [Department of Radiology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Chan, June L.; Freedman, Laura; Hayman, James A.; Jagsi, Reshma; Jolly, Shruti; Larouere, Janice; Soriano, Julie; Marsh, Robin; Pierce, Lori J. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States)

2011-01-01T23:59:59.000Z

189

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

190

Predicting the radiation exposure of terrestrial wildlife in the Chernobyl exclusion zone : an international comparison of approaches.  

Science Conference Proceedings (OSTI)

There is now general acknowledgement that there is a requirement to demonstrate that species other than humans are protected from anthropogenic releases of radioactivity. A number of approaches have been developed for estimating the exposure of wildlife and some of these are being used to conduct regulatory assessments. There is a requirement to compare the outputs of such approaches against available data sets to ensure that they are robust and fit for purpose. In this paper we describe the application of seven approaches for predicting the whole-body ({sup 90}Sr, {sup 137}Cs, {sup 241}Am and Pu isotope) activity concentrations and absorbed dose rates for a range of terrestrial species within the Chernobyl exclusion zone. Predictions are compared against available measurement data, including estimates of external dose rate recorded by thermoluminescent dosimeters attached to rodent species. Potential reasons for differences between predictions between the various approaches and the available data are explored.

Beresford, N. A.; Barnett, C. L.; Brown, J. E.; Cheng, J.-J.; Copplestone, D.; Gaschak, S.; Hosseini, A.; Howard, B. J.; Kamboj, S.; Nedveckaite, T.; Olyslaegers, G.; Smith, J. T.; Vives i Batlle, J.; Vives-Lynch, S.; Yu, C.; Environmental Science Division; Centre for Ecology and Hydrology; Norwegian Radiation Protection Authority; England and Wales Environment Agency; International Radioecology Lab.; Inst. of Physics, Radiation Protection,; Belgian Nuclear Research Centre; Univ. of Portsmouth; Westlakes Research Inst.

2010-06-09T23:59:59.000Z

191

Occupational Radiation Exposure at Commercial Nuclear Power Reactors and Other Facilities 2010, Prepared for the Nuclear Regulatory Commission, Office of Nuclear Regulatory Research, May 2012  

SciTech Connect

This report summarizes the occupational exposure data that are maintained in the U.S. Nuclear Regulatory Commission’s (NRC) Radiation Exposure Information and Reporting System (REIRS). The bulk of the information contained in the report was compiled from the 2010 annual reports submitted by five of the seven categories of NRC licensees subject to the reporting requirements of 10 CFR 20.2206. Because there are no geologic repositories for high-level waste currently licensed and no NRC-licensed low-level waste disposal facilities currently in operation, only five categories will be considered in this report. The annual reports submitted by these licensees consist of radiation exposure records for each monitored individual. These records are analyzed for trends and presented in this report in terms of collective dose and the distribution of dose among the monitored individuals. Annual reports for 2010 were received from a total of 190 NRC licensees. The summation of reports submitted by the 190 licensees indicated that 192,424 individuals were monitored, 81,961 of whom received a measurable dose. When adjusted for transient workers who worked at more than one licensee during the year, there were actually 142,471 monitored individuals and 62,782 who received a measurable dose. The collective dose incurred by these individuals was 10,617 person-rem, which represents a 12% decrease from the 2009 value. This decrease was primarily due to the decrease in collective dose at commercial nuclear power reactors, as well as a decrease in the collective dose for most of the other categories of NRC licensees. The number of individuals receiving a measurable dose also decreased, resulting in an average measurable dose of 0.13 rem for 2010. The average measurable dose is defined as the total effective dose equivalent (TEDE) divided by the number of individuals receiving a measurable dose. In calendar year 2010, the average annual collective dose per reactor for light water reactor (LWR) licensees was 83 person-rem. This represents a 14% decrease from the value reported for 2009 (96 person-rem). The decrease in collective dose for commercial nuclear power reactors was due to an 11% decrease in total outage hours in 2010. During outages, activities involving increased radiation exposure such as refueling and maintenance are performed while the reactor is not in operation. The average annual collective dose per reactor for boiling water reactors (BWRs) was 137 personrem for 35 BWRs, and 55 person-rem for 69 pressurized water reactors (PWRs). Analyses of transient individual data indicate that 29,333 individuals completed work assignments at two or more licensees during the monitoring year. The dose distributions are adjusted each year to account for the duplicate reporting of transient individuals by multiple licensees. The adjustment to account for transient individuals has been specifically noted in footnotes in the figures and tables for commercial nuclear power reactors. In 2010, the average measurable dose per individual for all licensees calculated from reported data was 0.13 rem. Although the average measurable dose per individual from data submitted by licensees was 0.13 rem, a corrected dose distribution resulted in an average measurable dose per individual of 0.17 rem.

D. E. Lewis D. A. Hagemeyer Y. U. McCormick

2012-07-07T23:59:59.000Z

192

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,

193

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

194

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

195

Radiation doses for Marshall Islands Atolls Affected by U.S. Nuclear Testing:All Exposure Pathways, Remedial Measures, and Environmental Loss of 137Cs  

SciTech Connect

The United States conducted 24 nuclear tests at Bikini Atoll with a total yield of 76.8 Megatons (MT). The Castle series produced about 60% of this total and included the Bravo test that was the primary source of contamination of Bikini Island and Rongelap and Utrok Atolls. One of three aerial drops missed the atoll and the second test of the Crossroads series, the Baker test, was an underwater detonation. Of the rest, 17 were on barges on water and 3 were on platforms on an island; they produced most of the contamination of islands at the atoll. There were 42 tests conducted at Enewetak Atoll with a total yield of 31.7 MT (Simon and Robison, 1997; UNSCEAR, 2000). Of these tests, 18 were on a barge over wateror reef, 7 were surface shots, 2 aerial drops, 2 under water detonations, and 13 tower shots on either land or reef. All produced some contamination of various atoll islands. Rongelap Atoll received radioactive fallout as a result of the Bravo test on March 1, 1954 that was part of the Castle series of tests. This deposition was the result of the Bravo test producing a yield of 15 MT, about a factor of three to four greater than the predicted yield that resulted in vaporization of more coral reef and island than expected and in the debris-cloud reaching a much higher altitude than anticipated. High-altitude winds were to the east at the time of detonation and carried the debris-cloud toward Rongelap Atoll. Utrok Atoll also received fallout from the Bravo test but at much lower air and ground-level concentrations than at Rongelap atoll. Other atolls received Bravo fallout at levels below that of Utrok [other common spellings of this island and atoll (Simon, et al., 2009)]. To avoid confusion in reading other literature, this atoll and island are spelled in a variety of ways (Utrik, Utirik, Uterik or Utrok). Dose assessments for Bikini Island at Bikini Atoll (Robison et al., 1997), Enjebi Island at Enewetak Atoll (Robison et al., 1987), Rongelap Island at Rongelap Atoll (Robison et al., 1994; Simon et al., 1997), and Utrok Island at Utrok Atoll (Robison, et al., 1999) indicate that about 95-99% of the total estimated dose to people who may return to live at the atolls today (Utrok Island is populated) is the result of exposure to {sup 137}Cs. External gamma exposure from {sup 137}Cs in the soil accounts for about 10 to 15% of the total dose and {sup 137}Cs ingested during consumption of local food crops such as drinking coconut meat and fluid (Cocos nucifera L.), copra meat and milk, Pandanus fruit, and breadfruit accounts for about 85 to 90%. The other 1 to 2% of the estimated dose is from {sup 90}Sr, {sup 239+240}Pu, and {sup 241}Am. The {sup 90}Sr exposure is primarily through the food chain while the exposure to {sup 239+240}Pu, and {sup 241}Am is primarily via the inhalation pathway as a result of breathing re-suspended soil particles.

Robison, W L; Hamilton, T F

2009-04-20T23:59:59.000Z

196

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

197

RADIATION SOURCES  

DOE Patents (OSTI)

A novel long-lived source of gamma radiation especially suitable for calibration purposes is described. The source of gamma radiation is denoted mock iodine131, which comprises a naixture of barium-133 and cesium-137. The barium and cesium are present in a barium-cesium ratio of approximately 5.7/1 to 14/1, uniformly dispersed in an ion exchange resin and a filter surrounding the resin comprised of a material of atomic number below approximately 51, and substantially 0.7 to 0.9 millimeter thick.

Brucer, M.H.

1958-04-15T23:59:59.000Z

198

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

199

GAMMA PROPORTIONAL COUNTER CONTAINING HIGH Z GAS AND LOW Z MODERATOR  

DOE Patents (OSTI)

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

Fox, R.

1963-07-23T23:59:59.000Z

200

Observations of Gamma-Ray Burst Afterglows with the AEOS Burst Camera.  

E-Print Network (OSTI)

??Gamma-ray bursts (GRBs), are variable bursts of gamma-ray radiation, that lasts from milliseconds to hundreds of seconds. These bursts of gamma rays are detected in… (more)

Flewelling, Heather Anne

2009-01-01T23:59:59.000Z

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


201

Plutonium radiation surrogate  

DOE Patents (OSTI)

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

Frank, Michael I. (Dublin, CA)

2010-02-02T23:59:59.000Z

202

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

203

Radiation Field Control Manual  

Science Conference Proceedings (OSTI)

The EPRI Radiation Management Program is dedicated to reducing nuclear power plant worker personnel exposure by developing practices and technologies to increase the radiation protection of the worker, and to implement methods to reduce radiation fields. The nuclear power industry has recently implemented the RP2020 Initiative to promote positive radiation protection trends. Control of radiation fields is crucial to one of the initiative goals of reducing exposure. This manual provides the current state ...

2004-12-16T23:59:59.000Z

204

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

205

Radiation Exposure Monitoring Systems (REMS)  

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

format. HEADLINES... 2012 Annual Report 2012 draft data available through the REMS query tool 2012 Submittal Notification REMS Reporting Guide, containing the required format...

206

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

207

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

208

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

Science Conference Proceedings (OSTI)

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

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

1982-09-01T23:59:59.000Z

209

DOE 2011 Occupational Radiation Exposure report, _Prepared for the U.S. Department of Energy, Office of Health, Safety and Security. December 2012  

Science Conference Proceedings (OSTI)

This report discusses radiation protection and dose reporting requirements, presents the 2011 occupational radiation dose data along with trends over the past 5 years, and provides instructions to submit successful as low as reasonably achievable (ALARA) projects.

Derek Hagemeyer, Yolanda McCormick

2012-12-12T23:59:59.000Z

210

Underwater radiation detector  

DOE Patents (OSTI)

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

Kruse, Lyle W. (Albuquerque, NM); McKnight, Richard P. (Albuquerque, NM)

1986-01-01T23:59:59.000Z

211

Genome Wide Evaluation of Normal Human Tissue in Response to Controlled, In vivo Low-Dose Low LET Ionizing Radiation Exposure: Pathways and Mechanisms Final Report, September 2013  

SciTech Connect

During course of this project, we have worked in several areas relevant to low-dose ionizing radiation. Using gene expression to measure biological response, we have examined the response of human skin exposed in-vivo to radation, human skin exposed ex-vivo to radiation, and a human-skin model exposed to radiation. We have learned a great deal about the biological response of human skin to low-dose ionizing radiation.

Rocke, David M. [University of California Davis

2013-09-09T23:59:59.000Z

212

Composition for radiation shielding  

DOE Patents (OSTI)

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

Kronberg, James W. (Aiken, SC)

1994-01-01T23:59:59.000Z

213

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

E-Print Network (OSTI)

date of death, internal radiation and exposure period, thedeath, death year, internal radiation, exposure period, andexposures (chemical and smoking), internal doses, and types of radiation.

Britton, Julie

2010-01-01T23:59:59.000Z

214

WI Radiation Protection  

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

This statute seeks to regulate radioactive materials, to encourage the constructive uses of radiation, and to prohibit and prevent exposure to radiation in amounts which are or may be detrimental...

215

Introduction and Fundamentals: Course on Advances in Radiation  

E-Print Network (OSTI)

exposure to Ionizing Radiation - is it really necessary?"Sternglass, "Environmental Radiation and Human Health," op.on the Effects of Atomic Radiation Sources and Effects of

Thomas, Ralph H.

2010-01-01T23:59:59.000Z

216

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

217

Low Dose Radiation Research Program: Biologically Based Analysis of Lung  

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

Biologically Based Analysis of Lung Cancer Incidence in a Large Biologically Based Analysis of Lung Cancer Incidence in a Large Canadian Occupational Cohort with Low-LET Low-dose Radiation Exposure, and Comparison with Japanese Atomic Bomb Survivors. Authors: W.D. Hazelton, D. Krewski, S.H. Moolgavkar Lung cancer incidence is analyzed in a large Canadian National Dose Registry (CNDR) cohort with individual annual dosimetry for low-dose occupational exposure to gamma and tritium radiation using several types of multistage models. The primary analysis utilizes the two-stage clonal expansion model (TSCE), with sensitivity analyses using extensions of this model incorporating additional stages. Characteristic and distinct temporal patterns of risk are found for dose-response affecting early, middle, or late stages of carcinogenesis, e.g., initiation with one or more stages,

218

Radiation Safety Manual Dec 2012 Page 1 RADIATION SAFETY  

E-Print Network (OSTI)

. Management Commitment B. Training C. Monitoring of Individual Radiation Exposures D. Program Reviews 1 of Radiation A. Research Applications 1. Non-Human User 2. Animal Use 3. Human Use B. Clinical Applications C Materials Chapter VI: Occupational Exposure to Radiation and Personnel Monitoring and Bioassay Program #12;A

Grishok, Alla

219

Radiation-induced changes in the cuticular hydrocarbons of the granary weevil and their relationship to desiccation and adult mortality  

Science Conference Proceedings (OSTI)

Radiation from the nuclear waste products, such as Cesium-137, offers a scope and could be used for large scale disinfestation of grain. It is known that 0.15 to 0.20 kGy dose of gamma radiation is sufficient to kill insects in grain and grain products. However, the mode of action (in terms of lethal effects) is not understood. The purpose of this project, therefore, is to study the ways in which gamma radiation causes death in the granary weevil. Sitophilus granarius (L.) is a major and cosmopolitan pest of stored grain all over the world. Radiation damage, in particular the specific effects on the physiology of the insects exposed to radiation has been elucidated. In stored grain insects, conservation of water is a critical factor for their survival. Epicuticular hydrocarbons play an important role in water proofing. The laboratory rearing of the granary weevil was standardized so that large numbers of weevils of known ages could be produced for experimentation. Stock cultures were maintained at 27 {plus minus} 2{degree}C and 65 {plus minus} 5% R.H. Tests with various age groups (adults) and different doses of gamma radiation indicate that lethal effects are both age and dose related. Younger weevils, in general, survive for a longer period after irradiation compared to older weevils. Complete mortality results within about two weeks after exposure to gamma radiation at dose of 0.15 kGy or above. Data on wet and dry weights of the weevils kept at different (low, medium and higher) levels of humidity after irradiation indicate that gamma radiation induces greater water loss leading to desiccation and early death. Low humidity environment (17% R.H.) greatly accelerates lethal effects.

Sriharan, S. (Selma Univ., AL (USA). Div. of Natural and Applied Sciences)

1989-07-01T23:59:59.000Z

220

Low Dose Radiation Research Program: Using a Low LET Electron Microbeam to  

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

a Low LET Electron Microbeam to Investigate Non-Targeted Effects of a Low LET Electron Microbeam to Investigate Non-Targeted Effects of Low Dose Radiation William F. Morgan Radiation Oncology Research Laboratory, Pacific Northwest National Laboratory Why this Project? To examine genomic instability and bystander effects as non-targeted effects associated with low dose radiation exposure. Project Goals To provides a robust, reliable, highly sensitive assay for detecting delayed events occurring in cells exposed to low doses of ionizing radiation. Experimental Approach To mimic radiation damage from gamma and x-ray sources, a low-LET electron microbeam that generates energetic electrons has been designed such that high-energy electrons deposit energy in a pre-selected subset of cells leaving neighboring cells unirradiated. Using a novel green fluorescence gene (GFP) reporter assay, a high through

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


221

The Mechanism of Low Dose Radiation Risk Associated with Diagnostic X-rays,  

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

Mechanism of Low Dose Radiation Risk Associated with Diagnostic X-rays, Mechanism of Low Dose Radiation Risk Associated with Diagnostic X-rays, PET, and Gamma-rays Douglas Boreham McMaster University Abstract The goal of this project was to investigate low dose ionizing radiation effects associated with exposure to diagnostic computed tomography (CT) or positron emission tomography (PET) scans. Biological effects were evaluated in wild type and Trp53+/- heterozygous females, following in vivo exposure to diagnostic CT (75kVp, 200µ) or PET (18F-FDG) scans. The short term biological effects following CT or PET scans were evaluated in order to understand biological modification of mechanisms, such as DNA repair processes and apoptosis, that might alter long term cancer risk. Corresponding life-time cancer risk studies are in progress. Short-term

222

For Radiation Detection Systems – Specific Methods  

Science Conference Proceedings (OSTI)

... The test procedures outlined within this TTOP will cover radiation detection instruments used for gamma-ray and neutron detection as well as ...

2013-01-10T23:59:59.000Z

223

NIST Ionizing Radiation Division 1998 - Current Directions  

Science Conference Proceedings (OSTI)

... Cs gamma-ray ranges, and the low-energy photon ... beam, and a high-dose- rate Gammacell used in our radiation-processing dosimetry ...

224

High resistivity aluminum antimonide radiation detector  

DOE Patents (OSTI)

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

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

2007-12-18T23:59:59.000Z

225

Remote Gamma Scanning System for Characterization of BWR and PWR Fuel Rod Sections  

SciTech Connect

Sometimes challenges with the design and deployment of automated equipment in remote environments deals more with the constraints imposed by the remote environment than it does with the details of the automation. This paper discusses the development of a scanning system used to provide gamma radiation profiles of irradiated fuel rod segments. The system needed the capability to provide axial scans of cut segments of BWR and PWR fuel rods. The scanning location is A-Cell at the Radiochemical Processing Laboratory (RPL) at the Hanford site in Washington State. The criteria for the scanning equipment included axial scanning increments of a tenth of an inch or less, ability to scan fuel rods with diameters ranging from 3/8 inch to 5/8 inch in diameter, and fuel rod segments up to seven feet in length. Constraints imposed by the environment included having the gamma detector and operator controls on the outside of the hot cell and the scanning hardware on the inside of the hot cell. This entailed getting a narrow, collimated beam of radiation from the fuel rod to the detector on the outside of the hot cell while minimizing the radiation exposure caused by openings for the wires and cables traversing the hot cell walls. Setup and operation of all of the in-cell hardware needed to accommodate limited access ports and use of hot cell manipulators. The radiation levels inside the cell also imposed constraints on the materials used.

Crowell, Shannon L.; Alzheimer, James M.

2011-08-08T23:59:59.000Z

226

Fundamentals of health physics for the radiation-protection officer  

SciTech Connect

The contents of this book on health physics include chapters on properties of radioactive materials, radiation instrumentation, radiation protection programs, radiation survey programs, internal exposure, external exposure, decontamination, selection and design of radiation facilities, transportation of radioactive materials, radioactive waste management, radiation accidents and emergency preparedness, training, record keeping, quality assurance, and appraisal of radiation protection programs. (ACR)

Murphy, B.L.; Traub, R.J.; Gilchrist, R.L.; Mann, J.C.; Munson, L.H.; Carbaugh, E.H.; Baer, J.L.

1983-03-01T23:59:59.000Z

227

"We will die and become science" : the production of invisibility and public knowledge about Chernobyl radiation effects in Belarus  

E-Print Network (OSTI)

external radiation exposure and internal accumulation ofinternal accumulation), or it might (incorrectly) refer to external radiation exposure.radiation exposure should not be forgotten. Patients, for example, can be checked for their internal

Kuchinskaya, Olga

2007-01-01T23:59:59.000Z

228

GammaCam Technology Demonstration at ORNL Buildings 3026C and 3026D  

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

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

229

ESTIMATING HISTORICAL TRICHLOROETHYLENE EXPOSURE IN A URANIUM ENRICHMENT, GASEOUS DIFFUSION PLANT.  

E-Print Network (OSTI)

??Previous studies at two uranium enrichment plants have looked at radiation exposures, but not an extensive list of chemical exposures, limiting evaluation of potential interactions.… (more)

MOSER, ADRIANE

2005-01-01T23:59:59.000Z

230

Low Dose Radiation Program: Radiation Biology and the Radiation Research  

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

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

231

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

232

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

233

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

Science Conference Proceedings (OSTI)

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

Dubovichenko, S. B., E-mail: sergey@dubovichenko.ru [V.G. Fessenkov Astrophysical Institute (Kazakhstan)

2012-02-15T23:59:59.000Z

234

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

235

Radiation induction of cancer of the skin  

SciTech Connect

The induction of epidermal tumors was studied using exposures to 25 kV x-rays with or without subsequent exposures to 12-0-tetradeconyl phorbol-13 acetate (TPA) or ultraviolet radiation (uvr) 280-400 nm. Fractionation regimens and total exposure up to 4000R produced no squamous cell carcinomas. When these regimes were followed by TPA an incidence of about 80% was obtained, and incidence of 60% when uvr exposures followed the x-irradiation. A dose-dependent increase in fibrosarcomas was found when x-irradiation was followed by 24 weeks of topical treatment with TPA. These results support the contention that uvr can enhance the expression of cells initiated by x-rays. The experimental evidence is compared with the data from the tinea capitis patients treated with x-rays. In C3HF/He male mice exposed to 50, 100, 150 and 200 rads /sup 137/Cs gamma rays the induction rate for fibrosarcomas was 2.9 x 10/sup -4/ per cGy/per mouse. This result compares with 2.5 x 10/sup -6/ transformations per surviving cell per cGy with 10T1/2 cells that are fibroblasts derived from C3H mice. 16 refs., 1 fig., 1 tab.

Fry, R.J.M.; Storer, J.B.; Burns, F.J.

1985-01-01T23:59:59.000Z

236

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

Science Conference Proceedings (OSTI)

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

Byrne-Kelly, D.; Hart, A.; Brown, Ch.; Jordan, D. [MSE Technology Applications, Inc., Montana (United States); Phillips, E. [U.S. Department of Energy, Oak Ridge Operations Office, Oak Ridge, Tennessee (United States)

2008-07-01T23:59:59.000Z

237

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

238

Radiation shielding composition  

DOE Patents (OSTI)

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

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

1998-01-01T23:59:59.000Z

239

Radiation shielding composition  

DOE Patents (OSTI)

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

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

2000-12-26T23:59:59.000Z

240

The One Million U.S. Radiation Worker Study  

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

for chronic radiation exposure. Much knowledge has been gained from the study of atomic bomb survivors, but exposure was acute and 2 among a Japanese population living in...

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

Construction and operation of an improved radiation calibration facility at Brookhaven National Laboratory. Environmental assessment  

Science Conference Proceedings (OSTI)

Calibration of instruments used to detect and measure ionizing radiation has been conducted over the last 20 years at Brookhaven National Laboratory`s (BNL) Radiation Calibration Facility, Building 348. Growth of research facilities, projects in progress, and more stringent Department of Energy (DOE) orders which involve exposure to nuclear radiation have placed substantial burdens on the existing radiation calibration facility. The facility currently does not meet the requirements of DOE Order 5480.4 or American National Standards Institute (ANSI) N323-1978, which establish calibration methods for portable radiation protection instruments used in the detection and measurement of levels of ionizing radiation fields or levels of radioactive surface contaminations. Failure to comply with this standard could mean instrumentation is not being calibrated to necessary levels of sensitivity. The Laboratory has also recently obtained a new neutron source and gamma beam irradiator which can not be made operational at existing facilities because of geometry and shielding inadequacies. These sources are needed to perform routine periodic calibrations of radiation detecting instruments used by scientific and technical personnel and to meet BNL`s substantial increase in demand for radiation monitoring capabilities. To place these new sources into operation, it is proposed to construct an addition to the existing radiation calibration facility that would house all calibration sources and bring BNL calibration activities into compliance with DOE and ANSI standards. The purpose of this assessment is to identify potential significant environmental impacts associated with the construction and operation of an improved radiation calibration facility at BNL.

NONE

1994-10-01T23:59:59.000Z

242

Low Dose Radiation Research Program: Using a Low LET Electron Microbeam to  

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

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

243

Radiation-Induced Bystander Effects and Relevance to Human Radiation  

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

Radiation-Induced Bystander Effects and Relevance to Human Radiation Radiation-Induced Bystander Effects and Relevance to Human Radiation Exposures Review of phenomenon appears in Radiation Research Pamela Sykes and Benjamin Blyth One concern of radiobiologists is the effect radiation exposure might have on nearby unirradiated cells. For example, when only a small fraction of cells are directly hit by radiation energy, are the surrounding unirradiated cells also at an increased risk of cancer? The term "radiation-induced bystander effect" is used to describe radiation-induced biological changes that occur in unirradiated cells within an irradiated cell population. Radiation-induced bystander effects have become established in the vernacular and are considered as an authentic radiation response. However, there is still no consensus on a precise definition of the term, which

244

Composition for radiation shielding  

DOE Patents (OSTI)

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

Kronberg, J.W.

1994-08-02T23:59:59.000Z

245

Analysis of radiation exposure - service personnel on Rongerik Atoll: Operation Castle - Shot Bravo. Technical report, 12 March 1985-12 June 1987  

Science Conference Proceedings (OSTI)

External and internal doses are reconstructed for the 28 American servicemen stationed on Rongerik Atoll, Marshall Islands, who were exposed to fallout on 1-2 March 1954 from Shot Bravo of Operation CASTLE. External doses are determined from limited radiation survey and film-badge information. Internal-dose commitments are derived from urinalysis data. The magnitude of the calculated activity intake suggests the principal pathways. Reconstructed film-badge doses are approximately 40 rem, with adjustments from individual activity scenarios, as available. Internal dose commitments to the thyroid and large intestine (nearly all first-year dose) provide the only significant increments to the external dose. Total doses are approximately 230 rem to the thyroid, 115 rem to the lower large intestine, 85 rem to the upper large intestine, and about 40 to 50 rem to all other organs.

Goetz, J.; Klemm, J.; Phillips, J.; Thomas, C.

1987-07-09T23:59:59.000Z

246

Mammalian Tissue Response to Low Dose Ionizing Radiation: The Role of Oxidative Metabolism and Intercellular Communication  

SciTech Connect

The objective of the project was to elucidate the mechanisms underlying the biological effects of low dose/low dose rate ionizing radiation in organs/tissues of irradiated mice that differ in their susceptibility to ionizing radiation, and in human cells grown under conditions that mimic the natural in vivo environment. The focus was on the effects of sparsely ionizing cesium-137 gamma rays and the role of oxidative metabolism and intercellular communication in these effects. Four Specific Aims were proposed. The integrated outcome of the experiments performed to investigate these aims has been significant towards developing a scientific basis to more accurately estimate human health risks from exposures to low doses ionizing radiation. By understanding the biochemical and molecular changes induced by low dose radiation, several novel markers associated with mitochondrial functions were identified, which has opened new avenues to investigate metabolic processes that may be affected by such exposure. In particular, a sensitive biomarker that is differentially modulated by low and high dose gamma rays was discovered.

Azzam, Edouard I

2013-01-16T23:59:59.000Z

247

Dynamical instability of collapsing radiating fluid  

SciTech Connect

We take the collapsing radiative fluid to investigate the dynamical instability with cylindrical symmetry. We match the interior and exterior cylindrical geometries. Dynamical instability is explored at radiative and non-radiative perturbations. We conclude that the dynamical instability of the collapsing cylinder depends on the critical value {gamma} < 1 for both radiative and nonradiative perturbations.

Sharif, M., E-mail: msharif.math@pu.edu.pk; Azam, M., E-mail: azammath@gmail.com [University of the Punjab, Department of Mathematics (Pakistan)

2013-06-15T23:59:59.000Z

248

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

249

An assessment of crew exposures during nuclear-powered manned Mars missions  

E-Print Network (OSTI)

The National Aeronautics and Space Administration (NASA) is currently studying a variety of mission scenarios designed to establish a permanent human presence on the surface of Mars. Nuclear Electric Propulsion (NEP) is one of the possible designs for this program. During the initial stages of vehicle design work, careful consideration must be given to, not only the shielding requirements of natural space radiations, but to the shielding and configuration requirements of the on-board reactors. In this work, the radiation transport code MCNP has been used to make initial estimates of crew exposures to reactor radiation fields for a specific manned NIFP vehicle design. In this design, three 25 MWt scaled SP-1 00-class reactor radiations are shielded by three identical shields. Each shield layers beryllium, tungsten, and lithium hydride between the reactor and the crew compartment. In a related project, separate calculations are made of both the exiting neutron and gamma fluxes from the reactors during beginning-of-life, full-power operation. This data is then used as the source terms for particle transport in MCNP. The total gamma and neutron fluxes exiting the reactor shields are recorded and separate transport calculations are then performed for a 10 g cm-2 crew compartment aluminum thickness. Estimates of crew exposures have been assessed for various thicknesses of the shield tungsten and lithium hydride layers. A minimal tungsten thickness of 20 cm is required to shield the reactor photons below the 0.05 Sv y-I limit. In addition to a 20-.cm thick tungsten layer, a 40-cm thick lithium hydride layer is required to shield the reactor neutrons below the annual lin-At. If the tungsten layer is 30-cm thick, the lithium hydride layer should be at least 30-cm thick. These estimates do not take the photons generated by neutron interactions inside the shield into account because the neutron MCNP cross sections did not allow reliable estimates of photon production.

Delisle, Christine Louise

1994-01-01T23:59:59.000Z

250

ORISE: Worker Health Studies - Beryllium Exposure Studies and...  

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

of Energy Radiation Exposure Monitoring System (REMS) DOE IISP 10-Year Summary Report Resources Overview Reports Peer-Reviewed Journal Articles Human Subjects Resource Book...

251

Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivi...  

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

Our research utilizes radiation cataract as a model system to study the effects of low-dose ionizing radiation exposure in a complex, highly differentiated tissue. We believe...

252

Improved Radiation Dosimetry/Risk Estimates to Facilitate Environmental Management of Plutonium-Contaminated Sites  

SciTech Connect

This report summarizes 4 years of research achievements in this Office of Science (BER), U.S. Department of Energy (DOE) project. The research described was conducted by scientists and supporting staff at Lovelace Respiratory Research Institute (LRRI)/Lovelace Biomedical and Environmental Research Institute (LBERI) and the Southern Urals Biophysics Institute (SUBI). All project objectives and goals were achieved. A major focus was on obtaining improved cancer risk estimates for exposure via inhalation to plutonium (Pu) isotopes in the workplace (DOE radiation workers) and environment (public exposures to Pu-contaminated soil). A major finding was that low doses and dose rates of gamma rays can significantly suppress cancer induction by alpha radiation from inhaled Pu isotopes. The suppression relates to stimulation of the body's natural defenses, including immunity against cancer cells and selective apoptosis which removes precancerous and other aberrant cells.

Scott, Bobby R.; Tokarskaya, Zoya B.; Zhuntova, Galina V.; Osovets, Sergey V.; Syrchikov, Victor A., Belyaeva, Zinaida D.

2007-12-14T23:59:59.000Z

253

Optical Measurement Technologies for High Temperature, Radiation Exposure, and Corrosive Environments—Significant Activities and Findings: In-vessel Optical Measurements for Advanced SMRs  

Science Conference Proceedings (OSTI)

Development of advanced Small Modular Reactors (aSMRs) is key to providing the United States with a sustainable, economically viable, and carbon-neutral energy source. The aSMR designs have attractive economic factors that should compensate for the economies of scale that have driven development of large commercial nuclear power plants to date. For example, aSMRs can be manufactured at reduced capital costs in a factory and potentially shorter lead times and then be shipped to a site to provide power away from large grid systems. The integral, self-contained nature of aSMR designs is fundamentally different than conventional reactor designs. Future aSMR deployment will require new instrumentation and control (I&C) architectures to accommodate the integral design and withstand the extreme in-vessel environmental conditions. Operators will depend on sophisticated sensing and machine vision technologies that provide efficient human-machine interface for in-vessel telepresence, telerobotic control, and remote process operations. The future viability of aSMRs is dependent on understanding and overcoming the significant technical challenges involving in-vessel reactor sensing and monitoring under extreme temperatures, pressures, corrosive environments, and radiation fluxes

Anheier, Norman C.; Cannon, Bret D.; Qiao, Hong (Amy); Suter, Jonathan D.

2012-09-01T23:59:59.000Z

254

Radiation coloration resistant glass  

SciTech Connect

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

Tomozawa, Minoru (Troy, NY); Watson, E. Bruce (Troy, NY); Acocella, John (Troy, NY)

1986-01-01T23:59:59.000Z

255

Current Trends in Gamma Ray Detection for Radiological Emergency Response  

SciTech Connect

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

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

2011-08-18T23:59:59.000Z

256

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

257

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

258

radiation.cdr  

Office of Legacy Management (LM)

Radiation-It's a Fact of Life Radiation-It's a Fact of Life It has been with us since the beginning of time. Everyone who has ever walked on this planet has been exposed to radiation. For the most part, nature is the largest source of exposure. It's in the air we breathe, the ground we walk on, and even the food we eat. The radiation we receive from all natural and some man-made sources is called "background radiation." The millirem (mrem) is a unit used for measuring radiation received by a person. The total average background for radiation received by people living in the United States is 360 millirem per year (mrem/yr), of which 300 mrem/yr is from natural sources, and 60 mrem/yr is man-made. Cosmic Radiation from the sun and stars Internal Radiation from naturally radioactive

259

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

260

Safety Around Sources of Radiation  

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

Keeping Exposure Low Keeping Exposure Low Working Safely Around Radioactive Contamination Types of Radiation Exposure Managing Radiation Emergencies Procedure Demonstration Is it safe to be around sources? Too much radiation exposure is harmful. The degree of radiation injury depends on the amount of radiation received and the time involved. In general, the higher the amount, the greater the severity of early effects (occurring within a few weeks) and the greater the possibility of late effects such as cancer. The BEIR V (Biological Effects of Ionizing Radiation) Committee of the National Research Council estimates that among 100,000 people exposed to a one-time dose of 10 rem (10,000 mrem) and followed over their life span, about 790 more would die of cancer than the estimated 20,000 cancer deaths that would be expected among a non-exposed group of the same size. NOTE: 10 rem = 100 millisieverts (100 mSv).

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

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

262

A Search for Muon Neutrinos from Gamma-Ray Bursts wih the IceCube 22-String Detector.  

E-Print Network (OSTI)

??Two searches are conducted for muon neutrinos from Gamma-Ray Bursts (GRBs) using the IceCube detector. Gamma-Ray Bursts are brief and transient emissions of keV/MeV radiation… (more)

Roth, A Philip

2009-01-01T23:59:59.000Z

263

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

264

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

265

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

E-Print Network (OSTI)

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

Jackman, Charles H.

266

Effects of atomic radiation  

SciTech Connect

This book focuses on the lifelong effects of atomic radiation exposure in language understandable by the concerned layperson or the specialist in another field. The base of knowledge used is the work of the Atomic Bomb Casualty Commission and its successor since 1975 the Radiation Effects Research Foundation. Within the range of Chronic effects on human health the book provides a thorough review, although effects of nonionizing radiation, effects on structures, effects on other living species, and acute effects are not discussed.

Schull, W.J.

1995-12-31T23:59:59.000Z

267

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

E-Print Network (OSTI)

exposure to radioactive fallout in radiation-associatedheight of the radioactive fallout deliberations in the early

Fabrikant, J.I.

2010-01-01T23:59:59.000Z

268

The cohort of the atomic bomb survivors major basis of radiation safety regulations  

E-Print Network (OSTI)

Since 1950 about 87 000 A-bomb survivors from Hiroshima and Nagasaki have been monitored within the framework of the Life Span Study, to quantify radiation-induced late effects. In terms of incidence and mortality, a statistically significant excess was found for leukemia and solid tumors. In another major international effort, neutron and gamma radiation doses were estimated, for those survivors (Dosimetry System DS02). Both studies combined allow the deduction of risk coefficients that serve as a basis for international safety regulations. As an example, current results on all solid tumors combined suggest an excess relative risk of 0.47 per Sievert for an attained age of 70 years, for those who were exposed at an age of 30 years. After exposure to an effective dose of one Sievert the solid tumor mortality would thus be about 50% larger than that expected for a similar cohort not exposed to any ionizing radiation from the bombs.

Rühm, W; Nekolla, E A

2006-01-01T23:59:59.000Z

269

Low Dose Radiation Research Program: DNA Damage in Acutely Irradiated F2  

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

DNA Damage in Acutely Irradiated F2 Mice with a History of Paternal DNA Damage in Acutely Irradiated F2 Mice with a History of Paternal F0 Germline Irradiation Authors: J.E. Baulch and O.G. Raabe Institutions: Center for Health and the Environment, University of California, Davis, CA. The main goal of this grant is to evaluate heritable, transgenerational effects of low dose, low-linear-energy-transfer (LET) radiation (0.1 Gy attenuated 137Cs gamma rays) on Type B spermatogonia in 129SVE mice; wild-type and heterozygous for Ataxia-telangiectasia (AT). The ATM heterozygotes are carriers for a genetic mutation (AT mutated, ATM) that is thought to predispose both humans and mice to radiation sensitivity. Experiments conducted in our laboratory have demonstrated heritable effects of paternal germline exposure to ionizing radiation in mice using 1.0 Gy of

270

Low Dose Radiation Program: Links - Agencies with Radiation Regulatory  

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

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

271

Actively driven thermal radiation shield  

DOE Patents (OSTI)

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

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

2002-01-01T23:59:59.000Z

272

Fiber fed x-ray/gamma ray imaging apparatus  

SciTech Connect

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

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

1992-01-01T23:59:59.000Z

273

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

SciTech Connect

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

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

2005-08-08T23:59:59.000Z

274

Health effects models for nuclear power plant accident consequence analysis. Modification of models resulting from addition of effects of exposure to alpha-emitting radionuclides: Revision 1, Part 2, Scientific bases for health effects models, Addendum 2  

SciTech Connect

The Nuclear Regulatory Commission (NRC) has sponsored several studies to identify and quantify, through the use of models, the potential health effects of accidental releases of radionuclides from nuclear power plants. The Reactor Safety Study provided the basis for most of the earlier estimates related to these health effects. Subsequent efforts by NRC-supported groups resulted in improved health effects models that were published in the report entitled {open_quotes}Health Effects Models for Nuclear Power Plant Consequence Analysis{close_quotes}, NUREG/CR-4214, 1985 and revised further in the 1989 report NUREG/CR-4214, Rev. 1, Part 2. The health effects models presented in the 1989 NUREG/CR-4214 report were developed for exposure to low-linear energy transfer (LET) (beta and gamma) radiation based on the best scientific information available at that time. Since the 1989 report was published, two addenda to that report have been prepared to (1) incorporate other scientific information related to low-LET health effects models and (2) extend the models to consider the possible health consequences of the addition of alpha-emitting radionuclides to the exposure source term. The first addendum report, entitled {open_quotes}Health Effects Models for Nuclear Power Plant Accident Consequence Analysis, Modifications of Models Resulting from Recent Reports on Health Effects of Ionizing Radiation, Low LET Radiation, Part 2: Scientific Bases for Health Effects Models,{close_quotes} was published in 1991 as NUREG/CR-4214, Rev. 1, Part 2, Addendum 1. This second addendum addresses the possibility that some fraction of the accident source term from an operating nuclear power plant comprises alpha-emitting radionuclides. Consideration of chronic high-LET exposure from alpha radiation as well as acute and chronic exposure to low-LET beta and gamma radiations is a reasonable extension of the health effects model.

Abrahamson, S. [Wisconsin Univ., Madison, WI (United States); Bender, M.A. [Brookhaven National Lab., Upton, NY (United States); Boecker, B.B.; Scott, B.R. [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.; Gilbert, E.S. [Pacific Northwest Lab., Richland, WA (United States)

1993-05-01T23:59:59.000Z

275

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

276

Low Dose Radiation Research Program Publications  

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

for medical exposures. Environmental and Molecular Mutagenesis 53(4): 247259 Lynn Hlatky ( 2012) Double-Strand Break Motions Shift Radiation Risk Notions?. PNAS...

277

Radiation Machines and Radioactive Materials (Iowa)  

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

These chapters describe general provisions and regulatory requirements; registration, licensure, and transportation of radioactive materials; and exposure standards for radiation protection.

278

Low Dose Radiation Research Program: Aloke Chatterjee  

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

Chatterjee, A. and Holley, W.R. 1999 Workshop: Biological Effects of Low-Dose and Low-Dose-Rate Radiation Exposures: An Integrated Theoretical and Experimental Approach....

279

Low Dose Radiation Research Program: Mohan Natarajan  

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

of Survival Advantage, Bystander Effect, and Genomic Instability after Low-LET Low Dose Radiation Exposure Funded Project Real-Time Molecular Study of Bystander Effect Using...

280

ORISE Resources: Population Monitoring in Radiation Emergencies  

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

into the body Removal of external or internal contamination (decontamination) Radiation dose received and the resulting health risk from the exposure Long-term health...

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


281

US/French Joint Research Program regarding the behavior of polymer base materials subjected to beta radiation. Volume 1. Phase-1 normalization results  

Science Conference Proceedings (OSTI)

As part of the ongoing multi-year joint NRC/CEA international cooperative test program to investigate the dose-damage equivalence of gamma and beta radiation on polymer base materials, dosimetry and ethylene-propylene rubber (EPR) specimens were exchanged, irradiated, and evaluated for property changes at research facilities in the US (Sandia National Laboratories) and France (Compagnie ORIS Industrie). The purpose of this Phase-1 test series was to normalize and cross-correlate the results obtained by one research center to the other, in terms of exposure (1.0 MeV accelerated electrons and /sup 60/Co gammas) and postirradiation testing (ultimate elongation and tensile strength, hardness, and density) techniques. The dosimetry and material specimen results indicate good agreement between the two countries regarding the exposure conditions and postirradiation evaluation techniques employed.

Wyant, F.J.; Buckalew, W.H.; Chenion, J.; Carlin, F.; Gaussens, G.; Le Tutour, P.; Le Meur, M.

1986-06-01T23:59:59.000Z

282

US/French joint research program regarding the behavior of polymer base materials subjected to beta radiation: Volume 2, Phase-2a screening tests: (Final report)  

Science Conference Proceedings (OSTI)

As part of the ongoing joint NRC/CEA cooperative test program to investigate the relative effectiveness of beta and gamma irradiation to produce damage in polymer base materials, ethylene propylene rubber (EPR) specimens, in slab geometry, were exposed to Cobalt-60 gamma rays and accelerator produced electron beams. Specimens were irradiated and evaluated at research facilities in the US (Sandia National Laboratories) and France (Compagnie ORIS Industrie). These tests included several electron beam energies, sample thicknesses, exposure doses, and dose rates. Based on changes in the tensile properties, of the test specimens, results of these studies suggest that material damage resulting from electron and gamma irradiations can be correlated on the basis of absorbed radiation dose.

Buckalew, W.H.; Wyant, F.J.; Chenion, J.; Carlin, F.; Gaussens, G.; Le Tutour, P.; Le Meur, M.

1987-09-01T23:59:59.000Z

283

RADIATION EFFECTS ON EPOXY/CARBON FIBER COMPOSITE  

SciTech Connect

The Department of Energy Savannah River Site vitrifies nuclear waste incident to defense programs through its Defense Waste Processing Facility (DWPF). The piping in the DWPF seal pot jumper configuration must withstand the stresses during an unlikely but potential deflagration event, and maintain its safety function for a 20-year service life. Carbon fiber-reinforced epoxy composites (CFR) were proposed for protection and reinforcement of piping during such an event. The proposed CFR materials have been ASME-approved (Section XI, Code Case N-589-1) for post-construction maintenance and is DOT-compliant per 49CFR 192 and 195. The proposed carbon fiber/epoxy composite reinforcement system was originally developed for pipeline rehabilitation and post-construction maintenance in petrochemical, refineries, DOT applications and other industries. The effects of ionizing radiation on polymers and organic materials have been studied for many years. The majority of available data are based on traditional exposures to gamma irradiation at high dose rates ({approx}10,000 Gy/hr) allowing high total dose within reasonable test periods and general comparison of different materials exposed at such conditions. However, studies in recent years have shown that degradation of many polymers are sensitive to dose rate, with more severe degradation often observed at similar or even lower total doses when exposed to lower dose rates. This behavior has been primarily attributed to diffusion-limited oxidation which is minimized during very high dose rate exposures. Most test standards for accelerated aging and nuclear qualification of components acknowledge these limitations. The results of testing to determine the radiation resistance and microstructural effects of gamma irradiation exposure on a bisphenol-A based epoxy matrix composite reinforced with carbon fibers are presented. This work provides a foundation for a more extensive evaluation of dose rate effects on advanced epoxy reinforced composites.

Hoffman, E; Eric Skidmore, E

2008-12-12T23:59:59.000Z

284

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

285

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

286

Revised analyses of decommissioning for the reference boiling water reactor power station. Effects of current regulatory and other considerations on the financial assurance requirements of the decommissioning rule and on estimates of occupational radiation exposure - appendices. Final report  

SciTech Connect

The NRC staff is in need of decommissioning bases documentation that will assist them in assessing the adequacy of the licensee submittals, from the viewpoint of both the planned actions, including occupational radiation exposure, and the probable costs. The purpose of this reevaluation study is to update the needed bases documentation. This report presents the results of a review and reevaluation of the PNL 1980 decommissioning study of the Washington Public Power Supply System`s Washington Nuclear Plant Two (WNP-2) located at Richland, Washington, including all identifiable factors and cost assumptions which contribute significantly to the total cost of decommissioning the plant for the DECON, SAFSTOR, and ENTOMB decommissioning alternatives. These alternatives now include an initial 5-7 year period during which time the spent fuel is stored in the spent fuel pool prior to beginning major disassembly or extended safe storage of the plant. Included for information (but not presently part of the license termination cost) is an estimate of the cost to demolish the decontaminated and clear structures on the site and to restore the site to a {open_quotes}green field{close_quotes} condition. This report also includes consideration of the NRC requirement that decontamination and decommissioning activities leading to termination of the nuclear license be completed within 60 years of final reactor shutdown, consideration of packaging and disposal requirements for materials whose radionuclide concentrations exceed the limits for Class C low-level waste (i.e., Greater-Than-Class C), and reflects 1993 costs for labor, materials, transport, and disposal activities. Sensitivity of the total license termination cost to the disposal costs at different low-level radioactive waste disposal sites, to different depths of contaminated concrete surface removal within the facilities, and to different transport distances is also examined.

Smith, R.I.; Bierschbach, M.C.; Konzek, G.J.; McDuffie, P.N.

1996-07-01T23:59:59.000Z

287

Revised analyses of decommissioning for the reference boiling water reactor power station. Effects of current regulatory and other considerations on the financial assurance requirements of the decommissioning rule and on estimates of occupational radiation exposure - main report. Final report  

SciTech Connect

The NRC staff is in need of updated bases documentation that will assist them in assessing the adequacy of the licensee submittals, from the viewpoint of both the planned actions, including occupational radiation exposure, and the probable costs. The purpose of this reevaluation study is to update the needed bases documentation. This report presents the results of a review and reevaluation of the PNL 1980 decommissioning study of the Washington Public Power Supply System`s Washington Nuclear Plant Two (WNP-2), which is a boiling water reactor (BWR), located at Richland, Washington, including all identifiable factors and cost assumptions which contribute significantly to the total cost of decommissioning the plant for the DECON, SAFSTOR, and ENTOMB decommissioning alternatives. These alternatives now include an initial 5-7 year period during which time the spent fuel is stored in the spent fuel pool prior to beginning major disassembly or extended safe storage of the plant. Included for information (but not part of the license termination cost) is an estimate of the cost to demolish the decontaminated and clean structures on the site and to restore the site to a {open_quotes}green field{close_quotes} condition. This report also includes consideration of the NRC requirement that decontamination and decommissioning activities leading to termination of the nuclear license be completed within 60 years of final reactor shutdown, consideration of packaging and disposal requirements for materials whose radionuclide concentrations exceed the limits for Class C low- level waste (i.e., Greater-Than-Class C), and reflects 1993 costs for labor, materials, transport, and disposal activities. Sensitivity of the total license termination cost to the disposal costs at different low-level radioactive waste disposal sites, to different depths of contaminated concrete surface removal within the facilities, and to different transport distances is also examined.

Smith, R.I.; Bierschbach, M.C.; Konzek, G.J.; McDuffie, P.N.

1996-07-01T23:59:59.000Z

288

Revised analyses of decommissioning for the reference pressurized Water Reactor Power Station. Volume 2, Effects of current regulatory and other considerations on the financial assurance requirements of the decommissioning rule and on estimates of occupational radiation exposure: Appendices, Final report  

SciTech Connect

With the issuance of the final Decommissioning Rule (July 27, 1998), owners and operators of licensed nuclear power plants are required to prepare, and submit to the US Nuclear Regulatory Commission (NRC) for review, decommissioning plans and cost estimates. The NRC staff is in need of bases documentation that will assist them in assessing the adequacy of the licensee submittals, from the viewpoint of both the planned actions, including occupational radiation exposure, and the probable costs. The purpose of this reevaluation study is to provide some of the needed bases documentation. This report contains the results of a review and reevaluation of the 1978 PNL decommissioning study of the Trojan nuclear power plant (NUREG/CR-0130), including all identifiable factors and cost assumptions which contribute significantly to the total cost of decommissioning the nuclear power plant for the DECON, SAFSTOR, and ENTOMB decommissioning alternatives. These alternatives now include an initial 5--7 year period during which time the spent fuel is stored in the spent fuel pool, prior to beginning major disassembly or extended safe storage of the plant. Included for information (but not presently part of the license termination cost) is an estimate of the cost to demolish the decontaminated and clean structures on the site and to restore the site to a ``green field`` condition. This report also includes consideration of the NRC requirement that decontamination and decommissioning activities leading to termination of the nuclear license be completed within 60 years of final reactor shutdown, consideration of packaging and disposal requirements for materials whose radionuclide concentrations exceed the limits for Class C low-level waste (i.e., Greater-Than-Class C), and reflects 1993 costs for labor, materials, transport, and disposal activities.

Konzek, G.J.; Smith, R.I.; Bierschbach, M.C.; McDuffie, P.N.

1995-11-01T23:59:59.000Z

289

Revised analyses of decommissioning for the reference pressurized Water Reactor Power Station. Effects of current regulatory and other considerations on the financial assurance requirements of the decommissioning rule and on estimates of occupational radiation exposure, Volume 1, Final report  

Science Conference Proceedings (OSTI)

With the issuance of the final Decommissioning Rule (July 27, 1988), owners and operators of licensed nuclear power plants are required to prepare, and submit to the US Nuclear Regulatory Commission (NRC) for review, decommissioning plans and cost estimates. The NRC staff is in need of bases documentation that will assist them in assessing the adequacy of the licensee submittals, from the viewpoint of both the planned actions, including occupational radiation exposure, and the probable costs. The purpose of this reevaluation study is to provide some of the needed bases documentation. This report contains the results of a review and reevaluation of the {prime}978 PNL decommissioning study of the Trojan nuclear power plant (NUREG/CR-0130), including all identifiable factors and cost assumptions which contribute significantly to the total cost of decommissioning the nuclear power plant for the DECON, SAFSTOR, and ENTOMB decommissioning alternatives. These alternatives now include an initial 5--7 year period during which time the spent fuel is stored in the spent fuel pool, prior to beginning major disassembly or extended safe storage of the plant. Included for information (but not presently part of the license termination cost) is an estimate of the cost to demolish the decontaminated and clean structures on the site and to restore the site to a ``green field`` condition. This report also includes consideration of the NRC requirement that decontamination and decommissioning activities leading to termination of the nuclear license be completed within 60 years of final reactor shutdown, consideration of packaging and disposal requirements for materials whose radionuclide concentrations exceed the limits for Class C low-level waste (i.e., Greater-Than-Class C), and reflects 1993 costs for labor, materials, transport, and disposal activities.

Konzek, G.J.; Smith, R.I.; Bierschbach, M.C.; McDuffie, P.N. [Pacific Northwest Lab., Richland, WA (United States)

1995-11-01T23:59:59.000Z

290

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

291

RADIATION COUNTER  

DOE Patents (OSTI)

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

Goldsworthy, W.W.

1958-02-01T23:59:59.000Z

292

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

293

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

294

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

295

Low Dose Radiation Research Program: Thomas Weber  

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

2005 Workshop: A Paracrine Signal Mediates The Cell Transformation Response To Low Dose Gamma Radiation in JB6 Cells. Weber, T.J., Siegel, R.W., Markillie, L.M., Chrisler,...

296

Activation of nuclear factor kB in human lymphoblastoid cells by low-dose ionizing radiation  

SciTech Connect

Nuclear factor kB (NF-kB) is a pleiotropic transcription factor which is involved in the transcriptional regulation of several specific genes. Recent reports demonstrated that ionizing radiation in the dose range of 2-50 Gy results in expression of NF-kB in human KG-1 myeloid leukemia cells and human B-lymphocyte precursor cells; the precise mechanism involved and the significance are not yet known. The present report demonstrates that even lower doses of ionizing radiation, 0.25-2.0 Gy, are capable of inducing expression of NF-kB in EBV-transformed 244B human lymphoblastoid cells. These results are in a dose range where the viability of the cells remains very high. After exposure to {sup 137}Cs {gamma} rays at a dose rate of 1.17 Gy/min, a maximum in expression of NF-kB was seen at 8 h after a 0.5-Gy exposure. Time-course studies revealed a biphasic time-dependent expression after 0.5-, 1- and 2-Gy exposures. However, for each time examined, the expression of NF-kB was maximum after the 0.5-Gy exposure. The expression of the p50 and p65 NF-kB subunits was also shown to be regulated differentially after exposures to 1.0 and 2.0 Gy. 32 refs., 3 figs.

Prasad, A.V.; Mohan, N.; Meltz, M.L.; Chandrasekar, B. [Univ. of Texas Health Science Center, San Antonio, TX (United States)

1994-06-01T23:59:59.000Z

297

Anomalous Radiative Decay of Heavy Higgs Boson  

E-Print Network (OSTI)

The radiative decay width of a heavy Higgs boson $H \\rightarrow W^+W^-\\gamma$ for a {\\it hard} photon is calculated in the Standard Model and its extension with anomalous $\\gamma WW$ couplings. Its dependence on the Higgs mass, the two unknown anomalous couplings, and the photon energy cutoff are studied in detail. We show that this radiative decay of a heavy Higgs is not very sensitive to a wide range of the anomalous couplings compared to the Standard Model result.

Tzu Chiang Yuan

1992-05-27T23:59:59.000Z

298

METHODOLOGY FOR WORKER NEUTRON EXPOSURE EVALUATION IN THE PDCF FACILITY DESIGN  

Science Conference Proceedings (OSTI)

A project headed by Washington Group International is meant to design the Pit Disassembly and Conversion Facility (PDCF) to convert the plutonium pits from excessed nuclear weapons into plutonium oxide for ultimate disposition. Battelle staff are performing the shielding calculations that will determine appropriate shielding so that the facility workers will not exceed target exposure levels. The target exposure levels for workers in the facility are 5 mSv y?1 for the whole body and 100 mSv y?1 for the extremity, which presents a significant challenge to the designers of a facility that will process tons of radioactive material. The design effort depended on shielding calculations to determine appropriate thickness and composition for glove box walls, and concrete wall thicknesses for storage vaults. Pacific Northwest National Laboratory (PNNL) staff used ORIGEN-S and SOURCES to generate gamma and neutron source terms, and Monte Carlo (computer code for) neutron photon (transport) (MCNP-4C) to calculate the radiation transport in the facility. The shielding calculations were performed by a team of four scientists, so it was necessary to develop a consistent methodology. There was also a requirement for the study to be cost-effective, so efficient methods of evaluation were required. The calculations were subject to rigorous scrutiny by internal and external reviewers, so acceptability was a major feature of the methodology. Some of the issues addressed in the development of the methodology included selecting appropriate dose factors, developing a method for handling extremity doses, adopting an efficient method for evaluating effective dose equivalent in a non-uniform radiation field, modeling the reinforcing steel in concrete, and modularizing the geometry descriptions for efficiency. The relative importance of the neutron dose equivalent compared with the gamma dose equivalent varied substantially depending on the specific shielding conditions and lessons were learned from this effect. This paper addresses these issues and the resulting methodology.

Scherpelz, Robert I.; Traub, Richard J.; Pryor, Kathryn H.

2004-08-01T23:59:59.000Z

299

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

300

Exposure Reduction Through Optimized Planning and Scheduling  

Science Conference Proceedings (OSTI)

The industry is challenged with increasing material inspections and complex maintenance work in areas with high radiation fields. Compounding this problem is the drive to reduce worker exposure. Efficient job planning and monitoring of worker exposure becomes more important in light of these challenges. An essential component of the ALARA program is centered on accurate and detailed work control. Drawing on industry experience, best practices, and the experience of the EPRI ALARA assessment team, EPRI de...

2005-12-14T23:59:59.000Z

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301

Perspectives on Gamma-Ray Pulsar Emission  

SciTech Connect

Pulsars are powerful sources of radiation across the electromagnetic spectrum. This paper highlights some theoretical insights into non-thermal, magnetospheric pulsar gamma-ray radiation. These advances have been driven by NASA's Fermi mission, launched in mid-2008. The Large Area Telescope (LAT) instrument on Fermi has afforded the discrimination between polar cap and slot gap/outer gap acceleration zones in young and middle-aged pulsars. Altitude discernment using the highest energy pulsar photons will be addressed, as will spectroscopic interpretation of the primary radiation mechanism in the LAT band, connecting to both polar cap/slot gap and outer gap scenarios. Focuses will mostly be on curvature radiation and magnetic pair creation, including population trends that may afford probes of the magnetospheric accelerating potential.

Baring, Matthew G. [Department of Physics and Astronomy, MS-108, Rice University, P. O. Box 1892, Houston, TX 77251-1892 (United States)

2011-09-21T23:59:59.000Z

302

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

303

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

304

Mechanisms of Low Dose Radiation-induced T helper Cell Function  

SciTech Connect

Exposure to radiation above levels normally encountered on Earth can occur during wartime, accidents such as those at Three Mile Island and Chernobyl, and detonation of “dirty bombs” by terrorists. Relatively high levels of radiation exposure can also occur in certain occupations (low-level waste sites, nuclear power plants, nuclear medicine facilities, airline industry, and space agencies). Depression or dysfunction of the highly radiosensitive cells of the immune system can lead to serious consequences, including increased risk for infections, cancer, hypersensitivity reactions, poor wound healing, and other pathologies. The focus of this research was on the T helper (Th) subset of lymphocytes that secrete cytokines (proteins), and thus control many actions and interactions of other cell types that make up what is collectively known as the immune system. The Department of Energy (DOE) Low Dose Radiation Program is concerned with mechanisms altered by exposure to high energy photons (x- and gamma-rays), protons and electrons. This study compared, for the first time, the low-dose effects of two of these radiation forms, photons and protons, on the response of Th cells, as well as other cell types with which they communicate. The research provided insights regarding gene expression patterns and capacity to secrete potent immunostimulatory and immunosuppressive cytokines, some of which are implicated in pathophysiological processes. Furthermore, the photon versus proton comparison was important not only to healthy individuals who may be exposed, but also to patients undergoing radiotherapy, since many medical centers in the United States, as well as worldwide, are now building proton accelerators. The overall hypothesis of this study was that whole-body exposure to low-dose photons (gamma-rays) will alter CD4+ Th cell function. We further proposed that exposure to low-dose proton radiation will induce a different pattern of gene and functional changes compared to photons. Over the course of this research, tissues other than spleens were archived and with funding obtained from other sources, including the Department of Radiation Medicine at the Loma Linda University Medical Center, some additional assays were performed. Furthermore, groups of additional mice were included that were pre-exposed to low-dose photons before irradiating with acute photons, protons, and simulated solar particle event (SPE) protons. Hence, the original support together with the additional funding for our research led to generation of much valuable information that was originally not anticipated. Some of the data has already resulted in published articles, manuscripts in review, and a number of presentations at scientific conferences and workshops. Difficulties in reliable and reproducible quantification of secreted cytokines using multi-plex technology delayed completion of this study for a period of time. However, final analyses of the remaining data are currently being performed and should result in additional publications and presentations in the near future. Some of the most notable conclusions, thus far, are briefly summarized below: - Distribution of leukocytes were dependent upon cell type, radiation quality, body compartment analyzed, and time after exposure. Low-dose protons tended to have less effect on numbers of major leukocyte populations and T cell subsets compared to low-dose photons. - The patterns of gene and cytokine expression in CD4+ T cells after protracted low-dose irradiation were significantly modified and highly dependent upon the total dose and time after exposure. - Patterns of gene and cytokine expression differed substantially among groups exposed to low-dose photons versus low-dose protons; differences were also noted among groups exposed to much higher doses of photons, protons, and simulated SPE protons. - Some measurements indicated that exposure to low-dose photon radiation, especially 0.01 Gy, significantly “normalized” at least some adverse effects of simulated SPE protons, thereby suggesting that this l

Gridley, Daila S.

2008-10-31T23:59:59.000Z

305

On the mechanism of prompt emission of gamma-ray bursts  

E-Print Network (OSTI)

We propose a model in which prompt gamma emission of gamma-ray bursts is the synchrotron radiation of electron-positron plasma in the ordered magnetic field in the direct vicinity of horizon of a young black hole formed in the core collapse of a massive star. This mechanism can naturally explain high degree of polarization of the gamma-ray flux and hard low energy photon spectral index. Interaction of gamma-quanta with ambient matter provides a mechanism of formation of relativistic ejecta which are responsible for the gamma-ray burst afterglows.

Andrey Neronov

2003-11-05T23:59:59.000Z

306

Ion-induced gammas for photofission interrogation of HEU.  

Science Conference Proceedings (OSTI)

High-energy photons and neutrons can be used to actively interrogate for heavily shielded special nuclear material (SNM), such as HEU (highly enriched uranium), by detecting prompt and/or delayed induced fission signatures. In this work, we explore the underlying physics for a new type of photon source that generates high fluxes of mono-energetic gamma-rays from low-energy (ion accelerator experiments and radiation transport modeling. The data were used to assess gamma and neutron yields, background, and photofission-induced signal levels from several (p,{gamma}) target materials under consideration.

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

2006-03-01T23:59:59.000Z

307

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...

308

Low Dose Radiation Research Program: Low-Dose Dose-Response of  

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

Low-Dose Dose-Response of Proliferating Human Cells Exposed to Low Low-Dose Dose-Response of Proliferating Human Cells Exposed to Low Dose Rate g-Radiation. Authors: Louise Enns,1 Michael Weinfeld,1 Albert Murtha,1 and Kenneth Bogen2 Institutions: 1Cross Cancer Institute and 2Lawrence Livermore National Laboratory. Clinical and environmental exposure to ionizing radiation rarely exceeds 200 cGy. To examine cell proliferation at early times (up to 5 days) post-irradiation, we are utilizing an assay in which single cells encapsulated within ~30- to 70-µm-diameter agarose gel microdrops (GMDs) are exposed and cultured for 4 days at 37°C, then analyzed by flow cytometry (FC). Clonogenic proliferation is measured as the fraction of occupied GMDs containing multicellular microcolonies after 4 days in culture. This assay was applied to human A549 lung cells exposed to gamma

309

Mechanical properties of cables exposed to simultaneous thermal and radiation aging  

SciTech Connect

Sandia National Laboratories is conducting long-term aging research on representative samples of nuclear power plant Class 1E cables. The objectives of this program are to determine the suitability of these cables for extended life (beyond the 40-year design basis) and to assess various cable condition monitoring (CM) techniques for predicting remaining cable life. This paper provides the results of mechanical measurements that were performed on cable specimens cross-linked polyethylene neoprene jackets: chlorinated polyethylene jackets, fiberglass braid jackets, and chlorosulfonated polyethylene jackets aged at relatively mild, simultaneous thermal and radiation exposure conditions for periods of up to nine months. After aging, some of the aged samples, as well as some unaged samples, were exposed to accident gamma radiation at ambient temperature. The mechanical measurements discussed in this paper include tensile strength, ultimate elongation, and compressive modulus. 10 refs., 22 figs., 2 tabs.

Jacobus, M.J. (Sandia National Labs., Albuquerque, NM (USA)); Fuehrer, G.F. (Science and Engineering Associates, Inc., Albuquerque, NM (USA))

1990-01-01T23:59:59.000Z

310

Amorphous silicon radiation detectors  

DOE Patents (OSTI)

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

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

1992-01-01T23:59:59.000Z

311

Amorphous silicon radiation detectors  

DOE Patents (OSTI)

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

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

1992-11-17T23:59:59.000Z

312

Gamma-ray astronomy: From Fermi up to the HAWC high-energy {gamma}-ray observatory in Sierra Negra  

SciTech Connect

Gamma-rays represent the most energetic electromagnetic window for the study of the Universe. They are studied both from space at MeV and GeV energies, with instruments like the Fermi{gamma}-ray Space Telescope, and at TeV energies with ground based instruments profiting of particle cascades in the atmosphere and of the Cerenkov radiation of charged particles in the air or in water. The Milagro gamma-ray observatory represented the first instrument to successfully implement the water Cerenkov technique for {gamma}-ray astronomy, opening the ground for the more sensitive HAWC {gamma}-ray observatory, currently under development in the Sierra Negra site and already providing early science results.

Carraminana, Alberto [Instituto Nacional de Astrofisica, Optica y Electronica Luis Enrique Erro 1, Tonantzintla, Puebla 72840 (Mexico); Collaboration: HAWC Collaboration

2013-06-12T23:59:59.000Z

313

RADIATION SHIELDING DEVICE  

DOE Patents (OSTI)

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

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

1958-09-23T23:59:59.000Z

314

RADIATION SAFETY MANUAL  

E-Print Network (OSTI)

RADIATION SAFETY is the responsibility of all faculty, staff and students who are directly or indirectly involved in the use of radioisotopes or radiation-producing machines. In July 1963, the State of Texas granted The University of Texas at Austin a broad radioactive materials license for research, development and instruction. While this means a minimum of controls by the state, it requires that The University establish and pursue an effective Radiation Safety Program. The Radiation Safety Committee is responsible for The University's radiation control program outlined in this manual. The use of radiation in a university, where a large number of people may be unaware of their exposure to radiation hazards, makes strict adherence to procedures established by federal and state authorities of paramount importance for the protection of The University and the safety of its faculty, staff and students. It is the responsibility of all faculty, staff and students involved in radiation work to familiarize themselves thoroughly with The University's radiation control program and to comply with its requirements and all applicable federal and state regulations. I hope you will always keep in mind that radiation safety depends on a continuous awareness of potential hazards and on the acceptance

unknown authors

2005-01-01T23:59:59.000Z

315

Influence of gamma irradiation on the metabolic activity of sulfate-reducing bacteria  

SciTech Connect

When water is pumped into oil-bearing seams to increase oil production, the microorganisms in the injected water fall into favorable ecological conditions and, quickly adapting, form a biocenosis and begin to actively develop. Among the anaerobic microorganisms, the most hazardous from the corrosion viewpoint are the sulfate-reducing bacteria (SRB), which are the main producers of hydrogen sulfide as the product of anaerobic respiration. This paper reports on the effect of gamma rays on the metabolic study of SRB Desulfovibrio desulfuricans in the nutrient medium Postgate B. The radioactive source used is a /sup 60/CoK-125 unit with a power of 700 rad/sec. The required dose of gamma rays was calculated from the exposure times of samples with the test medium in the radiation zone o the isotope /sup 60/Co. The criterion characterizing the effectiveness of suppression of development of the bacteria is the concentration of biogenic hydrogen sulfide produced, as determined by iodometric titration.

Agaev, N.M.; Guseinov, M.M.; Smorodin, A.E.

1985-09-01T23:59:59.000Z

316

Radiation evaluation study of LSI RAM technologies. Final report  

SciTech Connect

Five commercial LSI static RAM technologies having a 1 kilobit capacity were radiation characterized. Arrays from the TTL, Schottky TTL, NMOS, CMOS, and CMOS/SOS families were evaluated. Radiation failure thresholds for gamma dose-rate logic upset, total gamma dose survivability, and neutron fluence survivability were determined. Included is a brief analysis of the radiation failure mechanism for each of the logic families tested.

Dinger, G.L.; Knoll, M.G.

1980-01-01T23:59:59.000Z

317

Los Alamos Lab: Radiation Protection: Annual Occupational Radiation  

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

Annual Occupational Radiation Dosimetry Report Print information on Annual Occupational Radiation Dosimetry Report (pdf). This webpage provides information to help you understand the dose quantities being reported to you on your Annual Occupational Radiation Dosimetry Report. If you would like general information about radiation exposure, please refer to www.radiationanswers.org. Title 10 Code of Federal Regulation Part 835, Occupational Radiation Protection (10 CFR 835), requires assessment, recording and reporting of radiation doses to individuals who are exposed to sources of radiation or radioactive contamination. This includes assessing external exposure from a variety of radiation types, such as, beta, photon, and neutron radiation. External exposures may be uniform over the whole body or occur in a non-uniform (i.e., limited body location) fashion. Internal doses occur when radioactive material is taken into the body through ingestion, inhalation, absorption or wounds. The requirements include assessing doses to the whole body, skin, lens of the eyes, extremities and various organs and tissues.

318

Fundamentals of Radiation Dosimetry  

Science Conference Proceedings (OSTI)

The basic concepts of radiation dosimetry are reviewed on basis of ICRU reports and text books. The radiation field is described with, among others, the particle fluence. Cross sections for indirectly ionizing radiation are defined and indicated is how they are related to the mass energy transfer and mass energy absorption coefficients. Definitions of total and restricted mass stopping powers of directly ionizing radiation are given. The dosimetric quantities, kerma, absorbed dose and exposure together with the relations between them are discussed in depth. Finally it is indicated how the absorbed dose can be measured with a calorimeter by measuring the temperature increase and with an ionisation chamber measuring the charge produced by the ionizing radiation and making use of the Bragg-Gray relation.

Bos, Adrie J. J. [Delft University of Technology, Faculty of Applied Sciences, Mekelweg 15, 2629JB Delft (Netherlands)

2011-05-05T23:59:59.000Z

319

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

320

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

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

Neutron And Gamma Detector Using An Ionization Chamber With An Integrated  

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

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

322

Chapter 15: Radiation Safety and Shielding 15-1 NSLS-II Conceptual Design Report  

E-Print Network (OSTI)

controls will only be employed as supplemental to control radiation exposure. An internal control level in the BNL Standards Based Management System. The maximum annual exposure to radiation workers and members 835.1001, measures will be taken to maintain radiation exposure as low as reasonably achievable (ALARA

Ohta, Shigemi

323

Population exposure from the fuel cycle: Review and future direction  

SciTech Connect

The legacy of radiation exposures confronting man arises from two historical sources of energy, the sun and radioactive decay. Contemporary man continues to be dependent on these two energy sources, which include the nuclear fuel cycle. Radiation exposures from all energy sources should be examined, with particular emphasis on the nuclear fuel cycle, incidents such as Chernobyl and Three Mile Island. In addition to risk estimation, concepts such as de minimis, life shortening as a measure of risk, and competing risks as projected into the future must be considered in placing radiation exposures in perspective. The utility of these concepts is in characterizing population exposures for decision makers in a manner that the public may judge acceptable. All these viewpoints are essential in the evaluation of population exposure from the nuclear fuel cycle.

Richmond, C.R.

1987-01-01T23:59:59.000Z

324

Radiation effects on humans  

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

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

325

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

326

Review of medical findings in a Marshallese population twenty-six years after accidental exposure to radioactive fallout  

SciTech Connect

In March 1954, radioactive debris from a thermonuclear weapon test at Bikini Atoll deviated from predicted trajectories and contaminated several atolls in the northern Marshall Islands. As a result, 239 native inhabitants of these islands along with 28 American servicemen and 23 Japanese fishermen received variably severe exposures to diverse ionizing radiations. Fallout material consisted largely of mixed fission products with small amounts of neutron-induced radionuclides and minimal amounts of fissionable elements, producing a complex spectrum of electromagnetic and particulate radiation. Individuals were exposed to deeply penetrating, whole-body gamma irradiation, to internal radiation emitters assimilated either by inhalation or by ingestion of contaminated water and food, and to direct radiation from material accumulating on body surfaces. That accident initiated a cascade of events, medical, social and political, which continue in varying forms to this day. Most of these have been discussed in the open medical literature and in periodic reports issued by the medical team headquartered at Brookhaven National Laboratory. This report attempts to summarize some of the principal findings of medical significnce that have been observed during the subsequent 26 years with particular emphasis on the last six years.

Conard, R.A.; Paglia, D.E.; Larsen, P.R.

1980-01-01T23:59:59.000Z

327

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

328

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

329

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

330

Ion Technique for Identifying Gamma Detector Candidates  

SciTech Connect

Recent demands for radiation detector materials with better energy resolution at room temperature have prompted research efforts on both accelerated material discovery and efficient analysis techniques. Ions can easily deposit their energy in thin films or small crystals and the radiation response can be used to identify material properties relevant to detector performance. In an effort to identify gamma detector candidates using small crystals or film samples, an ion technique is developed to measure relative light yield and energy resolution of candidate materials and to evaluate radiation detection performance. Employing a unique time-of-flight (TOF) telescope, light yield and energy resolution resulting from ion excitation are investigated over a continuous energy region. The efficiency of this ion technique is demonstrated using both organic (plastic scintillator) and inorganic (CaF2:Eu, YAP:Ce, CsI:Tl and BGO) scintillators.

Zhang, Yanwen; Xiang, Xia; Rausch, Julie L.; Zu, Xiaotao T.; Weber, William J.

2009-06-15T23:59:59.000Z

331

Literature survey of chemical analysis by thermal neutron induced capture gamma ray spectrometry  

DOE Green Energy (OSTI)

A brief discussion of the principles and techniques of chemical analysis by neutron capture gamma radiation is presented, and the widely scattered literature is collected into a single table arranged by element measured.

Gladney, E.S.

1979-09-01T23:59:59.000Z

332

Performance degradation of P3HT:PCBM Polymer/fullerene photovoltaic cells under gamma irradiation.  

E-Print Network (OSTI)

??The gamma radiation damage effect on polymer-based hybrid photovoltaic cells consisting of a blend of poly-3-hexylthiophene (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) is investigated.… (more)

Todd, Aaron

2009-01-01T23:59:59.000Z

333

A leptonic-hadronic model for the afterglow of gamma-ray burst 090510  

E-Print Network (OSTI)

We model multiwavelength afterglow data from the short Gamma-Ray Burst (GRB) 090510 using a combined leptonic-hadronic model of synchrotron radiation from an adiabatic blast wave. High energy, >100 MeV, emission in our model is dominated by proton-synchrotron radiation, while electron-synchrotron radiation dominates in the X ray and ultraviolet wavelengths. The collimation-corrected GRB energy, depending on the jet-break time, in this model could be as low as 3e51 erg but two orders of magnitude larger than the gamma-ray energy. We also calculated the opacities for electron-positron pair production by gamma rays and found that TeV gamma rays from proton-synchrotron radiation can escape the blast wave at early time, and their detection can provide evidence of a hadronic emission component dominating at high energies.

Soebur Razzaque

2010-04-20T23:59:59.000Z

334

About Radiation  

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

Radiation What is radiation? Radiation is a form of energy that is a part of our everyday lives. All of us receive a "dose" of radiation each day. Most of the dose comes from...

335

An Assessment of Aquatic Radiation Pathways in Northern Ireland  

E-Print Network (OSTI)

.1 The fishing industry 11 3.2 Fishing areas 11 4. INTERNAL RADIATION EXPOSURE PATHWAYS 12 4.1 Fish 12 4. ANALYSIS OF DATA 19 7.1 Internal radiation exposure 19 7.1.1 Fish consumption 19 7.1.2 Crustacean and clams 14 4.3.4 Razor fish and squid 15 5. EXTERNAL RADIATION EXPOSURE PATHWAYS 15 5.1 Beach and coastal

336

Radiation and viral DNA  

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

Radiation and viral DNA Radiation and viral DNA Name: Loretta L Lamb Age: N/A Location: N/A Country: N/A Date: N/A Question: Can viral DNA be changed through exposure to radiation? If so, what type of radiation will do this? Can these irradiated viruses cause changes in the genome of any human cells they may infect? Can these (or any) viruses actually cause cancer, or do they merely act as triggering devices for cancer? Replies: In theory, any nucleic acid (viral or otherwise) can be changed by exposure to many kinds of radiation. Depending on the type of virus, these may then change the human cells that they infect. Although there are many different things that are being implicated in causing cancers, it looks like a fairly common model involves the sequential "knockout" of several human genes. Viruses may be one cause of such gene changes, radiation and other environmental causes may also contribute. Some of these changes may be inherited through families, so it becomes more likely that the environmental factors may happen to "hit" the right places in cells to cause cancers in these families. If you ask something more specific, perhaps I can focus my response a bit more

337

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

338

Hard x-ray or gamma ray laser by a dense electron beam  

SciTech Connect

A dense electron beam propagating through a laser undulator can radiate a coherent x-ray or gamma ray. This lasing scheme is studied with the Landau damping theory. The analysis suggests that, with currently available physical parameters, coherent gamma rays of up to 50 keV can be generated. The electron quantum diffraction suppresses the free electron laser action, which limits the maximum radiation.

Son, S. [18 Caleb Lane, Princeton, New Jersey 08540 (United States); Joon Moon, Sung [8 Benjamin Rush Ln., Princeton, New Jersey 08540 (United States)

2012-06-15T23:59:59.000Z

339

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

E-Print Network (OSTI)

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

J. I. Katz

1999-08-19T23:59:59.000Z

340

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

E-Print Network (OSTI)

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

Britton, Julie

2010-01-01T23:59:59.000Z

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

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

342

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

343

Radiation of Hiroshima and Nagasaki builds foundation for risk estimates  

SciTech Connect

A discussion of the international cooperation between Japan and the United States in documenting radiation exposure and its medical effects on atomic bomb survivors is present.

Ketchum, L.E.

1985-08-01T23:59:59.000Z

344

NIST Ionizing Radiat. Div. - 2004: Strategic Focus 1  

Science Conference Proceedings (OSTI)

... and to determine exposure or dose-rate values ... to maximize the energy absorption of the ionizing radiation. ... the calibration of an 55 Fe low-energy x ...

345

A Review of the European Union's Directive on Limiting Exposure of Workers to Electromagnetic Fields  

Science Conference Proceedings (OSTI)

The European Union’s Directive on Limiting Exposure of Workers to Electromagnetic Fields (EMF) adopts exposure limits based on guidance from the International Commission on Non-Ionizing Radiation Protection (ICNIRP). This report presents a summary of the draft Directive concerning workplace exposure limits and compliance issues. The summary explains quantitative EMF exposure limits in general and clarifies the Directive’s use of the terms exposure limit values (ELV) and action ...

2013-06-05T23:59:59.000Z

346

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

347

The Inverse-Compton And Extragalactic Components Of The Diffuse Gamma-Ray Emission  

E-Print Network (OSTI)

We present spectra of the inverse-Compton and extragalactic components of the high-energy gamma-radiation based on an analysis of the emission at high galactic latitudes ($\\vert$b$\\vert$ $\\geq$ $30\\deg$). We correlate the gamma-ray intensity with a model consisting of an isotropic component, a component proportional to the 408 MHz synchrotron radiation, and a component proportional to atomic hydrogen (H I) column density with different emissivities in eight galactic octants. The spectrum of gamma-radiation that is correlated with the H I column density indicates that this component originates in cosmic-ray/matter interactions. The cosmic-ray electrons which produce the 408 MHz radio continuum emission also produce gamma-radiation through inverse-Compton interactions with interstellar photons. By correlating the gamma-radiation with the 408 MHz continuum, we measure the spectrum and absolute intensity of the IC emission. The isotropic component gives us the spectrum and intensity of the extragalactic gamma-radiation. We discuss interpretation of the extragalactic spectrum.

Andrew Chen; Joseph Dwyer; Philip Kaaret

1995-12-06T23:59:59.000Z

348

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

349

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

350

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

351

Neutron and gamma irradiation damage to organic materials.  

SciTech Connect

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

White, Gregory Von, II; Bernstein, Robert

2012-04-01T23:59:59.000Z

352

Storage of LWR spent fuel in air. Volume 3, Results from exposure of spent fuel to fluorine-contaminated air  

SciTech Connect

The Behavior of Spent Fuel in Storage (BSFS) Project has conducted research to develop data on spent nuclear fuel (irradiated U0{sub 2}) that could be used to support design, licensing, and operation of dry storage installations. Test Series B conducted by the BSFS Project was designed as a long-term study of the oxidation of spent fuel exposed to air. It was discovered after the exposures were completed in September 1990 that the test specimens had been exposed to an atmosphere of bottled air contaminated with an unknown quantity of fluorine. This exposure resulted in the test specimens reacting with both the oxygen and the fluorine in the oven atmospheres. The apparent source of the fluorine was gamma radiation-induced chemical decomposition of the fluoro-elastomer gaskets used to seal the oven doors. This chemical decomposition apparently released hydrofluoric acid (HF) vapor into the oven atmospheres. Because the Test Series B specimens were exposed to a fluorine-contaminated oven atmosphere and reacted with the fluorine, it is recommended that the Test Series B data not be used to develop time-temperature limits for exposure of spent nuclear fuel to air. This report has been prepared to document Test Series B and present the collected data and observations.

Cunningham, M.E.; Thomas, L.E.

1995-06-01T23:59:59.000Z

353

29th International Cosmic Ray Conference Pune (2005) 1, 301-302 Human Exploration of the Moon and Mars: Space Radiation Data,  

E-Print Network (OSTI)

and development of instrumentation to guide NASA in managing the radiation exposure of the crew during the manned to carefully manage the radiation exposure of the crew in real time because of the variability of the radiation occurs. This is especially true if it occurs during a lunar excursion. A substantial radiation exposure

Lin, Zi-wei

354

Low Dose Radiation  

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

Ancient Salt Beds Ancient Salt Beds Repository Science Renewable Energy The WIPP Underground may be ideal to study effects of Very Low Dose Rates on Biological Systems Low Background Radiation Experiment We're all bathing in it. It's in the food we eat, the water we drink, the soil we tread and even the air we breathe. It's background radiation, it's everywhere and we can't get away from it. But what would happen if you somehow "pulled the plug" on natural background radiation? Would organisms suffer or thrive if they grew up without their constant exposure to background radiation? That's what a consortium of scientists conducting an experiment at the Waste Isolation Pilot Plant aim to find out. Despite being an underground repository for transuranic radioactive waste,

355

Method for microbeam radiation therapy  

DOE Patents (OSTI)

A method of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation, in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue.

Slatkin, Daniel N. (Sound Beach, NY); Dilmanian, F. Avraham (Yaphank, NY); Spanne, Per O. (Shoreham, NY)

1994-01-01T23:59:59.000Z

356

Radiation control standards and procedures  

SciTech Connect

This manual contains the Radiation Control Standards'' and Radiation Control Procedures'' at Hanford Operations which have been established to provide the necessary control radiation exposures within Irradiation Processing Department. Provision is also made for including, in the form of Bulletins'', other radiological information of general interest to IPD personnel. The purpose of the standards is to establish firm radiological limits within which the Irradiation Processing Department will operate, and to outline our radiation control program in sufficient detail to insure uniform and consistent application throughout all IPD facilities. Radiation Control Procedures are intended to prescribe the best method of accomplishing an objective within the limitations of the Radiation Control Standards. A procedure may be changed at any time provided the suggested changes is generally agreeable to management involved, and is consistent with department policies and the Radiation Control Standards.

1956-12-14T23:59:59.000Z

357

Method for microbeam radiation therapy  

DOE Patents (OSTI)

A method is disclosed of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation. The dose is in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue. No Drawings

Slatkin, D.N.; Dilmanian, F.A.; Spanne, P.O.

1994-08-16T23:59:59.000Z

358

Radiation: Radiation Control (Indiana)  

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

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

359

Particle Acceleration and Gamma-Ray Production in Shell Remnants  

E-Print Network (OSTI)

A number of nearby Northern Hemisphere shell-type Supernova Remnants (SNRs) has been observed in TeV gamma rays, but none of them could be detected so far. This failure calls for a critical reevaluation of the theoretical arguments for gamma-ray emission of SNRs. The present paper discusses diffusive shock acceleration in shell-type SNRs in full kinetic theory. Emphasis is also given to the possible problems for VHE gamma-ray production due to the environmental conditions a SN progenitor finds itself in. Observational upper limits are compared with theoretical predictions for the gamma-ray flux. Empirical arguments from the observation of X-ray power law continua for electron-induced Inverse Compton gamma-ray emission at TeV energies are discussed in their relation to the nucleonic Pi-zero decay emission from the same objects. Finally, a point is made for the simplest case of SNe Ia, expected to explode in a uniform circumstellar medium. Here in particular the very recently detected Southern Hemisphere remnant of SN 1006 is compared with Tycho's SNR. On the basis of the assumed parameters for the two remnants SN 1006 is tentatively identified with a remnant whose TeV gamma-ray emission is dominated by Inverse Compton radiation. Tycho might be dominantly a Pi-zero decay gamma-ray source.

H. J. Volk

1997-11-18T23:59:59.000Z

360

Health Risks Associated with Low Doses of Radiation  

Science Conference Proceedings (OSTI)

Despite a wealth of information, there remains uncertainty concerning human radiation effects at low dose levels. This report provides background information and a literature review of research on the potential health hazards associated with exposure to low-level ionizing radiation. Topics include radiation characteristics, protection standards, epidemiologic data and risk models, the nature of human health exposure-related effects, important radiation health studies to date, and the scientific method fo...

1994-09-17T23:59:59.000Z

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

The ionizing radiation environment in space and its effects  

Science Conference Proceedings (OSTI)

The ionizing radiation environment in space poses a hazard for spacecraft and space crews. The hazardous components of this environment are reviewed and those which contribute to radiation hazards and effects identified. Avoiding the adverse effects of space radiation requires design, planning, monitoring and management. Radiation effects on spacecraft are avoided largely though spacecraft design. Managing radiation exposures of space crews involves not only protective spacecraft design and careful mission planning. Exposures must be managed in real time. The now-casting and forecasting needed to effectively manage crew exposures is presented. The techniques used and the space environment modeling needed to implement these techniques are discussed.

Adams, Jim; Falconer, David; Fry, Dan [Center for Space Plasma and Aeronomic Research (CSPAR), UA Huntsville (United States); Space Radiation Analysis Group, NASA Johnson Space Center (United States)

2012-11-20T23:59:59.000Z

362

Influence of Extraterrestrial Radiation on Radiation Portal Monitors  

Science Conference Proceedings (OSTI)

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

Keller, Paul E.; Kouzes, Richard T.

2009-06-01T23:59:59.000Z

363

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

364

ORIGINAL ARTICLE Biodistribution and radiation dosimetry of a positron  

E-Print Network (OSTI)

. Radiation-absorbed doses were estimated by the Medical Internal Radiation Dose scheme. Results After injecting 18 F-SP203, the two organs with highest radiation exposure were urinary bladder wallORIGINAL ARTICLE Biodistribution and radiation dosimetry of a positron emission tomographic ligand

Shen, Jun

365

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

366

Monte Carlo calculations of channeling radiation  

Science Conference Proceedings (OSTI)

Results of classical Monte Carlo calculations are presented for the radiation produced by ultra-relativistic positrons incident in a direction parallel to the (110) plane of Si in the energy range 30 to 100 MeV. The results all show the characteristic CR(channeling radiation) peak in the energy range 20 keV to 100 keV. Plots of the centroid energies, widths, and total yields of the CR peaks as a function of energy show the power law dependences of ..gamma../sup 1/ /sup 5/, ..gamma../sup 1/ /sup 7/, and ..gamma../sup 2/ /sup 5/ respectively. Except for the centroid energies and power-law dependence is only approximate. Agreement with experimental data is good for the centroid energies and only rough for the widths. Adequate experimental data for verifying the yield dependence on ..gamma.. does not yet exist.

Bloom, S.D.; Berman, B.L.; Hamilton, D.C.; Alguard, M.J.; Barrett, J.H.; Datz, S.; Pantell, R.H.; Swent, R.H.

1981-01-01T23:59:59.000Z

367

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

Science Conference Proceedings (OSTI)

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

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

1981-11-01T23:59:59.000Z

368

Protection Against Ionizing Radiation in Extreme Radiation ...  

Science Conference Proceedings (OSTI)

Protection Against Ionizing Radiation in Extreme Radiation-resistant Microorganisms. ... Elucidated radiation protection by intracellular halides. ...

2013-05-01T23:59:59.000Z

369

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

370

Spatiotemporal and spatial threshold models for relating UV exposures and skin cancer in the central United States  

Science Conference Proceedings (OSTI)

The exact mechanisms relating exposure to ultraviolet (UV) radiation and elevated risk of skin cancer remain the subject of debate. For example, there is disagreement on whether the main risk factor is duration of the exposure, its intensity, or some ...

Laura A. Hatfield; Richard W. Hoffbeck; Bruce H. Alexander; Bradley P. Carlin

2009-06-01T23:59:59.000Z

371

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

E-Print Network (OSTI)

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

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

2013-03-26T23:59:59.000Z

372

Beta Radiation  

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

Beta Radiation 1. Beta radiation may travel meters in air and is moderately penetrating. 2. Beta radiation can penetrate human skin to the "germinal layer," where new skin cells...

373

RADIATION MONITORING  

E-Print Network (OSTI)

of Monitoring for Radiation Protection of Workers" in ICRPNo. 9, in "Advances in Radiation Protection and Dosimetry inDosimetry f o r Stray Radiation Monitoring on the CERN S i t

Thomas, R.H.

2010-01-01T23:59:59.000Z

374

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

375

Engineering hot-cell windows for radiation protection  

SciTech Connect

Radiation protection considerations in the design and construction of hot-cell windows are discussed. The importance of evaluating the potential gamma spectra and neutron source terms is stressed. 11 references. (ACR)

Ferguson, K.R.; Courtney, J.C.

1983-01-01T23:59:59.000Z

376

Radiological Safety Training for Radiation-Producing (X-Ray)...  

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

for General Radiation Safety Installations Using Non-Medical X-Ray and Sealed Gamma-Ray Sources, Energies up to 10 MEV, ANSI Standard N43.3, American National Standards...

377

3D Radiation Field Estimation Algorithm v1.0  

Science Conference Proceedings (OSTI)

The product is a calculational subprogram to be used within CAD, Laser scan or GIS software products to extrapolate / interpolate gamma radiation dose rates at 3-D locations for which no field survey data had been ...

2013-04-24T23:59:59.000Z

378

Recent developments in radiative B decays  

E-Print Network (OSTI)

We report on recent theoretical progress in radiative B decays. We focus on a calculation of logarithmically enhanced QED corrections to the branching ratio and forward-backward asymmetry in the inclusive rare decay anti-B --> X(s) l+ l-, and present the results of a detailed phenomenological analysis. We also report on the calculation of NNLO QCD corrections to the inclusive decay anti-B --> X(s) gamma. As far as exclusive modes are concerned we consider transversity amplitudes and the impact of right-handed currents in the exclusive anti-B --> K^* l+ l- decay. Finally, we state results for exclusive B --> V gamma decays, notably the time-dependent CP-asymmetry in the exclusive B --> K^* gamma decay and its potential to serve as a so-called ``null test'' of the Standard Model, and the extraction of CKM and unitarity triangle parameters from B --> (rho,omega) gamma and B --> K^* gamma decays.

Huber, T

2008-01-01T23:59:59.000Z

379

Chronic Low Dose Radiation Effects on Radiation Sensitivity  

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

Chronic Low Dose Radiation Effects on Radiation Sensitivity Chronic Low Dose Radiation Effects on Radiation Sensitivity and Chromosome Instability Induction in TK6 Cells Schwartz J.L. 1 , Jordan R. 1 , Slovic J. 1 , Moruzzi A. 1 , Kimmel R. 2 , and Liber, H.L. 3 1 University of Washington, Seattle, WA; 2 Fred Hutchinson Cancer Research Center, Seattle, WA; 3 Colorado State University, Fort Collins, Colorado There are a number of cell responses that can be detected after low dose radiation exposures including the adaptive response, low dose hypersensitivity, and induced genomic instability. The relationship between these different phenomena is unknown. In this study, we measured adaptive responses, low dose hypersensitivity, and induced genomic instability in a human B-lymphoblastoid cell model, TK6, where we could genetically modify radiation responses by either over-expression of BCL-2 or deletion of TP53. TK6

380

RADIATION SHIELDING COMPOSITION  

DOE Patents (OSTI)

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

Dunegan, H.L.

1963-01-29T23:59:59.000Z

Note: This page contains sample records for the topic "gamma radiation exposure" 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
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381

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

E-Print Network (OSTI)

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

B. B. Jones

2002-02-04T23:59:59.000Z

382

Radiation effects at a high power accelerator and applications to advanced energy sources  

Science Conference Proceedings (OSTI)

Many materials are exposed to atom-displacing radiation at high-power accelerators such as the Los Alamos Meson Physics Facility (LAMPF). Beam current densities in the 800-MeV proton beam vary from 12.5 mA cm{sup {minus}2} (8 {times} 10{sup 16} p/cm{sup 2}s) on graphite targets to 20-{mu}A cm{sup {minus}2} (1.3 {times} 10{sup 14} p/cm{sup 2}s) on metal-alloy windows. High-level radiation damage results from these particle fluxes. As a consequence of secondary-particle generation in targets and windows and low-level beam losses that lead to particle interactions with structural material, various components are exposed to low-level proton fluxes, gamma radiation, and neutron fluxes of 10{sup 6}--10{sup 10} n/cm{sup 2}s. These include vacuum seals and vacuum chambers of stainless steel and aluminum alloys, solid-state devices for control, diagnostic, and data acquisition electronics, closed-loop cooling-water systems, and insulators. Properties of these materials are degraded by the radiation exposure. Studies of LAMPF and other accelerators, however, have produced solutions to materials problems, allowing the machines to operate for acceptable times without failure. Nevertheless, additional improvements are being investigated in order to further improve operational reliability and safety. 25 refs., 3 figs., 3 tabs.

Sommer, W.F.; Garner, F.A.; Brown, R.D.; Wechsler, M.S. (Los Alamos National Lab., NM (USA); Battelle Pacific Northwest Lab., Richland, WA (USA); Los Alamos National Lab., NM (USA); Iowa State Univ. of Science and Technology, Ames, IA (USA))

1989-01-01T23:59:59.000Z

383

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

384

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

385

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

386

Development of Radio Frequency Exposure Standards  

Science Conference Proceedings (OSTI)

While unconfirmed claims of adverse human health effects from electromagnetic radiation date to the 1930s, development of modern safety standards did not begin until the 1952 Hirsch study of eye damage at a microwave power density of 100 mW/cm2. Early work on standards focused on microwave frequencies due to rapid development of radar and microwave communications links. In the years since 1952, radio frequency (RF) exposure standards have kept pace with those technological advancements. While refinements...

2004-11-01T23:59:59.000Z

387

Low Dose Radiation Research Program: Impact of Genetic Factors on the  

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

Genetic Factors on the Heritable Effects of Paternal Exposure to Genetic Factors on the Heritable Effects of Paternal Exposure to Low-Dose Radiation Janet E. Baulch University of California, Davis Why This Project? There is concern about the possible genetic effects of low dose radiation exposure. As a result, much effort has gone towards understanding mutation of cells due to radiation exposure. While recognition of the potential for mutation from exposure to ionizing radiation has led to extensive research, less effort has been given to the possible delayed risk of radiation exposure transmitted to the offspring of the exposed parent. Data from animal models show that parental exposures to DNA-damaging agents, such as ionizing radiation, predispose the offspring to serious health effects, including cancer offspring. Additionally, data from both humans and animal

388

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

389

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

390

Optical Radiation  

Science Conference Proceedings (OSTI)

*. Bookmark and Share. Optical Radiation Measurements. Fees for services are located directly below the technical contacts ...

2013-04-09T23:59:59.000Z

391

Ionizing Radiation  

Science Conference Proceedings (OSTI)

*. Bookmark and Share. Ionizing Radiation Measurements. Fees for services are located directly below the technical contacts ...

2013-04-09T23:59:59.000Z

392

METHOD AND MEANS FOR RADIATION DOSIMETRY  

DOE Patents (OSTI)

This patent relates to a method and device for determining quantities of gamma radiation and x radiation by exposing to such radiation a mature of a purified halogenated hydrocarbon chosen from the class consisting of chloroform, bromoform, tetrachloroethane and 1,1,2trichloroethane, and a minor quantity of a sensitizer chosen from the class consisting of oxygen, benzoyl peroxide, sodium peroxide, and nitrobenzene, the proportion of the sensitizer being at least about 10/sup -5/ moles per cubic centimeter of halogenated hydrocarbon, the total amount of sensitizer depending upon the range of radiation to be measured, and chemically measuring the amount of decomposition generated by the irradiation of the sensitized halogenated hydrocarbon.

Shulte, J.W.; Suttle, J.F.

1958-02-18T23:59:59.000Z

393

Oxidative Stress and Skeletal Health with Low Dose, Ionizing Radiation  

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

Oxidative Stress and Skeletal Health with Low Dose, Ionizing Radiation Oxidative Stress and Skeletal Health with Low Dose, Ionizing Radiation Globus Ruth NASA Ames Research Center Abstract Osteoporosis profoundly affects the aging U.S. population and exposure to high doses of radiation causes bone loss similar to age-related osteoporosis, although the influence of low dose radiation exposures is not known. The central hypothesis of our DOE project (NASA supplement) is that low doses of radiation modulate subsequent skeletal degeneration via oxidative pathways. Our working hypothesis is that a prior exposure to low dose radiation regulates oxidative metabolism within bone and contributes to bone loss caused either by subsequent high, challenge doses of radiation or by aging. HZE source: Because astronauts are exposed to radiation from GCR and solar

394

Medical gamma ray imaging  

DOE Patents (OSTI)

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

Osborne, Louis S. (Lexington, MA); Lanza, Richard C. (Brookline, MA)

1984-01-01T23:59:59.000Z

395

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

396

Relationship Between Chromatin Structure and Sensitivity to Molecularly Targeted Auger Electron Radiation Therapy  

Science Conference Proceedings (OSTI)

Purpose: The open structure of euchromatin renders it susceptible to DNA damage by ionizing radiation (IR) compared with compact heterochromatin. The effect of chromatin configuration on the efficacy of Auger electron radiotherapy was investigated. Methods and Materials: Chromatin structure was altered in MDA-MB-468 and 231-H2N human breast cancer cells by suberoylanilide hydroxamic acid (SAHA), 5-aza-2-deoxycytidine, or hypertonic treatment. The extent and duration of chromatin structural changes were evaluated using the micrococcal nuclease assay. DNA damage ({gamma}H2AX assay) and clonogenic survival were evaluated after exposure to {sup 111}In-DTPA-hEGF, an Auger electron-emitting radiopharmaceutical, or IR. The intracellular distribution of {sup 111}In-DTPA-hEGF after chromatin modification was investigated in cell fractionation experiments. Results: Chromatin remained condensed for up to 20 minutes after NaCl and in a relaxed state 24 hours after SAHA treatment. The number of {gamma}H2AX foci per cell was greater in MDA-MB-468 and 231-H2N cells after IR (0.5 Gy) plus SAHA (1 {mu}M) compared with IR alone (16 {+-} 0.6 and 14 {+-} 0.3 vs. 12 {+-} 0.4 and 11 {+-} 0.2, respectively). More {gamma}H2AX foci were observed in MDA-MB-468 and 231-H2N cells exposed to {sup 111}In-DTPA-hEGF (6 MBq/{mu}g) plus SAHA vs. {sup 111}In-DTPA-hEGF alone (11 {+-} 0.3 and 12 {+-} 0.7 vs. 9 {+-} 0.4 and 7 {+-} 0.3, respectively). 5-aza-2-deoxycytidine enhanced the DNA damage caused by IR and {sup 111}In-DTPA-hEGF. Clonogenic survival was reduced in MDA-MB-468 and 231-H2N cells after IR (6 Gy) plus SAHA (1 {mu}M) vs. IR alone (0.6% {+-} 0.01 and 0.3% {+-} 0.2 vs. 5.8% {+-} 0.2 and 2% {+-} 0.1, respectively) and after {sup 111}In-DTPA-hEGF plus SAHA compared to {sup 111}In-DTPA-hEGF alone (21% {+-} 0.4% and 19% {+-} 4.6 vs. 33% {+-} 2.3 and 32% {+-} 3.7). SAHA did not affect {sup 111}In-DTPA-hEGF nuclear localization. Hypertonic treatment resulted in fewer {gamma}H2AX foci per cell after IR and {sup 111}In-DTPA-hEGF compared to controls but did not significantly alter clonogenic survival. Conclusions: Chromatin structure affects DNA damage and cell survival after exposure to Auger electron radiation.

Terry, Samantha Y.A. [CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford (United Kingdom); Vallis, Katherine A., E-mail: katherine.vallis@oncology.ox.ac.uk [CR-UK/MRC Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford (United Kingdom)

2012-07-15T23:59:59.000Z

397

NREL's Concentrated Solar Radiation User Facility  

DOE Green Energy (OSTI)

Declared a national user facility in 1993, NREL's Concentrated Solar Radiation User Facility (CSR) allows industry, government, and university researchers to examine the effects and applications of as much as 50,000 suns of concentrated solar radiation using a High-Flux Solar Furnace and long-term exposure using an ultraviolet (UV) concentrator.

Lewandowski, A.

1999-09-01T23:59:59.000Z

398

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

399

About Radiation  

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

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

400

Responses of Cell Renewal Systems to Long-term Low-Level Radiation Exposure: A Feasibility Study Applying Advanced Molecular Biology Techniques on Available Histological and Cytological Material of Exposed Animals and Men  

SciTech Connect

First results of this feasibility study showed that evaluation of the stored material of the chronically irradiated dogs with modern molecular biological techniques proved to be successful and extremely promising. Therefore an in deep analysis of at least part of the huge amount of remaining material is of outmost interest. The methods applied in this feasibility study were pathological evaluation with different staining methods, protein analysis by means of immunohistochemistry, strand break analysis with the TdT-assay, DNA- and RNA-analysis as well as genomic examination by gene array. Overall more than 50% of the investigated material could be used. In particular the results of an increased stimulation of the immune system within the dogs of the 3mSv group as both compared to the control and higher dose groups gives implications for the in depth study of the cellular events occurring in context with low dose radiation. Based on the findings of this study a further evaluation and statistically analysis of more material can help to identify promising biomarkers for low dose radiation. A systematic evaluation of a correlation of dose rates and strand breaks within the dog tissue might moreover help to explain mechanisms of tolerance to IR. One central problem is that most sequences for dog specific primers are not known yet. The discovery of the dog genome is still under progress. In this study the isolation of RNA within the dog tissue was successful. But up to now there are no gene arrays or gene chips commercially available, tested and adapted for canine tissue. The uncritical use of untested genomic test systems for canine tissue seems to be ineffective at the moment, time consuming and ineffective. Next steps in the investigation of genomic changes after IR within the stored dog tissue should be limited to quantitative RT-PCR of tested primer sequences for the dog. A collaboration with institutions working in the field of the discovery of the dog genome could have synergistic effects.

Fliedner Theodor M.; Feinendegen Ludwig E.; Meineke Viktor; Fritz Thomas E.

2005-02-28T23:59:59.000Z

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

Multiwavelength Observations of the Powerful Gamma-ray Quasar PKS 1510-089: Clues on the Jet Composition  

E-Print Network (OSTI)

We present the results from a multiwavelength campaign of the powerful Gamma-ray quasar PKS 1510-089. This campaign commenced with a deep Suzaku observation lasting three days for a total exposure time of 120 ks, and continued with Swift monitoring over 18 days. Besides Swift observations, the campaign included ground-based optical and radio data, and yielded a quasi-simultaneous broad-band spectral energy distribution from 10^9 Hz to 10^{19} Hz. The Suzaku observation provided a high S/N X-ray spectrum, which is well represented by an extremely hard power-law with photon index Gamma ~ 1.2, augmented by a soft component apparent below 1 keV, which is well described by a black-body model with temperature kT ~ 0.2 keV. Monitoring by Suzaku revealed temporal variability which is different between the low and high energy bands, again suggesting the presence of a second, variable component in addition to the primary power-law emission.We model the broadband spectrum of PKS 1510-089 assuming that the high energy spectral component results from Comptonization of infrared radiation produced by hot dust located in the surrounding molecular torus. In the adopted internal shock scenario, the derived model parameters imply that the power of the jet is dominated by protons but with a number of electrons/positrons exceeding a number of protons by a factor ~10. We also find that inhomogeneities responsible for the shock formation, prior to the collision may produce bulk-Compton radiation which can explain the observed soft X-ray excess and possible excess at ~18 keV. We note, however, that the bulk-Compton interpretation is not unique, and the observed soft excess could arise as well via some other processes discussed briefly in the text.

J. Kataoka; G. Madejski; M. Sikora; P. Roming; M. M. Chester; D. Grupe; Y. Tsubuku; R. Sato; N. Kawai; G. Tosti; D. Impiombato; Y. Y. Kovalev; Y. A. Kovalev; P. G. Edwards; S. J. Wagner; R. Moderski; L. Stawarz; T. Takahashi; S. Watanabe

2007-09-11T23:59:59.000Z

402

Low Dose Radiation Research Program: About  

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

About About Background. Extensive research on the health effects of radiation using standard epidemiological and toxicological approaches has been done for decades to characterize responses of populations and individuals to high radiation doses, and to set exposure standards to protect both the public and the workforce. These standards were set using models that extrapolated from the cancers observed following exposure to high doses of radiation to predicted, but not measurable, changes in cancer frequency at low radiation doses. The use of models was necessary because of our inability to detect changes in cancer incidence following low doses of radiation. Historically, the predominant approach has been the Linear-no-Threshold model (see Wikipedia entry) and collective dose concept that assumes each unit of radiation, no

403

Neutron and gamma irradiation damage to organic materials.  

Science Conference Proceedings (OSTI)

This document discusses open literature reports which investigate the damage effects of neutron and gamma irradiation on polymers and/or epoxies - damage refers to reduced physical chemical, and electrical properties. Based on the literature, correlations are made for an SNL developed epoxy (Epon 828-1031/DDS) with an expected total fast-neutron fluence of {approx}10{sup 12} n/cm{sup 2} and a {gamma} dosage of {approx}500 Gy received over {approx}30 years at irradiation concerns for Epon 828-1031/DDS. To enhance the fidelity of our hypotheses, in regards to radiation damage, we propose future work consisting of simultaneous thermal/irradiation (neutron and gamma) experiments that will help elucidate any damage concerns at these specified environmental conditions.

White, Gregory Von, II; Bernstein, Robert

2012-04-01T23:59:59.000Z

404

Fermi GBM Observations of Terrestrial Gamma-ray Flashes  

Science Conference Proceedings (OSTI)

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

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

2011-09-21T23:59:59.000Z

405

Pulsed Photofission Delayed Gamma Ray Detection for Nuclear Material Identification  

SciTech Connect

Innovative systems with increased sensitivity and resolution are in great demand to detect diversion and to prevent misuse in support of nuclear materials management for the U.S. fuel cycle. Nuclear fission is the most important multiplicative process involved in non-destructive active interrogation. This process produces the most easily recognizable signature for nuclear materials. High-energy gamma rays can also excite a nucleus and cause fission through a process known as photofission. After photofission reactions, delayed signals are easily distinguishable from the interrogating radiation. Linac-based, advanced inspection techniques utilizing the fission signals after photofission have been extensively studied for homeland security applications. Previous research also showed that a unique delayed gamma ray energy spectrum exists for each fissionable isotope. Isotopic composition measurement methods based on delayed gamma ray spectroscopy will be the primary focus of this work.

John Kavouras; Xianfei Wen; Daren R. Norman; Dante R. Nakazawa; Haori Yang

2012-11-01T23:59:59.000Z

406

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

407

Radiation Physics Portal  

Science Conference Proceedings (OSTI)

NIST Home > Radiation Physics Portal. Radiation Physics Portal. ... more. >> see all Radiation Physics programs and projects ... ...

2013-08-08T23:59:59.000Z

408

RADIATION FROM COMOVING POYNTING FLUX ACCELERATION  

Science Conference Proceedings (OSTI)

We derive analytic formulas for the radiation power output when electrons are accelerated by a relativistic comoving kinetic Poynting flux, and validate these analytic results with particle-in-cell simulations. We also derive analytically the critical frequency of the radiation spectrum. Potential astrophysical applications of these results are discussed. A quantitative model of gamma-ray bursts based on the breakout of kinetic Poynting flux is presented.

Liang, Edison; Noguchi, Koichi [Rice University, Houston TX 77005-1892 (United States)

2009-11-10T23:59:59.000Z

409

Radiation from Comoving Poynting Flux Acceleration  

E-Print Network (OSTI)

We derive analytic formulas for the radiation power output when electrons are accelerated by a relativistic comoving kinetic Poynting flux, and validate these analytic results with Particle-In-Cell simulations. We also derive analytically the critical frequency of the radiation spectrum. Potential astrophysical applications of these results are discussed. A quantitative model of gamma-ray bursts based on the breakout of kinetic Poynting flux is presented.

Liang, Edison

2009-01-01T23:59:59.000Z

410

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

411

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,

412

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. ...

413

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

414

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

415

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

E-Print Network (OSTI)

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

Xu, Ren-Xin

416

Gamma-ray Emission from Crushed Clouds in Supernova Remnants  

E-Print Network (OSTI)

It is shown that the radio and gamma-ray emission observed from newly-found "GeV-bright" supernova remnants (SNRs) can be explained by a model, in which a shocked cloud and shock-accelerated cosmic rays (CRs) frozen in it are simultaneously compressed by the supernova blastwave as a result of formation of a radiative cloud shock. Simple reacceleration of pre-existing CRs is generally sufficient to power the observed gamma-ray emission through the decays of neutral pions produced in hadronic interactions between high-energy protons (nuclei) and gas in the compressed-cloud layer. This model provides a natural account of the observed synchrotron radiation in SNRs W51C, W44 and IC 443 with flat radio spectral index, which can be ascribed to a combination of secondary and reaccelerated electrons and positrons.

Uchiyama, Yasunobu; Funk, Stefan; Tajima, Hiroyasu; Tanaka, Takaaki

2010-01-01T23:59:59.000Z

417

Stochastic wake field particle acceleration in Gamma-Ray Bursts  

E-Print Network (OSTI)

Gamma-Ray Burst (GRB) prompt emission can, for specific conditions, be so powerful and short-pulsed to strongly influence any surrounding plasma. In this paper, we briefly discuss the possibility that a very intense initial burst of radiation produced by GRBs satisfy the intensity and temporal conditions to cause stochastic wake-field particle acceleration in a surrounding plasma of moderate density. Recent laboratory experiments clearly indicate that powerful laser beam pulses of tens of femtosecond duration hitting on target plasmas cause efficient particle acceleration and betatron radiation up to tens of MeV. We consider a simple but realistic GRB model for which particle wake-field acceleration can first be excited by a very strong low-energy precursor, and then be effective in producing the observed prompt X-ray and gamma-ray GRB emission. We also briefly discuss some of the consequences of this novel GRB emission mechanism.

G. Barbiellini; F. Longo; N. Omodei; A. Celotti; M. Tavani

2006-04-11T23:59:59.000Z

418

The effect of gamma irradiation on optical isolators. Technical report  

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. (GRA)

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

1975-09-01T23:59:59.000Z

419

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

420

Are there cosmological evolution of Gamma-Ray Bursts?  

E-Print Network (OSTI)

The variability of gamma-ray burst (GRB) is thought to be correlated with its absolute peak luminosity, and this relation had been used to derive an estimate of the redshifts of GRBs. Recently Amati et al. present the results of spectral and energetic properties of several GRBs with know redshifts. Here we analyse the properties of two group GRBs, one group with known redshift from afterglow observation, and another group with redshift derived from the luminosity- variability relation. We study the redshift dependence of various GRBs features in their cosmological rest frames, including the burst duration, the isotropic luminosity and radiated energy, and the peak energy Ep of ?F? spectra. We find that the properties of these two group GRBs are very similar, which strongly implies that the redshift derived from the luminosity-variability relation may be reliable. If this is true, then we see that the burst properties, such as their intrinsic duration, luminosity, radiated energy and peak energy Ep, are all correlated with the redshift, which means that the GRBs features are redshift dependent, i.e. there are cosmological evolution of gamma-ray bursts, and this can provide an interesting clue to the nature of GRBs. Furthermore we find that the Ep- L relation strongly supports the idea that gamma-ray burst emission comes from the internal shock. Key words: gamma rays: bursts

D. M. Wei

2008-01-01T23:59:59.000Z

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421

Remote radiation dosimetry  

DOE Patents (OSTI)

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

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

1991-01-01T23:59:59.000Z

422

Remote radiation dosimetry  

DOE Patents (OSTI)

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

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

1991-03-12T23:59:59.000Z

423

Thermal Infrared Exposure of Cryogenic Indirect Drive ICF Targets  

DOE Green Energy (OSTI)

Cryogenic inertial confinement fusion targets at the National Ignition Facility and the Laser Megajoule will be protected from thermal infrared radiation by a cold shroud. As the shroud is removed just before the laser pulse, infrared radiation will heat and possibly degrade the symmetry of the solid hydrogen fuel layer. A lumped component mathematical model has been constructed to calculate how long an indirect drive target can be exposed to thermal radiation before the fuel layer degrades. The allowed exposure time sets the maximum shroud removal time and therefore has important implications for the design of the cryogenic shroud systems. The model predicts that the maximum exposure time is approximately 0.18 s for plastic capsules inside hohlraums with transparent laser entrance holes. By covering the laser entrance holes with a partially reflective coating, the exposure time can be increased to approximately 1 s. The exposure time can be increased to about 2 s by using beryllium capsules. Several other design concepts could increase the exposure time even further. Lengthening of the allowed exposure time to 1 s or longer could allow a significant cost savings for the shroud system.

London, R A; Moody, J D; Sanchez, J J; Sater, J D; Haid, B J; Bittner, D N

2005-07-08T23:59:59.000Z

424

Radiation Cataract  

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

radiation including patients undergoing diagnostic CT scans or radiotherapy, atomic bomb survivors, residents of radioactively contaminated buildings, victims of the...

425

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

426

Low Dose Radiation Research Program: Genetic Factors Affecting  

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

Affecting Susceptibility to Low-Dose Radiation Affecting Susceptibility to Low-Dose Radiation William F. Morgan Pacific Northwest National Laboratory Why This Project The short-term effects of high doses of ionizing radiation on cellular responses are relatively well understood. Less clear are the long-term consequences of exposure to low dose/low dose-rate radiation and the effects of radiation exposure on the progeny of surviving cells. If a cell survives radiation, it is generally thought to have repaired all the radiation-induced insults and be capable of a "normal healthy life". At a certain frequency, however, we have found that some cells surviving radiation grow normally, but will rearrange their genetic material during time in culture. We call this radiation-induced genomic instability. Many

427

KINEMATIC ORIGIN OF CORRELATIONS BETWEEN GAMMA-RAY BURST OBSERVABLES  

Science Conference Proceedings (OSTI)

Recently, several new correlations between gamma-ray burst (GRB) observables have been discovered. Like previously well-established correlations, they challenge GRB models. Here, we show that in the cannonball (CB) model of GRBs, the newly discovered correlations have the same simple kinematic origin as those discovered earlier. They all result from the strong dependence of the observed radiations on the Lorentz and Doppler factors of the jet of highly relativistic plasmoids (CBs) that produces the observed radiations by interaction with the medium through which it propagates.

Dado, Shlomo; Dar, Arnon, E-mail: dado@phep3.technion.ac.il, E-mail: arnon@physics.technion.ac.il [Physics Department, Technion, Haifa 32000 (Israel)

2012-04-20T23:59:59.000Z

428

GeV Emission from Collisional Magnetized Gamma Ray Bursts  

E-Print Network (OSTI)

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

P. Mészáros; M. J. Rees

2011-04-26T23:59:59.000Z

429

Initial radiation dosimetry at Hiroshima and Nagasaki  

Science Conference Proceedings (OSTI)

The dosimetry of A-bomb survivors at Hiroshima and Nagasaki is discussed in light of the new dosimetry developed in 1980 by the author. The important changes resulting from the new dosimetry are the ratios of neutron to gamma doses, particularly at Hiroshima. The implications of these changes in terms of epidemiology and radiation protection standards are discussed. (ACR)

Loewe, W.E.

1983-09-01T23:59:59.000Z

430

High-energy gamma rays in Hiroshima and Nagasaki: Implications for risk and W{sub R}  

SciTech Connect

Based on the DS86 dosimetry system, nearly all of the dose to survivors of the atomic bombings of Hiroshima and Nagasaki was due to unusually high-energy gamma rays, predominantly in the 2- to 5-MeV range. These high energies resulted in part from neutron capture gamma rays as the bomb neutrons penetrated large distances of air. Because of the inverse re