Significance of radioelement concentration measurements made by airborne gamma-ray spectrometry over the Canadian Shield

International Nuclear Information System (INIS)

Charbonneau, B.W.; Killeen, P.G.; Carson, J.M.; Cameron, G.W.; Richardson, K.A.

1976-01-01

Results of airborne gamma-ray spectrometer surveys conducted by the Geological Survey of Canada are presented as maps contoured in units of radioelement and concentration ratios. These contoured values represent the average surface concentrations of the radioelements over areas of the order of several square kilometres. The relationship between this ''average surface concentration'' and the radioelement concentration in bedrock underlying the area depends on: (1) the percentage of outcrop; (2) the relation between overburden and bedrock radioelement concentration; (3) percentage of marshland or surface water in the area; (4) soil moisture; and (5) density of vegetation. More than 2500 portable gamma-ray spectrometer analyses of outcrop and overburden have been made in the Bancroft, Elliot Lake and Fort Smith areas of the Canadian Precambrian Shield. In the areas examined, the radioelement concentrations in glacial drift reflect the concentrations in the underlying bedrock. Rocks with near-crustal average contents of thorium, uranium and potassium are overlain by glacial drift having approximately the same concentrations. As the concentration in bedrock increases, the concentration in the local overburden also increases, but not to the same extent. In addition, in-situ gamma-ray spectrometry measurements were made at almost 1000 stations within the area of airborne surveys near Mont Laurier and Elliot Lake. These ground measurements were compared with the airborne measurements by averaging the values for all those ground stations located in the areas between each contour level on airborne maps. Radioelement concentrations in bedrock are considerably higher than corresponding airborne measurements, and this difference between bedrock and airborne values increases at higher radioelement concentrations. Radioelement concentrations in glacial drift are only slightly higher than airborne contour values for the same area. Airborne contour maps of the radioelement ratios

Airborne gamma-ray spectrometer and magnetometer survey, Mitchell Quadrangle, South Dakota. Final report

International Nuclear Information System (INIS)

1981-04-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Mitchell map area. The purpose of this program is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1479 line miles are in this quadrangle

Airborne gamma-ray spectrometer and magnetometer survey: Huron quadrangle, South Dakota. Final report

International Nuclear Information System (INIS)

1981-04-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Huron map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1459 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

Determination of data correction coefficients and the sensitivities of the KIER air-borne gamma-ray spectrometer survey system

International Nuclear Information System (INIS)

Koo, J.H.; Cho, D.H.; Park, Y.S.

1982-01-01

In air-borne gamma-ray spectrometer survey, the observed data must be corrected for the background, Compton scattering and flight altitude. And the corrected data are usually converted into the radiometric elements equivalents of the ground, using the sensitivities of the survey system. Accordingly, the correction coefficients and the sensitivities are determined as follows for the KIER air-borne survey system. The stripping or Compton scattering coefficients α, β and γ at the ground level were first determined on the basis of the gamma-ray count rates due to the 5 concrete calibration pads of the Soosaek Airbase, together with the radiometric elements concentrations of the core samples taken from the pads. As for the determination of the exponential altitude coefficients anti μ(K), anti μ(U), anti μ(Th) and anti μ(Tc), the count rates observed over the Hongseong Test Strip of about 3 km length were used after they had been corrected for the background and Compton scattering. The background count rates mainly caused by the air-craft as well as cosmic radiations were determined with the data taken over the West Sea near Anmyon Island, Chung-cheongnam-do. And the corrected count rates observed over the Strip, combined with the average radiometric elements concentrations of the Strip, yielded the sensitivities k(K), k(U) and k(Th) at the 400 feet flight altitude. (author)

Airborne gamma-ray spectrometer and magnetometer survey. Volume I. Final report

International Nuclear Information System (INIS)

An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Mariposa, California and Nevada; Fresno, California; and Bakersfield, Caifornia 1:250,000 National Topographic Map Series (NTMS) 1 0 x 2 0 quadrangle maps. The survey was a part of DOE's National Aerial Radiometric Reconnaissance (ARR) program, which in turn is a part of the National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured throughout the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. These maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

Airborne gamma-ray spectrometer and magnetometer survey: Barrow Quadrangle, Alaska. Final report. Volume I

International Nuclear Information System (INIS)

1981-03-01

During the months of July-August 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 3 0 x 1 0 and one (1) 4 0 x 1 0 NTMS quadrangles of the Alaskan North Slope. This report discusses the results obtained over the Barrow map area. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps. The histograms and the multiparameter profiles are presented with the anomaly maps and flight path map in a separate bound volume. Complete data listings of both the reduced single record and the reduced averaged record data are found in the back of this report. The format of the printout of the microfiches and the format of the data files delivered on magnetic tape are in accordance with the specifications of the BFEC 1200-C and are described in appendices F through L of this report

Airborne gamma-ray spectrometer and magnetometer survey, New Rockford Quadrangle, North Dakota. Final report

International Nuclear Information System (INIS)

1981-04-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the New Rockford map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1397 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

Remote planetary geochemical exploration with the NEAR X-ray/gamma-ray spectrometer

International Nuclear Information System (INIS)

Trombka, J.I.; Boynton, W.V.; Brueckner, J.; Squyres, S.; Clark, P.E.; Starr, R.; Evans, L.G.; Floyd, S.R.; McClanahan, T.P.; Goldsten, J.; Mcnutt, R.; Schweitzer, J.S.

1999-01-01

The X-ray/gamma-ray spectrometer (XGRS) instrument onboard the Near Earth Asteroid Rendezvous (NEAR) spacecraft will map asteroid 433 Eros in the 0.2 keV to 10 MeV energy region. Measurements of the discrete line X-ray and gamma-ray emissions in this energy domain can be used to obtain both qualitative and quantitative elemental composition maps of the asteroid surface. The NEAR X-ray/gamma-ray spectrometer (XGRS) was turned on for the first time during the week of 7 April 1996. Rendezvous with Eros 433 is expected during December 1998. Observations of solar X-ray spectra during both quiescent and active periods have been made. A gamma-ray transient detection system has been implemented and about three gamma-ray transient events a week have been observed which are associated with either gamma-ray bursts or solar flares

Airborne Gamma-ray Measurements in the Chernobyl Plume

DEFF Research Database (Denmark)

Grasty, R. L.; Hovgaard, Jens; Multala, J.

1997-01-01

On 29 April 1986, the Geological Survey of Finland (GSF) survey aircraft with a gamma ray spectrometer flew through a radioactive plume from the Chernobyl nuclear accident. The aircraft became contaminated and the gamma spectrometer measured radioactivity in the plume as well as radioactivity...

The theoretical study of full spectrum analysis method for airborne gamma-ray spectrometric data

International Nuclear Information System (INIS)

Ni Weichong

2011-01-01

Spectra of airborne gamma-ray spectrometry was found to be the synthesis of spectral components of radioelement sources by analyzing the constitution of radioactive sources for airborne gamma-ray spectrometric survey and establishing the models of gamma-ray measurement. The mathematical equation for analysising airborne gamma-ray full spectrometric data can be expressed into matrix and related expansions were developed for the mineral resources exploration, environmental radiation measurement, nuclear emergency monitoring, and so on. Theoretical study showed that the atmospheric radon could be directly computed by airborne gamma-ray spectrometric data with full spectrum analysis without the use of the accessional upward-looking detectors. (authors)

Gamma-Ray Imaging Spectrometer (GRIS): a new balloon-borne experiment for gamma-ray line astronomy

International Nuclear Information System (INIS)

Teegarden, B.J.; Cline, T.L.; Gehrels, N.; Porreca, G.; Tueller, J.; Leventhal, M.; Huters, A.F.; Maccallum, C.J.; Stang, P.D.; Sandia Labs., Albuquerque, NM)

1985-01-01

High resolution gamma-ray spectroscopy is a relatively new field that holds great promise for further understanding of high energy astrophysical processes. When the high resolution gamma-ray spectrometer (GRSE) was removed from the GRO payload, a balloon program was initiated to permit continued development and improvement of instrumentation in this field, as well as continued scientific observations. The Gamma-Ray Imaging Spectrometer (GRIS) is one of the experiments selected as part of this program. The instrument contains a number of new and innovative features that are expected to produce a significant improvement in source location accuracy and sensitivity over previous balloon and satellite experiments

Large-scale radon hazard evaluation in the Oslofjord region of Norway utilizing indoor radon concentrations, airborne gamma ray spectrometry and geological mapping

International Nuclear Information System (INIS)

Smethurst, Mark Andrew; Strand, Terje; Sundal, Aud Venke; Rudjord, Anne Liv

2008-01-01

We test whether airborne gamma ray spectrometer measurements can be used to estimate levels of radon hazard in the Oslofjord region of Norway. We compile 43,000 line kilometres of gamma ray spectrometer data from 8 airborne surveys covering 10,000 km 2 and compare them with 6326 indoor radon measurements. We find a clear spatial correlation between areas with elevated concentrations of uranium daughters in the near surface of the ground and regions with high incidence of elevated radon concentrations in dwellings. This correlation permits cautious use of the airborne data in radon hazard evaluation where direct measurements of indoor radon concentrations are few or absent. In radon hazard evaluation there is a natural synergy between the mapping of radon in indoor air, bedrock and drift geology mapping and airborne gamma ray surveying. We produce radon hazard forecast maps for the Oslofjord region based on a spatial union of hazard indicators from all four of these data sources. Indication of elevated radon hazard in any one of the data sets leads to the classification of a region as having an elevated radon hazard potential. This approach is inclusive in nature and we find that the majority of actual radon hazards lie in the assumed elevated risk regions

Airborne gamma-ray spectrometer and magnetometer survey: Peoria, Decater, Belleville Quadrangles, (IL). Final report

International Nuclear Information System (INIS)

1981-01-01

An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Peoria, Decatur, and Belleville, 1:250,000 National Topographic Map Series (NTMS), quadrangle maps. The survey was part of DOE's National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer with a large crystal volume, and with a high sensitivity proton procession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test Range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The anomalies were interpreted and an interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data collection procedures, the data processing procedures, the data presentation, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

Use of airborne gamma-ray spectrometry for kaolin exploration

Science.gov (United States)

Tourlière, B.; Perrin, J.; Le Berre, P.; Pasquet, J. F.

2003-08-01

Airborne gamma-ray spectrometry was used to define targets with kaolin potential in the Armorican Massif of Brittany, France. This exploration method is based on the principle that kaolinite, an aluminosilicate clay mineral constituting kaolin, is formed by the hydrolysis of potash feldspar with the elimination of potassium. Therefore, potassium contrast between favourable host-rock such as a leucogranite and kaolin occurrence is likely a significant pathfinder. As the relationship between the potassium-40 recorded by an airborne gamma-ray spectrometer and total potassium is constant, such data provide us a direct measurement of the potassium content of the ground flown over. Our study tested this by calculating, for each geological unit, the difference between the measured and average potassium content calculated for a given geological formation. The study was based on (i) a recent (1998) high-definition airborne geophysical survey over the Armorican Massif undertaken on behalf of the French Government, and (ii) new geological compilation maps covering the same region. Depleted zones, where the measured potassium is less than the average potassium content calculated target areas with high potential of containing kaolin, provided that the unit was originally rich in potash feldspar. By applying this method to the entire Armorican Massif, it was possible to identify 150 potassium-depleted zones, including 115 that were subjected to rapid field checks and 36 that contained kaolin (21 new discoveries). This method, which is both safe for the environment and easy to use, is therefore a good tool for rapidly defining targets with kaolin potential at a regional scale. The method may also have possibilities in exploring for other types of deposit characterised by an enrichment or depletion in U, K and/or Th.

Assessment of background gamma radiation levels using airborne gamma ray spectrometer data over uranium deposits, Cuddapah Basin, India - A comparative study of dose rates estimated by AGRS and PGRS.

Science.gov (United States)

Srinivas, D; Ramesh Babu, V; Patra, I; Tripathi, Shailesh; Ramayya, M S; Chaturvedi, A K

2017-02-01

The Atomic Minerals Directorate for Exploration and Research (AMD) has conducted high-resolution airborne gamma ray spectrometer (AGRS), magnetometer and time domain electromagnetic (TDEM) surveys for uranium exploration, along the northern margins of Cuddapah Basin. The survey area includes well known uranium deposits such as Lambapur-Peddagattu, Chitrial and Koppunuru. The AGRS data collected for uranium exploration is utilised for estimating the average absorbed rates in air due to radio-elemental (potassium in %, uranium and thorium in ppm) distribution over these known deposit areas. Further, portable gamma ray spectrometer (PGRS) was used to acquire data over two nearby locations one from Lambapur deposit, and the other from known anomalous zone and subsequently average gamma dose rates were estimated. Representative in-situ rock samples were also collected from these two areas and subjected to radio-elemental concentration analysis by gamma ray spectrometer (GRS) in the laboratory and then dose rates were estimated. Analyses of these three sets of results complement one another, thereby providing a comprehensive picture of the radiation environment over these deposits. The average absorbed area wise dose rate level is estimated to be 130 ± 47 nGy h -1 in Lambapur-Peddagattu, 186 ± 77 nGy h -1 in Chitrial and 63 ± 22 nGy h -1 in Koppunuru. The obtained average dose levels are found to be higher than the world average value of 54 nGy h -1 . The gamma absorbed dose rates in nGy h -1 were converted to annual effective dose rates in mSv y -1 as proposed by the United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR). The annual average effective dose rates for the entire surveyed area is 0.12 mSv y -1 , which is much lower than the recommended limit of 1 mSv y -1 by International Commission on Radiation protection (ICRP). It may be ascertained here that the present study establishes a reference data set (baseline) in these areas

Laboratory calibrations of airborne gamma-ray spectrometers. Measurements and discussions of important parameters

International Nuclear Information System (INIS)

Korsbech, U.

1994-02-01

This report is the fourth of reports from The Department of Electrophysics covering measurement and interpretation of airborne gamma-spectrometry measurements. It describes different topics concerning the construction of a suitable calibration setup in the laboratory. The goal is to build a simple and cheap laboratory setup that can produce most of the gamma-ray data needed for an interpretation of spectra measured 50 to 120 m above ground level. A simple calibration setup has been build and tested. It may produce gamma-ray spectra similar to those measured in the air - from surface contamination with artificial nuclides and from 'bulk' natural radioactivity. It is possible to investigate the influence of the air above an aircraft carrying the detector (skyshine: scattering of gamma photons in the air above the detector). In order to reduce the influence of non-detected pile-up the count rates are kept low without reaching levels where the background spectra (to be subtracted) would cause unacceptable counting statistical fluctuations. Sources selected for the calibrations are heavy minerals sand (with thorium and uranium), potassium nitrate (with 40 K). These sources are 'bulk sources' of natural radioactivity. Cesium-137 has been selected as the basic artifical surface contamination nuclide. The report also discusses methods for comparing two spectra a priori assumed equal. Finally the properties of some materials that could be used as 'air-substitutes' in the calibration setup have been tested with respect to stability against moisture sorption. (au)

Particle transport simulation for spaceborne, NaI gamma-ray spectrometers

International Nuclear Information System (INIS)

Dyer, C.S.; Truscott, P.R.; Sims, A.J.; Comber, C.; Hammond, N.D.A.

1988-11-01

Radioactivity induced in detectors by protons and secondary neutrons limits the sensitivity of spaceborne gamma-ray spectrometers. Three dimensional Monte Carlo transport codes have been employed to simulate particle transport of cosmic rays and inner-belt protons in various representations of the Gamma Ray Observatory Spacecraft and the Oriented Scintillation Spectrometer Experiment. Results are used to accurately quantify the contributions to the radioactive background, assess shielding options and examine the effect of detector and space-craft orientation in anisotropic trapped proton fluxes. (author)

Airborne gamma-ray spectrometer and magnetometer survey, Wainwright Quadrangle, Alaska. Final report

International Nuclear Information System (INIS)

1981-03-01

The results obtained from a gamma-ray spectrometer and magnetometer survey over the Wainwright map area of Alaska are presented. Based on the criteria outlined in the general section of interpretation, a total of seven uranium anomalies have been outlined on the interpretation map. With the exception of Anomaly 1, all are located over the higher terrain of the foothills in the southern portion of the quadrangle. All seven anomalies are only weakly to moderately anomalous. There are no indications anywhere within the area of any significant preferential accumulations of uranium. None of the anomalies are thought to be of any economic importance. No follow-up work is recommended

Radon emanation and soil moisture effects on airborne gamma-ray measurements

International Nuclear Information System (INIS)

Grasty, R.L.

1997-01-01

A theoretical model is developed to explain variations in airborne gamma-ray measurements over a calibration range near Ottawa, Ontario. The gamma-ray flux from potassium and the thorium decay series showed an expected decrease with increasing soil moisture. However, the gamma-ray flux from the uranium decay series was highest in the spring when the ground was water-saturated and even covered with snow. These results are explained through the build-up of radon and its associated gamma-ray-emitting decay products in the clay soil of the calibration range with increasing soil moisture. Similar results were found from airborne measurements over other clay soils. However, measurements over sandy soils showed that the count rates from all three radio elements increased with decreasing soil moisture. This difference between soil types was attributed to the lower radon emanation of the more coarse-grained sandy soils compared to finer-grained clay soils. The theoretical and experimental results demonstrate that any estimate of the natural gamma-ray field caused by radium in the ground must take into consideration the radon emanation coefficient of the soil. The radon diffusion coefficient of the soil must also be considered since it depends strongly on soil moisture. This has significant implications for the assessment of outdoor radiation doses using laboratory analyses of soil samples and the use of ground and airborne gamma-ray measurements for radon potential mapping

Gamma-ray imaging spectrometer (GRIS): a new balloon-borne experiment for gamma-ray line astronomy

International Nuclear Information System (INIS)

Teegarden, B.J.; Cline, T.L.; Gehrels, N.; Porreca, G.; Tueller, J.; Leventhal, M.; Huters, A.F.; MacCallum, C.J.; Stang, P.D.

1985-01-01

High resolution gamma-ray spectroscopy is a relatively new field that holds great promise for further understanding of high energy astrophysical processes. Preliminary results such as the annihilation radiation from the galactic center, the 26 Al line from the galactic plane and cyclotron lines from neutron stars may well be just the initial discoveries of a rich and as yet undeveloped field. When the high resolution gamma-ray spectrometer (GRSE) was removed from the GRO payload NASA decided to initiate a balloon program to permit continued development and improvement of instrumentation in this field, as well as continued scientific observations. The Gamma-Ray Imaging Spectrometer (GRIS) is one of the experiments selected as part of this program. The instrument contains a number of new and innovative features that are expected to produce a significant improvement in source location accuracy and sensitivity over previous balloon and satellite experiments. 6 refs., 2 figs

A gamma-ray spectrometer system for fusion applications

CERN Document Server

Esposito, B; Kaschuck, Y A; Martin-Solis, J R; Portnov, D V

2002-01-01

A NaI scintillator spectrometer system for the measurement of gamma-ray spectra in tokamak discharges has been developed and installed on the Frascati Tokamak Upgrade. Two NaI scintillators are viewing the plasma at two different angles with respect to the equatorial plane. The main features of the spectrometer system (energy range: 0.3-23 MeV) and of the unfolding technique used to restore physical spectra from the pulse-height distributions are described: a method of solution with regularisation for matrix equations of large size, allowing to process count distributions with significant statistical noise, has been developed. A dedicated software, portable to any platform, has been written both for the acquisition and the analysis of the spectra. The typical gamma-ray spectra recorded in hydrogen and deuterium discharges, also with additional heating, are presented and discussed; two components have been observed: (a) thick-target Bremsstrahlung gamma-rays produced by runaway electrons hitting the Inconel po...

Portable gamma-ray spectrometers and spectrometry systems

International Nuclear Information System (INIS)

Shebell, P.

1999-01-01

The current state-of-the-art in portable gamma-ray spectrometers and portable spectrometry systems is discussed. A comparison of detector performance and features of commercially available systems are summarised. Finally, several applications of portable systems are described. (author)

Feasibility study for an airborne high-sensitivity gamma-ray survey of Alaska. Phase II (final) report: 1976--1979 program

International Nuclear Information System (INIS)

1975-01-01

This study constitutes a determination of the extent to which it is feasible to use airborne, high-sensitivity gamma spectrometer systems for uranium reconnaissance in the State of Alaska, and specification of a preliminary plan for surveying the entire state of the 1975--1979 time frame. Phase I included the design of a program to survey the highest priority areas in 1975 using available aircraft and spectrometer equipment. This has now resulted in a contract for 10,305 flight line miles to cover about 11 of the 1:250,000 scale quadrangles using a DC-3 aircraft with an average 6.25 x 25 mile grid of flight line. Phase II includes the design of alternative programs to cover the remaining 128 quadrangles using either a DC-3 and a Bell 205A helicopter or a Helio Stallion STOL aircraft and a Bell 205A helicopter during 1976-1979. The 1976-1979 time frame allows some time for possible new system developments in both airborne gamma-ray spectrometers and in ancillary equipment, and these are outlined. (auth)

Monitoring of Natural Soil Radioactivity with Portable Gamma-Ray Spectrometers

DEFF Research Database (Denmark)

Bøtter-Jensen, Lars; Løvborg, Leif; Kirkegaard, Peter

1979-01-01

Two portable NaI(Tl) spectrometers with four energy windows were used for the recording of gamma-ray counts over soil and rock of differing natural radioactivity. The exposure rates at the field sites were simultaneously measured with a high-pressure argon ionization chamber. Background measureme......Two portable NaI(Tl) spectrometers with four energy windows were used for the recording of gamma-ray counts over soil and rock of differing natural radioactivity. The exposure rates at the field sites were simultaneously measured with a high-pressure argon ionization chamber. Background...... measurements at sea were carried out in order to estimate the non-terrestrial contributions to the instrument readings. Counts recorded in the three high-energy windows of the spectrometers were converted into radiometrically equivalent concentrations of thorium, uranium, and potassium in the ground. Large....... The theoretical exposure rates deducible from the experimental radioelement concentrations at the field sites were in good agreement both with the ionization-chamber readings (corrected for cosmic-ray background) and with the exposure rates measured by total gamma-ray counting. From this and other results...

Improved yield of high resolution mercuric iodide gamma-ray spectrometers

International Nuclear Information System (INIS)

Gerrish, V.; van den Berg, L.

1990-01-01

Mercuric iodide (HgI 2 ) exhibits properties which make it attractive for use as a solid state nuclear radiation detector. The wide bandgap (E g = 2.1 eV) and low dark current allow room temperature operation, while the high atomic number provides a large gamma-ray cross section. However, poor hole transport has been a major limitation in the routine fabrication of high-resolution spectrometers using this material. This paper presents the results of gamma-ray response and charge transport parameter measurements conducted during the past year at EG ampersand G/EM on 96 HgI 2 spectrometers. The gamma-ray response measurements reveal that detector quality is correlated with the starting material used in the crystal growth. In particular, an increased yield of high-resolution spectrometers was obtained from HgI 2 which was synthesized by precipitation from an aqueous solution, as opposed to using material from commercial vendors. Data are also presented which suggest that better spectrometer performance is tied to improved hole transport. Finally, some initial results on a study of detector uniformity reveal spatial variations which may explain why the correlation between hole transport parameters and spectrometer performance is sometimes violated. 6 refs., 3 figs

Airborne gamma-ray spectrometry and computer data processing

International Nuclear Information System (INIS)

Raghuwanshi, S.S.; Bhishma Kumar; Tewari, S.G.

1993-01-01

The physical basis for the measurement of radioelemental concentrations of U, Th, and K on the surface of the earth by airborne gamma-ray spectrometry (AGRS) are described in this paper. The yield of an infinite radioactive plane source for a particular gamma energy helps to know the sampled volume in AGRS, the ground coverage, the ground resolution, the effective planning of the survey, flight line spacing, and sampling time. The infinite source-yield enables the determination of the attenuation coefficients in actual surveys and lays down the criteria for a standard test strip. Scattering of gamma-rays in matter is discussed in order to study its influence in the measurements from air. The theoretical gamma-ray spectrum from terrestrial U, Th, and K are discussed in contrast to its realistic picture which poses problems for their direct use for measurements. The criterion of FWHM (full width at half maximum) and inter-energy distance with their yields is described which finally helps to select the energy windows for (window and MCA) AGRS system. Factors which affect the measurements of radioelemental concentration in AGRS surveys include both correctable and non-correctable ones. Correctable factors are : (a) non-terrestrial sources of gamma-rays aircraft, cosmic, and airborne background (H) (B); (b) interference due to gamma-scattering inter channel effects (l); (c) height variations (H) due to navigation and topography; (d) temperature (T) of ambient air; and (e) pressure (P) of air at flying altitude. For removal of background effects, measurements over test strip and calibration pads are necessary for making the corrections in the order - BIH. These methods are described in the paper. The non-correctable factors include effects, due to terrain moisture, vegetation, and others. The possible ways to eliminate these effects are also briefly described. (author). 17 refs., 13 figs

Airborne gamma-ray spectrometer and magnetometer survey: Lund quadrangle, Ely quadrangle, Nevada. Volume I. Final report

International Nuclear Information System (INIS)

1980-01-01

An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Ely and Lund 1:250,000 National Topographic Map Series (NTMS quadrangle maps). The survey was part of DOE's National Uranium Resource Evaluation (NURE) Aerial Radiometric Reconnaissance program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and interpretation methodology. Volume II contains the data displays for a quadrangle and the interpretation results

Airborne Gamma-Ray Survey in Latvia 1995/96

DEFF Research Database (Denmark)

Bargholz, Kim

1998-01-01

Based on Airborne Gamma-Ray Spectrometry measurements performed with the Danish AGS equipment in 1995 and 1996 maps of the natural radioactivity have been produdced for selected areas in Latvia. The calibration of the quipment have been improved by comparisons with soil sample measurements....

Dose Rate Determination from Airborne Gamma-ray Spectra

DEFF Research Database (Denmark)

Bargholz, Kim

1996-01-01

The standard method for determination of ground level dose rates from airborne gamma-ray is the integral count rate which for a constant flying altitude is assumed proportional to the dose rate. The method gives reasonably results for natural radioactivity which almost always has the same energy...

SWEPP gamma-ray spectrometer system software user's guide

International Nuclear Information System (INIS)

Femec, D.A.

1994-08-01

The SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurement and Development Unit of the Idaho National Engineering Laboratory to assist in the characterization of the radiological contents of contact-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP). In addition to determining the concentrations of gamma-ray-emitting radionuclides, the software also calculates attenuation-corrected isotopic mass ratios of specific interest, and provides controls for SGRS hardware as required. This document serves as a user's guide for the data acquisition and analysis software associated with the SGRS system

A field-deployable gamma-ray spectrometer utilizing xenon at high pressure

International Nuclear Information System (INIS)

Smith, G.C.; Mahler, G.J.; Yu, B.; Salwen, C.; Kane, W.R.; Lemley, J.R.

1996-01-01

Prototype gamma-ray spectrometers utilizing xenon gas at high pressure, suitable for applications in the nuclear safeguards, arms control, and nonproliferation communities, have been developed at Brookhaven National Laboratory (BNL). These spectrometers function as ambient-temperature ionization chambers detecting gamma rays with good efficiency in the energy range 50 keV - 2 MeV, with an energy resolution intermediate between semiconductor (Ge) and scintillation (NaI) spectrometers. They are capable of prolonged, low-power operation without a requirement for cryogenic fluids or other cooling mechanisms, and with the addition of small quantities of 3 He gas, can function simultaneously as efficient thermal neutron detectors

Airborne gamma-ray spectrometer and magnetometer survey: Norton Bay Quadrangle (Alaska). Final report

International Nuclear Information System (INIS)

1980-01-01

During the months of July, August, and September 1979, an airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten 3 0 x 1 0 NTMS quadrangles of West-Central Alaska. The results obtained over the Norton Bay Map area are discussed. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps and flight path maps. The histograms and the multiparameter are presented with the anomaly maps and flight path map in a separate volume. A total of twenty (20) uranium anomalies have been indicated on the interpretation map. No thorium anomalies were found. The uranium anomalies are all weak and generally have only U/K or U/T expression. Often the uranium concentration within the zone is low, and generally is less than 2.5 ppM. Only zones 9, with an average of 3.0 ppM eU, and 14, with 2.6 ppm have above average uranium content. Zone 14 is also the only uranium anomaly with combined U/K and U/T ratio anomalies. No single uranium anomaly is believed to represent an economic follow-up target. The most prospective area appears to be the elongate zone of generally high uranium content, formed by the deposits of the Shaktolik group, to the east of the Ungalik conglomerate. This zone flanks an elongate area of relatively strong shallow magnetic sources, interpreted to be related to a monozonitic intrusive of which the Christmas mountain forms part. This intrusive rock contains in other neighboring areas often high thorium and uranium concentrations and may here as well served as a possible source of uranium deposits

SWEPP Gamma-Ray Spectrometer System software design description

International Nuclear Information System (INIS)

Femec, D.A.; Killian, E.W.

1994-08-01

To assist in the characterization of the radiological contents of contract-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP), the SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurements and Development Unit of the Idaho National Engineering Laboratory. The SGRS system software controls turntable and detector system activities. In addition to determining the concentrations of gamma-ray-emitting radionuclides, this software also calculates attenuation-corrected isotopic mass ratios of-specific interest. This document describes the software design for the data acquisition and analysis software associated with the SGRS system

SWEPP Gamma-Ray Spectrometer System software design description

Energy Technology Data Exchange (ETDEWEB)

Femec, D.A.; Killian, E.W.

1994-08-01

To assist in the characterization of the radiological contents of contract-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP), the SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurements and Development Unit of the Idaho National Engineering Laboratory. The SGRS system software controls turntable and detector system activities. In addition to determining the concentrations of gamma-ray-emitting radionuclides, this software also calculates attenuation-corrected isotopic mass ratios of-specific interest. This document describes the software design for the data acquisition and analysis software associated with the SGRS system.

Radon potential mapping of the Tralee-Castleisland and Cavan areas (Ireland) based on airborne gamma-ray spectrometry and geology.

Science.gov (United States)

Appleton, J D; Doyle, E; Fenton, D; Organo, C

2011-06-01

The probability of homes in Ireland having high indoor radon concentrations is estimated on the basis of known in-house radon measurements averaged over 10 km × 10 km grid squares. The scope for using airborne gamma-ray spectrometer data for the Tralee-Castleisland area of county Kerry and county Cavan to predict the radon potential (RP) in two distinct areas of Ireland is evaluated in this study. Airborne data are compared statistically with in-house radon measurements in conjunction with geological and ground permeability data to establish linear regression models and produce radon potential maps. The best agreement between the percentage of dwellings exceeding the reference level (RL) for radon concentrations in Ireland (% > RL), estimated from indoor radon data, and modelled RP in the Tralee-Castleisland area is produced using models based on airborne gamma-ray spectrometry equivalent uranium (eU) and ground permeability data. Good agreement was obtained between the % > RL from indoor radon data and RP estimated from eU data in the Cavan area using terrain specific models. In both areas, RP maps derived from eU data are spatially more detailed than the published 10 km grid map. The results show the potential for using airborne radiometric data for producing RP maps.

Geological interpretation of an airborne gamma-ray spectrometer survey of the Hearne Lake area, Northwest Territories

International Nuclear Information System (INIS)

Newton, A.R.; Slaney, V.R.

1978-01-01

This study shows how large volumes of airborne data can be displayed in a simple format which provides both mapping and exploration geologists with information not easily obtained from the original data. Eleven lines or part-lines from a gamma-ray survey of the Hearne Lake area were chosen as test lines, and airphotos were used to identify outcrops of each rock type and the distribution of overburden, swamp and water along each line. Geological maps were used to locate the test lines and to provide a listing of the rock types in the area. With this information, it was possible to calculate the average radioelement characteristics of each rock type and to group the rock signatures into a number of rock classes. The techniques described are most usefully applied to those areas where the outcrop is extensive, where some form of geological map already exists, where there are airphotos at scales of 1:30,000 or larger, and where the gamma-ray survey lines are less than 2.5 km apart

Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — We utilize a new detector material, polycrystalline mercuric iodide, for background suppression by active anticoincidence shielding in gamma-ray spectrometers. Two...

Application of NASVD method in the denoising of airborne gamma-ray data

International Nuclear Information System (INIS)

Yang Jia; Ge Liangquan; Zhang Qingxian; Gu Yi

2010-01-01

A noise reducing method based on multivariate statistical analysis f or gamma-ray spectra-the NASVD method (Noise Adjusted Singular Value Decomposition), main idea and algorithm for realizing of the NASVD are introduced in the paper. The NASVD method is used to an airborne gamma-ray data set, the result has show n that the method can dramatically remove statistical noise from raw gamma-ray spectra and the quality of processed data is much better than that of the conventional spectral denoising methods. (authors)

Determination of radionuclides for river sediment CRM with HPGe gamma-ray spectrometer

International Nuclear Information System (INIS)

Tan Jinbo; Hao Runlong; Tang Zhenxin

1994-01-01

The authors described the method and results for determination of seven radionuclides: 238 U, 235 U, 226 Ra, 232 Th, 40 K, 60 Co and 137 Cs in the river sediment Certified Reference Material (CRM) using a HPGe gamma-ray spectrometer. The accuracy and reliability of measurement results were improved through varieties of techniques, which include: precise calibration of the gamma-ray spectrometer, coincidence summing correction and interference peak correction, two kinds of peak analysis methods (TPA and function fit), and utilization of as many as possible characteristic gamma-rays. Present measurement results for the seven radionuclides were in agreement with the verification results of the CRM with 1 σ or 2σ uncertainty, and its relative deviation were in the range of +1.0%--6.5%

Properties of a large NaI(Tl) spectrometer for the energy measurement of high-energy gamma rays on the Gamma Ray Observatory

International Nuclear Information System (INIS)

Hughes, E.B.; Finman, L.C.; Hofstadter, R.; Lepetich, J.E.; Lin, Y.C.; Mattox, J.R.; Nolan, P.L.; Parks, R.; Walker, A.H.

1986-01-01

A large NaI(T1) spectrometer is expected to play a crucial role in the measurement of the energy spectra from an all-sky survey of high-energy celestial gamma rays on the Gamma Ray Observatory. The crystal size and requirements of space flight have resulted in a novel crystal-packaging and optics combination. The structure of this spectrometer and the operating characteristics determined in a test program using high energy positrons are described

Reducing Statistical Noise in Airborne Gamma-Ray Data

DEFF Research Database (Denmark)

Hovgaard, Jens; Grasty, R. L.

1997-01-01

By using the Noise Adjusted Singular Value Decomposition (NASVD) technique it is possible to reconstruct the measured airborne gamma-ray spectra with a noise content that is significant smaller than the noise contained in the original measured spectra. The method can be used for improving the out...... the output of the data processing for example mapping of Th, U, and K distribution....

Elpasolite Planetary Ice and Composition Spectrometer (EPICS): A Low-Resource Combined Gamma-Ray and Neutron Spectrometer for Planetary Science

Science.gov (United States)

Stonehill, L. C.; Coupland, D. D. S.; Dallmann, N. A.; Feldman, W. C.; Mesick, K.; Nowicki, S.; Storms, S.

2017-12-01

The Elpasolite Planetary Ice and Composition Spectrometer (EPICS) is an innovative, low-resource gamma-ray and neutron spectrometer for planetary science missions, enabled by new scintillator and photodetector technologies. Neutrons and gamma rays are produced by cosmic ray interactions with planetary bodies and their subsequent interactions with the near-surface materials produce distinctive energy spectra. Measuring these spectra reveals details of the planetary near-surface composition that are not accessible through any other phenomenology. EPICS will be the first planetary science instrument to fully integrate the neutron and gamma-ray spectrometers. This integration is enabled by the elpasolite family of scintillators that offer gamma-ray spectroscopy energy resolutions as good as 3% FWHM at 662 keV, thermal neutron sensitivity, and the ability to distinguish gamma-ray and neutron signals via pulse shape differences. This new detection technology will significantly reduce size, weight, and power (SWaP) while providing similar neutron performance and improved gamma energy resolution compared to previous scintillator instruments, and the ability to monitor the cosmic-ray source term. EPICS will detect scintillation light with silicon photomultipliers rather than traditional photomultiplier tubes, offering dramatic additional SWaP reduction. EPICS is under development with Los Alamos National Laboratory internal research and development funding. Here we report on the EPICS design, provide an update on the current status of the EPICS development, and discuss the expected sensitivity and performance of EPICS in several potential missions to airless bodies.

TIGRESS: TRIUMF-ISAC gamma-ray escape-suppressed spectrometer

Science.gov (United States)

Svensson, C. E.; Amaudruz, P.; Andreoiu, C.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Boston, A. J.; Chakrawarthy, R. S.; Chen, A. A.; Churchman, R.; Drake, T. E.; Finlay, P.; Garrett, P. E.; Grinyer, G. F.; Hackman, G.; Hyland, B.; Jones, B.; Kanungo, R.; Maharaj, R.; Martin, J. P.; Morris, D.; Morton, A. C.; Pearson, C. J.; Phillips, A. A.; Ressler, J. J.; Roy, R.; Sarazin, F.; Schumaker, M. A.; Scraggs, H. C.; Smith, M. B.; Starinsky, N.; Valiente-Dobón, J. J.; Waddington, J. C.; Watters, L. M.

2005-10-01

The TRIUMF-ISAC gamma-ray escape-suppressed spectrometer (TIGRESS) is a new γ-ray detector array being developed for use at TRIUMF's Isotope Separator and Accelerator (ISAC) radioactive ion beam facility. TIGRESS will comprise 12 32-fold segmented clover-type HPGe detectors coupled with 20-fold segmented modular Compton suppression shields and custom digital signal processing electronics. This paper provides an overview of the TIGRESS project and progress in its development to date.

Spectrum analysis with indoor multi-channels gamma-rays spectrometer (NaI(Tl))

International Nuclear Information System (INIS)

Hou Shengli; Fan Weihua

2005-01-01

Two calculational methods for analyzing the spectrum which measured by indoor low background multi-channels gamma-rays spectrometer (Na(Tl)) to get the specific activity of 226 Ra, 232 Th and 40 K of the sample are discussed, they are the spectrum analysis method and the characteristic energy peak method (inverse matrix method) respectively. The sample spectrum are analyzed with the program designed according to the two methods, and compared with the results by HPGe gamma-rays spectrometer, showing that the relative deviation is ≤10% with the two methods. (authors)

Development and study of airborne spectrometer system being compatible with nuclear emergency monitoring

International Nuclear Information System (INIS)

Jiangqi, Fang; Huaiwu, Wang; Mingkao, Hu; Renkang, Gu

2002-01-01

The exploitation and use of nuclear energy are of great importance to developing of national economy and maintaining state security. But it also has a possibility of serious accident. Based on the principles of airborne gamma ray spectrometry in the uranium exploration, nuclear emergency monitoring has been developed. This method has high sensitivity to the radioactive nuclides in the air and on the ground, and with the advantage of fast measuring in large area. Hence, in the middle of 1980s, some developed countries began to survey the scope and degree of nuclear accident contamination and environmental radiation level monitoring in the surrounding nuclear facilities, it can also be used to search for the lost radioactive sources. According to the actual situation and compatible guideline, National Nuclear Emergency Office consigned this project to our Center. After development and study on the Airborne gamma ray spectrometer system associated NaI(Tl) used for the uranium exploration, a compatible spectrometer system associated NaI(Tl) was established in a short period by us, which can fulfill airborne nuclear emergency survey basically. In normal situation, it was proved that the start-up time is less than two hours including transport to the airport. The system has high sensitivity to radioactive plume of 41 Ar and can respond rapidly to artificial sources, such as 192 Ir, 60 Co, 137 Cs and 131 I etc

The dynamic range of ultra-high-resolution cryogenic gamma-ray spectrometers

Energy Technology Data Exchange (ETDEWEB)

Ali, Shafinaz [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States); Terracol, Stephane F. [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States); Drury, Owen B. [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States); Friedrich, Stephan [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States)]. E-mail: friedrich1@llnl.gov

2006-04-15

We are developing high-resolution cryogenic gamma-ray spectrometers for nuclear science and non-proliferation applications. The gamma-ray detectors are composed of a bulk superconducting Sn foil absorber attached to a multilayer Mo/Cu transition-edge sensor (TES). The energy resolution of a detector with a 1x1x0.25 mm{sup 3} Sn absorber is 50-90 eV FWHM for {gamma}-rays up to 100 keV, and it decreases for larger absorbers. Here, we present the detector performance for different absorber volumes, and discuss the trade-offs between energy resolution and dynamic range.

Minimum detectable activities for natural radionuclides for IRIS-XP airborne gamma-spectrometer

International Nuclear Information System (INIS)

Ohera, Marcel; Sladek, Petr

2009-01-01

To subtract the 90 Sr background in the helicopter (the 90 Sr source is used as a freezing deposit indicator in Mi-17 helicopters), a spectrum at the altitude of more than 500 metre altitude above the ground for 10 minutes was acquired. The spectra at 50, 100 and 150 m altitude were corrected for the aircraft and the cosmics, stripping and height attenuation in K, U and Th peak windows. For IRIS-XP, better results have been obtained than presented so far. The new calculated minimum detectable activities (MDAs) are 114 Bq/kg for 40 K, 16 Bq/kg for 238 U and 8 Bq/kg for 232 Th at 95% confidence interval for 1 second spectra at 100 m altitude. This work deals with counting statistics and the estimate of the MDAs for natural radionuclides for the IRIS-XP airborne gamma-ray spectrometer (4 x 4 litre NaI(Tl)) produced by PICO Envirotec, Inc. in Toronto, Canada. The detection sensitivities (MDA) for 4 x 4 NaI(Tl) crystals at the altitude of 90 m presented by Pico Envirotec, Inc. are too high compared with the detection sensitivities presented by other airborne gamma-ray spectrometer producers. This was the reason why to calculate and verify the MDA for IRIS-XP. Firstly, the minimum detectable activities for IRIS-XP for 4 x 4 litre NaI(Tl) crystals were determined based on the data acquired on the calibration pads at the Holland Landing Airport in Toronto, Canada to test the method of calculation used. This method on calibration pads provides all available window sensitivities, stripping factors and counts in the natural radionuclide windows to verify the computing method. Secondly, the MDAs under the real flight conditions were also estimated for the IRIS-XP (4 x 4 litre NaI(Tl) crystals) which was delivered to the Czech Armed Forces. The MDAs were calculated based on the data acquired during the tests at the Military Training Area in Vyskov, Czech Republic. The data was collected at three different altitudes (50 m, 100 m and 150 m) when the Mi-17 helicopter with IRIS

Design and applications of an anticoincidence shielded low background gamma-ray spectrometer

Energy Technology Data Exchange (ETDEWEB)

Petri, H [Forschungszentrum Juelich GmbH (Germany). Zentralabteilung fuer Chemische Analysen

1997-03-01

A low background gamma-ray spectrometer has been constructed for measuring artificial and natural radioative isotopes. The design of the spectrometer, its properties and the application to the determination of natural radioactivity of dental ceramics are described. (orig.)

Conversion of Airborne Gamma ray Spectra to Ground Level Air Kerma Rates

DEFF Research Database (Denmark)

Bargholz, Kim; Korsbech, Uffe C C

1997-01-01

A new method for relating airborne gamma-ray spectra to dose rates and kerma rates at ground level is presented. Dependent on flying altitude 50 m to 125 m the method gives correct results for gamma energies above 250 keV respective 350 keV. At lower energies the method underestimate the dose...... or kerma rates; by having a large fraction of the ground level gamma-rays at energies below 350 keV special care should be taken at an interpretation of the results....

Ultralow background germanium gamma-ray spectrometer using superclean materials and cosmic-ray anticoincidence

International Nuclear Information System (INIS)

Reeves, J.H.; Hensley, W.K.; Brodzinski, R.L.; Ryge, P.

1983-10-01

Efforts to measure the double beta decay of 76 Ge as predicted by Grand Unified Theories have resulted in the development of a high resolution germanium diode gamma-ray spectrometer with an exceptionally low background. This paper describes the development of this system and how these techniques can be utilized to significantly reduce the background in high resolution photon spectrometers at only a moderate cost

Research on 3-D terrain correction methods of airborne gamma-ray spectrometry survey

International Nuclear Information System (INIS)

Liu Yanyang; Liu Qingcheng; Zhang Zhiyong

2008-01-01

The general method of height correction is not effectual in complex terrain during the process of explaining airborne gamma-ray spectrometry data, and the 2-D terrain correction method researched in recent years is just available for correction of section measured. A new method of 3-D sector terrain correction is studied. The ground radiator is divided into many small sector radiators by the method, then the irradiation rate is calculated in certain survey distance, and the total value of all small radiate sources is regarded as the irradiation rate of the ground radiator at certain point of aero- survey, and the correction coefficients of every point are calculated which then applied to correct to airborne gamma-ray spectrometry data. The method can achieve the forward calculation, inversion calculation and terrain correction for airborne gamma-ray spectrometry survey in complex topography by dividing the ground radiator into many small sectors. Other factors are considered such as the un- saturated degree of measure scope, uneven-radiator content on ground, and so on. The results of for- ward model and an example analysis show that the 3-D terrain correction method is proper and effectual. (authors)

Comparisons between digital gamma-ray spectrometer (DSPec) and standard nuclear instrumentation methods (NIM) systems

International Nuclear Information System (INIS)

Vo, D.T.; Russo, P.A.; Sampson, T.E.

1998-03-01

Safeguards isotopic measurements require the best spectrometer systems with excellent resolution, stability and throughput. Up until about a year ago, gamma ray spectroscopy has always been done using the analog amplifier, which processes the pulses from the preamplifier to remove the noise, reject the pile up signals, and shape the signals into some desirable form before sending them to the analog to digital converter (ADC) to be digitized. In late 1996, EG and G Ortec introduced a digital gamma ray spectrometer (DSPec) which uses digital technology to analyze the preamplifiers' pulses from all types of germanium and silicon detectors. Considering its performance, digital based spectroscopy may become the way of future gamma ray spectroscopy

Tandem collimators for the JET tangential gamma-ray spectrometer

International Nuclear Information System (INIS)

Soare, Sorin; Balshaw, Nick; Blanchard, Patrick; Craciunescu, Teddy; Croft, David; Curuia, Marian; Edlington, Trevor; Kiptily, Vasily; Murari, Andrea; Prior, Phil; Sanders, Steven; Syme, Brian; Zoita, Vasile

2011-01-01

The tangential gamma-ray spectrometer (TGRS) of the JET tokamak fusion facility is an important diagnostics for investigating the fast particle evolution. A well defined field of view for the TGRS diagnostics is essential for its proper operation and this is to be determined by a rather complex system of collimators and shields both for the neutron and gamma radiations. A conceptual design for this system has been carried out with the main design target set to maximize the signal-to-background ratio at the spectrometer detector, the ratio being defined in terms of the plasma emitted gamma radiation and the gamma-ray background. As a first phase of the TGRS diagnostics upgrade a set of two tandem collimators has been designed with the aim of determining a quasi-tangential field of view through JET tokamak plasmas. A modular design of the tandem system has been developed in order to allow for the construction of different configurations for deuterium and deuterium-tritium discharges. The internal structure of the collimators consists of nuclear grade lead and high density polyethylene slabs arranged in an optimized pattern. The performance of a simplified geometry of the tandem collimator configuration has been evaluated by neutron and photon transport calculations and the numerical results show that the design parameters can be attained.

Utilizing experimentally derived multi-channel gamma-ray spectra for the analysis of airborne data

International Nuclear Information System (INIS)

Grasty, R.L.

1982-01-01

Gamma-ray spectra derived from measurements on radioactive concrete calibration pads using plywood sheets to simulate the attenuation effect of air have been successfully tested on airbone data. Cesium-137 at 662 keV, from atomic weapons tests was found to contribute significantly to the airborne spectrum. By fitting the experimental spectra, above the cesium energy, to airborne data, significant increases in accuracy were obtained for the measurement of uranium and thorium, compared to the standard 3-window method. By including a cesium spectrum is the analysis of gamma-ray data from a survey carried out in Saskatchewan, it was found that background radiation due to atmospheric bismuth-214 could be measured more reliably than by using a constant over-water background. Similar results were obtained by monitoring low energy lead-214 gamma-rays at 352 keV

Search for gamma-ray transients using the SMM spectrometer

Science.gov (United States)

Share, G. H.; Harris, M. J.; Leising, M. D.; Messina, D. C.

1993-01-01

Observations for transient radiation made by the Gamma Ray Spectrometer on the SMM satellite are summarized. Spectra were obtained from 215 solar flares and 177 gamma-ray bursts. No narrow or moderately broadened lines were observed in any of the bursts. The rate of bursts is consistent with a constant over the mission but is weakly correlated with solar activity. No evidence was found for bursts of 511 keV line emission, unaccompanied by a strong continuum, at levels not less than 0.05 gamma/sq cm s for bursts lasting not more than 16 s. No evidence was found for broad features near 1 MeV from Cyg X-1, the Galactic center, or the Crab in 12-d integrations at levels not less than 0.006 gamma/sq cm s. No evidence was found for transient celestial narrow-line emission from 300 keV to 7 MeV on min-to-hrs-long time scales from 1984 to 1989.

SWEPP gamma-ray spectrometer system software test plan and report

International Nuclear Information System (INIS)

Femec, D.A.

1994-09-01

The SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurements and Development Unit of the Idaho National Engineering Laboratory to assist in the characterization of the radiological contents of contact-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP). In addition to determining the concentrations of gamma-ray-emitting radionuclides, the software also calculates attenuation-corrected isotopic mass ratios of specific interest, and provides controls for SGRS hardware as required. This document presents the test plan and report for the data acquisition and analysis software associated with the SGRS system

The Dynamic Range of Ultra-High Resolution Cryogenic Gamma-ray Spectrometers

International Nuclear Information System (INIS)

Ali, S; Terracol, S F; Drury, O B; Friedrich, S

2005-01-01

We are developing high-resolution cryogenic gamma-ray spectrometers for nuclear science and non-proliferation applications. The gamma-ray detectors are composed of a bulk superconducting Sn foil absorber attached to multilayer Mo/Cu transition-edge sensors (TES). The energy resolution achieved with a 1 x 1 x 0.25 mm 3 Sn absorber is 50 -90eV for γ-rays up to 100 keV and it decreases for large absorber sizes. We discuss the trade-offs between energy resolution and dynamic range, as well as development of TES arrays for higher count rates and better sensitivity

Airborne gamma-ray spectrometer and magnetometer survey: Forsyth quadrangle, Round Up quadrangle, Hardin quadrangle (Montana), Sheridan quadrangle, (Wyoming). Final report

International Nuclear Information System (INIS)

1981-01-01

An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Forsyth, Hardin, and Sheridan, and Roundup, 1:250,000 National Topographic Map Series (NTMS), quadrangle maps. The survey was part of DOE's National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer with a large crystal volume, and with a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration Pads and the Lake Mead Dynamic Test Range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The anomalies were interpreted and an interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data collection procedures, the data processing procedures, the data presentation, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

Levelling Airborne and Ground Gamma-Ray Spectrometric Data to Assist Uranium Exploration

Energy Technology Data Exchange (ETDEWEB)

Matolin, M., E-mail: matolin@natur.cuni.cz [Charles University, Prague (Czech Republic); Minty, B. [Geoscience Australia, Canberra (Australia)

2014-05-15

Geophysical methods can be used for mapping in both 2 and 3 dimensions, as well as the direct detection of ore bodies. The gamma-ray spectrometric method is an efficient method for the regional assessment of uranium potential and the detection of surface mineralization. However, the full potential of the method can only be realized when the data are adequately standardized. Examples of this standardization at both regional and local scales are dealt in this paper. At a regional scale, it is shown how the levelling of airborne gamma-ray spectrometry data over Australia increases the value of the resulting data, and on a local scale a geometrical correction for ground gamma-ray spectrometry in shallow holes that improves the accuracy of measurements is introduced. (author)

Determination of altitude-dependence of standard spectra and stripping ratios for the GR820 Airborne Gamma Ray Spectrometry

International Nuclear Information System (INIS)

Heincke, Bjoern H.; Watson, Robin J.; Moeller, Thomas

2010-01-01

NGUs Airborne Gamma Ray Spectrometer system is used both for geological mapping, and for monitoring radioactive materials in the event of nuclear emergencies. Traditional methods of processing spectrometer data use channel windows around the radionuclides of interest; more advanced methods make use of the full spectra information. Such advanced methods require prior knowledge of the dependence of standard spectra with height. Height-dependent measurements have been made using concrete calibration pads, and polythene sheets to simulate the effects of altitude. The height-dependent standard spectra were determined using singular value decomposition and a global inversion scheme. Using the first two eigenimages, together with suitable scaling factors, we were able to recreate the measured height-dependent standard spectra. The height dependence of standard Th, U and K stripping ratios were also calculated from these standard spectra.(Au)

Orbital Normalization of MESSENGER Gamma-Ray Spectrometer Data

Science.gov (United States)

Rhodes, E. A.; Peplowski, P. N.; Evans, L. G.; Hamara, D. K.; Boynton, W. V.; Solomon, S. C.

2011-12-01

The MESSENGER Gamma-Ray Spectrometer (GRS) measures energy spectra of gamma rays emanating from the surface of Mercury. Analysis of these spectra provides elemental abundances of surface material. The MESSENGER mission necessarily provides some data normalization challenges for GRS analysis. So as to keep the spacecraft cool while orbiting the dayside of the planet, the orbits are highly eccentric, with altitudes varying from 200-500 km to ~ 15,000 km. A small fraction of time is spent at the low altitudes where gamma-ray signals are largest, requiring a large number of orbits to yield sufficient counting statistics for elemental analysis. Also, the sunshade must always shield the spacecraft from the Sun, which causes the orientation of the GRS often to be far from nadir-pointing, so the detector efficiency and attenuation of gamma rays from the planet must be known for a wide range of off-nadir orientations. An efficiency/attenuation map for the expected ranges of orientations and energies was constructed in a ground calibration experiment for a limited range of orientations using a nuclear reactor and radioisotope sources, and those results were extended to other orientations by radiation transport computations using as input a computer-aided design model of the spacecraft and its composition. This normalization has allowed abundance determinations of elements K, Th, and U from radioisotopes of these elements in the Mercury regolith during the first quarter of the year-long mission. These results provide constraints on models of Mercury's chemical and thermal evolution. The normalization of gamma-ray spectra for surface elements not having radioisotopes is considerably more complex; these gamma rays come from neutron inelastic-scatter and capture reactions in the regolith, where the neutrons are generated by cosmic ray impact onto the planet. A radiation transport computation was performed to generate the expected count rates in the neutron-generated gamma-ray

An efficiency study of a high resolution gamma-ray spectrometer

International Nuclear Information System (INIS)

Marti Climent, J.M.

1987-01-01

A review of the different curves for the efficiency fit of a high resolution gamma-ray spectrometer was made. These curves are used to fit the efficiency of our detector system. In order to study the goodness of the different fits various standards were used, and the ICRP GAM-83 exercise results were employed. (author)

Application of airborne gamma-ray spectrometry in soil/regolith mapping and applied geomorphology

International Nuclear Information System (INIS)

Wilford, J.R.; Bierwirth, P.N.; Craig, M.A.

1997-01-01

Gamma-ray spectrometric surveys are an important source of information for soil, regolith and geomorphological studies, as demonstrated by the interpretation of airborne surveys in Western Australia, central New South Wales and north Queensland. Gamma-rays emitted from the ground surface relate to the primary mineralogy and geochemistry of the bedrock, and the secondary weathered materials. Weathering modifies the distribution and concentration of radioelements from the original bedrock source. Once the radioelement response of bedrock and weathered materials is understood, the gamma-ray data can provide information on geomorphic processes and soil/regolith properties, including their mineralogy, texture, chemistry and style of weathering. This information can contribute significantly to an understanding of the weathering and geomorphic history of a region and, therefore, has the potential to be used in developing more effective land-management strategies and refining geochemical models in support of mineral exploration. Gamma-ray imagery is enhanced when combined with Landsat TM bands and digital elevation models (DEM). This synergy enables geochemical information derived from the gamma-ray data to be interpreted within a geomorphic framework. Draping gamma-ray images over DEMs as 3D landscape perspective views aids interpretation and allows the interpreter to visualise complex relationships between the gamma-ray response and landform features. 44 refs.,1 tab., 11 figs

Characteristics of bursts observed by the SMM Gamma-Ray Spectrometer

Science.gov (United States)

Share, G. H.; Messina, D. C.; Iadicicco, A.; Matz, S. M.; Rieger, E.; Forrest, D. J.

1992-01-01

The Gamma Ray Spectrometer (GRS) on the SMM completed close to 10 years of highly successful operation when the spacecraft reentered the atmosphere on December 2, 1989. During this period the GRS detected 177 events above 300 keV which have been classified as cosmic gamma-ray bursts. A catalog of these events is in preparation which will include time profiles and spectra for all events. Visual inspection of the spectra indicates that emission typically extends into the MeV range, without any evidence for a high-energy cutoff; 17 of these events are also observed above 10 MeV. We find no convincing evidence for line-like emission features in any of the time-integrated spectra.

Thermal neutron detector and gamma-ray spectrometer utilizing a single material

Science.gov (United States)

Stowe, Ashley; Burger, Arnold; Lukosi, Eric

2017-05-02

A combined thermal neutron detector and gamma-ray spectrometer system, including: a detection medium including a lithium chalcopyrite crystal operable for detecting thermal neutrons in a semiconductor mode and gamma-rays in a scintillator mode; and a photodetector coupled to the detection medium also operable for detecting the gamma rays. Optionally, the detection medium includes a .sup.6LiInSe.sub.2 crystal. Optionally, the detection medium comprises a compound formed by the process of: melting a Group III element; adding a Group I element to the melted Group III element at a rate that allows the Group I and Group III elements to react thereby providing a single phase I-III compound; and adding a Group VI element to the single phase I-III compound and heating; wherein the Group I element includes lithium.

Imaging of gamma rays with the WINKLER high-resolution germanium spectrometer

Energy Technology Data Exchange (ETDEWEB)

Fisher, T.R.; Hamilton, T.W.; Hawley, J.D.; Kilner, J.R.; Murphy, M.J.; Nakano, G.H. (Luckheed Palo Alto Research Lab., Palo Alto, CA (US))

1990-06-01

The WINKLER spectrometer is a matrix of nine high-purity {ital n}-type germanium detectors developed for astrophysical observations and terrestrial radiation monitoring. The spectrometer has been fitted with a set of modulation collimator grids designed for imaging hard x-ray and gamma-ray sources by the Mertz, Nakano, and Kilner method. This technique employs a pair of gridded collimators in front of each detector with the number of grid bars varying from one to {ital N}, where {ital N} is the number of detectors. When the collimator pairs are rotated through a full 360-degree angular range, the detector signals provide the information for a two-dimensional band-limited Fourier reconstruction of order {ital N}. Tests of the spectrometer with single and multiple point sources as well as continuous source distributions are reported.

Instrumental and atmospheric background lines observed by the SMM gamma-ray spectrometer

Science.gov (United States)

Share, G. H.; Kinzer, R. L.; Strickman, M. S.; Letaw, J. R.; Chupp, E. L.

1989-01-01

Preliminary identifications of instrumental and atmospheric background lines detected by the gamma-ray spectrometer on NASA's Solar Maximum Mission satellite (SMM) are presented. The long-term and stable operation of this experiment has provided data of high quality for use in this analysis. Methods are described for identifying radioactive isotopes which use their different decay times. Temporal evolution of the features are revealed by spectral comparisons, subtractions, and fits. An understanding of these temporal variations has enabled the data to be used for detecting celestial gamma-ray sources.

Study on direct determination of uranium and efficient equilibrium factor by gamma-ray spectrometer

International Nuclear Information System (INIS)

Liu Chunkui

1990-01-01

The test principle, test set and surveying methods for conducting gamma-ray spectrometry on conveyer are presented. The conversion coefficient of the spectrometer has been found by using duallinear regression analysis of uranium and radon and their higher and lower bands of gamma-ray spectra. The efficient equilibrium factor can be quickly determined, and the direct determination of uranium in the non-equilibrium condition of uranium and radium can be made

Handbook on Mobile Gamma-ray Spectrometry

DEFF Research Database (Denmark)

Aage, Helle Karina; Korsbech, Uffe C C

2003-01-01

Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing......Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing...

A gamma scintillation spectrometer

Energy Technology Data Exchange (ETDEWEB)

Symbalisty, S

1952-07-01

A scintillation type gamma ray spectrometer employing coincidence counting, designed and built at the Physics Department of the University of Western Ontario is described. The spectrometer is composed of two anthracene and photomultiplier radiation detectors, two pulse analyzing channels, a coincidence stage, three scalers and a high voltage stabilized supply. A preliminary experiment to test the operation of the spectrometer was performed and the results of this test are presented. (author)

Multichannel CdZnTe Gamma Ray Spectrometer

International Nuclear Information System (INIS)

Doty, F.P.; Lingren, C. L.; Apotovsky, B. A.; Brunsch, J.; Butler, J. F.; Collins, T.; Conwell, R.L.; Friesenhahn, S.; Gormley, J.; Pi, B.; Zhao, S.; Augustine, F.L.; Bennet, B. A.; Cross, E.; James, R. B.

1998-01-01

A 3 cm 3 multichannel gamma spectrometer for DOE applications is under development by Digirad Corporation. The device is based on a position sensitive detector packaged in a compact multi-chip module (MCM) with integrated readout circuitry. The modular, multichannel design will enable identification and quantitative analysis of radionuclides in extended sources, or sources containing low levels of activity. The MCM approach has the advantages that the modules are designed for imaging applications, and the sensitivity can be arbitrarily increased by increasing the number of pixels, i.e. adding modules to the instrument. For a high sensitivity probe, the outputs for each pixel can be corrected for gain and offset variations, and summed digitally. Single pixel results obtained with discrete low noise readout indicate energy resolution of 3 keV can be approached with currently available CdZnTe. The energy resolution demonstrated to date with MCMs for 511 keV gamma rays is 10 keV

Pocket PC-based portable gamma-ray spectrometer

Directory of Open Access Journals (Sweden)

Kamontip Ploykrachang

2011-04-01

Full Text Available A portable gamma-ray spectrometer based on a Pocket PC has been developed. A 12-bit pipeline analog-to-digitalconverter (ADC associated with an implemented pulse height histogram function on field programmable gate array (FPGAoperating at 15 MHz is employed for pulse height analysis from built-in pulse amplifier. The system, which interfaces withthe Pocket PC via an enhanced RS-232 serial port under the microcontroller facilitation, is utilized for spectrum acquisition,display and analysis. The pulse height analysis capability of the system was tested and it was found that the ADC integralnonlinearity of ±0.45% was obtained with the throughput rate at 160 kcps. The overall system performance was tested usinga PIN photodiode-CsI(Tl crystal coupled scintillation detector and gamma standard radioactive sources of Cs-137 andCo-60. Low cost and the compact system size as a result of the implemented logical function are also discussed.

Calibration of Ge gamma-ray spectrometers for complex sample geometries and matrices

Energy Technology Data Exchange (ETDEWEB)

Semkow, T.M., E-mail: thomas.semkow@health.ny.gov [Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY 12201 (United States); Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Rensselaer, NY 12144 (United States); Bradt, C.J.; Beach, S.E.; Haines, D.K.; Khan, A.J.; Bari, A.; Torres, M.A.; Marrantino, J.C.; Syed, U.-F. [Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY 12201 (United States); Kitto, M.E. [Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY 12201 (United States); Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Rensselaer, NY 12144 (United States); Hoffman, T.J. [Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY 12201 (United States); Curtis, P. [Kiltel Systems, Inc., Clyde Hill, WA 98004 (United States)

2015-11-01

A comprehensive study of the efficiency calibration and calibration verification of Ge gamma-ray spectrometers was performed using semi-empirical, computational Monte-Carlo (MC), and transfer methods. The aim of this study was to evaluate the accuracy of the quantification of gamma-emitting radionuclides in complex matrices normally encountered in environmental and food samples. A wide range of gamma energies from 59.5 to 1836.0 keV and geometries from a 10-mL jar to 1.4-L Marinelli beaker were studied on four Ge spectrometers with the relative efficiencies between 102% and 140%. Density and coincidence summing corrections were applied. Innovative techniques were developed for the preparation of artificial complex matrices from materials such as acidified water, polystyrene, ethanol, sugar, and sand, resulting in the densities ranging from 0.3655 to 2.164 g cm{sup −3}. They were spiked with gamma activity traceable to international standards and used for calibration verifications. A quantitative method of tuning MC calculations to experiment was developed based on a multidimensional chi-square paraboloid. - Highlights: • Preparation and spiking of traceable complex matrices in extended geometries. • Calibration of Ge gamma spectrometers for complex matrices. • Verification of gamma calibrations. • Comparison of semi-empirical, computational Monte Carlo, and transfer methods of Ge calibration. • Tuning of Monte Carlo calculations using a multidimensional paraboloid.

Calibration of Ge gamma-ray spectrometers for complex sample geometries and matrices

International Nuclear Information System (INIS)

Semkow, T.M.; Bradt, C.J.; Beach, S.E.; Haines, D.K.; Khan, A.J.; Bari, A.; Torres, M.A.; Marrantino, J.C.; Syed, U.-F.; Kitto, M.E.; Hoffman, T.J.; Curtis, P.

2015-01-01

A comprehensive study of the efficiency calibration and calibration verification of Ge gamma-ray spectrometers was performed using semi-empirical, computational Monte-Carlo (MC), and transfer methods. The aim of this study was to evaluate the accuracy of the quantification of gamma-emitting radionuclides in complex matrices normally encountered in environmental and food samples. A wide range of gamma energies from 59.5 to 1836.0 keV and geometries from a 10-mL jar to 1.4-L Marinelli beaker were studied on four Ge spectrometers with the relative efficiencies between 102% and 140%. Density and coincidence summing corrections were applied. Innovative techniques were developed for the preparation of artificial complex matrices from materials such as acidified water, polystyrene, ethanol, sugar, and sand, resulting in the densities ranging from 0.3655 to 2.164 g cm −3 . They were spiked with gamma activity traceable to international standards and used for calibration verifications. A quantitative method of tuning MC calculations to experiment was developed based on a multidimensional chi-square paraboloid. - Highlights: • Preparation and spiking of traceable complex matrices in extended geometries. • Calibration of Ge gamma spectrometers for complex matrices. • Verification of gamma calibrations. • Comparison of semi-empirical, computational Monte Carlo, and transfer methods of Ge calibration. • Tuning of Monte Carlo calculations using a multidimensional paraboloid

Horizontal Ampoule Growth and Characterization of Mercuric Iodide at Controlled Gas Pressures for X-Ray and Gamma Ray Spectrometers

International Nuclear Information System (INIS)

Douglas, S.; McGregor Elsa; Ariesanti Bridget Corcoran

2004-01-01

The project developed a new method for producing high quality mercuric iodide crystals of x-ray and gamma spectrometers. Included are characterization of mercuric iodide crystal properties as a function of growth environment and fabrication and demonstration of room-temperature-operated high-resolution mercuric iodide spectrometers

Airborne gamma-ray spectrometer and magnetometer survey: Crescent Quadrangle, Burns Quadrangle, Canyon City Quadrangle, Bend Quadrangle, Salem Quadrangle (Oregon). Final report

International Nuclear Information System (INIS)

1981-01-01

An airborne combining radiometric and magnetic survey was performed for the Department of Energy over the area covered by the Burns, Crescent, Canyon City, Bend, and Salem, Washington 1:250,000 National Topographic Map Series, 1 0 x 2 0 quadrangle maps. The survey was a part of DOE's National Aerial Radiometric Reconnaissance program, which is in turn a part of the National Uranium Resource Evaluation program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured throughout the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. These maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

Time series data correction for the Chang'E-1 gamma-ray spectrometer

Institute of Scientific and Technical Information of China (English)

Li-Yan Zhang; Yong-Liao Zou; Jian-Zhong Liu; Jian-Jun Liu; Ji Shen; Ling-Li Mu; Xin Ren; Wei-Bin Wen; Chun-Lai Li

2011-01-01

The main goal of the gamma-ray spectrometer (GRS) onboard Chang'E-l (CE-1) is to acquire global maps of elemental abundances and their distributions on the moon, since such maps will significantly improve our understanding of lunar formation and evolution. To derive the elemental maps and enable research on lunar formation and evolution, raw data that are received directly from the spacecraft must be converted into time series corrected gamma-ray spectra. The data correction procedures for the CE-1 GRS time series data are thoroughly described. The processing procedures to create the time series gamma-ray spectra described here include channel processing, optimal data selection, energy calibration, gain correction, dead time correction, geometric correction, orbit altitude normalization, eliminating unusable data and galactic cosmic ray correction. Finally, descriptions are also given on data measurement uncertainties, which will help the interested scientists to understand and estimate various uncertainties associated with the above data processing.

Time series data correction for the Chang'E-1 gamma-ray spectrometer

International Nuclear Information System (INIS)

Zhang Liyan; Zou Yongliao; Liu Jianzhong; Liu Jianjun; Shen Ji; Mu Lingli; Ren Xin; Wen Weibin; Li Chunlai

2011-01-01

The main goal of the gamma-ray spectrometer (GRS) onboard Chang'E-1 (CE-1) is to acquire global maps of elemental abundances and their distributions on the moon, since such maps will significantly improve our understanding of lunar formation and evolution. To derive the elemental maps and enable research on lunar formation and evolution, raw data that are received directly from the spacecraft must be converted into time series corrected gamma-ray spectra. The data correction procedures for the CE-1 GRS time series data are thoroughly described. The processing procedures to create the time series gamma-ray spectra described here include channel processing, optimal data selection, energy calibration, gain correction, dead time correction, geometric correction, orbit altitude normalization, eliminating unusable data and galactic cosmic ray correction. Finally, descriptions are also given on data measurement uncertainties, which will help the interested scientists to understand and estimate various uncertainties associated with the above data processing. (research papers)

MESSENGER E/V/H GRNS 2 GAMMA RAY SPECTROMETER RAW DATA V1.0

Data.gov (United States)

National Aeronautics and Space Administration — Abstract ======== This data set consists of the MESSENGER GRS uncalibrated observations, also known as EDRs. The GRS experiment is a gamma ray spectrometer designed...

Airborne gamma-ray survey around the Negoro fault. 1; Negoro danso shuhen chiiki ni okeru kuchu {gamma} sen tansa. 1

Energy Technology Data Exchange (ETDEWEB)

Nakayama, E.; Kasuya, Y.; Hasegawa, H. [Aero Asahi Corp., Tokyo (Japan); Tsukuda, E. [Geological Survey of Japan, Tsukuba (Japan)

1997-05-27

An airborne gamma-ray survey was carried out to investigate the active fault system in the central structure line in the peripheral area of the city of Wakayama. At the same time, with an objective to enhance applicability of the airborne gamma-ray survey to active fault investigation, fundamental data were acquired and discussed. The measurement data were processed according to the standard method specified by IAEA. An ID-FFT filter and a nonlinear filter were employed to extract anomalous gamma-ray intensity values. The gamma-ray intensity distribution chart shows a noticeable positive anomalous area extending from the central part of the western edge to the north-east direction. This area agrees nearly well with the Negoro fault, but its peak portion is positioned slightly more to south than the position of the Negoro fault shown in existing data. The Sakuraike fault and the vicinity of the central structure line also show positive anomaly as a whole, particularly remarkably in the vicinity of their converging portion. However, differing from the vicinity of the Negoro fault, the areas are not extracted as an anomalous area which has directionality and extends in a line form. One of the factors for this would be that it is a fault in unsolidified deposits with low opening trend, differing from the one in solidified rocks. 1 fig., 3 tabs.

Characterization of leveling problems of Patagonia gamma-ray spectrometry survey, Chubut province (Argentina)

International Nuclear Information System (INIS)

Ford, Kenneth L.; Lopez, Luis E.

1998-01-01

Measuring the radioelement concentrations of the soils along traverses perpendicular to the flight line direction was performed in order to gather useful information in support of the leveling of the airborne gamma-ray spectrometer survey of Patagonia. Two sites were selected as test areas which ground and airborne spectrometric data were systematically compared to asses the nature of the leveling problems. It is suspected that variations in soil moisture may play a significant roll in the leveling variations. (author)

Airborne gamma-ray spectrometry data processing using 1.5D inversion.

Science.gov (United States)

Druker, Eugene

2017-10-01

Standard processing of Airborne Gamma-Ray Spectrometry data generally gives good results when the measurement conditions are almost constant within several footprint area sizes, with the possible exception of flight height variations in a small range. In practice, deviations, such as large or abrupt changes of flight height and/or rugged terrain are not so rare and lead to certain problems. This article proposes a different approach where the solutions of inverse problems are used for data processing. The approach is quite natural in the processing of field data measured along the flight lines: it explicitly takes into account 1.5D survey models and flight parameters - from topography to sources distribution on the surface. Also, it clearly demonstrates that the inverse problem of the Airborne Gamma-Ray Spectrometry does not have a unique solution. This feature can be used in accordance with the underlying geological problem since various formulations of inverse problems can lead to various geological solutions. The use of the approach is illustrated by several examples given for flight lines and survey areas. This approach can be particularly useful in situations where geological, geophysical and/or geographic survey conditions are far from the standard assumptions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gamma-to-electron magnetic spectrometer (GEMS): An energy-resolved {gamma}-ray diagnostic for the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Kim, Y.; Herrmann, H. W.; Mack, J. M.; Young, C. S.; Barlow, D. B.; Schillig, J. B.; Sims, J. R. Jr.; Lopez, F. E.; Mares, D.; Oertel, J. A.; Hayes-Sterbenz, A. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Hilsabeck, T. J.; Wu, W. [General Atomics, PO Box 85608, San Diego, California 92186 (United States); Moy, K. [National Security Technologies, Special Technologies Laboratory, Santa Barbara, California 93111 (United States); Stoeffl, W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2012-10-15

The gamma-to-electron magnetic spectrometer, having better than 5% energy resolution, is proposed to resolve {gamma}-rays in the range of E{sub o}{+-} 20% in single shot, where E{sub o} is the central energy and is tunable from 2 to 25 MeV. Gamma-rays from inertial confinement fusion implosions interact with a thin Compton converter (e.g., beryllium) located at approximately 300 cm from the target chamber center (TCC). Scattered electrons out of the Compton converter enter an electromagnet placed outside the NIF chamber (approximately 600 cm from TCC) where energy selection takes place. The electromagnet provides tunable E{sub o} over a broad range in a compact manner. Energy resolved electrons are measured by an array of quartz Cherenkov converters coupled to photomultipliers. Given 100 detectable electrons in the energy bins of interest, 3 Multiplication-Sign 10{sup 14} minimum deuterium/tritium (DT) neutrons will be required to measure the 4.44 MeV {sup 12}C {gamma}-rays assuming 200 mg/cm{sup 2} plastic ablator areal density and 3 Multiplication-Sign 10{sup 15} minimum DT neutrons to measure the 16.75 MeV DT {gamma}-ray line.

Using airborne GAMMA-ray spectrometry (uranium, thorium, potassium) to quantify weathering and erosion processes

International Nuclear Information System (INIS)

Carrier, F.

2005-01-01

The airborne gamma-ray spectrometry survey carried out on the Armorican Massif provided soil contents in U, Th and K in ppm. Chemical and mechanical erosion processes within a homogeneous geological unit have been estimated using their variations and those of the 137 Cs. Our new approach, based on a multivariate analysis (hierarchic ascending classification), integrates the airborne gamma-ray spectrometry data, with their broad spatial distribution, together with precisely located station data (major elements, traces and isotopic geochemistry) resulting from a soil and river water erosion products survey. The total export of potassium was estimated in any point of an area catchment (50-m resolution) until 17+2 t/km 2 /a for a 50-m thick weathering profile. Erosion study by river sampling provide important biases, for the perennial river does not integrate the whole range of erosion products: the geochemical signature of the valleys is currently more represented than plateau areas. (author)

A carborne gamma-ray spectrometer system for natural radioactivity mapping and environmental monitoring

International Nuclear Information System (INIS)

Grasty, R.L.; Cox, J.R.

1997-01-01

This paper summarizes the experience gained in the use of a carborne gamma-ray spectrometer system for mapping both natural and man-made radiation. Particular emphasis is placed on the calibration of the system for converting the gamma-ray measurements to ground concentrations of potassium, uranium and thorium and the activity of 137 Cs. During the Finnish Emergency Response Exercise (Resume95), the carborne system was shown to be effective in mapping both natural and man-made radiation from 137 Cs fallout and in locating radioactive sources. The application of the carborne system for mineral exploration is also demonstrated. (au)

An airborne gamma ray snow survey of a forest covered area with a deep snowpack

International Nuclear Information System (INIS)

Glynn, J.E.; Carroll, T.R.; Holman, P.B.; Grasty, R.L.

1988-01-01

Problems arising from the airborne gamma ray measurement of snow water equivalent over a forest covered deep snowpack are examined. The principal sources of error are believed to be due to the radioactivity in the biomass and to variability in the snow cover. A theoretical model is developed to correct the airborne measurements for these sources of error. The application of the theory to data collected over the St. John River Basin, located in the eastern part of Canada and the United States, is found to significantly improve the airborne results

Reset charge sensitive amplifier for NaI(Tl) gamma-ray spectrometer

International Nuclear Information System (INIS)

Zeng, Guoqiang; Tan, Chengjun; Li, Qiang; Ge, Liangquan; Liu, Xiyao; Luo, Qun

2015-01-01

The time constant of the output signal of the front-end readout circuit of a traditional gamma-ray spectrometer with a NaI(Tl)+PMT structure is affected by temperature, measurement environment and the signal transmission cable, so it is difficult to get a good resolution spectrum, especially at higher counting rates. In this paper, a reset charge sensitive amplifier (RCSA) is designed for the gamma-ray spectrometer with a NaI(Tl)+PMT structure. The designed RCSA outputs a step signal, thus enabling the acquisition of double-exponential signals with a stable time constant by using the next stage of a CR differentiating circuit. The designed RCSA is mainly composed of a basic amplifying circuit, a reset circuit and a dark current compensation circuit. It provides the output step signal through the integration of the PMT output charge signal. When the amplitude of the step signal exceeds a preset voltage threshold, it triggers the reset circuit to generate a reset pulse (about 5 µs pulse width) to reset the output signal. Experimental results demonstrated that the designed RCSA achieves a charge sensitivity of 4.26×10 10 V/C, with a zero capacitance noise of 51.09 fC and a noise slope of 1.98 fC/pF. Supported by the digital shaping algorithm of the digital multi-channel analyzer (DMCA), it can maintain good energy resolution with high counting rates up to 150 kcps and with a temperature range from −19 °C to 50 °C. - Highlights: • A new reset type charge sensitive amplifier for gamma-ray spectrometer based on a photomultiplier tube is proposed. • Reset circuit formed by constant current source output a fixed width pulse to reset charge sensitive amplifier. • Photomultiplier tube dark current compensation circuit could increase the pulse through rate by decreasing reset frequency. • This amplifier outputs a step function signal that could match next stage circuit easily

Gamma-Ray Imaging Spectrometer (GRIS) instrument and plans for serving SN 1987A

International Nuclear Information System (INIS)

Tueller, J.; Barthelmy, S.; Gehrels, N.; Teegarden, B.J.; Leventhal, M.; MacCallum, C.J.

1988-01-01

The Gamma-Ray Imaging Spectrometer (GRIS) is a powerful second-generation high-resolution gamma-ray spectrometer. It consists of an array of seven large (typically >200 cm 3 ) n-type Germanium detectors surrounded by a thick (15 m) NaI active shield. Its energy range is 0.02 to 10 MeV. A new detector segmentation technique will be employed to reduce the detector background. The β-decay background component, which is expected to be dominant in the 0.2--2 MeV range, will be suppressed by roughly a factor of 20. The 3σ GRIS sensitivity to a narrow Fe line at 847 keV (expected to be the most intense from a supernova) will be ∼2 x 10 -4 photons/cm 2 -s for an 8 hr observation of the LMC over Alice Springs, Australia with unsegmented detectors. The instrument in simplified form will be ready to observe SN 1987A in early 1988

A high resolution gamma-ray spectrometer based on superconducting microcalorimeters

Energy Technology Data Exchange (ETDEWEB)

Bennett, D. A.; Horansky, R. D. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); University of Denver, Denver, Colorado 80208 (United States); Schmidt, D. R.; Doriese, W. B.; Fowler, J. W.; Kotsubo, V.; Mates, J. A. B. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); University of Colorado, Boulder, Colorado 80309 (United States); Hoover, A. S.; Winkler, R.; Rabin, M. W. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Alpert, B. K.; Beall, J. A.; Fitzgerald, C. P.; Hilton, G. C.; Irwin, K. D.; O' Neil, G. C.; Reintsema, C. D.; Schima, F. J.; Swetz, D. S.; Vale, L. R. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); and others

2012-09-15

Improvements in superconductor device fabrication, detector hybridization techniques, and superconducting quantum interference device readout have made square-centimeter-sized arrays of gamma-ray microcalorimeters, based on transition-edge sensors (TESs), possible. At these collecting areas, gamma microcalorimeters can utilize their unprecedented energy resolution to perform spectroscopy in a number of applications that are limited by closely-spaced spectral peaks, for example, the nondestructive analysis of nuclear materials. We have built a 256 pixel spectrometer with an average full-width-at-half-maximum energy resolution of 53 eV at 97 keV, a useable dynamic range above 400 keV, and a collecting area of 5 cm{sup 2}. We have demonstrated multiplexed readout of the full 256 pixel array with 236 of the pixels (91%) giving spectroscopic data. This is the largest multiplexed array of TES microcalorimeters to date. This paper will review the spectrometer, highlighting the instrument design, detector fabrication, readout, operation of the instrument, and data processing. Further, we describe the characterization and performance of the newest 256 pixel array.

A mobile gamma ray spectrometer system for nuclear hazard mapping

CERN Document Server

Smethurst, M A

2000-01-01

The Geological Survey of Norway has developed a system for mobile gamma ray spectrometer surveying suitable for use in nuclear emergencies where potentially dangerous radioactive materials have been released into the environment. The measuring system has been designed for use with different kinds of transportation platforms. These include fixed-wing aircraft, helicopters and vans. The choice of transportation platform depends on the nature of the nuclear emergency. Widespread fallout from a distant source can be mapped quickly from the air while local sources of radiation can be delineated by a car-borne system. The measuring system processes gamma ray spectra in real time. The operator of the system is therefore able to guide surveying in accordance with meaningful data values and immediately report these values to decision making The operator is presented with a number of different displays suited to different kinds of nuclear emergencies that lead to more efficient surveying. Real time processing of data m...

Manual for the application of NURE 1974--1977 aerial gamma-ray spectrometer data

International Nuclear Information System (INIS)

Saunders, D.F.; Potts, M.J.

1977-09-01

This manual was prepared as an aid to those interested in the interpretation and application of high-sensitivity aerial gamma-ray spectrometer data in uranium exploration. Particular emphasis is on the first 10 radiometric surveys performed under the National Uranium Resource Evaluation (NURE) program. The primary purpose of aerial gamma-ray spectrometer surveys in the NURE program is to map regional distributions of near-surface natural radioelements, i.e., the uranium and thorium decay series, and potassium-40. These data along with an understanding of the geochemical behavior of the pertinent isotopes under a variety of conditions allow uranium-enriched areas of the earth's crust (uraniferous provinces) to be identified as part of the regional appraisal phase of prospecting. Uranium ore deposits tend to occur more frequently in these generally enriched regions than elsewhere, and, consequently, uraniferous provinces constitute preferred territory for follow-up exploration methods such as detailed aerial or surface radiometric prospecting, geological studies, etc., to define potential prospects. These in turn may be investigated by still more detailed surface geological studies perhaps supplemented by radon or uranium geochemical surveys and exploration drilling and logging. This manual outlines the fundamentals of uranium geology and geochemistry along with interpretive approaches which may be used to identify statistically and geochemically significant uranium anomalies and uraniferous provinces. Follow-up prospecting methods are summarized along with guides to recent literature. Specific suggestions are made as to interpretive approaches and applicable follow-up prospecting procedures tailored to fit the data characteristics and general environment of each of the first 10 NURE aerial gamma-ray spectrometer surveys performed by Geodata International, Inc. and Texas Instruments Incorporated

A carborne gamma-ray spectrometer system for natural radioactivity mapping and environmental monitoring

Energy Technology Data Exchange (ETDEWEB)

Grasty, R.L.; Cox, J.R. [Exploranium Ltd., Mississauga, Ontario (Canada)

1997-12-31

This paper summarizes the experience gained in the use of a carborne gamma-ray spectrometer system for mapping both natural and man-made radiation. Particular emphasis is placed on the calibration of the system for converting the gamma-ray measurements to ground concentrations of potassium, uranium and thorium and the activity of {sup 137}Cs. During the Finnish Emergency Response Exercise (Resume95), the carborne system was shown to be effective in mapping both natural and man-made radiation from {sup 137}Cs fallout and in locating radioactive sources. The application of the carborne system for mineral exploration is also demonstrated. (au). 10 refs.

A carborne gamma-ray spectrometer system for natural radioactivity mapping and environmental monitoring

Energy Technology Data Exchange (ETDEWEB)

Grasty, R L; Cox, J R [Exploranium Ltd., Mississauga, Ontario (Canada)

1998-12-31

This paper summarizes the experience gained in the use of a carborne gamma-ray spectrometer system for mapping both natural and man-made radiation. Particular emphasis is placed on the calibration of the system for converting the gamma-ray measurements to ground concentrations of potassium, uranium and thorium and the activity of {sup 137}Cs. During the Finnish Emergency Response Exercise (Resume95), the carborne system was shown to be effective in mapping both natural and man-made radiation from {sup 137}Cs fallout and in locating radioactive sources. The application of the carborne system for mineral exploration is also demonstrated. (au). 10 refs.

Wireless, low-cost, FPGA-based miniature gamma ray spectrometer

Energy Technology Data Exchange (ETDEWEB)

Becker, E.M., E-mail: beckere@engr.orst.edu; Farsoni, A.T.

2014-10-11

A compact, low-cost, wireless gamma-ray spectrometer is a tool sought by a number of different organizations in the field of radiation detection. Such a device has applications in emergency response, battlefield assessment, and personal dosimetry. A prototype device fitting this description has been constructed in the Advanced Radiation Instrumentation Laboratory at Oregon State University. The prototype uses a CsI(Tl) scintillator coupled to a solid-state photomultiplier and a 40 MHz, 12-bit, FPGA-based digital pulse processor to measure gamma radiation, and is able to be accessed wirelessly by mobile phone. The prototype device consumes roughly 420 mW, weighs about 28 g (not including battery), and measures 2.54×3.81 cm{sup 2}. The prototype device is able to achieve 5.9% FWHM energy resolution at 662 keV.

A Liquid-Cryogen-Free Cryostat for Ultrahigh Resolution Gamma-Ray Spectrometers

International Nuclear Information System (INIS)

Dreyer, J.G.; Hertrich, T.; Drury, O.B.; Hohne, J.; Friedrich, S.

2008-01-01

We are developing ultra-high energy resolution gamma-ray detectors based on superconducting transition edge sensors (TESs) for nuclear non-proliferation and fundamental science applications. They use bulk tin absorbers attached to molybdenum-copper multilayer TESs, and have achieved an energy resolution between 50 and 90 eV FWHM for gamma-ray energies below 122 keV. For increased user-friendliness, we have built a cryostat that attains the required detector operating temperature of 0.1 K at the push of a button without the use of cryogenic liquids. It uses a two-stage mechanical pulse tube refrigerator for precooling to ∼3 K, and a two-stage adiabatic demagnetization refrigerator for cooling to the base temperature. The cryostat is fully automated, attains a base temperature below 30 mK without the use of cryogenic liquids, and has a hold time of ∼2 days at 0.1 K between 1-hour demagnetization cycles. Here we discuss the performance of the cryostat for operation in a Gamma-spectrometer with 112-pixel arrays of superconducting TES detectors

An ultralow background germanium gamma-ray spectrometer

International Nuclear Information System (INIS)

Reeves, R.H.; Brodzinski, R.L.; Hensley, W.K.; Ryge, P.

1984-01-01

The monitoring of minimum detectable activity is becoming increasingly important as environmental concerns and regulations require more sensitive measurement of the radioactivity levels in the workplace and the home. In measuring this activity, however, the background becomes one of the limiting factors. Anticoincidence systems utilizing both NaI(T1) and plastic scintillators have proven effective in reducing some components of the background, but radiocontaminants in the various regions of these systems have limited their effectiveness, and their cost is often prohibitive. In order to obtain a genuinely low background detector system, all components must be free of detectable radioactivity, and the cosmic ray produced contribution must be significantly reduced. Current efforts by the authors to measure the double beta decay of Germanium 76 as predicted by Grand Unified Theories have resulted in the development of a high resolution germanium diode gamma spectrometer with an exceptionally low background. This paper describes the development of this system, outlines the configuration and operation of its preamplifier, linear amplifier, analog-to-digital converter, 4096-channel analyzer, shielding consisting of lead-sandwiched plastic scintillators wrapped in cadmium foil, photomultiplier, and its pulse generator and discriminator, and then discusses how the system can be utilized to significantly reduce the background in high resolution photon spectrometers at only moderate cost

Application of wavelet domain wiener filter in denoising of airborne γ-ray data

International Nuclear Information System (INIS)

Luo Yaoyao; Ge Liangquan; Xiong Chao; Xu Lipeng; Hua Yongtao

2012-01-01

The wavelet domain Wiener filter method, which combines the traditional wavelet method and the wiener filter, is established at CUT to reduce noising in as-recorded airborne gamma-ray spectra. It was used to treat an airborne gamma-ray data collected from an area m Inner Mongolia. The results showed that using this method, statistical noise could be greatly removed from the raw airborne gamma-ray spectra, and quality of the processed data is much better than those by conventional spectral denoising methods. (authors)

Research on digital airborne gamma-ray spectrometry

International Nuclear Information System (INIS)

Ge Liangquan; Lai Wanchang; Zeng Guoqiang; Fan Zhenguo; Xiong Shengqing; Ni Weizhong

2010-01-01

Airborne Gamma-ray Spectrometry (AGS) is a main supporting technique for looking for uranium deposits and other non-radioactive mineral deposit, as well as for investigating environmental radiation pollution and monitoring nuclear equipment. This paper describes the newest achievements about the AGS instrument developed by Chengdu university of Technology. Those are: 1) the probe of AGS is composed of 5 NaI(Tl) + PMT scintillation counters with 10 x 10 x 40 mm size, and a special temperature sensor, preamplifier with circuit negative feedback and high voltage with lower electronic noise have been designed. 2)A Y/U double channel digital controlled gain amplifier for adjusting the spectrum drift finely and high speed ADC and CPLD are designed to perform digitalized spectroscopy and to improve the energy resolution and pulse through output rate (more than 100k/s). 3) Two self-stabilization spectrum loops have been designed for spectrum stability: The first loop is roughly adjusted by temperature and the second loop is finely by Kalman filter. 4) The significant characters of new AGS system are: the detective gamma energy range is 0.02∼10.0 MeV, the spectrum drift is ±1 channel, the collecting period is 0.5-1 s, and 20 NaI(Tl)+PMT scintillation counters can be operated at the same time. (authors)

Gamma ray energy spectrum of a buried radioactive source

Energy Technology Data Exchange (ETDEWEB)

Massey, N B

1957-07-01

Because of current attempts to utilize airborne gamma-ray scintillation spectrometers as a means of detecting and identifying buried radioactive mineral deposits, it has become important to study the effects of multiple scattering on the gamma-ray energy spectrum of a source buried in a semi-infinite medium. A series of ten experiments was made. First a scintillation detector was located in air at a fixed distance above a 250 microcurie cobalt-60 source suspended in a large tank. The level of water was raised from 25 cm below the source to 50 cm above, and the gamma-ray energy spectrum was observed. It was found that the high energy portion of the cobalt-60 spectrum remained identifiable even when the source was submerged more than five half-lengths. Further, the ratio of the counting rate of the total incident gamma radiation to the counting rate of the primary 1.33 MeV radiation was found to be very nearly linearly proportional to the depth of water cover. This leads to an empirical method for determining the depth of burial of a cobalt-60 point source. (author)

Gamma-ray spectrometer system with high efficiency and high resolution

International Nuclear Information System (INIS)

Moss, C.E.; Bernard, W.; Dowdy, E.J.; Garcia, C.; Lucas, M.C.; Pratt, J.C.

1983-01-01

Our gamma-ray spectrometer system, designed for field use, offers high efficiency and high resolution for safeguards applications. The system consists of three 40% high-purity germanium detectors and a LeCroy 3500 data acquisition system that calculates a composite spectrum for the three detectors. The LeCroy 3500 mainframe can be operated remotely from the detector array with control exercised through modems and the telephone system. System performance with a mixed source of 125 Sb, 154 Eu, and 155 Eu confirms the expected efficiency of 120% with the overall resolution showing little degradation over that of the worst detector

Regional radiometric map of Syria, using gamma-ray spectrometer

International Nuclear Information System (INIS)

Aissa, M.; Al-Hent, R.; Nasser, R.

2005-01-01

The regional radiometric gamma-ray spectrometry map of Syria, scaled 1/1000000, for surficial concentration of the total radioactivity (Ur), eU, eTh and %K was completely achieved after normalizing the airborne and carbon data sets to match each other. It worthy notice that, the anomalies found to be closely related to either phosphate and/or glauconite deposits. It is worth mentioning that throughout the survey work many scattered occurrences of secondary uranium mineralization were found as spots in some formations and phosphate rocks. Where this phenomena attributes to chemical and physical disseminating instead of accumulating the radioelements. So, that leads to a weak expectation for usual surface uranium deposits where attributed to the oxidizing condition. Then this expectation remains, as an open question requires answering through planning to subsurface prospecting. (Author)

Spectrum-to-dose conversion operator value function of a Ge(Li) in-situ environmental gamma-ray spectrometer

International Nuclear Information System (INIS)

Terada, Hiromi; Sakai, Eiji; Katagiri, Masaki

1976-05-01

A spectrum-to-dose conversion operator value function was obtained for a 73cm 3 closed-end coaxial Ge(Li) in-situ environmental gamma-ray spectrometer; factors influencing the function are considered. (auth.)

Performance of the prototype LaBr{sub 3} spectrometer developed for the JET gamma-ray camera upgrade

Energy Technology Data Exchange (ETDEWEB)

Rigamonti, D., E-mail: davide.rigamonti@mib.infn.it; Nocente, M.; Gorini, G. [Dipartimento di Fisica “G. Occhialini,” Università degli Studi di Milano-Bicocca, Milano (Italy); Istituto di Fisica del Plasma “P. Caldirola,” CNR, Milano (Italy); Muraro, A.; Giacomelli, L.; Cippo, E. P.; Tardocchi, M. [Istituto di Fisica del Plasma “P. Caldirola,” CNR, Milano (Italy); Perseo, V. [Dipartimento di Fisica “G. Occhialini,” Università degli Studi di Milano-Bicocca, Milano (Italy); Boltruczyk, G.; Gosk, M.; Korolczuk, S.; Mianowski, S.; Zychor, I. [Narodowe Centrum Badań Jądrowych (NCBJ), 05-400 Otwock-Swierk (Poland); Fernandes, A.; Pereira, R. C. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); Figueiredo, J. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); EUROfusion Programme Management Unit, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Kiptily, V. [Culham Science Centre for Fusion Energy, Culham (United Kingdom); Murari, A. [EUROfusion Programme Management Unit, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Consorzio RFX (CNR, ENEA, INFN, Universita’ di Padova, Acciaierie Venete SpA), Padova (Italy); Collaboration: EUROfusion Consortium, JET, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

2016-11-15

In this work, we describe the solution developed by the gamma ray camera upgrade enhancement project to improve the spectroscopic properties of the existing JET γ-ray camera. Aim of the project is to enable gamma-ray spectroscopy in JET deuterium-tritium plasmas. A dedicated pilot spectrometer based on a LaBr{sub 3} crystal coupled to a silicon photo-multiplier has been developed. A proper pole zero cancellation network able to shorten the output signal to a length of 120 ns has been implemented allowing for spectroscopy at MHz count rates. The system has been characterized in the laboratory and shows an energy resolution of 5.5% at E{sub γ} = 0.662 MeV, which extrapolates favorably in the energy range of interest for gamma-ray emission from fast ions in fusion plasmas.

High performance gamma-ray spectrometer for runaway electron studies on the FT-2 tokamak

Energy Technology Data Exchange (ETDEWEB)

Shevelev, A.E., E-mail: Shevelev@cycla.ioffe.ru [Ioffe Institute, Politekhnicheskaya 26, St. Petersburg 194021 (Russian Federation); Khilkevitch, E.M.; Lashkul, S.I.; Rozhdestvensky, V.V.; Altukhov, A.B.; Chugunov, I.N.; Doinikov, D.N.; Esipov, L.A.; Gin, D.B.; Iliasova, M.V.; Naidenov, V.O.; Nersesyan, N.S.; Polunovsky, I.A.; Sidorov, A.V. [Ioffe Institute, Politekhnicheskaya 26, St. Petersburg 194021 (Russian Federation); Kiptily, V.G. [CCFE, Culham Science Centre, Abingdon, Oxon X14 3DB (United Kingdom)

2016-09-11

A gamma-ray spectrometer based on LaBr{sub 3}(Ce) scintillator has been used for measurements of hard X-ray emission generated by runaway electrons in the FT-2 tokamak plasmas. Using of the fast LaBr{sub 3}(Ce) has allowed extending count rate range of the spectrometer by a factor of 10. A developed digital processing algorithm of the detector signal recorded with a digitizer sampling rate of 250 MHz has provided a pulse height analysis at count rates up to 10{sup 7} s{sup −1}. A spectrum deconvolution code DeGaSum has been applied for inferring the energy distribution of runaway electrons escaping from the plasma and interacting with materials of the FT-2 limiter in the vacuum chamber. The developed digital signal processing technique for LaBr{sub 3}(Ce) spectrometer has allowed studying the evolution of runaways energy distribution in the FT-2 plasma discharges with time resolution of 1–5 ms.

{gamma}-Ray background sources in the VESUVIO spectrometer at ISIS spallation neutron source

Energy Technology Data Exchange (ETDEWEB)

Pietropaolo, A. [CNISM Milano-Bicocca, Universita degli Studi di Milano-Bicocca, Dipartimento di Fisica ' G. Occhialini' , Piazza della Scienza 3, 20126 Milano (Italy); NAST Center (Nanoscienze-Nanotecnologie-Strumentazione), Universita degli Studi di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy)], E-mail: antonino.pietropaolo@mib.infn.it; Perelli Cippo, E. [Universita degli Studi di Milano-Bicocca, Dipartimento di Fisica ' G. Occhialini' , Piazza della Scienza 3, 20126 Milano (Italy); Gorini, G. [CNISM Milano-Bicocca, Universita degli Studi di Milano-Bicocca, Dipartimento di Fisica ' G. Occhialini' , Piazza della Scienza 3, 20126 Milano (Italy); NAST Center (Nanoscienze-Nanotecnologie-Strumentazione), Universita degli Studi di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy); Tardocchi, M. [Universita degli Studi di Milano-Bicocca, Dipartimento di Fisica ' G. Occhialini' , Piazza della Scienza 3, 20126 Milano (Italy); Schooneveld, E.M. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire 0QX OX11 (United Kingdom); Andreani, C.; Senesi, R. [Universia degli Studi di Roma Tor Vergata, Dipartimento di Fisica and NAST Center (Nanoscienze-Nanotecnologie-Strumentazione), via della Ricerca Scientifica 1, 00133 Roma (Italy)

2009-09-01

An investigation of the gamma background was carried out in the VESUVIO spectrometer at the ISIS spallation neutron source. This study, performed with a yttrium-aluminum-perovskite (YAP) scintillator, follows high resolution pulse height measurements of the gamma background carried out on the same instrument with the use of a high-purity germanium detector. In this experimental work, a mapping of the gamma background was attempted, trying to find the spatial distribution and degree of directionality of the different contributions identified in the previous study. It is found that the gamma background at low times is highly directional and mostly due to the gamma rays generated in the moderator-decoupler system. The other contributions, consistently to the findings of a previous experiment, are identified as a nearly isotropic one due to neutron absorption in the walls of the experimental hall, and a directional one coming from the beam dump.

Study of TGEs and Gamma-Flashes from thunderstorms in 20-3000 keV energy range with SINP MSU Gamma-Ray spectrometers

International Nuclear Information System (INIS)

Bogomolov, V.V.; Svertilov, S.I.; Maximov, I.A.; Panasyuk, M.I.; Garipov, G.K.

2016-01-01

SINP MSU provided a number of experiments with scintillator gamma-spectrometers for study of spectral, temporal and spatial characteristics of TGEs as well as for search of fast hard x-ray and gamma-ray flashes probably appearing at the moment of lightning. The measurements were done in Moscow region and in Armenia at Aragats Mountain. Each instrument used in this work was able to record data in so called “event mode”: the time of each interaction was recorded with ∼15 mcs accuracy together with detailed spectral data. Such design allowed one to look for fast sequences of gamma-quanta, coming at the moments of discharges during thunderstorms. The pulse-shape analysis made by detector electronics was used to separate real gammaray events and possible imitations of flashes by electrical disturbances when discharges occur. During the time period from spring to autumn of 2015 a number of TGEs were detected. Spectral analysis of received data showed that the energy spectrum of coming radiation in 20-3000 kev range demonstrate a set of gamma-ray lines that can be interpreted as radiation from Rn-222 daughter isotopes. The increase of Rn-222 radiation was detected during rainfalls with thunderstorm as well as during rainy weather without thunderstorms. Variations of Rn-222 radiation dominate in low energies (<2.6MeV) and must be taken into account in the experiments performed to measure low energy gamma-radiation from the electrons accelerated in thunderclouds. In order to determine the direction from which the additional gamma-quanta come the experiment with collimated gamma-spectrometer placed on rotated platform was done. The results of this experiment realized in Moscow region from august, 2015 will be presented as well as the results of comparison of different TGEs measured in Moscow region and in Armenia. (author)

A comparative study of LaBr3(Ce(3+)) and CeBr3 based gamma-ray spectrometers for planetary remote sensing applications.

Science.gov (United States)

Kozyrev, A; Mitrofanov, I; Owens, A; Quarati, F; Benkhoff, J; Bakhtin, B; Fedosov, F; Golovin, D; Litvak, M; Malakhov, A; Mokrousov, M; Nuzhdin, I; Sanin, A; Tretyakov, V; Vostrukhin, A; Timoshenko, G; Shvetsov, V; Granja, C; Slavicek, T; Pospisil, S

2016-08-01

The recent availability of large volume cerium bromide crystals raises the possibility of substantially improving gamma-ray spectrometer limiting flux sensitivities over current systems based on the lanthanum tri-halides, e.g., lanthanum bromide and lanthanum chloride, especially for remote sensing, low-level counting applications or any type of measurement characterized by poor signal to noise ratios. The Russian Space Research Institute has developed and manufactured a highly sensitive gamma-ray spectrometer for remote sensing observations of the planet Mercury from the Mercury Polar Orbiter (MPO), which forms part of ESA's BepiColombo mission. The Flight Model (FM) gamma-ray spectrometer is based on a 3-in. single crystal of LaBr3(Ce(3+)) produced in a separate crystal development programme specifically for this mission. During the spectrometers development, manufacturing, and qualification phases, large crystals of CeBr3 became available in a subsequent phase of the same crystal development programme. Consequently, the Flight Spare Model (FSM) gamma-ray spectrometer was retrofitted with a 3-in. CeBr3 crystal and qualified for space. Except for the crystals, the two systems are essentially identical. In this paper, we report on a comparative assessment of the two systems, in terms of their respective spectral properties, as well as their suitability for use in planetary mission with respect to radiation tolerance and their propensity for activation. We also contrast their performance with a Ge detector representative of that flown on MESSENGER and show that: (a) both LaBr3(Ce(3+)) and CeBr3 provide superior detection systems over HPGe in the context of minimally resourced spacecraft and (b) CeBr3 is a more attractive system than LaBr3(Ce(3+)) in terms of sensitivities at lower gamma fluxes. Based on the tests, the FM has now been replaced by the FSM on the BepiColombo spacecraft. Thus, CeBr3 now forms the central gamma-ray detection element on the MPO spacecraft.

High-sensitivity multidimensional gamma-ray spectrometer, PRIPYAT` for low-level measurements

Energy Technology Data Exchange (ETDEWEB)

Andrukhovich, S K [and others

1996-12-31

The design of the gamma spectrometer PRIPYAT` intended for gamma spectra measurement in the energy range 0.2-3 MeV is discussed. The spectrometer may be used for the food and water control as well as for massive control of environmental contamination. Its background at Cs{sup 134} + Cs{sup 137} measurement regime is less then 9 c/s. 1 fig.

Characterization of a new modular decay total absorption gamma-ray spectrometer (DTAS) for FAIR

International Nuclear Information System (INIS)

Montaner Pizá, A.; Taín, J. L.; Agramunt, J.; Algora, A.; Guadilla, V.; Marín, E.; Rice, S.; Rubio, B.

2013-01-01

Beta-decay studies are one of the main goals of the DEcay SPECtroscopy experiment (DESPEC) to be installed at the future Facility for Antiproton and Ion Research (FAIR). DESPEC aims at the study of nuclear structure of exotic nuclei. A new modular Decay Total Absorption gamma-ray Spectrometer (DTAS) is being built at IFIC and is specially adapted to studies at fragmentation facilities such as the Super Fragment Separator (Super-FRS) at FAIR. The designed spectrometer is composed of 16 identical NaI(Tl) scintillation crystals. This work focuses on the characterization of these independent modules, as an initial step for the characterization of the full spectrometer. Monte Carlo simulations have been performed in order to understand the detector response.

Airborne system for mapping and tracking extended gamma ray sources

International Nuclear Information System (INIS)

Stuart, T.P.; Hendricks, T.J.; Wallace, G.G.; Cleland, J.R.

1976-01-01

An airborne system was developed for mapping and tracking extended sources of airborne or terrestrially distributed γ-ray emitters. The system records 300 channel γ-ray spectral data every three seconds on magnetic tape. Computer programs have been written to isolate the contribution from the particular radionuclide of interest. Aircraft position as sensed by a microwave ranging system is recorded every second on magnetic tape. Measurements of airborne stack releases of 41 A concentrations versus time or aircraft position agree well with computer code predictions

A microprocessor-based gamma-ray spectrometer with gain stabilized single-channel analyzers

International Nuclear Information System (INIS)

Borg, P.J.; Huppert, P.; Phillips, P.L.; Waddington, P.J.

1985-01-01

The design and performance of a self-contained microprocessor-based gamma-ray spectrometer for use in geophysical measurements using nuclear techniques is described. The instrument uses single-channel analyzers which are inherently simpler and faster than the Wilkinson or successive approximation ADC. A novel technique of gain stabilization together with a simple means of energy calibration has been developed. The modular design of the equipment makes it suitable for multidetector usage, required in a number of nucleonic gauges for the quantitative measurement of chemical constituents. (orig.)

Efficiency calibration and minimum detectable activity concentration of a real-time UAV airborne sensor system with two gamma spectrometers.

Science.gov (United States)

Tang, Xiao-Bin; Meng, Jia; Wang, Peng; Cao, Ye; Huang, Xi; Wen, Liang-Sheng; Chen, Da

2016-04-01

A small-sized UAV (NH-UAV) airborne system with two gamma spectrometers (LaBr3 detector and HPGe detector) was developed to monitor activity concentration in serious nuclear accidents, such as the Fukushima nuclear accident. The efficiency calibration and determination of minimum detectable activity concentration (MDAC) of the specific system were studied by MC simulations at different flight altitudes, different horizontal distances from the detection position to the source term center and different source term sizes. Both air and ground radiation were considered in the models. The results obtained may provide instructive suggestions for in-situ radioactivity measurements of NH-UAV. Copyright © 2016 Elsevier Ltd. All rights reserved.

Efficiency calibration and minimum detectable activity concentration of a real-time UAV airborne sensor system with two gamma spectrometers

International Nuclear Information System (INIS)

Tang, Xiao-Bin; Meng, Jia; Wang, Peng; Cao, Ye; Huang, Xi; Wen, Liang-Sheng; Chen, Da

2016-01-01

A small-sized UAV (NH-UAV) airborne system with two gamma spectrometers (LaBr_3 detector and HPGe detector) was developed to monitor activity concentration in serious nuclear accidents, such as the Fukushima nuclear accident. The efficiency calibration and determination of minimum detectable activity concentration (MDAC) of the specific system were studied by MC simulations at different flight altitudes, different horizontal distances from the detection position to the source term center and different source term sizes. Both air and ground radiation were considered in the models. The results obtained may provide instructive suggestions for in-situ radioactivity measurements of NH-UAV. - Highlights: • A small-sized UAV airborne sensor system was developed. • Three radioactive models were chosen to simulate the Fukushima accident. • Both the air and ground radiation were considered in the models. • The efficiency calculations and MDAC values were given. • The sensor system is able to monitor in serious nuclear accidents.

Real-time airborne gamma-ray background estimation using NASVD with MLE and radiation transport for calibration

Energy Technology Data Exchange (ETDEWEB)

Kulisek, J.A., E-mail: Jonathan.Kulisek@pnnl.gov; Schweppe, J.E.; Stave, S.C.; Bernacki, B.E.; Jordan, D.V.; Stewart, T.N.; Seifert, C.E.; Kernan, W.J.

2015-06-01

Helicopter-mounted gamma-ray detectors can provide law enforcement officials the means to quickly and accurately detect, identify, and locate radiological threats over a wide geographical area. The ability to accurately distinguish radiological threat-generated gamma-ray signatures from background gamma radiation in real time is essential in order to realize this potential. This problem is non-trivial, especially in urban environments for which the background may change very rapidly during flight. This exacerbates the challenge of estimating background due to the poor counting statistics inherent in real-time airborne gamma-ray spectroscopy measurements. To address this challenge, we have developed a new technique for real-time estimation of background gamma radiation from aerial measurements without the need for human analyst intervention. The method can be calibrated using radiation transport simulations along with data from previous flights over areas for which the isotopic composition need not be known. Over the examined measured and simulated data sets, the method generated accurate background estimates even in the presence of a strong, {sup 60}Co source. The potential to track large and abrupt changes in background spectral shape and magnitude was demonstrated. The method can be implemented fairly easily in most modern computing languages and environments.

Progress with the Konus-W gamma-ray burst spectrometer on GGS-Wind

International Nuclear Information System (INIS)

Mazets, E. P.; Aptekar, R. L.; Frederiks, D. D.; Golenetskii, S. V.; Ilynskii, V. N.; Terekhov, M. M.; Cline, T. L.; Butterworth, P. S.; Stilwell, D. E.

1996-01-01

The cosmic gamma-ray burst spectrometer Konus-W has been successfully making observations for nearly one year, since the launch of the GGS-Wind spacecraft. The instrument consists of two large scintillator units of size and shape very nearly the same as the spectroscopy detectors on CGRO BATSE. These face towards the ecliptic poles so as to survey the sky in a moderately uniform fashion. At least 114 gamma ray bursts have triggered the system in the first 330 days of operation, yielding detailed time histories and spectra. A large number of additional events are seen in the background mode at much coarser resolution. These observations can be combined with those of the Interplanetary Network to reduce the total area of the segmented annular source fields derived from several degrees to about one degree in length, although the data cannot obtained from this spacecraft in the rapid turnaround mode needed to benefit the BACODINE system. The Konus spectra can be summarized presently as providing little indication of the frequent occurrence of major spectral features

Coincidence gamma-ray spectrometry

DEFF Research Database (Denmark)

Markovic, Nikola; Roos, Per; Nielsen, Sven Poul

2017-01-01

Gamma-ray spectrometry with high-purity germanium (HPGe) detectors is often the technique of choice in an environmental radioactivity laboratory. When measuring environmental samples associated activities are usually low so an important parameter that describes the performance of the spectrometer...... for a nuclide of interest is the minimum detectable activity (MDA). There are many ways for lowering the MDAs in gamma spectrometry. Recently, developments of fast and compact digital acquisition systems have led to growing number of multiple HPGe detector spectrometers. In these applications all detected...

Radioactivity observed in the sodium iodide gamma-ray spectrometer returned on the Apollo 17 mission

Science.gov (United States)

Dyer, C. S.; Trombka, J. I.; Schmadebeck, R. L.; Eller, E.; Bielefeld, M. J.; Okelley, G. D.; Eldridge, J. S.; Northcutt, K. J.; Metzger, A. E.; Reedy, R. C.

1975-01-01

In order to obtain information on radioactive background induced in the Apollo 15 and 16 gamma-ray spectrometers (7 cm x 7 cm NaI) by particle irradiation during spaceflight, and identical detector was flown and returned to earth on the Apollo 17 mission. The induced radioactivity was monitored both internally and externally from one and a half hours after splashdown. When used in conjunction with a computation scheme for estimating induced activation from calculated trapped proton and cosmic-ray fluences, these results show an important contribution resulting from both thermal and energetic neutrons produced in the heavy spacecraft by cosmic-ray interactions.

Car-borne multichannel gamma-ray spectrometric system model CZD-6

International Nuclear Information System (INIS)

Lu Shili; Zhai Yugui; Ma Yanfang; Jiao Cangwen; Zhang Biao

1998-01-01

The car-borne multichannel gamma-ray spectrometric system Mode CZD-6 is composed of a HDY-256 of portable multichannel gamma-ray spectrometer developed by the Beijing Research Institute of Uranium Geology and a large volume scintillation detector. the position for each measurement point is determined by the GPS instrument. Its latitude and longitude, as well as measured 256 channels of γ-spectrometric data are collected by a notebook computer, which can show the 256 channels of spectra for each point during measuring processes. The complete system can be loaded in a field car. This system has been used to environmental radioactive monitoring after calibration by airborne radiometric models in Shijiazhuang, Hebei province. A lot of data confirm that the system works stably and reliably, and is a fast and advanced approach for environmental γ-spectrometric monitoring. It can be used not only to determination of contents of natural radioactive elements in environments, but also to monitoring nuclear pollution and emergency treatment in nuclear accidents significantly

ICIT contribution to JET gamma-ray diagnostics enhancement

International Nuclear Information System (INIS)

Soare, S.; Curuia, M.; Zoita, V.

2010-01-01

Full text: Gamma-ray emission of tokamak plasmas is the result of the interaction of fast ions (fusion reaction products, including alpha particles, NBI ions, ICRH-accelerated ions) with main plasma impurities (e.g., carbon, beryllium). Gamma-ray diagnostics involve both gamma-ray imaging (cameras) and gamma-ray spectrometry (spectrometers). For the JET tokamak, gamma-ray diagnostics have been used to provide information on the characteristics of the fast ion population in plasmas. Two gamma-ray diagnostics enhancements project have been launched by JET and the MEdC/EURATOM Association has agreed to lead both of them with ICIT as projects leader. (authors)

Ultimate detection sensitivity of Ge-Li γ-ray spectrometers

International Nuclear Information System (INIS)

1978-06-01

This paper presents the principal results of a study concerning low-level counting capabilities of GeLi gamma-ray spectrometers. The expression adopted for the theoretical sensitivity limit of gamma spectrometers has been experimentally verified with very low activity samples, using 17 installations of various characteristics. This expression sets off the influence of the efficiency, the environmental conditions on the sensitivity limits. It can be used also to eliminate the fraudulents peaks in automatical analysis of gamma-ray spectras. At last, it provides a list of criteria to determine the most suitable characteristics of a detector according to a special problem. Informations which have to be obtained from the manufacturers are specified [fr

Study and development of a spectrometer with Compton suppression and gamma coincidence counting

International Nuclear Information System (INIS)

Masse, D.

1990-10-01

This paper presents the characteristics of a spectrometer consisting of a Ge detector surrounded by a NaI(T1) detector that can operate in Compton-suppression and gamma-gamma coincidence modes. The criteria that led to this measurement configuration are discussed and the spectrometer performances are shown for 60 Co and 137 Cs gamma-ray sources. The results for the measurement of 189 Ir (Compton suppression) and for the measurement of 101 Rh (gamma-gamma coincidence) in the presence of other radioisotopes are given. 83 Rb and 105 Ag isotopes are also measured with this spectrometer [fr

The gamma ray spectrometer GA.SP

Energy Technology Data Exchange (ETDEWEB)

Bazzacco, D [Instituto Nazionale di Fisica Nucleare, Sezione di Padova, Padova (Italy)

1992-08-01

GA.SP is a general purpose 4{pi} detector array for advanced {gamma}-spectroscopy and, in the same time, a suitable system for reaction mechanism studies. The detector is sited at the LNL Tandem+Linac accelerator and has been built as a joint project of INFN Padova, LNL, Milano and Firenze. The array consists of 40 Compton suppressed HPGe detectors and of a 4{pi} calorimeter composed of 80 BGO crystals. The detector houses a reaction chamber of 34 cm diameter where a charged particles multiplicity filter composed of 40 Si detectors is going to be installed. Evaporation residues produced in the centre of GA.SP can be injected into the recoil mass spectrometer (RMS, named CAMEL) in use at LNL, without the need to remove any of the gamma detectors. The coupled operation of GA.SP, RMS and Si ball will give a unique instrument for identification and study of weak reaction channels. (author). 6 figs.

Control system and automation of the spectrum acquisition for a perturbed gamma-gamma angular correlation spectrometer

International Nuclear Information System (INIS)

Stachowski, Ademir F.A.; Lapolli, André L.; Carbonari, Artur W.; Saxena, Rajendra N.

2017-01-01

This work reports results from the automation of data acquisition for a gamma-gamma perturbed angular correlation (PAC) spectrometer located in the hyperfine interactions laboratory (LIH) of IPEN. A PAC spectrometer comprises usually four scintillation detectors (BaF_3 for example) and carries out time measurements from gamma rays of any two combinations of detectors in coincidence. Gamma rays come from the decay of probe nuclei embedded into the material to be studied. Measurements are generally performed as a function of temperature. The fourth-detectors PAC spectrometer was automated in Java language because it is a multi platform and object oriented programming language, having, therefore, portability and longer lifetime due to the ease of implementation of peripherals. Finally, the software has a friendly and intuitive interface with the user being able to operate the hardware manually or automatically with time acquisitions up to 100 consecutive hours. Before each acquisition, the software sets the temperature, waits for temperature stability and records data in different files. Moreover, the software also saves in a file all information of relevant parameters during acquisition. (author)

Control system and automation of the spectrum acquisition for a perturbed gamma-gamma angular correlation spectrometer

Energy Technology Data Exchange (ETDEWEB)

Stachowski, Ademir F.A.; Lapolli, André L.; Carbonari, Artur W.; Saxena, Rajendra N., E-mail: alapolli@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2017-11-01

This work reports results from the automation of data acquisition for a gamma-gamma perturbed angular correlation (PAC) spectrometer located in the hyperfine interactions laboratory (LIH) of IPEN. A PAC spectrometer comprises usually four scintillation detectors (BaF{sub 3} for example) and carries out time measurements from gamma rays of any two combinations of detectors in coincidence. Gamma rays come from the decay of probe nuclei embedded into the material to be studied. Measurements are generally performed as a function of temperature. The fourth-detectors PAC spectrometer was automated in Java language because it is a multi platform and object oriented programming language, having, therefore, portability and longer lifetime due to the ease of implementation of peripherals. Finally, the software has a friendly and intuitive interface with the user being able to operate the hardware manually or automatically with time acquisitions up to 100 consecutive hours. Before each acquisition, the software sets the temperature, waits for temperature stability and records data in different files. Moreover, the software also saves in a file all information of relevant parameters during acquisition. (author)

A simple method for conversion of airborne gamma-ray spectra to ground level doses

DEFF Research Database (Denmark)

Korsbech, Uffe C C; Bargholz, Kim

1996-01-01

A new and simple method for conversion of airborne NaI(Tl) gamma-ray spectra to dose rates at ground level has been developed. By weighting the channel count rates with the channel numbers a spectrum dose index (SDI) is calculated for each spectrum. Ground level dose rates then are determined...... by multiplying the SDI by an altitude dependent conversion factor. The conversion factors are determined from spectra based on Monte Carlo calculations. The results are compared with measurements in a laboratory calibration set-up. IT-NT-27. June 1996. 27 p....

A comparative study of LaBr{sub 3}(Ce{sup 3+}) and CeBr{sub 3} based gamma-ray spectrometers for planetary remote sensing applications

Energy Technology Data Exchange (ETDEWEB)

Kozyrev, A., E-mail: kozyrev@mx.iki.rssi.ru; Mitrofanov, I.; Bakhtin, B.; Fedosov, F.; Golovin, D.; Litvak, M.; Malakhov, A.; Mokrousov, M.; Nuzhdin, I.; Sanin, A.; Tretyakov, V.; Vostrukhin, A. [Space Research Institute of the Russian Academy of Sciences (IKI), 84/32 Profsoyuznaya St., Moscow 117997 (Russian Federation); Owens, A.; Benkhoff, J. [European Space Agency, ESTEC, Keplerlaan, 2200 AG Noordwijk (Netherlands); Quarati, F. [AP, RST, FAME, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Gonitec BV, J. Bildersstraat 60, 2596 EJ Den Haag (Netherlands); Timoshenko, G.; Shvetsov, V. [Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980 (Russian Federation); Granja, C.; Slavicek, T.; Pospisil, S. [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 12800 Prague 2 (Czech Republic)

2016-08-15

The recent availability of large volume cerium bromide crystals raises the possibility of substantially improving gamma-ray spectrometer limiting flux sensitivities over current systems based on the lanthanum tri-halides, e.g., lanthanum bromide and lanthanum chloride, especially for remote sensing, low-level counting applications or any type of measurement characterized by poor signal to noise ratios. The Russian Space Research Institute has developed and manufactured a highly sensitive gamma-ray spectrometer for remote sensing observations of the planet Mercury from the Mercury Polar Orbiter (MPO), which forms part of ESA’s BepiColombo mission. The Flight Model (FM) gamma-ray spectrometer is based on a 3-in. single crystal of LaBr{sub 3}(Ce{sup 3+}) produced in a separate crystal development programme specifically for this mission. During the spectrometers development, manufacturing, and qualification phases, large crystals of CeBr{sub 3} became available in a subsequent phase of the same crystal development programme. Consequently, the Flight Spare Model (FSM) gamma-ray spectrometer was retrofitted with a 3-in. CeBr{sub 3} crystal and qualified for space. Except for the crystals, the two systems are essentially identical. In this paper, we report on a comparative assessment of the two systems, in terms of their respective spectral properties, as well as their suitability for use in planetary mission with respect to radiation tolerance and their propensity for activation. We also contrast their performance with a Ge detector representative of that flown on MESSENGER and show that: (a) both LaBr{sub 3}(Ce{sup 3+}) and CeBr{sub 3} provide superior detection systems over HPGe in the context of minimally resourced spacecraft and (b) CeBr{sub 3} is a more attractive system than LaBr{sub 3}(Ce{sup 3+}) in terms of sensitivities at lower gamma fluxes. Based on the tests, the FM has now been replaced by the FSM on the BepiColombo spacecraft. Thus, CeBr{sub 3} now forms

Airborne geophysical survey, Wind River Basin area, Wyoming

International Nuclear Information System (INIS)

1974-01-01

Results are reported of AEC-sponsored, high sensitivity, reconnaisance airborne gamma-ray survey of the Wind River Basin area, Wyoming. The objective of the survey was to define those areas showing surface indications of a generally higher uranium content (uraniferous provinces) and where detailed exploration for uranium would most likely be successful. For the data collection tasks, a TI high sensitivity gamma-ray system consisting of seven large-volume NaI detectors, two 400-channel analyzers, and ancillary geophysical and electronic equipment was used. Gamma-ray spectrometric data were processed to correct for variations in atmospheric and flight conditions and statistically evaluated to remove the effect of surface geologic variations. Data were then compared to regional geomorphic lineaments derived from ERTS-1 imagery. Aeromagnetic data were collected simultaneously with the airborne gamma-ray survey and interpreted in terms of regional structure. Ten major anomalous uranium areas and ten less strong anomalous areas were defined within the region surveyed. These anomalies and the known mining districts and uranium occurrences demonstrated good correlation with the ERTS lineaments. The basins were defined by the aeromagnetic data. It is suggested that gamma-ray spectrometer data be supplemented by both the ERTS and aeromagnetic data to best define the targets of greatest potential for further exploration. (U.S.)

Model H-90A gamma-ray spectrometer with microcomputer

International Nuclear Information System (INIS)

Zhang Biao; Dong Chen; Zhao Zhiming

1994-11-01

Model H-90A is a 4-channel differential Gamma-ray spectrometer with microcomputer. It consists of a console and NaI(TL) crystal detector with a diameter of φ75 mm x 75 mm. The instrument has excellent performance such as automatic spectrum stabilization, automatic regular timing measurement and automatic calculation of uranium, thorium and potassium contents and their ratios. Original data can be manually and automatically stored. The instrument is provided with shut down supply protective device, reading out can be repeated or be further processed through RS-232 interface output in the case of connection with computer. The working command is inputted by 'soft key' and performed by slice microcomputer automatically through software. It can be used not only in radioactive geological mapping, geochemical research and rapid field assay of radioactive elements in mineral and rock samples, but also for exploration and reconnaissance survey for uranium, thorium, potassium and seeking gold, as well as environmental monitoring

A new processing technique for airborne gamma-ray data

DEFF Research Database (Denmark)

Hovgaard, Jens

1997-01-01

The mathematical-statistical background for at new technique for processing gamma-ray spectra is presented. The technique - Noise Adjusted Singular Value Decomposition - decomposes at set of gamma-ray spectra into a few basic spectra - the spectral components. The spectral components can be proce...

Further development of a cosmic veto gamma-spectrometer

International Nuclear Information System (INIS)

Burnett, J.L.; Davies, A.V.; McLarty, J.L.

2013-01-01

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is supported by a network of certified laboratories that perform high-resolution gamma-spectrometry on global air filter samples for the identification of 85 radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), a novel cosmic veto gamma-spectrometer has been developed to improve the sensitivity of measurements for treaty compliance. The system consists of plastic scintillation plates operated in time-stamp mode to detect coincident cosmic-ray interactions within an HPGe gamma-spectrometer. This provides a mean background reduction of 75.2 % with MDA improvements of 45.6 %. The CTBT requirement for a 140 Ba MDA is achievable after 1.5 days counting compared to 5-7 days using conventional systems. The system does not require dedicated coincidence electronics, and remains easily configurable with dual acquisition of unsuppressed and suppressed spectra. Performance has been significantly improved by complete processing of the cosmic-ray spectrum (0-25 MeV) combined with the Canberra Lynx TM multi-channel analyser. The improved sensitivity has been demonstrated for a CTBT air filter sample collected after the Fukushima incident. (author)

Cosmic gamma ray detection and discovery potential with the AMS-2 spectrometer; Detection de rayons {gamma} cosmiques et potentiel de decouvertes avec le spectrometre AMS-02

Energy Technology Data Exchange (ETDEWEB)

Girard, L

2004-12-15

Yet designed to measure charged component of the cosmic rays, the foreseen Alpha Magnetic Spectrometer (AMS-02) could also release {gamma}-ray studies, in the energy range from GeV to TeV, using the tracker system, for {gamma}-rays converted in e{sup +}e{sup -} pair, and the electromagnetic calorimeter. In the first part of the thesis are described the calibrations and the performances of the engineering model of the calorimeter, obtained from the analysis of data taken during a test-beam performed at CERN in July 2002. In the second part of the thesis, the AMS-02 discovery potential for {gamma}-astrophysics is presented. While exposure maps of the {gamma}--sky are computed for one year of data taking with the {gamma}--detectors, the acceptance of the calorimeter is obtained from Monte-Carlo simulations. The AMS-02 potential is then estimated for signals from the Vela pulsar and for some supersymmetric signals from the Galactic Center. (author)

Conceptual design of the Radial Gamma Ray Spectrometers system for α particle and runaway electron measurements at ITER

DEFF Research Database (Denmark)

Nocente, Massimo; Tardocchi, Marco; Barnsley, Robin

2017-01-01

We here present the principles and main physics capabilities behind the design of the radial gamma ray spectrometers (RGRS) system for alpha particle and runaway electron measurements at ITER. The diagnostic benefits from recent advances in gamma-ray spectrometry for tokamak plasmas and combines...... the measurements sensitive to α particles at characteristic resonant energies and to possible anisotropies of their slowing down distribution function. An independent assessment of the neutron rate by gamma-ray emission is also feasible. In case of runaway electrons born in disruptions with a typical duration...... of 100ms, a time resolution of at least 10ms for runaway electron studies can be achieved depending on the scenario and down to a current of 40 kA by use of external gas injection. We find that the bremsstrahlung spectrum in the MeV range from confined runaways is sensitive to the electron velocity space...

Matrix of response functions for xenon gamma-ray detector

International Nuclear Information System (INIS)

Shustov, A.E.; Vlasik, K.F.; Grachev, V.M.; Dmitrenko, V.V.; Novikov, A.S.; P'ya, S.N.; Ulin, S.E.; Uteshev, Z.M.; Chernysheva, I.V.

2014-01-01

An approach of creation of response matrix using simulation GEANT4 gamma-ray Monte-Carlo method has been described for gamma-ray spectrometer based on high pressure xenon impulse ionization chamber with a shielding grid [ru

An X-ray perspective on a gamma-ray mission

DEFF Research Database (Denmark)

Lund, Niels

2003-01-01

The most recent astrophysics mission of ESA is INTEGRAL, a mission dedicated to gamma-ray astronomy (Winkler et al. 2003). INTEGRAL carries two gamma-ray instruments: the imager, IBIS, and the spectrometer, SPI, and in addition an optical monitor, OMC, and an X-ray monitor, JEM-X. INTEGRAL is an ...... is an observatory mission with 70% of the observation time available to the general astronomical community through a peer-reviewed selection process. This paper describes the INTEGRAL mission primarily as seen from the JEM-X perspective....

Airborne gamma-ray and magnetic anomaly signatures of serpentinite in relation to soil geochemistry, northern California

Science.gov (United States)

McCafferty, A.E.; Van Gosen, B. S.

2009-01-01

Serpentinized ultramafic rocks and associated soils in northern California are characterized by high concentrations of Cr and Ni, low levels of radioelements (K, Th, and U) and high amounts of ferrimagnetic minerals (primarily magnetite). Geophysical attributes over ultramafic rocks, which include airborne gamma-ray and magnetic anomaly data, are quantified and provide indirect measurements on the relative abundance of radioelements and magnetic minerals, respectively. Attributes are defined through a statistical modeling approach and the results are portrayed as probabilities in chart and map form. Two predictive models are presented, including one derived from the aeromagnetic anomaly data and one from a combination of the airborne K, Th and U gamma-ray data. Both models distinguish preferential values within the aerogeophysical data that coincide with mapped and potentially unmapped ultramafic rocks. The magnetic predictive model shows positive probabilities associated with magnetic anomaly highs and, to a lesser degree, anomaly lows, which accurately locate many known ultramafic outcrops, but more interestingly, locate potentially unmapped ultramafic rocks, possible extensions of ultramafic bodies that dip into the shallow subsurface, as well as prospective buried ultramafic rocks. The airborne radiometric model shows positive probabilities in association with anomalously low gamma radiation measurements over ultramafic rock, which is similar to that produced by gabbro, metavolcanic rock, and water bodies. All of these features share the characteristic of being depleted in K, Th and U. Gabbro is the only rock type in the study area that shares similar magnetic properties with the ultramafic rock. The aerogeophysical model results are compared to the distribution of ultramafic outcrops and to Cr, Ni, K, Th and U concentrations and magnetic susceptibility measurements from soil samples. Analysis of the soil data indicates high positive correlation between

Development of gamma spectrometer using silicon photomultiplier (SiPM)

International Nuclear Information System (INIS)

Kim, Chan Kyu

2011-02-01

Gamma spectroscopy is used to determine the identity and quantity of gamma-emitters in nuclear physics, geochemistry and astrophysics. The scintillation detectors are being used as a gamma spectrometer generally, because of their higher gamma-ray detection efficiency and cheaper price than germanium semi-conductor detectors. A typical scintillation detector is composed of a scintillator, a window, and a photodetector. The photomultiplier (PM) tube has been the most widely used as a photodetector because of its advantages like high sensitivity, high signal-to-noise ratio, and wide dynamic range. Recently, the Silicon Photomultiplier (SiPM) is being studied as a substitute of PM tube. The SiPM has almost same performance compared to PM tube but it has additional advantages; low operating voltage, small volume, and cheap production cost. In this research, the gamma spectrometer using SiPM instead of PM tube is developed. The use of SiPM as a photodetector makes the gamma spectrometer smaller, cheaper, easier to use. For photon transport and collection from the large area scintillator to the small area SiPM, a light guide is applied in this gamma spectrometer system. Before fabrication of light guide, DETECT simulation is performed to study and prospect characteristics of light guide structure. And actual light guides are fabricated on the basis of this simulation result. Poly(methyl methacrylate) (PMMA) is chosen as material of light guide, 5 sample light guides are fabricated in different lengths and coatings. As a scintillator crystal, same NaI(Tl) crystal is chosen. For measurement and analysis of gamma spectrometer system, 3 gamma spectrometer systems are composed: PM tube-based system, PM tube-based system with the light guide, SiPM-based system with the light guide. Through comparison between the results of each gamma spectrometer, the performances of gamma spectrometer system are analyzed by each component. Measurement results of the second system is well

A New Method for Processing Airborne Gamma Ray Spectrometry Data for Mapping Low Level Contaminations

DEFF Research Database (Denmark)

Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim

1999-01-01

A new technique for processing airborne gamma ray spectrometry data has been developed. It is based on the noise adjusted singular value decomposition method introduced by Hovgaard in 1997. The new technique opens for mapping of very low contamination levels. It is tested with data from Latvia...... where the remaining contamination from the 1986 Chernobyl accident together with fallout from the atmospheric nuclear weapon tests includes Cs-137 at levels often well below 1 kBq/m(2) equivalent surface contamination. The limiting factors for obtaining reliable results are radon in the air, spectrum...

Evidence for solar flare directivity from the Gamma-Ray Spectrometer aboard the SMM satellite

Science.gov (United States)

Vestrand, W. T.; Forrest, D. J.; Chupp, E. L.; Rieger, E.; Share, G. H.

1986-01-01

A number of observations from the SMM Gamma-Ray Spectrometer are presented that altogether strongly indicate that the high-energy emission from flares is anisotropic. They are: (1) the fraction of events detected at energies above 300 keV near the limb is significantly higher than is expected for isotropically emitting flares; (2) there is a statistically significant center-to-limb variation in the 300-1000-keV spectra of flares; and (3) nearly all of the events detected at above 10 MeV are located near the limb.

Methods for fitting of efficiency curves obtained by means of HPGe gamma rays spectrometers

International Nuclear Information System (INIS)

Cardoso, Vanderlei

2002-01-01

The present work describes a few methodologies developed for fitting efficiency curves obtained by means of a HPGe gamma-ray spectrometer. The interpolated values were determined by simple polynomial fitting and polynomial fitting between the ratio of experimental peak efficiency and total efficiency, calculated by Monte Carlo technique, as a function of gamma-ray energy. Moreover, non-linear fitting has been performed using a segmented polynomial function and applying the Gauss-Marquardt method. For the peak area obtainment different methodologies were developed in order to estimate the background area under the peak. This information was obtained by numerical integration or by using analytical functions associated to the background. One non-calibrated radioactive source has been included in the curve efficiency in order to provide additional calibration points. As a by-product, it was possible to determine the activity of this non-calibrated source. For all fittings developed in the present work the covariance matrix methodology was used, which is an essential procedure in order to give a complete description of the partial uncertainties involved. (author)

Airborne gamma ray spectrometry in certain areas of the Islamic Republic of Iran and its results - correlation to the other usages

International Nuclear Information System (INIS)

Soleimani, G.; Yegani, F.S.

1997-01-01

Airborne survey can be utilized as a multipurpose data in different fields such as exploration, health physics, environmental studies and so on. The well known advantages of airborne survey include rapidity, more extent of surveyed area, the possibility of application in unaccessible regions where no other methods can be utilized. More than one third of Iran territory i.e. about 600,000 km 2 has been surveyed by magnetic and spectral gamma ray airborne. This survey is one of the largest and most highly specified survey of its type ever attempted. Extremely large quantities of data were generated during the survey which can be used as a baseline information. (author)

Low background gamma ray spectrometer using the anticoincidence shield technique at KAERI

International Nuclear Information System (INIS)

Byun, Jong In; Choi, Yun Ho; Kwak, Seung Im; Hwang, Han Yull; Chung, Kun Ho; Choi, Geun Sik; Park, Doo Won; Lee, Chang Woo

2002-01-01

We develop a ultra-low background gamma ray spectrometer, using active and passive shielding technique at the same time. Cosmic ray induced background is suppressed by means of active shield devices consisting of plastic scintillating plates of 50 mm thick and anti-coincidence electronic system. The shield is made of 150 mm thick walls of very low activity lead, especially 20 mm with activity of -1 and 0.36 s -1 with and without active shield, respectively, on the regions from 50 keV to 3 MeV. The detection efficiency curve has been precisely measured for regions from 80 keV to 2 MeV with a 10 3 ml marinelli beaker sample, made with calibrated mixed-sources consists of 109 Cd, 57 Co, 139 Ce, 203 Hg, 113 Sn, 85 Sr, 137 Cs, 60 Co and 88 Y. The virtues of the method are demonstrated by applying on experiment that requires the lowest detection limit

Polarimetric Analysis of the Long Duration Gamma-Ray Burst GRB 160530A With the Balloon Borne Compton Spectrometer and Imager

Energy Technology Data Exchange (ETDEWEB)

Lowell, A. W.; Boggs, S. E; Chiu, C. L.; Kierans, C. A.; Sleator, C.; Tomsick, J. A.; Zoglauer, A. C. [Space Sciences Laboratory, University of California, Berkeley (United States); Chang, H.-K.; Tseng, C.-H.; Yang, C.-Y. [Institute of Astronomy, National Tsing Hua University, Taiwan (China); Jean, P.; Ballmoos, P. von [IRAP Toulouse (France); Lin, C.-H. [Institute of Physics, Academia Sinica, Taiwan (China); Amman, M. [Lawrence Berkeley National Laboratory (United States)

2017-10-20

A long duration gamma-ray burst, GRB 160530A, was detected by the Compton Spectrometer and Imager (COSI) during the 2016 COSI Super Pressure Balloon campaign. As a Compton telescope, COSI is inherently sensitive to the polarization of gamma-ray sources in the energy range 0.2–5.0 MeV. We measured the polarization of GRB 160530A using (1) a standard method (SM) based on fitting the distribution of azimuthal scattering angles with a modulation curve and (2) an unbinned, maximum likelihood method (MLM). In both cases, the measured polarization level was below the 99% confidence minimum detectable polarization levels of 72.3% ± 0.8% (SM) and 57.5% ± 0.8% (MLM). Therefore, COSI did not detect polarized gamma-ray emission from this burst. Our most constraining 90% confidence upper limit on the polarization level was 46% (MLM).

Computers in activation analysis and gamma-ray spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Carpenter, B. S.; D' Agostino, M. D.; Yule, H. P. [eds.

1979-01-01

Seventy-three papers are included under the following session headings: analytical and mathematical methods for data analysis; software systems for ..gamma..-ray and x-ray spectrometry; ..gamma..-ray spectra treatment, peak evaluation; least squares; IAEA intercomparison of methods for processing spectra; computer and calculator utilization in spectrometer systems; and applications in safeguards, fuel scanning, and environmental monitoring. Separate abstracts were prepared for 72 of those papers. (DLC)

Multi-dimensional analysis of high resolution {gamma}-ray data

Energy Technology Data Exchange (ETDEWEB)

Flibotte, S.; Huettmeier, U.J.; France, G. de; Haas, B.; Romain, P.; Theisen, Ch.; Vivien, J.P.; Zen, J. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires

1992-12-31

A new generation of high resolution {gamma}-ray spectrometers capable of recording high-fold coincidence events with a large efficiency will soon be available. Algorithms are developed to analyze high-fold {gamma}-ray coincidences. As a contribution to the software development associated with the EUROGAM spectrometer, the performances of computer codes designed to select multi-dimensional gates from 3-, 4- and 5-fold coincidence databases were tested. The tests were performed on events generated with a Monte Carlo simulation and also on real experimental triple data recorded with the 8{pi} spectrometer and with a preliminary version of the EUROGAM array. (R.P.) 14 refs.; 3 figs.; 3 tabs.

Fast neutron and gamma-ray spectra measurements with a NE-213 spectrometer in the FNG Copper Benchmark Experiment

International Nuclear Information System (INIS)

Klix, Axel; Angelone, Maurizio; Fischer, Ulrich; Pillon, Mario

2016-01-01

Highlights: • Fast neutron and gamma-ray spectra were measured in a copper assembly irradiated with DT neutrons. • The results were compared with MCNP calculations. • Primary aim was to provide experimental data for checking and validation of nuclear data evaluations of copper. - Abstract: A neutronics benchmark experiment on a pure Copper assembly was performed at the Frascati Neutron Generator. The work aimed at testing of recent nuclear data libraries. This paper focuses on the measurement of fast neutron and gamma-ray flux spectra in the Copper assembly under DT neutron irradiation in two selected positions with a spectrometer based on the organic liquid scintillator NE-213. The measurement results were compared with Monte Carlo radiation transport calculations using MCNP and nuclear data from the JEFF-3.1.1 library. Calculations have been done with Cu data from JEFF-3.1.1, JEFF-3.2, FENDL-3 and ENDF/B-7.0. Discrepancies appear in the intermediate neutron energy range between experiment and calculation. Large discrepancies were observed in the gamma-ray spectra calculated with JEFF-3.2.

Fast neutron and gamma-ray spectra measurements with a NE-213 spectrometer in the FNG Copper Benchmark Experiment

Energy Technology Data Exchange (ETDEWEB)

Klix, Axel, E-mail: axel.klix@kit.edu [Karlsruhe Institute of Technology, Institute for Neutron Physics and Reactor Technology Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Angelone, Maurizio [ENEA Dipartimento Fusione e Tecnologie per la Sicurezza Nucleare, C.R. Frascati, via E. Fermi 45, 00044 Frascati (Italy); Fischer, Ulrich [Karlsruhe Institute of Technology, Institute for Neutron Physics and Reactor Technology Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Pillon, Mario [ENEA Dipartimento Fusione e Tecnologie per la Sicurezza Nucleare, C.R. Frascati, via E. Fermi 45, 00044 Frascati (Italy)

2016-11-01

Highlights: • Fast neutron and gamma-ray spectra were measured in a copper assembly irradiated with DT neutrons. • The results were compared with MCNP calculations. • Primary aim was to provide experimental data for checking and validation of nuclear data evaluations of copper. - Abstract: A neutronics benchmark experiment on a pure Copper assembly was performed at the Frascati Neutron Generator. The work aimed at testing of recent nuclear data libraries. This paper focuses on the measurement of fast neutron and gamma-ray flux spectra in the Copper assembly under DT neutron irradiation in two selected positions with a spectrometer based on the organic liquid scintillator NE-213. The measurement results were compared with Monte Carlo radiation transport calculations using MCNP and nuclear data from the JEFF-3.1.1 library. Calculations have been done with Cu data from JEFF-3.1.1, JEFF-3.2, FENDL-3 and ENDF/B-7.0. Discrepancies appear in the intermediate neutron energy range between experiment and calculation. Large discrepancies were observed in the gamma-ray spectra calculated with JEFF-3.2.

Determination of correction factor of radioelement content data generated from Exploranium GR-320 Gamma spectrometer

International Nuclear Information System (INIS)

Nasrun, S; Syamsul-Hadi, M; Sumardi

2000-01-01

Gamma-ray Spectrometer Exploranium GR-320 is the instrument radiometric survey which is able to measure radioelement content directly in field based on partial gamma-ray energy of elements. Because of the instrument is new and it was granted from the lAEA, so it is necessarily to create a correction factor for the instrument due to be gaining the better data. Correction factor was generated from comparing gamma spectrometer's radioelement content to those of chemical analysed data of calibration pad. The correction factor for Potassium (K) is 1.31, uranium is 1.46, and thorium is 0.39

Exploring atmospheric radon with airborne gamma-ray spectroscopy

Science.gov (United States)

Baldoncini, Marica; Albéri, Matteo; Bottardi, Carlo; Minty, Brian; Raptis, Kassandra G. C.; Strati, Virginia; Mantovani, Fabio

2017-12-01

222Rn is a noble radioactive gas produced along the 238U decay chain, which is present in the majority of soils and rocks. As 222Rn is the most relevant source of natural background radiation, understanding its distribution in the environment is of great concern for investigating the health impacts of low-level radioactivity and for supporting regulation of human exposure to ionizing radiation in modern society. At the same time, 222Rn is a widespread atmospheric tracer whose spatial distribution is generally used as a proxy for climate and pollution studies. Airborne gamma-ray spectroscopy (AGRS) always treated 222Rn as a source of background since it affects the indirect estimate of equivalent 238U concentration. In this work the AGRS method is used for the first time for quantifying the presence of 222Rn in the atmosphere and assessing its vertical profile. High statistics radiometric data acquired during an offshore survey are fitted as a superposition of a constant component due to the experimental setup background radioactivity plus a height dependent contribution due to cosmic radiation and atmospheric 222Rn. The refined statistical analysis provides not only a conclusive evidence of AGRS 222Rn detection but also a (0.96 ± 0.07) Bq/m3 222Rn concentration and a (1318 ± 22) m atmospheric layer depth fully compatible with literature data.

The Danish airborne gamma-ray surveying results

Energy Technology Data Exchange (ETDEWEB)

Hovgaard, J. [Danish Emergency Management Agency, Birkeroed (Denmark)

1997-12-31

The Danish Emergency Management Agency (DEMA) in co-operation with the Technical University of Denmark (TUD), Department of Automation, participated in the international exercise RESUME-95 arranged in Finland in August 1995. DEMA performed measurement with their airborne gamma-ray surveying system. Surveys were done in the three areas known as AREA I, II, III. Results from AREA II (3 km x 6 km) show that the apparent {sup 137}Cs deposition assuming a deposition profile equal to the profile in AREA I based on soil samples varies from a few 10th kBqm{sup -2} up to 110 kBqm{sup -2}. However, a detailed analysis using a new method, Noise Adjusted Singular Value Decomposition (NASVD), shows that the true variations probably are smaller and that the observed differences to some extend are due to major variations in the depth distribution of the cesium. For example agricultural areas appears to have cesium much deeper deposit than the undisturbed areas. Another interesting result is that the NASVD analysis shows that the ration of {sup 134}Cs to {sup 137}Cs is fixed and approximately 0.03 (August 1995) a number in good agreement with the expected ratio from the Chernobyl accident. No true real-time software for source detection is yet integrated in the Danish system. Results from AREA III, however, show that the implemented software for rapid post processing of data worked excellent for detection of radioactive sources. Post analysis using NASVD demonstrates that all sources except for a small {sup 137}Cs source can be localized. (au).

The Danish airborne gamma-ray surveying results

Energy Technology Data Exchange (ETDEWEB)

Hovgaard, J [Danish Emergency Management Agency, Birkeroed (Denmark)

1998-12-31

The Danish Emergency Management Agency (DEMA) in co-operation with the Technical University of Denmark (TUD), Department of Automation, participated in the international exercise RESUME-95 arranged in Finland in August 1995. DEMA performed measurement with their airborne gamma-ray surveying system. Surveys were done in the three areas known as AREA I, II, III. Results from AREA II (3 km x 6 km) show that the apparent {sup 137}Cs deposition assuming a deposition profile equal to the profile in AREA I based on soil samples varies from a few 10th kBqm{sup -2} up to 110 kBqm{sup -2}. However, a detailed analysis using a new method, Noise Adjusted Singular Value Decomposition (NASVD), shows that the true variations probably are smaller and that the observed differences to some extend are due to major variations in the depth distribution of the cesium. For example agricultural areas appears to have cesium much deeper deposit than the undisturbed areas. Another interesting result is that the NASVD analysis shows that the ration of {sup 134}Cs to {sup 137}Cs is fixed and approximately 0.03 (August 1995) a number in good agreement with the expected ratio from the Chernobyl accident. No true real-time software for source detection is yet integrated in the Danish system. Results from AREA III, however, show that the implemented software for rapid post processing of data worked excellent for detection of radioactive sources. Post analysis using NASVD demonstrates that all sources except for a small {sup 137}Cs source can be localized. (au).

Gamma-ray tracking: Characterisation of the AGATA symmetric prototype detectors

International Nuclear Information System (INIS)

Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Dimmock, M.R.; Nelson, L.; Nolan, P.J.; Rigby, S.; Lazarus, I.; Simpson, J.; Medina, P.; Santos, C.; Parisel, C.

2007-01-01

Each major technical advance in gamma-ray detection devices has resulted in significant new insights into the structure of atomic nuclei. The next major step in gamma-ray spectroscopy involves achieving the goal of a 4pi ball of Germanium detectors by using the technique of gamma-ray energy tracking in electrically segmented Germanium crystals. The resulting spectrometer will have an unparalleled level of detection power for nuclear electromagnetic radiation. Collaborations have been established in Europe (AGATA) [J. Simpson, Acta Phys. Pol. B 36 (2005) 1383. ] and the USA (GRETA/GRETINA) to build gamma-ray tracking spectrometers. This paper discusses the performance of the AGATA (Advanced Gamma Tracking Array) symmetric prototype detectors that have been tested at University of Liverpool. The use of a fully digital data acquisition system has allowed detector charge pulse shapes from a selection of well defined photon interaction positions to be analysed, yielding important information on the position sensitivity of the detector

Gamma-ray tracking: Characterisation of the AGATA symmetric prototype detectors

Energy Technology Data Exchange (ETDEWEB)

Boston, A.J. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom)]. E-mail: ajboston@liv.ac.uk; Boston, H.C. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom); Cresswell, J.R. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom); Dimmock, M.R. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom); Nelson, L. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom); Nolan, P.J. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom); Rigby, S. [Oliver Lodge Laboratory, University of Liverpool, Oxford Street, Liverpool L69 7ZE (United Kingdom); Lazarus, I. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Medina, P. [Institut de Recherches Subatomiques, Strasbourg BP28 67037 (France); Santos, C. [Institut de Recherches Subatomiques, Strasbourg BP28 67037 (France); Parisel, C. [Institut de Recherches Subatomiques, Strasbourg BP28 67037 (France)

2007-08-15

Each major technical advance in gamma-ray detection devices has resulted in significant new insights into the structure of atomic nuclei. The next major step in gamma-ray spectroscopy involves achieving the goal of a 4pi ball of Germanium detectors by using the technique of gamma-ray energy tracking in electrically segmented Germanium crystals. The resulting spectrometer will have an unparalleled level of detection power for nuclear electromagnetic radiation. Collaborations have been established in Europe (AGATA) [J. Simpson, Acta Phys. Pol. B 36 (2005) 1383. ] and the USA (GRETA/GRETINA) to build gamma-ray tracking spectrometers. This paper discusses the performance of the AGATA (Advanced Gamma Tracking Array) symmetric prototype detectors that have been tested at University of Liverpool. The use of a fully digital data acquisition system has allowed detector charge pulse shapes from a selection of well defined photon interaction positions to be analysed, yielding important information on the position sensitivity of the detector.

Long-term variations in the gamma-ray background on SMM

Science.gov (United States)

Kurfess, J. D.; Share, G. H.; Kinzer, R. L.; Johnson, W. N.; Adams, J. H., Jr.

1989-01-01

Long-term temporal variations in the various components of the background radiation detected by the gamma-ray spectrometer on the Solar Maximum Mission are presented. The SMM gamma-ray spectrometer was launched in February, 1980 and continues to operate normally. The extended period of mission operations has provided a large data base in which it is possible to investigate a variety of environmental and instrumental background effects. In particular, several effects associated with orbital precession are introduced and discussed.

The calculation of external gamma-ray doses from airborne and deposited radionuclides in the environmental code NECTAR

International Nuclear Information System (INIS)

Corbett, J.O.

1982-02-01

A computer program has been developed for the rapid evaluation of external gamma-ray doses from airborne and deposited radionuclide mixtures. Based on a gaussian dispersion model, the program calculates the dose at any position, including points high above ground level or upwind of the source. Meteorological frequency data for wind speed, direction, atmospheric stability and rainfall are fully taken into account. The calculational model assumes that the ground surface is perfectly flat and that gamma-ray paths are entirely in air; the possible errors caused by these and other assumptions are discussed, with suggested correction factors. The program applies various criteria to determine the best approximation or numerical integration method for each target point; execution times (on an IBM 370 machine) thus vary from less than 0.01s to about 0.3s per target point for a single weather category. The program has been incorporated in the environmental release program NECTAR. (author)

Gamma-ray remote sensing of soil properties in a forested area near Batlow, NSW

International Nuclear Information System (INIS)

Bierwirth, P.N.; Aspin, S.J.; Ryan, P.J.; McKenzie, N.J.

1998-01-01

In forested and agricultural areas, reflective remote sensing methods are of limited utility for soil studies due to the variable effects of vegetation. Airborne gamma-ray remote sensing is presented here as a useful technique for soils. Short wavelength gamma-rays are detected from the upper 0.30-0.45 m of the soil . They are emitted from radioactive elements in the soil and largely pass through vegetation cover. In this paper, images of gamma parent elements (K, Th and U) are presented and element associations with soil properties and vegetation are analysed for a forested area near Batlow, NSW. Effects of vegetation are evident in gamma-ray data and in Landsat TM along powerlines and in clearings. A technique for removing this effect in the gamma-ray data is demonstrated. Detailed soil and rock chemistry together with ground gamma-spectrometer measurements were collected to support the interpretation and analysis of the image data. The work focuses mainly on the variation of soil properties within areas mapped as granodiorite lithology. Many areas of deep red soils are accurately mapped by the radiometric K data. The precise origin of these soils is not clear and their parent materials may include contributions from aeolian deposition, in situ weathering of granodiorite, and remnant basalt. . In areas of granodiorite, K patterns are interpreted to be a function of the degree of mineral weathering and can be related to soil depth and erosion status. This study demonstrates the effectiveness of gamma-ray remote sensing for directly mapping soil units and properties (authors). Copyright (1998) Remote Sensing and Photogrammetry Association of Australasia Ltd

A mobile gamma ray spectrometer system for nuclear hazard mapping

International Nuclear Information System (INIS)

Smethurst, Mark A.

2000-12-01

The Geological Survey of Norway has developed a system for mobile gamma ray spectrometer surveying suitable for use in nuclear emergencies where potentially dangerous radioactive materials have been released into the environment. The measuring system has been designed for use with different kinds of transportation platforms. These include fixed-wing aircraft, helicopters and vans. The choice of transportation platform depends on the nature of the nuclear emergency. Widespread fallout from a distant source can be mapped quickly from the air while local sources of radiation can be delineated by a car-borne system. The measuring system processes gamma ray spectra in real time. The operator of the system is therefore able to guide surveying in accordance with meaningful data values and immediately report these values to decision making authorities. The operator is presented with a number of different displays suited to different kinds of nuclear emergencies that lead to more efficient surveying. Real time processing of data means that the results of a survey can be delivered to decision makers immediately upon return to base. It is also possible to deliver data via a live mobile telephone link while surveying is underway. The measuring system can be adjusted to make measurements lasting between 1 second and 5 seconds. The spatial density of measuring positions depends on the duration of each measurement and the speed of travel of the measuring system. Measuring with 1 s intervals while travelling at 50 km/h in a car results in a measurement every 14 m along the road. Measuring with 1 s intervals in an aeroplane travelling at 250 km/h produces a measurement for every 70 m travelled. Eight hours surveying can produce up to 30000 measurements over a region hundreds of kilometres across. (Author)

Quantitative Cs-137 distributions from airborne gamma ray data

International Nuclear Information System (INIS)

Oberlercher, G.; Seiberl, W.

1997-01-01

The Chernobyl reactor accident caused in Austria Cs-137 activities up to 180 kBq/m 2 . The following paper explains how airborne NaJ-spectroscopy, originally designed for geological surveys, was used as an accurate method to obtain the ground activity of Cs-137 in certain regions of Austria. To retrieve the net count rate in a Cs-137 window it is necessary to subtract all background contributions from the peak, including the Compton continuum and the contribution of overlapping peaks. Therefore the measurement of Cs-137 with a NaJ detector system must take into account radioactive elements with gamma-ray lines near the peak energy of Cs-137 at 662 keV. In regions with higher concentrations of the natural radioactive elements uranium and thorium a peak near 600 keV is found, containing the 609 keV line of Bi-214 and the 585 keV line of TI-208. Additionally a Cs-134 line is located at 604 keV. Because of the poor energy resolution of NaJ detectors it is not possible to find a clear separation between these peaks and the Cs-137 peak. The following section describes the method that was used to obtain accurate quantified Cs-137 activity values. (author)

Gamma ray spectroscopy with Arduino UNO

Science.gov (United States)

Lavelle, C. M.

2018-05-01

We review a simple gamma ray spectrometer constructed on a solderless breadboard. The spectrometer's detector consists of a CsI(Tl) scintillator and silicon photomultiplier (SiPM) and its readout is facilitated by an Arduino UNO. The system is low cost and utilizes a minimum of components while still achieving satisfactory charge linearity and noise levels. This instrument can be used in instructional laboratories to introduce both radiation detection and analog signal processing concepts. We also expect it will be of interest to those seeking to introduce gamma spectroscopy to the expanding ecosystem of Arduino hardware.

Environmental monitoring system based on airborne gamma ray spectrometry developed at Geoinstitut Beograd

International Nuclear Information System (INIS)

Milojevic, M.; Strumberger, V.

1997-01-01

The continuous hazard of nuclear reactor failures, which may exceed in consequences that of the Chernobyl accident on 26 April 1986, makes it imperative for us to develop and introduce soil, water and air contamination control systems to protect the environment. A most efficient means of the contamination control at the artificial radioactive radiation sources is the complex MONITORING SYSTEM controlled from a centre by competent and recognised experts. Such systems have been used for years now many western world countries (USA, Canada, Sweden, etc.). The modest purpose of this paper is at least to leave a trace of the efforts, both individual and of the institute, made in developing a component of the monitoring system - airborne gamma-ray contamination control, which in western systems is a principal technique of remote detection. (author)

Use of Airborne Gamma-Ray Spectrometry in case of emergency. Example of HELGA exercise - collaboration between France and Germany

International Nuclear Information System (INIS)

Guillot, L.

2004-01-01

Since Chernobyl accident, airborne gamma-ray spectrometry has been recognised as a useful tool to evaluate consequences of an accident over large areas. Nine European countries have capabilities to perform such measurements. Between 1996 and 2003, a collaboration between these teams was supported by European community. In 2002, an exercise involving airborne and ground-based measurements was organised in Scotland. This exercise demonstrated the ability of European countries to provide assistance to one of them in case of emergency. Since this project has been completed, the French and German team decided to continue a collaboration. The CEA team (France) went in Germany in 2003 to participate to a survey with the German team. In September 2004, an exercise including mapping of contaminated areas and orphan sources search is planned in France. Such actions are good opportunities to exchange technical information about the acquisition systems and operating procedures. It is also essential to improve the availability of teams to obtain comparable and compatible results. The AGRS (airborne gamma ray spectrometry) systems involved in this exercise will be described and compared in this paper. The capacity of teams to work in collaboration in various situation (orphan source search, contamination mapping) will be then evaluated. In particular, a European Radiometric and Spectrometry format defined during Eccomags project will be used to create a database of raw and processed data. The aim is to produce quickly composite maps with data recorded by different teams. A choice of results will be presented and an assessment of capability of teams to work in collaboration will be done. (author)

Very high energy gamma ray astrophysics

International Nuclear Information System (INIS)

Lamb, R.C.; Lewis, D.A.

1991-01-01

The Whipple Observatory High Resolution Camera will be used in a vigorous program of observations to search for new sources of very-high-energy gamma rays. In addition, a search for antimatter using the moon-earth system as an ion spectrometer will be begun. The first phase of GRANITE, the new 37-element 11-m camera, will be concluded with first light scheduled for September, 1991. The two cameras will operate in support of the Gamma Ray Observatory mission in the winter of 1991/2

Aircraft gamma-ray spectrometry in snow-water equivalent measurement

International Nuclear Information System (INIS)

Kuittinen, R.; Vironmaeki, J.

1979-01-01

During the winter periods 1976-1977 and 1977-1978 the Hydrological Office at the National Board of Waters and the Geological Survey of Finland carried out a joint study to evaluate usefuluess of gamma-ray spectrometry in snow-water equivalent measurement. A multichannel gamma-ray spectrometer was fitted in a DC-3 aircraft. Fourteen snow courses were operated using both the gravimetric method and the gamma-ray method. The snow courses were located in southern Finland in forest, swamp and agricultural land. The results shows that the gamma ray method can be considered suitable for use in Finnish conditions and the accuracy of the gamma-ray method is almost of the same magnitude as the accuracy of the gravimetric method. (Auth.)

Aircraft gamma-ray spectrometry in snow-water equivalent measurement

Energy Technology Data Exchange (ETDEWEB)

Kuittinen, R [National Board of Waters (Finland); Vironmaeki, J [Geological Survey of Finland

1979-01-01

During the winter periods 1976-1977 and 1977-1978 the Hydrological Office at the National Board of Waters and the Geological Survey of Finland carried out a joint study to evaluate usefuluess of gamma-ray spectrometry in snow-water equivalent measurement. A multichannel gamma-ray spectrometer was fitted in a DC-3 aircraft. Fourteen snow courses were operated using both the gravimetric method and the gamma-ray method. The snow courses were located in southern Finland in forest, swamp and agricultural land. The results shows that the gamma ray method can be considered suitable for use in Finnish conditions and the accuracy of the gamma-ray method is almost of the same magnitude as the accuracy of the gravimetric method.

High resolution gamma-ray spectroscopy applied to bulk sample analysis

International Nuclear Information System (INIS)

Kosanke, K.L.; Koch, C.D.; Wilson, R.D.

1980-01-01

A high resolution Ge(Li) gamma-ray spectrometer has been installed and made operational for use in routine bulk sample analysis by the Bendix Field Engineering Corporation (BFEC) geochemical analysis department. The Ge(Li) spectrometer provides bulk sample analyses for potassium, uranium, and thorium that are superior to those obtained by the BFEC sodium iodide spectrometer. The near term analysis scheme permits a direct assay for uranium that corrects for bulk sample self-absorption effects and is independent of the uranium/radium disequilibrium condition of the sample. A more complete analysis scheme has been developed that fully utilizes the gamma-ray data provided by the Ge(Li) spectrometer and that more properly accounts for the sample self-absorption effect. This new analysis scheme should be implemented on the BFEC Ge(Li) spectrometer at the earliest date

Review of superconducting transition-edge sensors for x-ray and gamma-ray spectroscopy

International Nuclear Information System (INIS)

Ullom, Joel N; Bennett, Douglas A

2015-01-01

We present a review of emerging x-ray and gamma-ray spectrometers based on arrays of superconducting transition-edge sensors (TESs). Special attention will be given to recent progress in TES applications and in understanding TES physics. (paper)

Data management and analysis techniques used in the near X-ray and gamma-ray spectrometer systems

International Nuclear Information System (INIS)

McClanahan, T.P.; Trombka, J.I.; Floyd, S.R.; Boynton, W.V.; Mikheeva, I.; Bailey, H.; Liewicki, C.; Bhangoo, J.; Starr, R.; Clark, P.E.; Evans, L.G.; Squyres, S.; McNutt, R.; Brueckner, J.

1999-01-01

The NEAR Earth Asteroid Rendezvous (NEAR) spacecraft will encounter the 433Eros asteroid for a one year orbital mission in December 1998. Its on-board remote sensing instrumentation includes X-ray and gamma-ray (XGRS) spectrometers. NEAR is an orbital mission and long integrations over spatially specific asteroid regions are generally not possible. A methodology for simulating longer integrations has been developed for XGRS and uses unique management, correlative and analytical ground systems to render mapping data products. Evaluation of the spatial environment is accomplished through virtual renderings of the asteroid surface giving incidence, emission and surface roughness factors. Extended computer plate modeling information is employed to optimize ground computer systems processing time. Interactive visualization systems have been developed to manage close to a million spectra that will be collected during the encounter. Feedback systems are employed to inspect, tag and calibrate spectral data products. Mission planning, systems development and managerial responsibilities have been distributed to cooperating science organizations at The Goddard Space Flight Center, The University of Arizona, Cornell University, The Applied Physics Laboratory and The Max Plank Institute

Search for Doppler-shifted gamma-ray emission from SS 433 using the SMM spectrometer

International Nuclear Information System (INIS)

Geldzahler, B.J.; Share, G.H.; Kinzer, R.L.; Magura, J.; Chupp, E.L.

1989-01-01

Data accumulated from 1980 to 1983 with the Gamma Ray Spectrometer aboard NASA's Solar Maximum Mission (SMM) satellite were searched for evidence of red and blue Doppler-shifted 1.37 MeV Mg-24 nuclear lines from SS 433. The SMM data base covers 270 days when SS 433 was in the field of view and includes periods of radio flaring and quiescence. No evidence was found for Doppler-shifted line emission in any of the spectra. The range of 3-sigma upper limits for individual 9 day integration periods was 0.0008-0.0023 photons/sq cm per sec for the blue beam, encompassing the reported about 1.5 MeV line, and 0.0008-0.002 photons/sq cm per sec for the red beam, encompassing the reported about 1.2 MeV line; the average 3-sigma upper limit in each beam for shifted about 1.37 MeV lines is 0.0015 photons/sq cm per sec for single 9 day integrations. The 3-sigma upper limit on 1.37 MeV gamma-ray emission over 23 9-day integration intervals for the red beam and 28 intervals for the blue beam is 0.0002 photons/sq cm per sec. These new limits from SMM can be reconciled with the HEAO 3 results only if SS 433 emits gamma radiation at or above the SMM sensitivity limit on rare occasions due to variable physical conditions in the system. 19 refs

Search for Doppler-shifted gamma-ray emission from SS 433 using the SMM spectrometer

Science.gov (United States)

Geldzahler, B. J.; Share, G. H.; Kinzer, R. L.; Magura, J.; Chupp, E. L.

1989-01-01

Data accumulated from 1980 to 1983 with the Gamma Ray Spectrometer aboard NASA's Solar Maximum Mission (SMM) satellite were searched for evidence of red and blue Doppler-shifted 1.37 MeV Mg-24 nuclear lines from SS 433. The SMM data base covers 270 days when SS 433 was in the field of view and includes periods of radio flaring and quiescence. No evidence was found for Doppler-shifted line emission in any of the spectra. The range of 3-sigma upper limits for individual 9 day integration periods was 0.0008-0.0023 photons/sq cm per sec for the blue beam, encompassing the reported about 1.5 MeV line, and 0.0008-0.002 photons/sq cm per sec for the red beam, encompassing the reported about 1.2 MeV line; the average 3-sigma upper limit in each beam for shifted about 1.37 MeV lines is 0.0015 photons/sq cm per sec for single 9 day integrations. The 3-sigma upper limit on 1.37 MeV gamma-ray emission over 23 9-day integration intervals for the red beam and 28 intervals for the blue beam is 0.0002 photons/sq cm per sec. These new limits from SMM can be reconciled with the HEAO 3 results only if SS 433 emits gamma radiation at or above the SMM sensitivity limit on rare occasions due to variable physical conditions in the system.

System for Gamma an X rays fluorescence spectrometric

International Nuclear Information System (INIS)

Alonso Abad, D.; Arista Romeu, E.; Bolanos Perez, L. and others

1997-01-01

A system for spectrometry of gamma or fluorescence X rays is presented. It sis composed by a Si(Li) semiconductors detector, a charge sensitive preamplifier, a high voltage power supply, a spectrometric amplifier and a monolithic 1024 channels multichannel analyzers or an IBM compatible 4096 channels add - on- card multichannel analyzer. The system can be configured as a 1024 or 4096 channels gamma or fluorescent X rays spectrometer

The gamma ray spectrometer GA.SP

International Nuclear Information System (INIS)

Bazzacco, D.

1992-01-01

GA.SP is a general purpose 4π detector array for advanced γ-spectroscopy and, in the same time, a suitable system for reaction mechanism studies. The detector is sited at the LNL Tandem+Linac accelerator and has been built as a joint project of INFN Padova, LNL, Milano and Firenze. The array consists of 40 Compton suppressed HPGe detectors and of a 4π calorimeter composed of 80 BGO crystals. The detector houses a reaction chamber of 34 cm diameter where a charged particles multiplicity filter composed of 40 Si detectors is going to be installed. Evaporation residues produced in the centre of GA.SP can be injected into the recoil mass spectrometer (RMS, named CAMEL) in use at LNL, without the need to remove any of the gamma detectors. The coupled operation of GA.SP, RMS and Si ball will give a unique instrument for identification and study of weak reaction channels. (author). 6 figs

GammaLog Playback 1.0 - mobile gamma ray spectrometry software

International Nuclear Information System (INIS)

Watson, R.J.; Smethurst, M.A.

2011-01-01

The Geological Survey of Norway (NGU) operates a mobile gamma ray spectrometer system which can be used in nuclear emergency situations to determine the location and type of orphan sources, or the extent and type of fallout contamination. The system consists of a 20 litre (16 litre downward and 4 litre upward looking) RSX-5 NaI detector and spectrometer, and can be mounted in fixed wing aircraft, helicopters, or vans/cars as appropriate. NGU has developed its own data acquisition and analysis software for this system. GammaLog (Smethurst 2005) controls the acquisition, display, and storage of data from the spectrometer, and performs real-time data analysis including estimation of dose rates and fallout concentrations, and separation of geological and anthropogenic components of the signal. The latter is particularly important where the geological radioisotope signal varies strongly from one place to another, and makes it easier to locate and identify anthropogenic sources which might otherwise be difficult to separate from the geological background signal. A modified version of GammaLog has been developed, GammaLog Playback, which allows the replay of previously acquired GammaLog datasets, while performing similar processing and display as the GammaLog acquisition software. This allows datasets to be reviewed and compared in the field or during post-survey analysis to help plan subsequent measurement strategies.(Au)

Measuring the energies and multiplicities of prompt gamma-ray emissions from neutron-induced fission of $^{235}$U using the STEFF spectrometer

CERN Document Server

AUTHOR|(CDS)2093036; Smith, Alastair Gavin; Wright, Tobias James

Following a NEA high priority nuclear data request, an experimental campaign to measure the prompt $\\gamma$-ray emissions from $^{235}$U has been performed. This has used the STEFF spectrometer at the new Experimental Area 2 (EAR2) within the neutron timeof-flight facility (n_TOF), a white neutron source facility at CERN with energies from thermal to approximately 1 GeV. Prior to the experimental campaign, STEFF has been optimised for the environment of EAR2. The experimental hall features a high background $\\gamma$-ray rate, due to the nature of the spallation neutron source. Thus an investigation into reduction of the background $\\gamma$-ray rate, encountered by the NaI(Tl) detector array of STEFF, has been carried out. This has been via simulations using the simulation package FLUKA. Various materials and shielding geometries have been investigated but the effects determined to be insufficient in reducing the background rate by a meaningful amount. The NaI(Tl) detectors have been modified to improve their ...

Research progress in airborne surveys of terrestrial gamma radiation

International Nuclear Information System (INIS)

Burson, Z.G.

1974-01-01

Progress during the last few years in airborne surveys of terrestrial gamma radiation, i.e. in the measuring, recording, and interpreting of gamma ray signals in NaI(Tl) crystals, is discussed. Non-terrestrial background contributions have been accurately characterized. The feasibility of determining the water equivalent of snow cover by aerial survey techniques has been demonstrated. Repeat surveys over areas surrounding reactor sites can now be used to detect average differences of less than 1.0 μR/hr in terrestrial gamma radiation levels. New data acquisition and recording systems allow isotope concentrations and total inventories to be measured in spatial resolutions of a few hundred feet. Aerial survey data have been combined with population distribution data to obtain population exposure values from natural terrestrial gamma radiation around reactor sites

Stabilization of spectra provided by a gamma-ray spectrometer. Application to the construction of a stabilizer

International Nuclear Information System (INIS)

Detourne, G.

1967-06-01

This research is concerned with the stabilization of spectra provided by a gamma-ray spectrometer. It is required to hold the calibration straight line of the spectrometer in a position which is fixed initially to better than 5x10 -5 channel. A prototype numerical stabilizer has been constructed : the SPECTROSTAB; it is made up of two independent control loops; one of these makes the spectrometer gain depend on the derivatives of a reference peak at high energies; the other makes the origin of the energy scale depend on the derivatives of a second reference peak at low energies A theoretical study of the behaviour of a control loop shows that a direct action stabilizer gives the most accurate stabilization; the loss in resolving power on the theoretical peaks of the spectra attains about 1 % with a scintillation detector, and 10 % with a semi-conductor detector. Various tests show that the expected results are obtained and that the displacement of the spectral peaks produced by the derivatives are hidden by errors in the calculation of the peak abscissae. (author) [fr

Development of a cosmic veto gamma-spectrometer

International Nuclear Information System (INIS)

Burnett, J.L.; Davies, A.V.

2012-01-01

Cosmic radiation contributes significantly towards the background radiation measured by a gamma-spectrometer. A novel cosmic veto gamma-spectrometer has been developed that provides a mean background reduction of 54.5%. The system consists of plastic scintillation plates operated in time-stamp mode to detect coincident muon interactions within an HPGe gamma-spectrometer. The instrument is easily configurable and provides improved sensitivity for radionuclides indicative of nuclear weapons tests and reactor incidents, including 140 Ba, 95 Zr, 99 Mo, 141 Ce, 147 Nd, 131 I, 134 Cs and 137 Cs. This has been demonstrated for Comprehensive Nuclear-Test-Ban Treaty applications to obtain the required 140 Ba MDA of 24 mBq within 2 days counting. Analysis of an air filter sample collected during the Fukushima incident indicates improved sensitivity compared to conventional gamma-spectrometers. (author)

The sample of INTEGRAL SPI-ACS gamma-ray bursts

International Nuclear Information System (INIS)

Rau, A.; Kienlin, A. von; Licht, G.G.; Hurley, K.

2005-01-01

The anti-coincidence system of the spectrometer on board INTEGRAL is operated as a nearly omni directional gamma-ray burst detector above ∼ 75 KeV. During the elapsed mission time 324 burst candidates were detected. As part of the 3rd Interplanetary Network of gamma-ray detectors the cosmic origin of 115 burst was confirmed. Here we present a preliminary analysis of the SPI-ACS gamma-ray burst sample. In particular we discuss the origin of a significant population of short events (duration < 0.2 s) and a possible method for a flux calibration of the data

An Analysis on Some Factors Which Affect the Energy Resolution of a Low-background Anti-compton HPGe Gamma-ray Spectrometer

International Nuclear Information System (INIS)

Zhou Chunlin; Dai Junjie; Lei Junniu; Zhang Jiaoyu

2009-01-01

This paper describes the basic construction and performing theory of a set of low-background anti-compton high purity germanium gamma-ray spectrometer. On the basis of experiments, some factors which affect the energy resolution of the system are discussed. The optimum parameters configuration for the system is presented and it provides a decision-making ground for purchasing, installation and alignment of analogous system. (authors)

Characterization of Compton-suppressed TIGRESS detectors for high energy gamma-rays

International Nuclear Information System (INIS)

Kshetri, R.; Andreoiu, C.; Cross, D.S.; Galinski, N.; Ball, G.C.; Djongolov, M.; Garnsworthy, A.B.; Hackman, G.; Orce, J.N.; Pearson, C.; Triambak, S.; Williams, S.J.; Drake, T.; Smalley, D.; Svensson, C.E.

2009-01-01

The TRIUMF-ISAC Gamma-Ray Escape- Suppressed Spectrometer (TIGRESS) will consist of 12 large-volume, 32-fold segmented HPGe clover detectors. Each detector is shielded by a 20-fold segmented Compton suppression shield. For performing discrete gamma-ray spectroscopy of light mass nuclei with TIGRESS, we need information about full energy peak efficiency, resolution and lineshape of full energy peaks for high energy gamma-rays. However, suitable radioactive sources having decay gamma-rays of energies greater than ∼ 3.5 MeV are not easily available. So the characteristics of gamma spectrometers at energies higher than 3.5 MeV are usually determined from simulation data. Predictions from GEANT4 simulations (experimentally validated from 0.3 to 3 MeV) indicate that TIGRESS will be capable for single 10 MeV gamma-rays of absolute detection efficiency of 1.5% for backward configuration of the array. It has been observed experimentally that simulation results work well up to certain energies and might deviate at higher energies. So, it is essential to check the validity of simulation results for energies above 3.3 MeV. We have investigated the high energy performance of seven TIGRESS detectors up to 8 MeV

Observations of Galactic gamma-radiation with the SMM spectrometer

Science.gov (United States)

Share, G. H.; Kinzer, R. L.; Messina, D. C.; Purcell, W. R.; Chupp, E. L.

1986-01-01

Preliminary results from the SMM gamma-ray spectrometer are reported which indicate the detection of a constant source of 0.511-MeV annihilation radiation from the Galaxy. Year-to-year variability appears to be less than 30 percent. The radiation probably comes from a diffuse source and is not associated with the reported compact object at the Galactic center.

Distribution of iron and titanium on the lunar surface from lunar prospector gamma ray spectra

International Nuclear Information System (INIS)

Prettyman, T.H.; Feldman, W.C.; Lawrence, David J.; Elphic, R.C.; Gasnault, O.M.; Maurice, S.; Moore, K.R.; Binder, A.B.

2001-01-01

Gamma ray pulse height spectra acquired by the Lunar Prospector (LP) Gamma-Ray Spectrometer (GRS) contain information on the abundance of major elements in the lunar surface, including O, Si, Ti, Al, Fe, Mg, Ca, K, and Th. With the exception of Th and K, prompt gamma rays produced by cosmic ray interactions with surface materials are used to determine elemental abundance. Most of these gamma rays are produced by inelastic scattering of fast neutrons and by neutron capture. The production of neutron-induced gamma rays reaches a maximum deep below the surface (e.g. ∼140 g/cm 2 for inelastic scattering and ∼50 g/cm 2 for capture). Consequently, gamma rays sense the bulk composition of lunar materials, in contrast to optical methods (e.g. Clementine Spectral Reflectance (CSR)), which only sample the top few microns. Because most of the gamma rays are produced deep beneath the surface, few escape unscattered and the continuum of scattered gamma rays dominates the spectrum. In addition, due to the resolution of the spectrometer, there are few well-isolated peaks and peak fitting algorithms must be used to deconvolve the spectrum in order to determine the contribution of individual elements.

Guidelines for radioelement mapping using gamma ray spectrometry data

International Nuclear Information System (INIS)

2003-07-01

The purpose of the report is to provide an up-to-date review on the use of gamma ray spectrometry for radioelement mapping and, where appropriate, provide guidelines on the correct application of the method. It is a useful training guide for those new to the method. It gives a broad coverage of all aspects of the gamma ray method and provides a comprehensive list of references. The report gives an overview of the theoretical background to radioactivity and the gamma ray spectrometric method followed by a review of the application of the method to mapping the radiation environment. A brief outline is presented of the principles of radioactivity, the interaction of gamma rays with matter, instrumentation applied to the measurement of gamma rays, and the quantities and units in contemporary use in gamma ray spectrometry. This is followed by a review of the fundamentals of gamma ray spectrometry, and its application to ground and airborne mapping. Covered are also all aspects of the calibration and data processing procedures required for estimating the ground concentrations of the radioelements. The procedures required for the recovery of older survey data are also presented as well as an overview of data presentation and integration for mapping applications

Initial studies of the gamma resonance of the 109mAg isomer with a gravitational gamma spectrometer

International Nuclear Information System (INIS)

Alpatov, V. G.; Bayukov, Yu. D.; Davydov, A. V.; Isaev, Yu. N.; Kartashov, G. R.; Korotkov, M. M.; Migachev, V. V.

2008-01-01

The problem of observing the Moessbauer resonance absorption of gamma rays from long-lived isomers is briefly outlined, first and foremost for 109m Ag taken as an example. Experiments indicative of a small broadening of the Moessbauer gamma line of this isomer in metallic silver are described. This circumstance made it possible to develop and manufacture a gravitational gamma spectrometer and to perform the first experiments with it, which confirm once again the previous data on a small width of the gamma line in question. The broadening factor obtained from these data proved to be 6.3 -1.9 +5.2 .

Spectral analysis and compositing techniques for the Near Earth Asteroid Rendezvous (NEAR Shoemaker), X-ray and Gamma-Ray Spectrometers (XGRS)

CERN Document Server

McClanahan, T P; Nittler, L R; Boynton, W V; Bruckner, J; Squyres, S W; Evans, L G; Bhangoo, J S; Clark, P E; Floyd, S R; McCartney, E; Mikheeva, I; Starr, R D

2001-01-01

An X-ray and Gamma-Ray Spectrometer (XGRS) is on board the Near Earth Asteroid Rendezvous (NEAR) spacecraft to determine the elemental composition of the surface of the asteroid 433 Eros. The Eros asteroid is highly oblate and irregular in shape. As a result, analysis methodologies are in many ways a divergence from comparable techniques. Complex temporal, spatial and instrument performance relationships must be accounted for during the analysis process. Field of view and asteroid surface geometry measurements must be modeled and then combined with real measurements of solar, spectral and instrument calibration information to derive scientific results. NEAR is currently orbiting 433 Eros and is in the initial phases of its primary data integration and mapping phases. Initial results have been obtained and bulk chemistry assessments have been obtained through specialized background assessment and data reduction techniques.

Gamma-ray tracking - A new detector concept for nuclear spectroscopy

International Nuclear Information System (INIS)

Gast, W.

2001-01-01

In the framework of an European collaboration the nest generation of large efficiency, high resolution spectrometers for nuclear spectroscopy is under development. The new spectrometers are large volume, segmented Ge-detectors featuring 3D position sensitivity in order to allow Gamma-Ray Tracking. That is, knowing the interaction positions and the energies released at each interaction, the track each gamma-ray follows during its scattering process inside the detector volume can be reconstructed on basis of the Compton-scattering formula. The resulting high add-back efficiency an effective granularity significantly improves peak-to-total ratio, efficiency, and Doppler-broadening of the spectrometer. In this contribution the states of the project concerning detector design and development of digital signal processing techniques to achieve an optimal 3D position sensitivity is presented. (authors)

Nuclear Forensics using Gamma-ray Spectroscopy

Directory of Open Access Journals (Sweden)

Norman E. B.

2016-01-01

Full Text Available Much of George Dracoulis’s research career was devoted to utilising gamma-ray spectroscopy in fundamental studies in nuclear physics. This same technology is useful in a wide range of applications in the area of nuclear forensics. Over the last several years, our research group has made use of both high- and low-resolution gamma-ray spectrometers to: identify the first sample of plutonium large enough to be weighed; determine the yield of the Trinity nuclear explosion; measure fission fragment yields as a function of target nucleus and neutron energy; and observe fallout in the U. S. from the Fukushima nuclear reactor accident.

Developments in gamma-ray spectrometry: systems, software, and methods-II. 3. Low-Energy Gamma-Ray Spectrometry Using a Compton-Suppressed Telescope Detector

International Nuclear Information System (INIS)

Sigg, R.A.; DiPrete, D.P.

2001-01-01

The Savannah River Technology Center (SRTC) utilizes gamma-ray spectrometry in studying numerous areas of applied interest to the Savannah River Site (SRS). For example, analyses of long-lived gamma-ray-emitting fission products and actinides are required to meet waste characterization, process holdup, environmental restoration, and decontamination and decommissioning efforts. A significant portion of the overall effort centers on measurements of gamma rays having energies below several hundred kilo-electron-volts. To assist these efforts, the SRTC recently acquired a spectrometer system that provides lower natural and Compton scattered background levels while achieving relatively high counting efficiencies for low-energy gamma rays. The combination of high efficiency and low background provides factor-of- 2-to-4 improvements in minimum detectable activities and allows meeting programmatic objectives with shorter measurement times. Numerous Compton-suppression spectrometers have been reported since the concept was first advanced. The spectrometer consists of two high-purity germanium detectors in a telescope configuration surrounded by a background /Compton-suppression sodium iodide detector. The front germanium detector is a 20-mm-thick x 60-mm-diam broad energy spectrometer, and the rear detector is a 40% efficient 61- mm-diam x 60-cm-thick closed-end coaxial spectrometer. The cryostat housing the germanium detectors (a) includes a carbon composite window for transmitting low-energy gamma rays, (b) is in a J-type configuration to mask the germanium detectors from natural activities in the cryo-pumping media, and (c) is fabricated from materials selected for low background. The telescope detector is in the 8.6-cm-inside-diameter annulus of a 22.9- x 22.9-cm sodium iodide detector encased in a 10-cm-thick lead shield. The counting system is located in a basement counting room having ∼60-cm-thick concrete walls. Initial tests show that the low-energy segment of

High energy X-ray observations of COS-B gamma-ray sources from OSO-8

Science.gov (United States)

Dolan, J. F.; Crannell, C. J.; Dennis, B. R.; Frost, K. J.; Orwig, L. E.; Caraveo, P. A.

1985-01-01

During the three years between satellite launch in June 1975 and turn-off in October 1978, the high energy X-ray spectrometer on board OSO-8 observed nearly all of the COS-B gamma-ray source positions given in the 2CG catalog (Swanenburg et al., 1981). An X-ray source was detected at energies above 20 keV at the 6-sigma level of significance in the gamma-ray error box containing 2CG342 - 02 and at the 3-sigma level of significance in the error boxes containing 2CG065 + 00, 2CG195 + 04, and 2CG311 - 01. No definite association between the X-ray and gamma-ray sources can be made from these data alone. Upper limits are given for the 2CG sources from which no X-ray flux was detected above 20 keV.

Gamma ray spectroscopy monitoring method and apparatus

Science.gov (United States)

Stagg, William R; Policke, Timothy A

2017-05-16

The present invention relates generally to the field of gamma ray spectroscopy monitoring and a system for accomplishing same to monitor one or more aspects of various isotope production processes. In one embodiment, the present invention relates to a monitoring system, and method of utilizing same, for monitoring one or more aspects of an isotope production process where the monitoring system comprises: (A) at least one sample cell; (B) at least one measuring port; (C) at least one adjustable collimator device; (D) at least one shutter; and (E) at least one high resolution gamma ray spectrometer.

The calibration facilities of gamma-ray spectrometer oil logging system

International Nuclear Information System (INIS)

Zhao Yunlong; Liu Yuzhang; Duan Wenxian

1993-08-01

The construction technology for the calibration facilities of gamma-ray spectrometer oil logging system is introduced. It is referenced to the experience from similar calibration facilities at home and abroad. Facilities consist of 9 models. The effective diameter of each model is 1.5 m and the height is 6 m. Each borehole has U ore zone, Th ore zone, K ore zone, high mixed zone, high mixed thin zone, low mixed zone and barren zone. There are 45 zones in total. Each element model has 6 in, 8.5 in and 12 in of different diameters. The preventing radon migration and complete sealing technology are used for each zone to prevent radon from escaping. The density of models, homogeneity and moisture of radio elements have been measured that gives a complete data for calibration adjusting of the instrument. The sizes of facilities and the concentration of radioactivity are reasonable designed and conformed to the recommendation of IAEA. Parameters are consistent with the parameters of calibration facilities built by Houston University in America. The emanation coefficient of the facilities is lees than 1%. The dry density of filling is 2.12 g/cm 3 and the relative standard deviation is +- 1.9%

Monte Carlo simulation of muon-induced background of an anti-Compton gamma-ray spectrometer placed in a surface and underground laboratory

CERN Document Server

Vojtyla, P

2005-01-01

Simulations of cosmic ray muon induced background of an HPGe detector placed inside an anti-Compton shield on the surface and in shallow underground is described. Investigation of several model set-ups revealed some trends useful for design of low-level gamma-ray spectrometers. It has been found that background spectrum of an HPGe detector can be scaled down with the shielding depth. No important difference is observed when the same set-up of the anti-Compton spectrometer is positioned horizontally or vertically. A cosmic-muon rejection factor of at least 40 (at around 1 MeV) can be reached when the anti-Compton suppression is operational. The cosmicmuon background can be reduced to such a level that other background components prevail, like those from the residual contamination of the detector and shield materials and/or from radon, especially for the underground facilities.

Measurements of keV-neutron capture {gamma} rays of fission products. 3

Energy Technology Data Exchange (ETDEWEB)

Igashira, Masayuki [Tokyo Inst. of Tech. (Japan). Research Lab. for Nuclear Reactors

1997-03-01

{gamma} rays from the keV-neutron capture reactions by {sup 143,145}Nd and {sup 153}Eu have been measured in a neutron energy region of 10 to 80 keV, using a large anti-Compton NaI(Tl) {gamma}-ray spectrometer and the {sup 7}Li(p,n){sup 7}Be pulsed neutron source with a 3-MV Pelletron accelerator. The preliminary results for the capture cross sections and {gamma}-ray spectra of those nuclei are presented and discussed. (author)

A 3D simulation look-up library for real-time airborne gamma-ray spectroscopy

Science.gov (United States)

Kulisek, Jonathan A.; Wittman, Richard S.; Miller, Erin A.; Kernan, Warnick J.; McCall, Jonathon D.; McConn, Ron J.; Schweppe, John E.; Seifert, Carolyn E.; Stave, Sean C.; Stewart, Trevor N.

2018-01-01

A three-dimensional look-up library consisting of simulated gamma-ray spectra was developed to leverage, in real-time, the abundance of data provided by a helicopter-mounted gamma-ray detection system consisting of 92 CsI-based radiation sensors and exhibiting a highly angular-dependent response. We have demonstrated how this library can be used to help effectively estimate the terrestrial gamma-ray background, develop simulated flight scenarios, and to localize radiological sources. Source localization accuracy was significantly improved, particularly for weak sources, by estimating the entire gamma-ray spectra while accounting for scattering in the air, and especially off the ground.

Gamma-ray response of NE-213 measured between 2 and 11.5 MeV

International Nuclear Information System (INIS)

Ingersoll, D.T.; Wehring, B.W.; Starr, R.D.

1976-01-01

Because of the capability to discriminate between neutrons and gamma rays, NE-213 scintillators are useful as both fast-neutron and gamma-ray spectrometers. However, measured NE-213 Compton-recoil spectra require unfolding to yield gamma-ray energy spectra which entails a detailed knowledge of the gamma-ray response of the NE-213 detector system. Absolute measurements of the gamma-ray response of an NE-213 scintillator in the energy range of 2 to 11.5 MeV were made. The measurements were made using the University of Illinois superconducting electron microtron equipped with a gamma-ray monochromator. The response measurements will be used to construct a gamma-ray response matrix for NE-213 to be used with the FORIST unfolding code

Gamma-ray impurities of {sup 111}In, {sup 201}Tl, {sup 177}Lu and {sup 99m}Tc determined by means of a HPGE spectrometer

Energy Technology Data Exchange (ETDEWEB)

Koskinas, Marina F.; Almeida, Jamille da Silveira; Moreira, Denise Simões; Semmler, Renato; Dias, Mauro da Silva, E-mail: koskinas@ipen.br, E-mail: jamillealmeida@gmail.com, E-mail: denise.moreira@ipen.br, E-mail: rsemmler@ipen.br, E-mail: msdias@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2017-11-01

This work aims to present the radioactive impurities gamma rays emitters detected in some radiopharmaceuticals widely applied to diagnosis and therapy purposes, supplied to nuclear medicine services in Brazil by the Radiopharmaceutical Center(CR) of Nuclear and Energy Research Institute, IPEN, in São Paulo. The analysis was undertaken by means of an HPGe gamma spectrometer. The radiopharmaceuticals analyzed were: {sup 111}In, {sup 201}Tl, {sup 177}Lu and {sup 99m}Tc. (author)

Mercuric Iodide Anticoincidence Shield for Gamma-Ray Spectrometer, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We propose to utilize a new detector material, polycrystalline mercuric iodide, for background suppression by active anticoincidence shielding in gamma-ray...

SMM hard X-ray observations of the soft gamma-ray repeater 1806-20

Science.gov (United States)

Kouveliotou, C.; Norris, J. P.; Cline, T. L.; Dennis, B. R.; Desai, U. D.; Orwig, L. E.

1987-01-01

Six bursts from the soft gamma-ray repeater (SGR) 1806-20 have been recorded with the SMM Hard X-ray Burst Spectrometer during a highly active phase in 1983. Rise and decay times of less than 5 ns have been detected. Time profiles of these events indicate low-level emission prior to and after the main peaks. The results suggest that SGRs are distinguished from classical gamma-ray bursts by repetition, softer nonvarying spectra, short durations, simple temporal profiles, and a tendency for source locations to correlate with Population I objects. SGR characteristics differ from those of type I X-ray bursts, but they appear to have similarities with the type II bursts from the Rapid Burster.

SMM hard X-ray observations of the soft gamma-ray repeater 1806-20

International Nuclear Information System (INIS)

Kouveliotou, C.; Norris, J.P.; Cline, T.L.; Dennis, B.R.; Desai, U.D.; Orwig, L.E.

1987-01-01

Six bursts from the soft gamma-ray repeater (SGR) 1806-20 have been recorded with the SMM Hard X-ray Burst Spectrometer during a highly active phase in 1983. Rise and decay times of less than 5 ns have been detected. Time profiles of these events indicate low-level emission prior to and after the main peaks. The results suggest that SGRs are distinguished from classical gamma-ray bursts by repetition, softer nonvarying spectra, short durations, simple temporal profiles, and a tendency for source locations to correlate with Population I objects. SGR characteristics differ from those of type I X-ray bursts, but they appear to have similarities with the type II bursts from the Rapid Burster. 19 references

Ground tests with prototype of CeBr{sub 3} active gamma ray spectrometer proposed for future venus surface missions

Energy Technology Data Exchange (ETDEWEB)

Litvak, M.L., E-mail: litvak@mx.iki.rssi.ru [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Sanin, A.B.; Golovin, D.V. [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Jun, I. [Jet Propulsion Laboratory, Pasadena, CA (United States); Mitrofanov, I.G. [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Shvetsov, V.N.; Timoshenko, G.N. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Vostrukhin, A.A. [Space Research Institute, RAS, Moscow 117997 (Russian Federation)

2017-03-11

The results of a series of ground tests with a prototype of an active gamma-ray spectrometer based on a new generation of scintillation crystal (CeBr{sub 3}) are presented together with a consideration to its applicability to future Venus landing missions. We evaluated the instrument's capability to distinguish the subsurface elemental composition of primary rock forming elements such as O, Na, Mg, Al, Si, K and Fe. Our study uses heritage from previous ground and field tests and applies to the analysis of gamma lines from activation reaction products generated by a pulsed neutron generator. We have estimated that the expected accuracies achieved in this approach could be as high as 1–10% for the particular chemical element being studied.

Computer model for calculating gamma-ray pulse-height spectra for logging applications

International Nuclear Information System (INIS)

Evans, M.L.

1981-01-01

A generalized computer model has been devised to simulate the emission, transport, and detection of natural gamma radiation from various logging environments. The model yields high-resolution gamma-ray pulse-height spectra that can be used to correct both gross gamma and spectral gamma-ray logs. The technique can help provide corrections to airborne and surface radiometric survey logs for the effects of varying altitude, formation composition, and overburden. Applied to borehole logging, the model can yield estimates of the effects of varying borehole fluid and casing attenuations, as well as varying formation porosity and saturation

Conceptual design of the radial gamma ray spectrometers system for α particle and runaway electron measurements at ITER

Science.gov (United States)

Nocente, M.; Tardocchi, M.; Barnsley, R.; Bertalot, L.; Brichard, B.; Croci, G.; Brolatti, G.; Di Pace, L.; Fernandes, A.; Giacomelli, L.; Lengar, I.; Moszynski, M.; Krasilnikov, V.; Muraro, A.; Pereira, R. C.; Perelli Cippo, E.; Rigamonti, D.; Rebai, M.; Rzadkiewicz, J.; Salewski, M.; Santosh, P.; Sousa, J.; Zychor, I.; Gorini, G.

2017-07-01

We here present the principles and main physics capabilities behind the design of the radial gamma ray spectrometers (RGRS) system for alpha particle and runaway electron measurements at ITER. The diagnostic benefits from recent advances in gamma-ray spectrometry for tokamak plasmas and combines space and high energy resolution in a single device. The RGRS system as designed can provide information on α ~ particles on a time scale of 1/10 of the slowing down time for the ITER 500 MW full power DT scenario. Spectral observations of the 3.21 and 4.44 MeV peaks from the 9\\text{Be}≤ft(α,nγ \\right){{}12}\\text{C} reaction make the measurements sensitive to α ~ particles at characteristic resonant energies and to possible anisotropies of their slowing down distribution function. An independent assessment of the neutron rate by gamma-ray emission is also feasible. In case of runaway electrons born in disruptions with a typical duration of 100 ms, a time resolution of at least 10 ms for runaway electron studies can be achieved depending on the scenario and down to a current of 40 kA by use of external gas injection. We find that the bremsstrahlung spectrum in the MeV range from confined runaways is sensitive to the electron velocity space up to E≈ 30 -40 MeV, which allows for measurements of the energy distribution of the runaway electrons at ITER.

Cosmic-ray contribution in measurement of environmental gamma-ray dose

International Nuclear Information System (INIS)

Nagaoka, Kazunori; Honda, Kouichirou; Miyano, Keiji

1996-01-01

Nowadays several kinds of dosimeters are being used for environmental gamma-ray monitoring. However the results measured by those instruments are not always in good agreement. It may be caused from the different characteristics of dosimeters. In particular the different responses of the instruments to cosmic-rays give significant influence on the results. Environmental radiation measurements at various altitudes on Mt. Fuji were carried out using a scintillation spectrometer with 3''φ spherical NaI(Tl), a pressurized ionization chamber (PIC), an air-equivalent ionization chamber (IC), thermoluminescence dosimeters (TLD), radiophotoluminescence glass dosimeters (RPLD) and NaI(Tl) scintillation survey meters so that the response characteristics of these instruments to cosmic-rays could be clarified. Cosmic-ray contributions for all instruments were correlated with counting rate over 3 MeV by the spectrometer. Each contribution can be estimated by measurement of the counting rate. Conversion factors (nGy/h/cpm) for IC, PIC, TLD, RPLD and NaI survey meters (TCS166 and TCS121C) were 0.33, 0.32, 0.25, 0.24, 0.06 and -0.01, respectively. Self-doses of these instruments were estimated by measurements at Nokogiriyama facilities of the Institute for Cosmic Ray Research, University of Tokyo. Self-doses for TLD and RPLD were approximately 6 nGy/h. The self dose effect should be taken into consideration in environmental dose measurements. These data are expected to be useful in estimating the cosmic-ray contribution and self-dose in the measurement of environmental gamma-ray dose. (author)

EE's gamma-ray spectrometer answers the national need for a portable, rugged, self-contained radioisotope analyzer

International Nuclear Information System (INIS)

McGibbon, A.L.

1976-01-01

Growing national interest in public safety has produced a sudden need for a type of radiation-monitoring equipment that doesn't exist anywhere commercially. An easily portable, very rugged, and completely self-contained instrument is required that can be set up quickly and virtually anywhere to detect and identify radioactive isotopes. The Electronics Engineering Department has responded to this need by designing and developing the first equipment that can fulfill all these requirements. This instrument, a 1024-channel gamma-ray spectrometer, has already gone into limited production to provide health physicists at LLL and other Energy Research and Development Administration (ERDA) laboratories with an effective tool for monitoring possible sources of radioactivity

Sun and aureole spectrometer for airborne measurements to derive aerosol optical properties.

Science.gov (United States)

Asseng, Hagen; Ruhtz, Thomas; Fischer, Jürgen

2004-04-01

We have designed an airborne spectrometer system for the simultaneous measurement of the direct Sun irradiance and aureole radiance. The instrument is based on diffraction grating spectrometers with linear image sensors. It is robust, lightweight, compact, and reliable, characteristics that are important for airborne applications. The multispectral radiation measurements are used to derive optical properties of tropospheric aerosols. We extract the altitude dependence of the aerosol volume scattering function and of the aerosol optical depth by using flight patterns with descents and ascents ranging from the surface level to the top of the boundary layer. The extinction coefficient and the product of single scattering albedo and phase function of separate layers can be derived from the airborne measurements.

Direction-Sensitive Hand-Held Gamma-Ray Spectrometer

Energy Technology Data Exchange (ETDEWEB)

Mukhopadhyay, S.

2012-10-04

A novel, light-weight, hand-held gamma-ray detector with directional sensitivity is being designed. The detector uses a set of multiple rings around two cylindrical surfaces, which provides precise location of two interaction points on two concentric cylindrical planes, wherefrom the source location can be traced back by back projection and/or Compton imaging technique. The detectors are 2.0 × 2.0 mm europium-doped strontium iodide (SrI2:Eu2+) crystals, whose light output has been measured to exceed 120,000 photons/MeV, making it one of the brightest scintillators in existence. The crystal’s energy resolution, less than 3% at 662 keV, is also excellent, and the response is highly linear over a wide range of gamma-ray energies. The emission of SrI2:Eu2+ is well matched to both photo-multiplier tubes and blue-enhanced silicon photodiodes. The solid-state photomultipliers used in this design (each 2.0 × 2.0 mm) are arrays of active pixel sensors (avalanche photodiodes driven beyond their breakdown voltage in reverse bias); each pixel acts as a binary photon detector, and their summed output is an analog representation of the total photon energy, while the individual pixel accurately defines the point of interaction. A simple back-projection algorithm involving cone-surface mapping is being modeled. The back projection for an event cone is a conical surface defining the possible location of the source. The cone axis is the straight line passing through the first and second interaction points.

NURE aerial gamma ray and magnetic reconnaissance survey, Thorpe area, Newark NK18-11 Quadrangle. Volume I. Narrative report

International Nuclear Information System (INIS)

1977-11-01

During the flying seasons of 1976 and 1977 LKB Resources, Inc. conducted a rotary wing combined airborne high sensitivity gamma-ray and magnetic survey of four 1:250,000 quadrangles covering portions of Pennsylvania, New Jersey, and New York. The airborne system, field operations, data reduction, gamma-ray and magnetic data presentation, geology and uranium deposits of the Thorpe Area, photogeologic enhancement study of the Thorpe Area, and data interpretation are discussed

Current instrument status of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)

Science.gov (United States)

Eastwood, Michael L.; Sarture, Charles M.; Chrien, Thomas G.; Green, Robert O.; Porter, Wallace M.

1991-01-01

An upgraded version of AVIRIS, an airborne imaging spectrometer based on a whiskbroom-type scanner coupled via optical fibers to four dispersive spectrometers, that has been in operation since 1987 is described. Emphasis is placed on specific AVIRIS subsystems including foreoptics, fiber optics, and an in-flight reference source; spectrometers and detector dewars; a scan drive mechanism; a signal chain; digital electronics; a tape recorder; calibration systems; and ground support requirements.

Very high-energy gamma rays from gamma-ray bursts.

Science.gov (United States)

Chadwick, Paula M

2007-05-15

Very high-energy (VHE) gamma-ray astronomy has undergone a transformation in the last few years, with telescopes of unprecedented sensitivity having greatly expanded the source catalogue. Such progress makes the detection of a gamma-ray burst at the highest energies much more likely than previously. This paper describes the facilities currently operating and their chances for detecting gamma-ray bursts, and reviews predictions for VHE gamma-ray emission from gamma-ray bursts. Results to date are summarized.

European coordination of environmental airborne gamma ray spectrometry. Final report 1999

International Nuclear Information System (INIS)

Sanderson, D.C.; McLeod, J.J.

1999-04-01

This Concerted Action was funded under the EURATOM Nuclear Fission Safety Programme of the Fourth Framework Programme, and was initiated to address transnational issues relating to environmental airborne gamma ray spectrometry (AGS). Significant development of AGS systems and teams has taken place within Europe during the period following the Chernobyl accident. The technique is increasingly recognised as particularly relevant to emergency response. It is also uniquely capable of acquiring data on anthropogenic and natural radionuclides on regional, national and international scales, for reference purposes, ecological studies and epidemiological research. Prior to this EU programme the methodologies and systems used by European AGS teams had undergone rapid and largely uncoordinated development. This raised questions about comparability of systems, applications, and data between teams, duplication of research, the scope for transnational cooperation and standardisation, and future research and development needs in the field. This project, which brought together ten AGS teams from across Europe, was formed to address these issues. The work was conducted in three stages and has largely succeeded in its objectives. An active communication network was developed for collaboration and exchange of information, and to start the process of harmonisation of the different methodologies used by individual AGS teams. Two formal partners' meetings were organised, the first aimed at defining the EU capability in AGS, the second, in the form of an international symposium (RADMAGS), was aimed at reviewing developments on future research needs and the scope for standardisation. This report gives full details of the project and its deliverables together with discussion of the further needs in support of transnational harmonisation of this topic. The European Capability for AGS was defined at an early stage of the project, and monitored throughout. An EU Bibliography on AGS

The use of car-borne gamma-ray spectrometric survey in a basin

International Nuclear Information System (INIS)

Liu Tengyao; Lu Shili; Luo Zongquan.

1985-01-01

This paper describes the geological results in a basin in the Inner Mongolia which were obtained by using our newly-developed and assembled car-borne gamma-ray spectrometric system. Combined with the work of regional geology and remote sensing, five relatively favourable uranium zones were located within the working area. The field procedures of car-borne gamma-ray spectrometry for less rigid regions is discussed. The gamma-ray spectrometric profiling is mainly used for regional reconnaissance. In the case of enhanced anomalious radioactivity the profiling with varying directions is adopted and the data are plotted on scale 1:50000 topographic map. It is suggested that the car-borne gamma-ray spectrometric system can be calibrated both by the pads specified for portable spectrometers and by testing site when the calibration facility for the car-borne gamma-ray spectrometric system is not available. The effect of rainfall on car-borne gamma-ray spectrometric survey and the simplified field qualitative determination of U-Ra disequilibrium are also briefly discussed

Calibration and control modules for gamma-ray borehole loggers

International Nuclear Information System (INIS)

1983-01-01

A calibration pad for quantitative evaluation of gamma-ray logs, developed and constructed by CNEA is described. The facility is composed of a set of mineralized modules with which it is intended to reproduce the natural variable conditions found in boreholes drilled for uranium mineral exploration, such as the ore concentration, rock's density and porosity, water content, etc. The facility is able to operate under different radiometric models, as follow: 1) gross-count gamma-ray models; 2) gamma-spectrometer models; 3) neutronic-fission models, and 4) models for determination of magnetic susceptibility, density, neutron-neutron, etc. The gathered information allows the adequate quantitative radiometric evaluation of the ore bodies crossed by exploration holes, and also allows the correlation of gamma-ray logs obtained by different logger-equipments. The paper includes the description of the project development and the standards established for the facility's operation. (M.E.L.) [es

Karoo airborne geophysical survey: preliminary report on airborne radiometric data from block 12

International Nuclear Information System (INIS)

Day, R.W.; Wright, O.M.

1980-02-01

The analogue gamma-ray spectrometer records of block 12 of the Karoo airborne geophysical survey were studied and significant uranium anomalies were selected and graded. The anomalies were plotted on 1:50 000 scale maps and the co-ordinates of the anomalies were tabulated. The anomalies were transferred to 1:250 000 scale maps which are included in this report. The geological setting of the anomalies has been studied. Ground follow-up work has been recommended for anomalies which occur over mineralized pans and drainage channels, and the Lower Beaufort Stage. Other anomalies which occur over the Ecca Series, the Middle Beaufort Stage, the Upper Beaufort Stage and the Stormberg Series have also been recommended for ground investigation

Use of a low-background and anti-Compton HpGe gamma-spectrometer in analyses of environmental samples

Energy Technology Data Exchange (ETDEWEB)

Qiong, Su; Yamin, Gao [Ministry of Public Health, Beijing, BJ (China). Lab. of Industrial Hygiene

1989-12-01

The results of application of a HpGe gamma-spectrometer in the analyses of enviromental samples are reported. The spectrometer has very low background and good property of Compton suppression. By comparison between the gamma-spectra with and without anti-coincidence shield for the same samples, the advantage in analysing environmental samples became apparent. In the analyses of carp samples, the ratio of specific activities of {sup 226}Ra in the flesh and bone of the carp was 1 to 35, which is basically in agreement with the ratio of the accumulation factors 1:37, as reported in the literature. Thus the spectrometer would play an important role in the research of the transfer of radionuclides of low activity in the environment. The method of gamma-ray data processing is also described.

Use of a low-background and anti-Compton HpGe gamma-spectrometer in analyses of environmental samples

International Nuclear Information System (INIS)

Su Qiong; Gao Yamin

1989-01-01

The results of application of a HpGe gamma-spectrometer in the analyses of enviromental samples are reported. The spectrometer has very low background and good property of Compton suppression. By comparison between the gamma-spectra with and without anti-coincidence shield for the same samples, the advantage in analysing environmental samples became apparent. In the analyses of carp samples, the ratio of specific activities of 226 Ra in the flesh and bone of the carp was 1 to 35, which is basically in agreement with the ratio of the accumulation factors 1:37, as reported in the literature. Thus the spectrometer would play an important role in the research of the transfer of radionuclides of low activity in the environment. The method of gamma-ray data processing is also described

Neutron and gamma-ray spectra of 239PuBe and 241AmBe

International Nuclear Information System (INIS)

Vega-Carrillo, H.R.; Manzanares-Acuna, Eduardo; Becerra-Ferreiro, A.M.; Carrillo-Nunez, Aureliano

2002-01-01

Neutron and gamma-ray spectra of 239 PuBe and 241 AmBe were measured and their dosimetric features were calculated. Neutron spectra were measured using a multisphere neutron spectrometer with a 6 LiI(Eu) scintillator. The 239 PuBe neutron spectrum was measured in an open environment, while the 241 AmBe neutron spectrum was measured in a closed environment. Gamma-ray spectra were measured using a NaI(Tl) scintillator using the same experimental conditions for both sources. The effect of measuring conditions for the 241 AmBe neutron spectrum indicates the presence of epithermal and thermal neutrons. The low-resolution neutron spectra obtained with the multisphere spectrometer allows one to calculate the dosimetric features of neutron sources. At 100 cm both sources produce approximately the same count rate as that of the 4.4 MeV gamma-ray per unit of alpha emitter activity

Distributed control and data acquisition for the EUROGAM gamma ray spectrometer

International Nuclear Information System (INIS)

Owen, E.C.G.

1992-01-01

EUROGAM is an Anglo/French Gamma Ray Detector which will alternate between the Tandem Van der Graaf at Daresbury and the Vivitron at Strasbourg. Because of the need to conform to the standards of Laboratories in two different countries, and the very sensitive nature of electronics for Germanium Gamma Ray telescopes, the newly emerging VXlbus (VMEbus EXtensions for Instrumentation) was chosen as the basis for control and data acquisition. This entailed a major programme of development for both the signal processing front end modules for Germanium and Bismuth Germanate detectors, and also for the hardware and software management of resources from within the VXI environment. The paper will concentrate mainly on the latter areas. (author)

Dose Rate and Mass Attenuation Coefficients of Gamma Ray for Concretes

CERN Document Server

Abdel-Latif, A A; Kansouh, W A; El-Sayed, F H

2003-01-01

This work is concerned with the study of the leakage gamma ray dose and mass attenuation coefficients for ordinary, basalt and dolomite concretes made from local ores. Concretes under investigation were constructed from gravel, basalt and dolomite ores, and then reconstructed with the addition of 3% steel fibers by weight. Measurements were carried out using a collimated beam from sup 6 sup 0 Co gamma ray source and sodium iodide (3x3) crystal with the genie 2000 gamma spectrometer. The obtained fluxes were transformed to gamma ray doses and displayed in the form of gamma ray dose rates distribution. The displayed curves were used to estimate the linear attenuation coefficients (mu), the relaxation lengths (lambda), half value layer (t sub 1 /2) and tenth value layer (t sub 1 /10). Also, The total mass attenuation coefficients of gamma ray have been calculated to the concerned concretes using XCOM (version 3.1) program and database elements cross sections from Z=1 to 100 at energies from 10 keV to 100 MeV. In...

Cosmic ray and gamma astrophysics with the AMS-02 experiment

International Nuclear Information System (INIS)

Natale, Sonia

2006-01-01

The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed to operate on the International Space Station (ISS) for a minimum period of three years. The aim of AMS is the direct detection of charged particles in the rigidity range from 0.5 GV to few TV to perform high statistics studies of cosmic rays in space and a search for antimatter and dark matter. AMS will provide precise gamma measurements in the GeV range. In addition, the good angular resolution and identification capabilities of the detector will allow clean studies of galactic and extra-galactic sources, the diffuse gamma background and gamma ray bursts

Common Gamma-ray Glows above Thunderclouds

Science.gov (United States)

Kelley, Nicole; Smith, David; Dwyer, Joseph; Hazelton, Bryna; Grefenstette, Brian; Lowell, Alex; Splitt, Michael; Lazarus, Steven; Rassoul, Hamid

2013-04-01

Gamma-ray glows are continuous, long duration gamma- and x-ray emission seen coming from thunderclouds. The Airborne for Energetic Lightning Emissions (ADELE) observed 12 gamma-ray glows during its summer 2009 flight campaign over the areas of Colorado and Florida in the United States. For these glows we shall present their spectra, relationship to lightning activity and how their duration and size changes as a function of distance. Gamma-ray glows follow the relativistic runaway electron avalanche (RREA) spectrum and have been previously measured from the ground and inside the cloud. ADELE measured most glows as it flew above the screening layer of the cloud. During the brightest glow on August 21, 2009, we can show that we are flying directly into a downward facing relativistic runaway avalanche, indicative of flying between the upper positive and negative screening layer of the cloud. In order to explain the brightness of this glow, RREA with an electric field approaching the limit for relativistic feedback must be occurring. Using all 12 glows, we show that lightning activity diminishes during the onset of the glow. Using this along with the fact that glows occur as the field approaches the level necessary for feedback, we attempt to distinguish between two possibilities: that glows are evidence that RREA with feedback, rather than lightning, is sometimes the primary channel for discharging the cloud, or else that the overall discharging is still controlled by lightning, with glows simply appearing during times when a subsidence of lightning allows the field to rise above the threshold for RREA.

Portable scintillation gamma-spectrometer for field measurement of radioactivity in extensive objects

International Nuclear Information System (INIS)

Besshejko, O.A.; Vishnevskij, I.N.; Denisenko, R.V.; Malyuk, I.A.; Petrosyan, Eh.E.; Karpenko, S.A.; Prijmak, V.N.

2011-01-01

The portable scintillated gamma-spectrometer for field measurement of radioactivity in the volume objects was designed. The crystal CdWO 4 that has weak dependence of light yield from temperature in combination with PMT was applied as the gamma-rays detector. The design of the device provides the possibility for measuring radioactivity of the extensive objects in 4π-geometry without background measurements. In this case the value of the efficiency needed for specific activity calculation in close approximation depends only from crystal geometry and density of measuring object and may be set as the device parameter without efficiency calibration procedure during the operation. The spectrometer does not have an auxiliary radio-active source and connecting cables in the composition. The smartphone operated under Windows Mobile is used as the control module. Bluetooth connection provides data exchange between smartphone and measurement head.

A search for spectral lines in gamma-ray bursts using TGRS

International Nuclear Information System (INIS)

Kurczynski, P.; Palmer, D.; Seifert, H.; Teegarden, B. J.; Gehrels, N.; Cline, T. L.; Ramaty, R.; Hurley, K.; Madden, N. W.; Pehl, R. H.

1998-01-01

We present the results of an ongoing search for narrow spectral lines in gamma-ray burst data. TGRS, the Transient Gamma-Ray Spectrometer aboard the Wind satellite is a high energy-resolution Ge device. Thus it is uniquely situated among the array of space-based, burst sensitive instruments to look for line features in gamma-ray burst spectra. Our search strategy adopts a two tiered approach. An automated 'quick look' scan searches spectra for statistically significant deviations from the continuum. We analyzed all possible time accumulations of spectra as well as individual spectra for each burst. Follow-up analysis of potential line candidates uses model fitting with F-test and χ 2 tests for statistical significance

Remote sensing of acid sulfate soils using multispectral and gamma-ray data

International Nuclear Information System (INIS)

Bierwirth, P.N.; Graham, T.L.

1998-01-01

overlies the potential acid sulfate soils. The combined use of multispectral data to identify active acid sulfate areas and airborne gamma-radiometrics to understand sediment stratigraphy is presented here as a valuable reconnaissance approach.Whereas airborne gamma-ray spectrometer data is a powerful method for mapping surficial soils, preliminary results for the Clarence floodplain indicates that it is limited in its capacity to directly identify acid sulfate soils. It does however, offer potential as a surrogate for a detailed DEM in demarcating low-lying areas and constraining the Landsat TM data. Copyright (1998) Remote Sensing and Photogrammetry Association of Australasia Ltd

Determination of gamma ray shielding parameters of rocks and concrete

Science.gov (United States)

Obaid, Shamsan S.; Gaikwad, Dhammajyot K.; Pawar, Pravina P.

2018-03-01

Gamma shielding parameters such as mass attenuation coefficient (μ/ρ), effective atomic number (Zeff) and electron density (Neff) have been measured and calculated for rocks and concrete in the energy range 122-1330 keV. The measurements have been carried out at 122, 356, 511, 662, 1170, 1275, 1330 keV gamma ray energies using a gamma spectrometer includes a NaI(Tl) scintillation detector and MCA card. The atomic and electronic cross sections have also been investigated. Experimental and calculated (WinXCom) values were compared, and good agreement has been observed within the experimental error. The obtained results showed that feldspathic basalt, compact basalt, volcanic rock, dolerite and pink granite are more efficient than the sandstone and concrete for gamma ray shielding applications.

A study of radioactive elements of various rocks in Pattani Province with gamma ray spectrometer

Directory of Open Access Journals (Sweden)

Kaewtubtim, P.

2002-01-01

Full Text Available The radioactivity of the three elements, potassium, uranium and thorium, in rocks of various types in Pattani Province was investigated by using a gamma ray spectrometer. It was found that potassium contents in igneous rocks, sedimentary rocks and metamorphic rocks were 6.29 %, 2.21% and 1.54 % respectively. Uranium equivalent contents in igneous rock, sedimentary rocks and metamorphic rocks were found to be 22.51 ppm, 11.25 ppm and 14.13 ppm, while thorium contents in these rocks were 21.78 ppm, 18.88 ppm and 18.15 ppm respectively. The results obtained were similar to those reported by Pungtip Ranglek (1995 for igneous rock at Liwong Pluton site in Thepha, Na Thawi, Chana and Saba Yoi Districts, Songkhla Province, and were about six times higher than those reported by Kittichai Wattananikorn (1994 for igneous rock in the northern part of Thailand.

Prognoses of prospective areas for uranium metallogenesis with full-spectrum information of airborne gamma-ray survey

International Nuclear Information System (INIS)

Hu Mingkao; Shen Zhengxin; Li Binghai; Cai Genqing

2010-01-01

This paper briefly introduces the development of airborne radioactive survey and the background of carrying out full-spectrum study. It also introduces the method, standard and application example of using the full-spectrum information of airborne gamma spectrum to predict U-metallogenic prospective areas. The field checking has found that uranium in the water of the prospective area is three magnitude higher than that in the normal area. The developmment and the application of this method will play a multiplier role in reusing the library stored data evaluating uranium resource potential in our Country. (authors)

Advances in gamma ray resonant scattering and absorption long-lived isomeric nuclear states

CERN Document Server

Davydov, Andrey V

2015-01-01

This book presents the basics and advanced topics of research of gamma ray physics. It describes measuring of  Fermi surfaces with gamma resonance spectroscopy and the theory of angular distributions of resonantly scattered gamma rays. The dependence of excited-nuclei average lifetime on the shape of the exciting-radiation spectrum and electron binding energies in the spectra of scattered gamma rays is described. Resonant excitation by gamma rays of nuclear isomeric states with long lifetime leads to the emission and absorption lines. In the book, a new gamma spectroscopic method, gravitational gamma spectrometry, is developed. It has a resolution hundred million times higher than the usual Mössbauer spectrometer. Another important topic of this book is resonant scattering of annihilation quanta by nuclei with excited states in connection with positron annihilation. The application of the methods described is to explain the phenomenon of Coulomb fragmentation of gamma-source molecules and resonant scatt...

Use of planar HPGe detector as a part of X-ray fluorescent spectrometer for educational purposes

International Nuclear Information System (INIS)

Verenchikova, M.S.; Kalinin, V.N.; Mikhajlov, V.A.

2011-01-01

This work shows the possibility of use of the nondedicated gamma and X-ray detection head on the basis of planar HPGe detector with a big sensitive area equal to 2000 mm''2 as a part of X-ray fluorescent spectrometer during students' practicum.

Gamma ray generator

Science.gov (United States)

Firestone, Richard B; Reijonen, Jani

2014-05-27

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

Airborne gamma anomalies in the Elbe Valley near Koenigstein, Germany - Origin and variation with time

International Nuclear Information System (INIS)

Ruhrmann, G.; Schmeling, B.; Schauer, M.; Gatzweiler, R.

1997-01-01

In 1982, an airborne gamma spectrometer survey was undertaken by SDAG WISMUT which was directed at the detection of further uranium mineralization in Saxony and Thuringia. Anomalies outlined along the Elbe river near the existing Koenigstein uranium mine were attributed to one or a combination of the following causes: radioactive residues from uranium processing facilities located upstream, temporary accumulation of Rn-decay products attached to dust particles in the atmosphere at the time of the survey, and radioactive waters emerging from uraniferous rocks along tectonic structures. In 1994, WISMUT GmbH re-evaluated the survey to determine the need for implementing cleanup measures. Subsequent to the verification of the original airborne data, ground surveys were undertaken that included gamma spectrometry, percussion probing and river sediment sampling. The new results did not confirm the magnitude of most of the 1982 airborne anomalies. The general decline of the radioactivity pointed out by the 1994 ground measurements is interpreted to be a result of the partial erosion and dilution of radionuclides in fluvial sediments as well as burial by additional river sediments since. Additional anomalous copper and zinc concentrations are attributed to sources other than mining. The ground follow-up delineated a new anomalous zone that is caused by radionuclides discharged with treated process and mine water. It is the only area, which may require further investigations and possible remedial action. (author)

Portable scintillation gamma-spectrometer for field measurement of radioactivity in extensive objects

Directory of Open Access Journals (Sweden)

O. A. Bezshyyko

2011-12-01

Full Text Available The portable scintillated gamma-spectrometer for field measurement of radioactivity in the volume objects was designed. The crystal CdWO4 that has weak dependence of light yield from temperature in combination with PMT was applied as the gamma-rays detector. The design of the device provides the possibility for measuring radioactivity of the extensive objects in 4-geometry without background measurements. In this case the value of the efficiency needed for specific activity calculation in close approximation depends only from crystal geometry and density of measuring object and may be set as the device parameter without efficiency calibration procedure during the operation. The spectrometer does not have an auxiliary radio-active source and connecting cables in the composition. The smartphone operated under Windows Mobile is used as the control module. Bluetooth connection provides data exchange between smartphone and measurement head.

An airborne gamma ray survey of parts of SW Scotland in February 1993. Final Report

International Nuclear Information System (INIS)

Sanderson, D.C.W.; Allyson, J.D.; Tyler, A.N.; Ni Riain, S.; Murphy, S.

1994-01-01

An airborne gamma ray survey was conducted for the Scottish Office Environment Department of coastal and inland parts of SW Scotland to define existing background levels, to locate features worthy of further attention, and to demonstrate the emergency response capabilities of radiometric methods. Coastal areas were surveyed with 500 m line spacing. Inland areas were specified to 2 km line spacing, however it was possible to achieve 1 km line spacing in the majority of the inland zone. The radiometric maps show clearly the distributions of each individual nuclide and indicate the contribution which individual localised features make to the overall gamma ray dose rate. Naturally occurring nuclides reflect the underlying geological and geomorphological contexts of the landscapes. The main granite intrusions, most notably at Cairnsmore of Fleet, the Loch Doon Granodiorite, Glencairn of Carsphairn, the Dalbeattie granite, and Criffel Pluton are readily visible in 40 K, 214 Bi and 208 Tl maps, and control their local radiation environments. A number of areas of enhanced 214 Bi, which may reflect radon potential, were noted. A transient radon associated 214 Bi signal was observed on the west of the Wigtown peninsular during the survey. Examination of spectral data in the vicinity Dundrennan has confirmed that there is no evidence of widespread terrestrial contamination arising from the use of depleted uranium projectiles on the range. The 137 Cs map indicates the environmental distribution of this nuclide in considerable detail. Levels of 137 Cs range from approximately 2 kBq m -2 , a level consistent with global weapons' testing fallout, from 2-40 kBq m -2 on terrestrial sites affected by deposition from the Chernobyl accident, and from 40 kBq m -2 to over 200 kBq m -2 on tide washed pastures which have accumulated marine sediments from the Irish sea. (author)

Final report of the environmental measurement-while-drilling-gamma ray spectrometer system technology demonstration at the Savannah River Site F-Area Retention Basin

Energy Technology Data Exchange (ETDEWEB)

Lockwood, G.J.; Normann, R.A.; Williams, C.V.

1997-08-01

The environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides real-time environmental and drill bit data during drilling operations. The EMWD-GRS technology was demonstrated at Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration consisted of continuously monitoring for gamma-radiation-producing contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes passed near previously sampled vertical borehole locations where concentrations of contaminant levels of cesium had been measured. Contaminant levels continuously recorded by the EMWD-GRs system during drilling are compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples.

Final report of the environmental measurement-while-drilling-gamma ray spectrometer system technology demonstration at the Savannah River Site F-Area Retention Basin

International Nuclear Information System (INIS)

Lockwood, G.J.; Normann, R.A.; Williams, C.V.

1997-08-01

The environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides real-time environmental and drill bit data during drilling operations. The EMWD-GRS technology was demonstrated at Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration consisted of continuously monitoring for gamma-radiation-producing contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes passed near previously sampled vertical borehole locations where concentrations of contaminant levels of cesium had been measured. Contaminant levels continuously recorded by the EMWD-GRs system during drilling are compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples

Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A

NARCIS (Netherlands)

Abbott, B. P.; Abbott, R.; Abbott, T. D.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Afrough, M.; Agarwal, B.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allen, G.; Allocca, A.; Aloy, M. A.; Altin, P. A.; Amato, A.; Ananyeva, A.; Anderson, S. B.; Anderson, W. G.; Angelova, S. V.; Antier, S.; Appert, S.; Arai, K.; Araya, M. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Atallah, D. V.; Aufmuth, P.; Aulbert, C.; AultONeal, K.; Austin, C.; Avila-Alvarez, A.; Babak, S.; Bacon, P.; Bader, M. K. M.; Bae, S.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Banagiri, S.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barkett, K.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Bawaj, M.; Bayley, J. C.; Bazzan, M.; Becsy, B.; Beer, C.; Bejger, M.; Belahcene, I.; Bell, A. S.; Berger, B. K.; Bergmann, G.; Bero, J. J.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Billman, C. R.; Birch, J.; Birney, R.; Birnholtz, O.; Biscans, S.; Biscoveanu, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blackman, J.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bode, N.; Boer, M.; Bogaert, G.; Bohe, A.; Bondu, F.; Bonilla, E.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bossie, K.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Broida, J. E.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brunett, S.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cabero, M.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Bustillo, J. Calderon; Callister, T. A.; Calloni, E.; Camp, J. B.; Canepa, M.; Canizares, P.; Cannon, K. C.; Cao, H.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Carney, M. F.; Diaz, J. Casanueva; Casentini, C.; Caudill, S.; Cavaglia, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerda-Duran, P.; Cerretani, G.; Cesarini, E.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chase, E.; Chassande-Mottin, E.; Chatterjee, D.; Chatziioannou, K.; Cheeseboro, B. D.; Chen, H. Y.; Chen, X.; Chen, Y.; Cheng, H. -P.; Chia, H.; Chincarini, A.; Chiummo, A.; Chmiel, T.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, A. J. K.; Chua, S.; Chung, A. K. W.; Chung, S.; Ciani, G.; Ciolfi, R.; Cirelli, C. E.; Cirone, A.; Clara, F.; Clark, J. A.; Clearwater, P.; Cleva, F.; Cocchieri, C.; Coccia, E.; Cohadon, P. -F.; Cohen, D.; Colla, A.; Collette, C. G.; Cominsky, L. R.; Constancio, M., Jr.; Conti, L.; Cooper, S. J.; Corban, P.; Corbitt, T. R.; Cordero-Carrion, I.; Corley, K. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J. -P.; Countryman, S. T.; Couvares, P.; Covas, P. B.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Creighton, J. D. E.; Creighton, T. D.; Cripe, J.; Crowder, S. G.; Cullen, T. J.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Dalya, G.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Dasgupta, A.; Costa, C. F. Da Silva; Dattilo, V.; Dave, I.; Davier, M.; Davis, D.; Daw, E. J.; Day, B.; De, S.; Debra, D.; Degallaix, J.; De laurentis, M.; Deleglise, S.; Del Pozzo, W.; Demos, N.; Denker, T.; Dent, T.; De Pietri, R.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; De Rossi, C.; DeSalvo, R.; de Varona, O.; Devenson, J.; Dhurandhar, S.; Diaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Renzo, F.; Doctor, Z.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Dorrington, I.; Douglas, R.; Alvarez, M. Dovale; Downes, T. P.; Drago, M.; Dreissigacker, C.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dupej, P.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H. -B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Eisenstein, R. A.; Essick, R. C.; Estevez, D.; Etienne, Z. B.; Etzel, T.; Evans, M.; Evans, T. M.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Farinon, S.; Farr, B.; Farr, W. M.; Fauchon-Jones, E. J.; Favata, M.; Fays, M.; Fee, C.; Fehrmann, H.; Feicht, J.; Fejer, M. M.; Fernandez-Galiana, A.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Finstad, D.; Fiori, I.; Fiorucci, D.; Fishbach, M.; Fisher, R. P.; Fitz-Axen, M.; Flaminio, R.; Fletcher, M.; Fong, H.; Font, J. A.; Forsyth, P. W. F.; Forsyth, S. S.; Fournier, J. -D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fries, E. M.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H.; Gadre, B. U.; Gaebel, S. M.; Gair, J. R.; Gammaitoni, L.; Ganija, M. R.; Gaonkar, S. G.; Garcia-Quiros, C.; Garufi, F.; Gateley, B.; Gaudio, S.; Gaur, G.; Gayathri, V.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, D.; George, J.; Gergely, L.; Germain, V.; Ghonge, S.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glover, L.; Goetz, E.; Goetz, R.; Gomes, S.; Goncharov, B.; Gonzalez, G.; Castro, J. M. Gonzalez; Gopakumar, A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Gretarsson, E. M.; Groot, P.; Grote, H.; Grunewald, S.; Gruning, P.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Halim, O.; Hall, B. R.; Hall, E. D.; Hamilton, E. Z.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hannuksela, O. A.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Haster, C. -J.; Haughian, K.; Healy, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hinderer, T.; Hoak, D.; Hofman, D.; Holt, K.; Holz, D. E.; Hopkins, P.; Horst, C.; Hough, J.; Houston, E. A.; Howell, E. J.; Hreibi, A.; Hu, Y. M.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Indik, N.; Inta, R.; Intini, G.; Isa, H. N.; Isac, J. -M.; Isi, M.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jimenez-Forteza, F.; Johnson, W. W.; Johnson-McDaniel, N. K.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; Junker, J.; Kalaghatgi, C. V.; Kalogera, V.; Kamai, B.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Kapadia, S. J.; Karki, S.; Karvinen, K. S.; Kasprzack, M.; Kastaun, W.; Katolik, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kawabe, K.; Kefelian, F.; Keitel, D.; Kemball, A. J.; Kennedy, R.; Kent, C.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chunglee; Kim, J. C.; Kim, K.; Kim, W.; Kim, W. S.; Kim, Y. -M.; Kimbrell, S. J.; King, E. J.; King, P. J.; Kinley-Hanlon, M.; Kirchhoff, R.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Knowles, T. D.; Koch, P.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kraemer, C.; Kringel, V.; Krishnan, B.; Krolak, A.; Kuehn, G.; Kumar, P.; Kumar, R.; Kumar, S.; Kuo, L.; Kutynia, A.; Kwang, S.; Lackey, B. D.; Lai, K. H.; Landry, M.; Lang, R. N.; Lange, J.; Lantz, B.; Lanza, R. K.; Lartaux-Vollard, A.; Lasky, P. D.; Laxen, M.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, H. W.; Lee, K.; Lehmann, J.; Lenon, A.; Leonardi, M.; Leroy, N.; Letendre, N.; Levin, Y.; Li, T. G. F.; Linker, S. D.; Littenberg, T. B.; Liu, J.; Lo, R. K. L.; Lockerbie, N. A.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lousto, C. O.; Lovelace, G.; Lueck, H.; Lumaca, D.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Macas, R.; Macfoy, S.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Hernandez, I. Magana; Magana-Sandoval, F.; Zertuche, L. Magana; Magee, R. M.; Majorana, E.; Maksimovic, I.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Marka, S.; Marka, Z.; Markakis, C.; Markosyan, A. S.; Markowitz, A.; Maros, E.; Marquina, A.; Martelli, F.; Martellini, L.; Martin, I. W.; Martin, R. M.; Martynov, D. V.; Mason, K.; Massera, E.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matas, A.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McCuller, L.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McNeill, L.; Mcrae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Mehmet, M.; Meidam, J.; Mejuto-Villa, E.; Melatos, A.; Mendell, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, B. B.; Miller, J.; Millhouse, M.; Milovich-Goff, M. C.; Minazzoli, O.; Minenkov, Y.; Ming, J.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moffa, D.; Moggi, A.; Mogushi, K.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Muniz, E. A.; Muratore, M.; Murray, P. G.; Napier, K.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Neilson, J.; Nelemans, G.; Nelson, T. J. N.; Nery, M.; Neunzert, A.; Nevin, L.; Newport, J. M.; Newton, G.; Ng, K. K. Y.; Nguyen, T. T.; Nichols, D.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Noack, A.; Nocera, F.; Nolting, D.; North, C.; Nuttall, L. K.; Oberling, J.; O'Dea, G. D.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Okada, M. A.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; Ormiston, R.; Ortega, L. F.; O'Shaughnessy, R.; Ossokine, S.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pace, A. E.; Page, J.; Page, M. A.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, Howard; Pan, Huang-Wei; Pang, B.; Pang, P. T. H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Parida, A.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patil, M.; Patricelli, B.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Perez, C. J.; Perreca, A.; Perri, L. M.; Pfeiffer, H. P.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pirello, M.; Pitkin, M.; Poe, M.; Poggiani, R.; Popolizio, P.; Porter, E. K.; Post, A.; Powell, J.; Prasad, J.; Pratt, J. W. W.; Pratten, G.; Predoi, V.; Prestegard, T.; Prijatelj, M.; Principe, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L. G.; Puncken, O.; Punturo, M.; Puppo, P.; Puerrer, M.; Qi, H.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rajbhandari, B.; Rakhmanov, M.; Ramirez, K. E.; Ramos-Buades, A.; Rapagnani, P.; Raymond, V.; Razzano, M.; Read, J.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Ren, W.; Reyes, S. D.; Ricci, F.; Ricker, P. M.; Rieger, S.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, R.; Romel, C. L.; Romie, J. H.; Rosinska, D.; Ross, M. P.; Rowan, S.; Ruediger, A.; Ruggi, P.; Rutins, G.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sampson, L. M.; Sanchez, E. J.; Sanchez, L. E.; Sanchis-Gual, N.; Sandberg, V.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O.; Savage, R. L.; Sawadsky, A.; Schale, P.; Scheel, M.; Scheuer, J.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schoenbeck, A.; Schreiber, E.; Schuette, D.; Schulte, B. W.; Schutz, B. F.; Schwalbe, S. G.; Scott, J.; Scott, S. M.; Seidel, E.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Shaddock, D. A.; Shaffer, T. J.; Shah, A. A.; Shahriar, M. S.; Shaner, M. B.; Shao, L.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Singer, L. P.; Singh, A.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, B.; Smith, R. J. E.; Smith, R. J. E.; Somala, S.; Son, E. J.; Sonnenberg, J. A.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Spencer, A. P.; Srivastava, A. K.; Staats, K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stevenson, S. P.; Stone, R.; Stops, D. J.; Strain, K. A.; Stratta, G.; Strigin, S. E.; Strunk, A.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Suresh, J.; Sutton, P. J.; Swinkels, B. L.; Szczepanczyk, M. J.; Tacca, M.; Tait, S. C.; Talbot, C.; Talukder, D.; Tanner, D. B.; Tapai, M.; Taracchini, A.; Tasson, J. D.; Taylor, J. A.; Taylor, R.; Tewari, S. V.; Theeg, T.; Thies, F.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tonelli, M.; Tornasi, Z.; Torres-Forne, A.; Torrie, C. I.; Toyra, D.; Travasso, F.; Traylor, G.; Trinastic, J.; Tringali, M. C.; Trozzo, L.; Tsang, K. W.; Tse, M.; Tso, R.; Tsukada, L.; Tsuna, D.; Tuyenbayev, D.; Ueno, K.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; van Beuzekom, M.; Van den Brand, J. F. J.; Van den Broeck, C.; Vander-Hyde, D. C.; Van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Varma, V.; Vass, S.; Vasuth, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Venugopalan, G.; Verkindt, D.; Vetrano, F.; Vicere, A.; Viets, A. D.; Vinciguerra, S.; Vine, D. J.; Vinet, J. -Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walet, R.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, J. Z.; Wang, W. H.; Wang, Y. F.; Ward, R. L.; Warner, J.; Was, M.; Watchi, J.; Weaver, B.; Wei, L. -W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wessel, E. K.; Wessels, P.; Westerweck, J.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; Whiting, B. F.; Whittle, C.; Wilken, D.; Williams, D.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Wofford, J.; Wong, K. W. K.; Worden, J.; Wright, J. L.; Wu, D. S.; Wysocki, D. M.; Xiao, S.; Yamamoto, H.; Yancey, C. C.; Yang, L.; Yap, M. J.; Yazback, M.; Yu, Hang; Yu, Haocun; Yvert, M.; Zadrozny, A.; Zanolin, M.; Zelenova, T.; Zendri, J. -P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, T.; Zhang, Y. -H.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, S. J.; Zhu, X. J.; Zimmerman, A. B.; Zucker, M. E.; Zweizig, J.; Burns, E.; Veres, P.; Kocevski, D.; Racusin, J.; Goldstein, A.; Connaughton, V.; Briggs, M. S.; Blackburn, L.; Hamburg, R.; Hui, C. M.; von Kienlin, A.; McEnery, J.; Preece, R. D.; Wilson-Hodge, C. A.; Bissaldi, E.; Cleveland, W. H.; Gibby, M. H.; Giles, M. M.; Kippen, R. M.; McBreen, S.; Meegan, C. A.; Paciesas, W. S.; Poolakkil, S.; Roberts, O. J.; Stanbro, M.; Savchenko, V.; Ferrigno, C.; Kuulkers, E.; Bazzano, A.; Bozzo, E.; Brandt, S.; Chenevez, J.; Courvoisier, T. J. -L.; Diehl, R.; Domingo, A.; Hanlon, L.; Jourdain, E.; Laurent, P.; Lebrun, F.; Lutovinov, A.; Mereghetti, S.; Natalucci, L.; Rodi, J.; Roques, J. -P.; Sunyaev, R.; Ubertini, P.

2017-01-01

On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International

Rapid determination of radon daughters and of artificial radionuclides in air by online gamma-ray spectrometry

International Nuclear Information System (INIS)

Hoetzl, H.; Winkler, R.

1993-01-01

For the determination of airborne radionuclide concentrations in real time, a fixed filter device was constructed which fits directly onto a germanium detector with standard nuclear electronics and a multichannel analyzer buffer connected via a data line to a personal computer for remote control and on-line spectrum evaluation. The on-line gamma-ray spectrometer was applied to the study of radon decay product concentrations in ground-level air and to the rapid detection of only contamination of the environmental air by artificial radionuclides. At Munich-Neuherberg, depending on the meteorological conditions, the measured air concentrations of 214 Pb, the first gamma-ray-emitting member of the 222 Rn decay series, varied from about 1 to 50 Bq m -3 . For the artifical radionuclides 60 Co, 131 I and 137 Cs the detection limits were determined as a function of the varying natural radon daughter concentrations at sampling and counting times of 1 h or 1 day. For these radionuclides minimum detectable air activity concentrations of 0.3 or 0.001 Bq m -3 , respectively, were obtained at low radon daughter levels. At high radon daughter levels the respective detection limits were found to be higher by a factor of only about 2. (orig.)

Rapid determination of radon daughters and of artificial radionuclides in air by online gamma-ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Hoetzl, H.; Winkler, R. (GSF-Forschungszentrum fuer Umwelt und Gesundheit, Neuherberg (Germany). Inst. fuer Strahlenschutz)

1993-04-01

For the determination of airborne radionuclide concentrations in real time, a fixed filter device was constructed which fits directly onto a germanium detector with standard nuclear electronics and a multichannel analyzer buffer connected via a data line to a personal computer for remote control and on-line spectrum evaluation. The on-line gamma-ray spectrometer was applied to the study of radon decay product concentrations in ground-level air and to the rapid detection of only contamination of the environmental air by artificial radionuclides. At Munich-Neuherberg, depending on the meteorological conditions, the measured air concentrations of [sup 214]Pb, the first gamma-ray-emitting member of the [sup 222]Rn decay series, varied from about 1 to 50 Bq m[sup -3]. For the artifical radionuclides [sup 60]Co, [sup 131]I and [sup 137]Cs the detection limits were determined as a function of the varying natural radon daughter concentrations at sampling and counting times of 1 h or 1 day. For these radionuclides minimum detectable air activity concentrations of 0.3 or 0.001 Bq m[sup -3], respectively, were obtained at low radon daughter levels. At high radon daughter levels the respective detection limits were found to be higher by a factor of only about 2. (orig.).

Gamma-ray identification of nuclear weapon materials

International Nuclear Information System (INIS)

Gosnell, T. B.; Hall, J. M.; Jam, C. L.; Knapp, D. A.; Koenig, Z. M.; Luke, S. J.; Pohl, B. A.; Schach Wittenau, A. von; Wolford, J. K.

1997-01-01

There has been an accelerating national interest in countering nuclear smuggling. This has caused a corresponding expansion of interest in the use of gamma-ray spectrometers for checkpoint monitoring, nuclear search, and within networks of nuclear and collateral sensors. All of these are fieldable instruments--ranging from large, fixed portal monitors to hand-held and remote monitoring equipment. For operational reasons, detectors with widely varying energy resolution and detection efficiency will be employed. In many instances, such instruments must be sensitive to weak signals, always capable of recognizing the gamma-ray signatures from nuclear weapons materials (NWM), often largely insensitive to spectral alteration by radiation transport through intervening materials, capable of real-time implementation, and able to discriminate against signals from commonly encountered legitimate gamma-ray sources, such as radiopharmaceuticals. Several decades of experience in classified programs have shown that all of these properties are not easily achieved and successful approaches were of limited scope--such as the detection of plutonium only. This project was originally planned as a two-year LDRD-ER. Since funding for 1997 was not sustained, this is a report of the first year's progress

Observations of the highest energy gamma-rays from gamma-ray bursts

International Nuclear Information System (INIS)

Dingus, Brenda L.

2001-01-01

EGRET has extended the highest energy observations of gamma-ray bursts to GeV gamma rays. Such high energies imply the fireball that is radiating the gamma-rays has a bulk Lorentz factor of several hundred. However, EGRET only detected a few gamma-ray bursts. GLAST will likely detect several hundred bursts and may extend the maximum energy to a few 100 GeV. Meanwhile new ground based detectors with sensitivity to gamma-ray bursts are beginning operation, and one recently reported evidence for TeV emission from a burst

Development of a Gamma Spectrometer using a Large NaI Scintillator and SiPMs

International Nuclear Information System (INIS)

Kim, Chankyu; Yoo, Hyunjun; Kim, Yewon and others

2014-01-01

A typical scintillation gamma spectrometer is composed of a NaI(Tl) scintillation crystal and a PM tube. From last years, a Silicon Photomultiplier (SiPM) is being developed and expanding its application area as a substitute of PM tube due to its advantages like low operating voltage, small volume, and cheap production cost, MR compatibility. This approach could make gamma spectrometer smaller, cheaper, easier to use, and these advantage are quite suitable to original purpose of scintillation gamma spectrometer. Gamma spectrometry and gamma spectrometer is used to analyze gamma source in nuclear science, geochemistry, and astrophysics. In this research, gamma spectrometer which uses SiPMs instead of PM tube is proposed. The proposed gamma spectrometer has advantages of low cost, small volume, low operation voltage; but it has disadvantages of performances. To reduce this loss in performances, a light guide of effective structure is required. (Material, reflection type, tapering angle) For design of the light guide, DETECT simulation was performed. And through DETECT simulation, the characteristics of light guide could be prospected. Actual light guide was manufactured on the basis of this simulation result. Using the light guide, gamma spectrometer system was composed and tested. In the test result, gamma spectrometer using SiPM shows degraded energy resolution. The reason of this degradation is being analyzed and the test system is under modification

Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A

DEFF Research Database (Denmark)

Abbott, B. P.; Abbott, R.; Abbott, T. D.

2017-01-01

On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International Gam...

Simulation of GRIS spectrometer response to the solar gamma-ray flare of 23 July 2002

International Nuclear Information System (INIS)

Trofimov, Yu A; Kotov, Yu D; Yurov, V N; Lupar, E E; Faradzhaev, R M; Glyanenko, A S

2017-01-01

GRIS is a prospective experiment designed to measure hard X-rays and γ-rays of solar flares in the energy range from 50 keV to 200 MeV as well as solar neutrons > 30 MeV. This study considers results of GEANT 4 simulation of GRIS detectors response to cosmic background radiation and to the solar flare SOL2002-07-23 (X4.8). It is shown that the GRIS spectrometers have enough sensitivity and energy resolution to measure redshifts of some narrow γ-rays in flare spectra, that the low energy thresholds of the detectors can be lowered considerably without a risk of counting rate saturation during high magnitude flares and that at a choice between LaBr 3 (Ce) and CeBr 3 the second one is a preferable scintillator for a hard X-ray and γ-ray spectrometer of solar flares. (paper)

Determination of protein content in seeds by prompt gamma-ray spectrometry

International Nuclear Information System (INIS)

Carbonari, A.W.; Pecequilo, B.R.S.

1984-01-01

The protein level in seeds can be directly calculated through the determination of the nitrogen content in grains. The authors show here that the radioactive thermal neutron capture prompt gamma-rays technique can be used to determine the nitrogen content in grains without chemical destruction, with good precision and relative rapidity, by detecting the prompt gamma rays emitted by the 14 N(n,γ) 15 N reaction product. The samples were irradiated in the tangential tube of the IEA-R1 research reactor, in Sao Paulo, and a pair spectrometer was used for the detection of the prompt gamma-rays. The nitrogen content was determined in several samples of soybean, common bean, peas and rice and the results compared with typical nitrogen content values for each grain. 33 references, 1 figure, 1 table

Design and environmental applications of an ultra-low-background, high-efficiency intrinsic Ge gamma-ray spectrometer

International Nuclear Information System (INIS)

Wogman, N.A.

1981-04-01

A coincidence shielded intrinsic Ge gamma-ray spectrometer incorporating a 25% efficient, high resolution coaxial diode inside a 30 cm diameter NaI(Tl) shield is described. System design eliminates the major cause of background and minimizes cosmic-ray created background events through the use of electronic means. The system provides a peak-to-Compton ratio of greater than 1000 to 1 for 137 Cs and high sensitivity for both low and high level radionuclide measurements. At 3 MeV the background is 0.000058 counts per minute per keV. At 1 MeV it is 0.00048 counts per minute per keV, and at 0.5 MeV it is 0.0045 counts per minute per keV. Traces of primordial radionuclides create background events such as at 2.614 MeV (0.016 counts per minute total peak area), at 2.448 MeV (0.0058 counts per minute per total peak area), and at 2.204 MeV (0.023 counts per minute per total peak area). The system is discussed with respect to its background design, methods to improve its design, and its application to measurements of neutron activated and environmental materials problems

Neutron-induced gamma-ray spectroscopy: simulations for chemical mapping of planetary surfaces

International Nuclear Information System (INIS)

Brueckner, J.; Waenke, H.; Reedy, R.C.

1986-01-01

Cosmic rays interact with the surface of a planetary body and produce a cascade of secondary particles, such as neutrons. Neutron-induced scattering and capture reactions play an important role in the production of discrete gamma-ray lines that can be measured by a gamma-ray spectrometer on board of an orbiting spacecraft. These data can be used to determine the concentration of many elements in the surface of a planetary body, which provides clues to its bulk composition and in turn to its origin and evolution. To investigate the gamma rays made by neutron interactions, thin targets were irradiated with neutrons having energies from 14 MeV to 0.025 eV. By means of foil activation technique the ratio of epithermal to thermal neutrons was determined to be similar to that in the Moon. Gamma rays emitted by the targets and the surrounding material were detected by a high-resolution germanium detector in the energy range of 0.1 to 8 MeV. Most of the gamma-ray lines that are expected to be used for planetary gamma-ray spectroscopy were found in the recorded spectra and the principal lines in these spectra are presented. 58 refs., 7 figs., 9 tabs

Inhomogeneity of neutron and gamma-ray attenuation in biological shields

Energy Technology Data Exchange (ETDEWEB)

El-bakkoush, F A; El-Ghobary, A M; Megahid, R M [Reactor and Neutron physics Department, Nuclear Research Center, A.E.A., Cairo (Egypt)

1997-12-31

Measurements have been carried-out to investigate the attenuation properties of some materials which are used as biological shields around nuclear radiation sources. Investigation was performed by measuring the transmitted fast neutron and gamma-spectra through cylindrical samples of magnetite- limonite, steel and cellulose shields. The neutron and gamma spectra were measured by a neutron-gamma spectrometer with stilbene scintillator. Discrimination between neutron and gamma pulses was achieved by a discrimination method. The obtained results are displayed in the form of neutron and gamma spectra and attenuation relations which are used to derive the total macroscopic cross-sections for neutrons and total linear attenuation coefficients for gamma-rays. The values of neutron and gamma relaxation lengths are also derived for the investigated materials. 10 figs., 1 tabs.

X-ray and gamma-ray response of a 2 '' x 2 '' LaBr3 : Ce scintillation detector

NARCIS (Netherlands)

Quarati, F.; Bos, A. J. J.; Brandenburg, S.; Dathy, C.; Dorenbos, P.; Kraft, S.; Ostendorf, R. W.; Ouspenski, V.; Owens, Alan

2007-01-01

Advances in material growth techniques have recently made large volume LaBr3:Ce crystals commercially available. These scintillators are currently being assessed by ESA for use as remote sensing gamma-ray spectrometers on future planetary missions. In addition to their superior scintillation

Spectra of gamma-ray bursts at high energies

International Nuclear Information System (INIS)

Matz, S.M.

1986-01-01

Between 1980 February and 1983 August the Gamma-Ray Spectrometer (GRS) on the Solar Maximum Mission satellite (SMM) observed 71 gamma-ray bursts. These events form a representative subset of the class of classical gamma-ray bursts. Since their discovery more than 15 years ago, hundreds of gamma-ray bursts have been detected; however, most observations have been limited to an energy range of roughly 30 keV-1 MeV. The large sensitive area and spectral range of the GRS allow, for the first time, an investigation of the high energy (>1 MeV) behavior of a substantial number of gamma-ray bursts. It is found that high-energy emission is seen in a large fraction of all events and that the data are consistent with all bursts emitting to at least 5 MeV with no cut-offs. Further, no burst spectrum measured by GRS has a clear high-energy cut-off. The high-energy emission can be a significant part of the total burst energy on the average about 30% of the observed energy above 30 keV is contained in the >1 MeV photons. The fact that the observations are consistent with the presence of high-energy emission in all events implies a limit on the preferential beaming of high-energy photons, from any mechanism. Single-photon pair-production in a strong magnetic field produces such beaming; assuming that the low-energy emission is isotropic, the data imply an upper limit of 1 x 10 12 G on the typical magnetic field at burst radiation sites

Neutron and gamma-ray spectra of {sup 239}PuBe and {sup 241}AmBe

Energy Technology Data Exchange (ETDEWEB)

Vega-Carrillo, H.R. E-mail: rvega@cantera.reduaz.mx; Manzanares-Acuna, Eduardo; Becerra-Ferreiro, A.M.; Carrillo-Nunez, Aureliano

2002-08-01

Neutron and gamma-ray spectra of {sup 239}PuBe and {sup 241}AmBe were measured and their dosimetric features were calculated. Neutron spectra were measured using a multisphere neutron spectrometer with a {sup 6}LiI(Eu) scintillator. The {sup 239}PuBe neutron spectrum was measured in an open environment, while the {sup 241}AmBe neutron spectrum was measured in a closed environment. Gamma-ray spectra were measured using a NaI(Tl) scintillator using the same experimental conditions for both sources. The effect of measuring conditions for the {sup 241}AmBe neutron spectrum indicates the presence of epithermal and thermal neutrons. The low-resolution neutron spectra obtained with the multisphere spectrometer allows one to calculate the dosimetric features of neutron sources. At 100 cm both sources produce approximately the same count rate as that of the 4.4 MeV gamma-ray per unit of alpha emitter activity.

Advanced techniques for high resolution spectroscopic observations of cosmic gamma-ray sources

International Nuclear Information System (INIS)

Matteson, J.L.; Pelling, M.R.; Peterson, L.E.

1985-08-01

We describe an advanced gamma-ray spectrometer that is currently in development. It will obtain a sensitivity of -4 ph/cm -2 -sec in a 6 hour balloon observation and uses innovative techniques for background reduction and source imaging

Are there nuclear contributions to gamma ray burst spectra

International Nuclear Information System (INIS)

Matz, S.M.; Chupp, E.L.; Forrest, D.J.; Share, G.H.; Nolan, P.L.; Rieger, E.

1984-01-01

We have examined the spectra of 38 γ-ray bursts observed by the Gamma Ray Spectrometer (GRS) on the Solar Maximum Mission (SMM) satellite for evidence of a nuclear contribution to the high energy flux. A sum of spectra from the nine bursts with detectable flux >4 MeV suggests but does not require a drop-off above 7 MeV. A cutoff between 7 and 8 MeV is consistent with a high energy spectrum dominated by nuclear lines

A gamma-gamma coincidence/anticoincidence spectrometer for low-level cosmogenic (22)Na/(7)Be activity ratio measurement.

Science.gov (United States)

Zhang, Weihua; Ungar, Kurt; Stukel, Matthew; Mekarski, Pawel

2014-04-01

In this study, a digital gamma-gamma coincidence/anticoincidence spectrometer was developed and examined for low-level cosmogenic (22)Na and (7)Be in air-filter sample monitoring. The spectrometer consists of two bismuth germanate scintillators (BGO) and an XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The spectrometer design allows a more selective measurement of (22)Na with a significant background reduction by gamma-gamma coincidence events processing. Hence, the system provides a more sensitive way to quantify trace amounts of (22)Na than normal high resolution gamma spectrometry providing a critical limit of 3 mBq within a 20 h count. The use of a list-mode data acquisition technique enabled simultaneous determination of (22)Na and (7)Be activity concentrations using a single measurement by coincidence and anticoincidence mode respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Mapping X-ray Fluorescence Spectrometer (MapX)

Science.gov (United States)

Sarrazin, P.; Blake, D. F.; Marchis, F.; Bristow, T.; Thompson, K.

2017-12-01

Many planetary surface processes leave traces of their actions as features in the size range 10s to 100s of microns. The Mapping X-ray Fluorescence Spectrometer (MapX) will provide elemental imaging at 100 micron spatial resolution, yielding elemental chemistry at a scale where many relict physical, chemical, or biological features can be imaged and interpreted in ancient rocks on planetary bodies and planetesimals. MapX is an arm-based instrument positioned on a rock or regolith with touch sensors. During an analysis, an X-ray source (tube or radioisotope) bombards the sample with X-rays or alpha-particles / gamma-rays, resulting in sample X-ray Fluorescence (XRF). X-rays emitted in the direction of an X-ray sensitive CCD imager pass through a 1:1 focusing lens (X-ray micro-pore Optic (MPO)) that projects a spatially resolved image of the X-rays onto the CCD. The CCD is operated in single photon counting mode so that the energies and positions of individual X-ray photons are recorded. In a single analysis, several thousand frames are both stored and processed in real-time. Higher level data products include single-element maps with a lateral spatial resolution of 100 microns and quantitative XRF spectra from ground- or instrument- selected Regions of Interest (ROI). XRF spectra from ROI are compared with known rock and mineral compositions to extrapolate the data to rock types and putative mineralogies. When applied to airless bodies and implemented with an appropriate radioisotope source for alpha-particle excitation, MapX will be able to analyze biogenic elements C, N, O, P, S, in addition to the cations of the rock-forming elements >Na, accessible with either X-ray or gamma-ray excitation. The MapX concept has been demonstrated with a series of lab-based prototypes and is currently under refinement and TRL maturation.

Outcrop Gamma-ray Analysis of the Cretaceous mesaverde Group: Jicarilla Apache Indian Reservation, New Mexico

Energy Technology Data Exchange (ETDEWEB)

Ridgley, Jennie; Dunbar, Robyn Wright

2001-04-25

This report presents the results of an outcrop gamma-ray survey of six selected measured sections included in the original report. The primary objective of this second study is to provide a baseline to correlate from the outcrop and reservoir model into Mesaverde strata in the San Juan Basin subsurface. Outcrop logs were generated using a GAD-6 gamma-ray spectrometer that simultaneously recorded total counts, potassium, uranium, and thorium data.

The worldwide NORM production and a fully automated gamma-ray spectrometer for their characterization

International Nuclear Information System (INIS)

Xhixha, G.; Callegari, I.; Guastaldi, E.; De Bianchi, S.; Fiorentini, G.; Universita di Ferrara, Ferrara; Istituto Nazionale di Fisica Nucleare; Kaceli Xhixha, M.

2013-01-01

Materials containing radionuclides of natural origin and being subject to regulation because of their radioactivity are known as Naturally Occurring Radioactive Material (NORM). By following International Atomic Energy Agency, we include in NORM those materials with an activity concentration, which is modified by human made processes. We present a brief review of the main categories of non-nuclear industries together with the levels of activity concentration in feed raw materials, products and waste, including mechanisms of radioisotope enrichments. The global management of NORM shows a high level of complexity, mainly due to different degrees of radioactivity enhancement and the huge amount of worldwide waste production. The future tendency of guidelines concerning environmental protection will require both a systematic monitoring based on the ever-increasing sampling and high performance of gamma-ray spectroscopy. On the ground of these requirements a new low-background fully automated high-resolution gamma-ray spectrometer MCA R ad has been developed. The design of lead and cooper shielding allowed to reach a background reduction of two order of magnitude with respect to laboratory radioactivity. A severe lowering of manpower cost is obtained through a fully automation system, which enables up to 24 samples to be measured without any human attendance. Two coupled HPGe detectors increase the detection efficiency, performing accurate measurements on small sample volume (180 cm 3 ) with a reduction of sample transport cost of material. Details of the instrument calibration method are presented. MCA R ad system can measure in less than one hour a typical NORM sample enriched in U and Th with some hundreds of Bq kg -1 , with an overall uncertainty less than 5 %. Quality control of this method has been tested. Measurements of three certified reference materials RGK-1, RGU-2 and RGTh-1 containing concentrations of potassium, uranium and thorium comparable to NORM have

Colorado School of Mines Fusion Gamma Ray Project

International Nuclear Information System (INIS)

Cecil, F.E.

1990-01-01

This report summarizes the activities and accomplishments of the CSM Fusion Gamma Ray Project for the calendar year 1989. As reported in last year's Technical Progress Report, the initial objective of the project was the design and bench testing of an eight channel, very high count rate gamma ray spectrometer. The next objective of the project was the installation and field testing of a comparable fifteen channel spectrometer on TFTR. This objective has been accomplished over the past year and the system has been operated successfully at count rates approaching 10 MHz during neutral beam injected (NBI) deuterium plasmas with injected beam powers in excess of 20 MW. The MFE computer network link between CSM and TFTR has been most valuable in the accomplishment of the year's objectives and should serve as a model for future collaborations of outside researchers with experiments on TFTR and CIT. The coming year's work includes the spectrometry of high energy fusion gamma rays during 3 He minority ICRH heating of deuterium plasmas and hydrogen minority ICRH heating during Lithium pellet injection as diagnostics of energetic alpha particle production. We include in this report selected results from our parallel grant from the DOE Office of High Energy and Nuclear Physics as they pertain to the present APP grant. These results include experimentally derived thermonuclear reactivities of various light ion fusion plasmas for temperatures up to 40 keV. We would emphasize that our APP project is highly collaborative in nature and that Sid Medley and other members of the TFTR staff deserve much of the credit and bore much of the cost for many of the important accomplishments summarized in this report

Neutron Capture Gamma-Ray Spectroscopy. Proceedings of the International Symposium on Neutron Capture Gamma-Ray Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

NONE

1969-11-15

Experimental capabilities in the field of neutron capture gamma-ray spectroscopy have expanded greatly in the last few years; this has been due in large part to the advent of high-quality Ge(Li) detectors, improvements in electronic data processing, and improvements in bent-crystal spectrometers. Previously unsuspected phenomena, such as the '5. 5-MeV1 anomaly, have appeared and new research tools, such as neutron guide tubes, have been brought into use. Equally exciting developments have occurred in the theory of neutron capture. Complex spectra have yielded to analysis after account had been taken of such effects as vibration, rotation and Coriolis forces, and the theoretical prediction of capture spectra seems to be a future possibility. In view of the International Atomic Energy Agency's close interest in this subject and the need for an international exchange of ideas to analyse and study the latest developments, the organizers of the Symposium felt that work on neutron capture gamma-ray spectroscopy had achieved such valuable and significant results that the time had come for this information to be presented, examined and discussed internationally.

Neutron Capture Gamma-Ray Spectroscopy. Proceedings of the International Symposium on Neutron Capture Gamma-Ray Spectroscopy

International Nuclear Information System (INIS)

1969-01-01

Experimental capabilities in the field of neutron capture gamma-ray spectroscopy have expanded greatly in the last few years; this has been due in large part to the advent of high-quality Ge(Li) detectors, improvements in electronic data processing, and improvements in bent-crystal spectrometers. Previously unsuspected phenomena, such as the '5. 5-MeV1 anomaly, have appeared and new research tools, such as neutron guide tubes, have been brought into use. Equally exciting developments have occurred in the theory of neutron capture. Complex spectra have yielded to analysis after account had been taken of such effects as vibration, rotation and Coriolis forces, and the theoretical prediction of capture spectra seems to be a future possibility. In view of the International Atomic Energy Agency's close interest in this subject and the need for an international exchange of ideas to analyse and study the latest developments, the organizers of the Symposium felt that work on neutron capture gamma-ray spectroscopy had achieved such valuable and significant results that the time had come for this information to be presented, examined and discussed internationally

Attenuation of neutrons and gamma-rays in homogeneous and multilayered shields

International Nuclear Information System (INIS)

Abdo, A.E.; Megahid, R.M.

1997-01-01

Measurements were carried-out to compare the attenuation properties of homogeneous shields and shields of two layers and three layers for fast neutrons and total gamma-rays. These were performed by measuring the fast neutron and total gamma-ray spectra behind homogeneous shields of magnetite-limonite, ilmenite-ilmenite and magnetite-magnetite concretes. The two layers assembly consists of iron and one of the above mentioned concretes, while the three layers shield consists of water, iron and one of the previously mentioned concretes. All measurements were carried-out using a neutron-gamma spectrometer with stilbene scintillator coupled to a fast photo multi player tube. Separation between pulses of recoil protons and recoil electrons was achieved by a pulse shape discrimination technique. 3 tabs., 10 figs., 13 refs

On background radiation gradients – the use of airborne surveys when searching for orphan sources using mobile gamma-ray spectrometry

International Nuclear Information System (INIS)

Kock, Peder; Rääf, Christopher; Samuelsson, Christer

2014-01-01

Systematic background radiation variations can lead to both false positives and failures to detect an orphan source when searching using car-borne mobile gamma-ray spectrometry. The stochastic variation at each point is well described by Poisson statistics, but when moving in a background radiation gradient the mean count rate will continually change, leading to inaccurate background estimations. Airborne gamma spectrometry (AGS) surveys conducted on the national level, usually in connection to mineral exploration, exist in many countries. These data hold information about the background radiation gradients which could be used at the ground level. This article describes a method that aims to incorporate the systematic as well as stochastic variations of the background radiation. We introduce a weighted moving average where the weights are calculated from existing AGS data, supplied by the Geological Survey of Sweden. To test the method we chose an area with strong background gradients, especially in the thorium component. Within the area we identified two roads which pass through the high-variability locations. The proposed method is compared with an unweighted moving average. The results show that the weighting reduces the excess false positives in the positive background gradients without introducing an excess of failures to detect a source during passage in negative gradients. -- Highlights: • We present a simple method to account for gradients in the natural background radiation. • Gradients in the natural radiation background can be modelled at the ground level using AGS data. • The number of false positives due to background gradients can be reduced by using airborne data

Study of SMM flares in gamma-rays and neutrons

Science.gov (United States)

Dunphy, Philip P.; Chupp, Edward L.

1992-01-01

This report summarizes the results of the research supported by NASA grant NAGW-2755 and lists the papers and publications produced through the grant. The objective of the work was to study solar flares that produced observable signals from high-energy (greater than 10 MeV) gamma-rays and neutrons in the Solar Maximum Mission (SMM) Gamma-Ray Spectrometer (GRS). In 3 of 4 flares that had been studied previously, most of the neutrons and neutral pions appear to have been produced after the 'main' impulsive phase as determined from hard x-rays and gamma-rays. We, therefore, proposed to analyze the timing of the high-energy radiation, and its implications for the acceleration, trapping, and transport of flare particles. It was equally important to characterize the spectral shapes of the interacting energetic electrons and protons - another key factor in constraining possible particle acceleration mechanisms. In section 2.0, we discuss the goals of the research. In section 3.0, we summarize the results of the research. In section 4.0, we list the papers and publications produced under the grant. Preprints or reprints of the publications are attached as appendices.

An Airborne Infrared Spectrometer for Solar Eclipse Observations

Science.gov (United States)

Samra, Jenna; DeLuca, Edward E.; Golub, Leon; Cheimets, Peter; Philip, Judge

2016-05-01

The airborne infrared spectrometer (AIR-Spec) is an innovative solar spectrometer that will observe the 2017 solar eclipse from the NSF/NCAR High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER). AIR-Spec will image five infrared coronal emission lines to determine whether they may be useful probes of coronal magnetism.The solar magnetic field provides the free energy that controls coronal heating, structure, and dynamics. Energy stored in coronal magnetic fields is released in flares and coronal mass ejections and ultimately drives space weather. Therefore, direct coronal field measurements have significant potential to enhance understanding of coronal dynamics and improve solar forecasting models. Of particular interest are observations of field lines in the transitional region between closed and open flux systems, providing important information on the origin of the slow solar wind.While current instruments routinely observe only the photospheric and chromospheric magnetic fields, AIR-Spec will take a step toward the direct observation of coronal fields by measuring plasma emission in the infrared at high spatial and spectral resolution. During the total solar eclipse of 2017, AIR-Spec will observe five magnetically sensitive coronal emission lines between 1.4 and 4 µm from the HIAPER Gulfstream V at an altitude above 14.9 km. The instrument will measure emission line intensity, width, and Doppler shift, map the spatial distribution of infrared emitting plasma, and search for waves in the emission line velocities.AIR-Spec consists of an optical system (feed telescope, grating spectrometer, and infrared detector) and an image stabilization system, which uses a fast steering mirror to correct the line-of-sight for platform perturbations. To ensure that the instrument meets its research goals, both systems are undergoing extensive performance modeling and testing. These results are shown with reference to the science requirements.

Determination of protein content in grains by radioactive thermal neutron capture prompt gamma rays analysis

International Nuclear Information System (INIS)

Carbonari, A.W.

1983-01-01

The radioactive thermal neutron capture prompt gamma rays technique can be used to determinate the nitrogen content in grains without chemical destruction, with good precision and relative rapidity. This determination is based on the detection of prompt gamma rays emitted by the 14 N(n,γ) 15 N reaction product. The samples has been irradiated the tanGencial tube of the IEA-R1 research reator and a pair spectrometer has been used for the detection of the prompt gamma rays. The nitrogen content is determinated in several samples of soybean, commonbean, peas and rice, and the results is compared with typical nitrogen content for each grain. (Autor) [pt

A study of the temporal and spectral characteristics of gamma ray bursts

International Nuclear Information System (INIS)

Norris, J.

1983-05-01

Gamma-ray burst data obtained from the ISEE-3 Gamma Ray Burst Spectrometer and the Solar Maximum Mission's Hard X-ray Burst Spectrometer (HXRBS) were analyzed to yield information on burst temporal and spectral characteristics. A Monte Carlo approach was used to simulate the HXRBS response to candidate spectral models. At energies above about 100 keV, the spectra are well fit by exponential forms. At lower energies, 30 keV to 60 keV, depressions below the model continua are apparent in some bursts. The depressions are not instrumental or data-reduction artifacts. The event selection criterion of the ISEE-3 experiment is based on the time to accumulate a present number of photons rather than the photon count per unit time and is consequently independent of event duration for a given burst intensity, unlike most conventional systems. As a result, a significantly greater percentage of fast, narrow events have been detected. The ratio of count rates from two ISEE-3 detectors indicates that bursts with durations or aprox. one second have much softer spectra than longer bursts

Borehole instrument for scintillation gamma spectrometer

International Nuclear Information System (INIS)

Sinitsyn, A.Ya.; Gabitov, R.M.

1979-01-01

Described are a schematic diagram and main specifications of a borehole instrument with autostabilization of energy scale measure by gamma bench-mark of 137 Cs, intended for the application in a logging gamma spectrometer to determine separately the concentrations of nature radioactive elements. The instrument may be connected to the KOBDFM-2 cable of 600 m length. It contains a scintillation counter for gamma quanta consisting of 30x70 mm NaI(Tl) crystal and a FEU-85 photoamplifier, an input conforming stage, a diagram of threshold pulse formation and regulating high-voltage generator. The borehole instrument has been proved under laboratory and field conditions at 10-40 deg C

Gamma-ray measurements for uranium enrichment standards

International Nuclear Information System (INIS)

Reilly, T.D.

1979-01-01

The gamma-ray spectroscopic measurement of uranium enrichment is one of the most widely used nondestructive analysis techniques. A study has been started of the precision and accuracy achievable with this technique and the physical parameters which affect it. The study was prompted by questions raised during the ongoing ESARDA-NBS experiment to produce uranium oxide reference counting materials for the technique. Results reported using a high-quality Ge(Li) spectrometer system show reproducibility comparable to that attainable with mass spectrometry

On The Utilization of (1-X)Cu-X Pb) Alloys for Gamma-Rays Shielding

International Nuclear Information System (INIS)

Abd El-Latif, A.A.; Saeid, Kh.S.; Abd El-Latif, A.A.

2011-01-01

The present work deals with the study of the attenuation properties of gamma rays for [(1-X) Cu -X Pb] alloys where, x=10%, 20%, 30%, and 40% Pb waste by weight. Investigation has been performed by measuring the transmitted gamma ray spectra behind cylindrical samples of [(1-X) Cu - X Pb] alloys of different thicknesses. A collimated beam of gamma ray measured by using γ - ray spectrometer NaI(Tl) Scintillation detector with multichannel analyzer (MCA) cassy. Total mass attenuation coefficients (μ/ρ) of γ-ray have been evaluated and calculated using measured results and XCOM code respectively . Comparison between measured and calculated results shows a reasonable divergence at 0.511 MeV ,and 0.662 MeV γ-ray energies, in addition there is a convergence at 1.17 MeV, 1.274 MeV, and 1.3 MeV γ-ray energies

Gamma-ray spectral determinations with a portable analyzer

International Nuclear Information System (INIS)

Eldridge, J.S.; Oakes, T.W.

1978-01-01

A portable sodium iodide spectrometer was used in a variety of field applications. The spectrometer is a battery-operated system complete with a 5 x 5 cm NaI(Tl) detector, 1024 channel memory divisible into four quadrants, special summation and calibration circuits, and a telemeter output for data transmittals. The portable spectrometer has been used to make in situ measurements around a radioactive waste burial ground. Typical spectra of 137 Cs and 60 Co were easily discernible at one such site. Uptake in vegetation near a sealed trench could be observed by placing the NaI(Tl) probe in the foliage. The extent of the spread of low-level contamination of 60 Co was determined in an area that had previously been decontaminated. The unique response of the two 60 Co gamma-rays could be obtained by subtracting the local background response within the computing spectrometer. The ability to perform qualitative identification and to assess hazards in emergency situations has been demonstrated

Eclipse Science Results from the Airborne Infrared Spectrometer (AIR-Spec)

Science.gov (United States)

Samra, J.; Cheimets, P.; DeLuca, E.; Golub, L.; Judge, P. G.; Lussier, L.; Madsen, C. A.; Marquez, V.; Tomczyk, S.; Vira, A.

2017-12-01

We present the first science results from the commissioning flight of the Airborne Infrared Spectrometer (AIR-Spec), an innovative solar spectrometer that will observe the 2017 solar eclipse from the NSF/NCAR High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER). During the eclipse, AIR-Spec will image five magnetically sensitive coronal emission lines between 1.4 and 4 microns to determine whether they may be useful probes of coronal magnetism. The instrument will measure emission line intensity, FWHM, and Doppler shift from an altitude of over 14 km, above local weather and most of the absorbing water vapor. Instrumentation includes an image stabilization system, feed telescope, grating spectrometer, infrared camera, and visible slit-jaw imager. Results from the 2017 eclipse are presented in the context of the mission's science goals. AIR-Spec will identify line strengths as a function of position in the solar corona and search for the high frequency waves that are candidates for heating and acceleration of the solar wind. The instrument will also identify large scale flows in the corona, particularly in polar coronal holes. Three of the five lines are expected to be strong in coronal hole plasmas because they are excited in part by scattered photospheric light. Line profile analysis will probe the origins of the fast and slow solar wind. Finally, the AIR-Spec measurements will complement ground based eclipse observations to provide detailed plasma diagnostics throughout the corona. AIR-Spec will measure infrared emission of ions observed in the visible from the ground, giving insight into plasma heating and acceleration at radial distances inaccessible to existing or planned spectrometers.

Design of airborne imaging spectrometer based on curved prism

Science.gov (United States)

Nie, Yunfeng; Xiangli, Bin; Zhou, Jinsong; Wei, Xiaoxiao

2011-11-01

A novel moderate-resolution imaging spectrometer spreading from visible wavelength to near infrared wavelength range with a spectral resolution of 10 nm, which combines curved prisms with the Offner configuration, is introduced. Compared to conventional imaging spectrometers based on dispersive prism or diffractive grating, this design possesses characteristics of small size, compact structure, low mass as well as little spectral line curve (smile) and spectral band curve (keystone or frown). Besides, the usage of compound curved prisms with two or more different materials can greatly reduce the nonlinearity inevitably brought by prismatic dispersion. The utilization ratio of light radiation is much higher than imaging spectrometer of the same type based on combination of diffractive grating and concentric optics. In this paper, the Seidel aberration theory of curved prism and the optical principles of Offner configuration are illuminated firstly. Then the optical design layout of the spectrometer is presented, and the performance evaluation of this design, including spot diagram and MTF, is analyzed. To step further, several types of telescope matching this system are provided. This work provides an innovational perspective upon optical system design of airborne spectral imagers; therefore, it can offer theoretic guide for imaging spectrometer of the same kind.

Gamma ray astronomy

International Nuclear Information System (INIS)

Fichtel, C.E.

1975-01-01

The first certain detection of celestial high energy gamma rays came from a satellite experiment flown on the third Orbiting Solar Observatory (OSO-111). A Gamma ray spark chamber telescope with substantively greater sensitivity and angular resolution (a few degrees) flown on the second Small Astronomy Satellite (SAS-II) has now provided a better picture of the gamma ray sky, and particularly the galactic plane and pulsars. This paper will summarize the present picture of gamma ray astronomy as it has developed at this conference from measurements made with experiments carried out on balloons, those remaining on the ground, and ones flown on satellites. (orig.) [de

Determining the solar-flare photospheric scale height from SMM gamma-ray measurements

Science.gov (United States)

Lingenfelter, Richard E.

1991-01-01

A connected series of Monte Carlo programs was developed to make systematic calculations of the energy, temporal and angular dependences of the gamma-ray line and neutron emission resulting from such accelerated ion interactions. Comparing the results of these calculations with the Solar Maximum Mission/Gamma Ray Spectrometer (SMM/GRS) measurements of gamma-ray line and neutron fluxes, the total number and energy spectrum of the flare-accelerated ions trapped on magnetic loops at the Sun were determined and the angular distribution, pitch angle scattering, and mirroring of the ions on loop fields were constrained. Comparing the calculations with measurements of the time dependence of the neutron capture line emission, a determination of the He-3/H ratio in the photosphere was also made. The diagnostic capabilities of the SMM/GRS measurements were extended by developing a new technique to directly determine the effective photospheric scale height in solar flares from the neutron capture gamma-ray line measurements, and critically test current atmospheric models in the flare region.

FAST TIMING ANALYSIS OF CYGNUS X-1 USING THE SPECTROMETER ON THE INTERNATIONAL GAMMA-RAY ASTROPHYSICS LABORATORY

International Nuclear Information System (INIS)

Cabanac, Clement; Roques, Jean-Pierre; Jourdain, Elisabeth

2011-01-01

We report for the first time the high-frequency analysis of Cyg X-1 up to hard X-ray using the spectrometer on International Gamma-Ray Astrophysics Laboratory (INTEGRAL). After analyzing the possible contribution from the background, and using the INTEGRAL archive from 2005 March to 2008 May, power density spectra were obtained up to 130 keV. First, we show that their overall shape is very similar to that observed at lower energies as they are well described by sets of Lorentzians. The strength of this fast variability (up to 40 Hz) does not drop at high energy since we show that it remains at ∼25% rms, even in the highest energy bands. Second, the hard X-ray variability patterns of Cyg X-1 are state dependent: the softer the spectrum (or the lower the hardness ratio), the lower the total fractional variability and the higher the typical frequencies observed. The strength of the total variability as a function of energy and state is then investigated. By comparison with simultaneous and published RXTE/Proportional Counter Array data, we show that in the hard state it remains quite constant in the 2-130 keV energy range. In the softer state it is also flat up to 50 keV and may increase at higher energy. The implications of this behavior on the models are then discussed.

Basics of Gamma Ray Detection

Energy Technology Data Exchange (ETDEWEB)

Stinnett, Jacob [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Venkataraman, Ram [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-09-13

The objective of this training is to explain the origin of x-rays and gamma rays, gamma ray interactions with matter, detectors and electronics used in gamma ray-spectrometry, and features of a gamma-ray spectrum for nuclear material that is safeguarded.

Method of incident low-energy gamma-ray direction reconstruction in the GAMMA-400 gamma-ray space telescope

International Nuclear Information System (INIS)

Kheymits, M D; Leonov, A A; Zverev, V G; Galper, A M; Arkhangelskaya, I V; Arkhangelskiy, A I; Yurkin, Yu T; Bakaldin, A V; Suchkov, S I; Topchiev, N P; Dalkarov, O D

2016-01-01

The GAMMA-400 gamma-ray space-based telescope has as its main goals to measure cosmic γ-ray fluxes and the electron-positron cosmic-ray component produced, theoretically, in dark-matter-particles decay or annihilation processes, to search for discrete γ-ray sources and study them in detail, to examine the energy spectra of diffuse γ-rays — both galactic and extragalactic — and to study gamma-ray bursts (GRBs) and γ-rays from the active Sun. Scientific goals of GAMMA-400 telescope require fine angular resolution. The telescope is of a pair-production type. In the converter-tracker, the incident gamma-ray photon converts into electron-positron pair in the tungsten layer and then the tracks are detected by silicon- strip position-sensitive detectors. Multiple scattering processes become a significant obstacle in the incident-gamma direction reconstruction for energies below several gigaelectronvolts. The method of utilising this process to improve the resolution is proposed in the presented work. (paper)

Study and validation of a gamma-ray spectrometer for the remote analysis of the chemical composition of planetary surfaces: application to a mission to the planet Mercury

International Nuclear Information System (INIS)

Pirard, B.

2006-12-01

This work deals with the design of a gamma-ray spectrometer for the remote analysis of the chemical composition of planetary surfaces and was performed in the frame of a mission scenario to explore the planet Mercury. The research studies consisted first in characterizing the detection performances of a gamma-ray spectrometer using a high-purity germanium crystal cooled actively at cryogenic temperatures. The high energy resolution of the detector allows an accurate measurement of the chemical composition for the main elements from oxygen to uranium. Thereafter the studies dealt with the critical issues addressed for the use of such a detector onboard a mission to the inner solar system. The radiation damage caused by solar protons in germanium crystals was investigated by experimental and numerical means. It has been shown that the detector resolution begins getting damaged for proton fluences over 5*10 8 p/cm 2 . An annealing session where the crystal is heated up to 80 C degrees for a 4-day period allows the detector to get back a sufficient resolution. Annealing over 100 C degrees gives back the detector its initial resolution. Finally, a numerical thermal model of the instrument as well as some tests on a thermal mockup were performed to validate the thermal design of the instrument

MESSENGER E/V/H GRNS 3 GAMMA RAY SPECTROMETER CALIBDATA V1.0

Data.gov (United States)

National Aeronautics and Space Administration — Abstract ======== This data set consists of the MESSENGER GRS calibrated observations (CDRs) and the reduced data product (RDR). The GRS experiment is a gamma ray...

A portable medium-resolution gamma-ray spectrometer and analysis software

Energy Technology Data Exchange (ETDEWEB)

Lavietes, A.D.; McQuaid, J.H.; Ruhter, W.D.; Buckley, W.M.; Clark, D-L. [Lawrence Livermore National Lab., CA (United States); Paulus, T.J. [EG and G ORTEC, Oak Ridge, TN (United States)

1996-07-01

There is a strong need for portable radiometric instrumentation that can both accurately confirm the presence of nuclear materials and allow isotopic analysis of radionuclides in the field. To fulfill this need the Safeguards Technology Program at LLNL has developed a hand-held, non-cryogenic, low-power gamma-ray and x-ray measurements and analysis instrument that can both search for and then accurately verify the presence of nuclear materials. We will report on the use of cadmium zinc telluride (CZT) detectors, detector electronics, and the new field-portable instrument being developed. We will also describe the isotopic analysis that allows enrichment measurements to be made accurately in the field. These systems provide capability for safeguards inspection and verification applications and could find application in counter-smuggling operations.

A portable medium-resolution gamma-ray spectrometer and analysis software

International Nuclear Information System (INIS)

Lavietes, A.D.; McQuaid, J.H.; Ruhter, W.D.; Buckley, W.M.; Clark, D-L.; Paulus, T.J.

1996-07-01

There is a strong need for portable radiometric instrumentation that can both accurately confirm the presence of nuclear materials and allow isotopic analysis of radionuclides in the field. To fulfill this need the Safeguards Technology Program at LLNL has developed a hand-held, non-cryogenic, low-power gamma-ray and x-ray measurements and analysis instrument that can both search for and then accurately verify the presence of nuclear materials. We will report on the use of cadmium zinc telluride (CZT) detectors, detector electronics, and the new field-portable instrument being developed. We will also describe the isotopic analysis that allows enrichment measurements to be made accurately in the field. These systems provide capability for safeguards inspection and verification applications and could find application in counter-smuggling operations

Determining a pre-mining radiological baseline from historic airborne gamma surveys: A case study

International Nuclear Information System (INIS)

Bollhöfer, Andreas; Beraldo, Annamarie; Pfitzner, Kirrilly; Esparon, Andrew; Doering, Che

2014-01-01

Knowing the baseline level of radioactivity in areas naturally enriched in radionuclides is important in the uranium mining context to assess radiation doses to humans and the environment both during and after mining. This information is particularly useful in rehabilitation planning and developing closure criteria for uranium mines as only radiation doses additional to the natural background are usually considered ‘controllable’ for radiation protection purposes. In this case study we have tested whether the method of contemporary groundtruthing of a historic airborne gamma survey could be used to determine the pre-mining radiological conditions at the Ranger mine in northern Australia. The airborne gamma survey was flown in 1976 before mining started and groundtruthed using ground gamma dose rate measurements made between 2007 and 2009 at an undisturbed area naturally enriched in uranium (Anomaly 2) located nearby the Ranger mine. Measurements of 226 Ra soil activity concentration and 222 Rn exhalation flux density at Anomaly 2 were made concurrent with the ground gamma dose rate measurements. Algorithms were developed to upscale the ground gamma data to the same spatial resolution as the historic airborne gamma survey data using a geographic information system, allowing comparison of the datasets. Linear correlation models were developed to estimate the pre-mining gamma dose rates, 226 Ra soil activity concentrations, and 222 Rn exhalation flux densities at selected areas in the greater Ranger region. The modelled levels agreed with measurements made at the Ranger Orebodies 1 and 3 before mining started, and at environmental sites in the region. The conclusion is that our approach can be used to determine baseline radiation levels, and provide a benchmark for rehabilitation of uranium mines or industrial sites where historical airborne gamma survey data are available and an undisturbed radiological analogue exists to groundtruth the data. - Highlights: �

Natural background gamma-ray spectrum. List of gamma-rays ordered in energy from natural radionuclides

Energy Technology Data Exchange (ETDEWEB)

Ichimiya, Tsutomu [Japan Radioisotope Association, Tokyo (Japan); Narita, Tsutomu; Kitao, Kensuke

1998-03-01

A quick index to {gamma}-rays and X-rays from natural radionuclides is presented. In the list, {gamma}-rays are arranged in order of increasing energy. The list also contains {gamma}-rays from radioactive nuclides produced in a germanium detector and its surrounding materials by interaction with cosmic neutrons, as well as direct {gamma}-rays from interaction with the neutrons. Artificial radioactive nuclides emitting {gamma}-rays with same or near energy value as that of the natural {gamma}-rays and X-rays are also listed. In appendix, {gamma}-ray spectra from a rock, uranium ore, thorium, monazite and uraninite and also background spectra obtained with germanium detectors placed in iron or lead shield have been given. The list is designed for use in {gamma}-ray spectroscopy under the conditions of highly natural background, such as in-situ environmental radiation monitoring or low-level activity measurements, with a germanium detector. (author)

Borehole Logging for Uranium by Gamma-Ray Spectrometry

DEFF Research Database (Denmark)

Løvborg, Leif; Nyegaard, P.; Christiansen, E. M.

1980-01-01

The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium-iodide, and the photo......The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium...... of the spectrometer system were determined by calculating the average number of U and thorium (Th) counts per meter of borehole and comparing these with the U-Th concentrations in 1-m sections of analyzed drill core. The sensitivity and the background count rate in the uranium window varied appreciably from one hole...

V/V(max) test applied to SMM gamma-ray bursts

Science.gov (United States)

Matz, S. M.; Higdon, J. C.; Share, G. H.; Messina, D. C.; Iadicicco, A.

1992-01-01

We have applied the V/V(max) test to candidate gamma-ray bursts detected by the Gamma-Ray Spectrometer (GRS) aboard the SMM satellite to examine quantitatively the uniformity of the burst source population. For a sample of 132 candidate bursts identified in the GRS data by an automated search using a single uniform trigger criterion we find average V/V(max) = 0.40 +/- 0.025. This value is significantly different from 0.5, the average for a uniform distribution in space of the parent population of burst sources; however, the shape of the observed distribution of V/V(max) is unusual and our result conflicts with previous measurements. For these reasons we can currently draw no firm conclusion about the distribution of burst sources.

Gamma-ray induced doppler broadening

International Nuclear Information System (INIS)

Robinson, S.J.

1992-01-01

The ultra high resolving power of the GAMS4 double-flat crystal spectrometer (M.S. Dewey et al Nucl. Instrum. Methods A 284 (1989) 151.) has been used to observe the Doppler broadening of gamma-rays emitted by nuclei recoiling at speeds as low as 10 -6 c. Such recoils may be induced by the previous emission of gamma-radiation following thermal neutron capture. If the population mechanism of an excited state is known (or can be approximated) and the slowing down mechanism can be modeled, then this technique can be used to extract the lifetime of excited nuclear states. The combination of this technique and the neutron capture reaction allows the study of states which cannot necessarily be accessed by other means. This has allowed the resolution of a number of long standing questions in low-spin nuclear structure. The basis of the technique is discussed and a number of examples given

BiI₃ Crystals for High Energy Resolution Gamma-Ray Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Nino, Juan C. [Univ. of Florida, Gainesville, FL (United States); Baciak, James [Univ. of Florida, Gainesville, FL (United States); Johns, Paul [Univ. of Florida, Gainesville, FL (United States); Sulekar, Soumitra [Univ. of Florida, Gainesville, FL (United States); Totten, James [Univ. of Florida, Gainesville, FL (United States); Nimmagadda, Jyothir [Univ. of Florida, Gainesville, FL (United States)

2017-04-12

BiI₃ had been investigated for its unique properties as a layered compound semiconductor for many decades. However, despite the exceptional atomic, physical, and electronic properties of this material, good resolution gamma ray spectra had never been reported for BiI₃. The shortcomings that previously prevented BiI₃ from reaching success as a gamma ray sensor were, through this project, identified and suppressed to unlock the performance of this promising compound. Included in this work were studies on a number of methods which have, for the first time, enabled BiI₃ to exhibit spectral performance rivaling many other candidate semiconductors for room temperature gamma ray sensors. New approaches to crystal growth were explored that allow BiI₃ spectrometers to be fabricated with up to 2.2% spectral resolution at 662 keV. Fundamental studies on trap states, dopant incorporation, and polarization were performed to enhance performance of this compound. Additionally, advanced detection techniques were applied to display the capabilities of high quality BiI₃ spectrometers. Overall, through this work, BiI₃ has been revealed as a potentially transformative material for nuclear security and radiation detection sciences.

Measuring planetary neutron albedo fluxes by remote gamma-ray sensing

International Nuclear Information System (INIS)

Haines, E.L.; Metzger, A.E.

1984-01-01

A remote-sensing γ-ray spectrometer (GRS) is capable of measuring planetary surface composition through the detection of characteristic gamma rays. In addition, the planetary neutron leakage flux may be detected by means of a thin neutron absorber surrounding the γ-ray detector which converts the neutron flux into a γ-ray flux having a unique energy signature. The γ rays representing the neutron flux are observed against interference consisting of cosmic γ rays, planetary continuum and line emission, and a variety of gamma rays arising from cosmic-ray particle interactions with the γ-ray spectrometer and spacecraft (SC). In this paper the amplitudes of planetary and non-planetary neutron fluxes are assessed and their impact on the sensitivity of measurement is calculated for a lunar orbiter mission and a comet nucleus rendezvous mission. For a 100 h observation period from an altitude of 100 km, a GRS on a lunar orbiter can detect a thermal neutron albedo flux as low as 0.002 cm -2 s -1 and measure the expected flux of approx.=0.6 cm -2 s -1 with an uncertainty of 0.001 cm -2 s -1 . A GRS rendezvousing with a comet at a distance equal to the radius of the comet's nucleus, again for a 100 h observation time, should detect a thermal neutron albedo flux at a level of 0.006 cm -2 s -1 and measure the expected flux of approx.=0.4 cm -2 s -1 with an uncertainty of 0.004 cm -2 s -1 . Mapping the planetary neutron flux jointly with the direct detection of H will not only provide a more accurate model for translating observed γ-ray fluxes into concentrations but will also extend the effective sampling depth and should provide a capability for simple stratigraphic modeling of hydrogen. (orig.)

Observing with a space-borne gamma-ray telescope: selected results from INTEGRAL

International Nuclear Information System (INIS)

Schanne, Stephane

2006-01-01

The International Gamma-Ray Astrophysics Laboratory, i.e. the INTEGRAL satellite of ESA, in orbit since about 3 years, performs gamma-ray observations of the sky in the 15 keV to 8 MeV energy range. Thanks to its imager IBIS, and in particular the ISGRI detection plane based on 16384 CdTe pixels, it achieves an excellent angular resolution (12 arcmin) for point source studies with good continuum spectrum sensitivity. Thanks to its spectrometer SPI, based on 19 germanium detectors maintained at 85 K by a cryogenic system, located inside an active BGO veto shield, it achieves excellent spectral resolution of about 2 keV for 1 MeV photons, which permits astrophysical gamma-ray line studies with good narrow-line sensitivity. In this paper we review some goals of gamma-ray astronomy from space and present the INTEGRAL satellite, in particular its instruments ISGRI and SPI. Ground and in-flight calibration results from SPI are presented, before presenting some selected astrophysical results from INTEGRAL. In particular results on point source searches are presented, followed by results on nuclear astrophysics, exemplified by the study of the 1809 keV gamma-ray line from radioactive 26 Al nuclei produced by the ongoing stellar nucleosynthesis in the Galaxy. Finally a review on the study of the positron-electron annihilation in the Galactic center region, producing 511 keV gamma-rays, is presented

Combined in-beam gamma-ray and conversion electron spectroscopy with radioactive ion beams

Directory of Open Access Journals (Sweden)

Konki J.

2013-12-01

Full Text Available In-beam gamma-ray and electron spectroscopy have been widely used as tools to study the broad variety of phenomena in nuclear structure. The SPEDE spectrometer is a new device to be used in conjunction with the MINIBALL germanium detector array to enable the detection of internal conversion electrons in coincidence with gamma rays from de-exciting nuclei in radioactive ion beam experiments at the upcoming HIE-ISOLDE facility at CERN, Switzerland. Geant4 simulations were carried out in order to optimise the design and segmentation of the silicon detector to achieve good energy resolution and performance.

X-ray echoes from gamma-ray bursts

International Nuclear Information System (INIS)

Dermer, C.D.; Hurley, K.C.; Hartmann, D.H.

1991-01-01

The identification of an echo of reflected radiation in time histories of gamma-ray burst spectra can provide important information about the existence of binary companions or accretion disks in gamma-ray burst systems. Because of the nature of Compton scattering, the spectrum of the echo will be attenuated at gamma-ray energies compared with the spectrum of the primary burst emission. The expected temporal and spectral signatures of the echo and a search for such echoes are described, and implications for gamma-ray burst models are discussed. 35 refs

The Gamma-ray Sky with Fermi

Science.gov (United States)

Thompson, David

2012-01-01

Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

Applied gamma-ray spectrometry

CERN Document Server

Dams, R; Crouthamel, Carl E

1970-01-01

Applied Gamma-Ray Spectrometry covers real life application of the gamma-ray and the devices used in their experimental studies. This book is organized into 9 chapters, and starts with discussions of the various decay processes, the possible interaction mechanisms of gamma radiation with matter, and the intrinsic and extrinsic variables, which affect the observed gamma-ray and X-ray spectra. The subsequent chapters deal with the properties and fabrication of scintillation detectors, semiconductor detectors, and proportional gas counters. These chapters present some of the most widely utilized

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

Energy Technology Data Exchange (ETDEWEB)

Jeon, Jong Ho, E-mail: jhjeon07@ibs.re.kr; Nakajima, Kazuhisa, E-mail: naka115@dia-net.ne.jp; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Yoo, Byung Ju; Shin, Kang Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Kim, Hyung Taek; Sung, Jae Hee; Lee, Seung Ku; Choi, Il Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Rhee, Yong Joo [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Shin, Jung Hun; Jo, Sung Ha [Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Hojbota, Calin; Cho, Byeoung Ick; Nam, Chang Hee [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of)

2015-12-15

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

Use of microcontroller in gamma-ray spectrometer construction using NaI(Tl) sensor, with emphasis in multichannel analyzer, to applications in nuclear and environmental geophysics

International Nuclear Information System (INIS)

Silva, Nilton

2005-01-01

In this work of nuclear geophysical instrumentation the main purpose was the development of a gamma-ray spectrometer prototype with multi channel analyzer, since the spectroscopic amplifier until your firmware. The heart of the digital part was an ATMEL 8 bits microcontroller (AT89S8252). All circuits were made and assembled in the Laboratory of Applied Geophysical Instrumentation (LIGA) of IAG-USP. A microcontroller software was completely developed in C ANSI language using the Small Device C Compiler version 2.4.8, that is a free software distributed under General Public License (GPL). At first, microcontroller was used to change all digital circuit of one classic SCINTREX GAD-6 differential gamma-ray spectrometer. Measurement times with order of 2 days became possible, and it could work in non climate ambient. Then, after this stage, had been started the development of a multichannel analyzer (MCA) working in pulse height analyzer mode with 4096 channels capacity, to use in many kinds of nuclear detection. Besides it, was developed an automatic gain system for photopeak stabilization, by the use of one radioactive source ( 133 Ba). This automatic gain system is very important in the case of NaI(Tl) scintillometric detectors, due PMT sensitivity with temperature and aging of some laboratory electronic circuits. Two power supplies with high stability, using pulse width modulation (PWM) techniques were developed, in order to all system became free of electrical line break off. One PWM power polarizes a photo multiplier tube (PMT) with high voltage and another supplies remaining developed circuits. Calibration in energy using standards sources 137 Cs and 60 Co showed that gamma detector developed has a good linearity and low thermal drift, even working in absent of air-conditioned. Concentrations measurements of K, U and Th were made in samples of soils, vegetables, etc. (author)'

Collimatorless imaging of gamma rays with help of gamma-ray tracking

CERN Document Server

Marel, J V D

2001-01-01

In many gamma-ray detector systems that are built for imaging purposes Compton scattered photons are suppressed as much as possible. However, the information from photons that scattered inside a detector system can be used to reconstruct the tracks of the photons with help of gamma-ray tracking. Estimates of the incident directions of the photons can be made and an image can be created. Examples of potential applications for this technique are the use as a gamma-camera in medical imaging (e.g. SPECT) or as a detector for PET. Due to the omission of collimators, much higher detection efficiencies can be achieved, reducing the doses required for an image. A gamma-ray tracking method, called backtracking, has been developed for nuclear spectroscopy. The method tracks gamma-rays originating from a point source in the center of a spherical detector system consisting of position-sensitive germanium detectors. This method can also be used as a tracking technique for imaging of an unknown source distribution. With he...

Calibration of angle response of a NaI(Tl) airborne spectrometer to 137Cs and 60Co point sources on the ground

International Nuclear Information System (INIS)

Liu Xinhua; Zhang Yongxing; Gu Renkang; Shen Ensheng

1998-01-01

The angle response function F(φ,θ) is a basic calibration of airborne spectrometers in airborne surveying for nuclear emergency monitoring. The author describes the method and results of angle response function calibration of a NaI(Tl) airborne spectrometer for 137 Cs and 60 Co point sources on the ground, with less than 20% uncertainty. By using the results, the calibration factors of the NaI(Tl) airborne spectrometer fixed in Yun-5 plane at different flying heights are calculated by numerical integral method for 137 Cs uniform area source on ground surface, with less than 25% uncertainty. The minimum detection limits (L D ) are calculated at 90 m and 120 m flying heights in the range of over Shijiazhuang airborne surveying for 137 Cs uniform area source on ground surface to be 3.83 and 5.62 kBq/m 2 , respectively

Measurement of the radiative decay width {gamma}[{lambda}(1520)->{lambda}{gamma}] with the SPHINX spectrometer

Energy Technology Data Exchange (ETDEWEB)

Antipov, Yu.M. [Institute for High Energy Physics, Protvino (Russian Federation); Artamonov, A.V. [Institute for High Energy Physics, Protvino (Russian Federation); Batarin, V.A. [Institute for High Energy Physics, Protvino (Russian Federation); Vavilov, D.V. [Institute for High Energy Physics, Protvino (Russian Federation); Victorov, V.A. [Institute for High Energy Physics, Protvino (Russian Federation); Eroshin, O.V. [Institute for High Energy Physics, Protvino (Russian Federation); Golovkin, S.V. [Institute for High Energy Physics, Protvino (Russian Federation); Gorin, Yu.P. [Institute for High Energy Physics, Protvino (Russian Federation); Kolganov, V.Z. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Kozhevnikov, A.P. [Institute for High Energy Physics, Protvino (Russian Federation); Konstantinov, A.S. [Institute for High Energy Physics, Protvino (Russian Federation); Kubarovsky, V.P. [Institute for High Energy Physics, Protvino (Russian Federation); Kurshetsov, V.F. [Institute for High Energy Physics, Protvino (Russian Federation); Landsberg, L.G. [Institute for High Energy Physics, Protvino (Russian Federation)]. E-mail: lgl@mx.ihep.su; Leontiev, V.M. [Institute for High Energy Physics, Protvino (Russian Federation); Lomkatsi, G.S. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Molchanov, V.V. [Institute for High Energy Physics, Protvino (Russian Federation)]. E-mail: molchanov@mx.ihep.su; Mukhin, V.A. [Institute for High Energy Physics, Protvino (Russian Federation); Nilov, A.F. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Patalakha, D.I. [Institute for High Energy Physics, Protvino (Russian Federation); Petrenko, S.V. [Institute for High Energy Physics, Protvino (Russian Federation); Smolyankin, V.T. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)

2004-12-16

The radiative decay {lambda}(1520)->{lambda}{gamma} was measured directly in the study of the exclusive diffractive-like reaction p+N->{lambda}(1520)K{sup +}+N, {lambda}(1520)->{lambda}{gamma} with the SPHINX spectrometer. The values of the branching and partial width of this radiative decay were obtained: BR[{lambda}(1520)->{lambda}{gamma}]=(1.02+/-0.21(stat)+/-0.15(syst))x10{sup -2} and {gamma}[{lambda}(1520)->{lambda}{gamma}]=159+/-33(stat)+/-26(syst)-bar keV.

γ-Ray background sources in the VESUVIO spectrometer at ISIS spallation neutron source

International Nuclear Information System (INIS)

Pietropaolo, A.; Perelli Cippo, E.; Gorini, G.; Tardocchi, M.; Schooneveld, E.M.; Andreani, C.; Senesi, R.

2009-01-01

An investigation of the gamma background was carried out in the VESUVIO spectrometer at the ISIS spallation neutron source. This study, performed with a yttrium-aluminum-perovskite (YAP) scintillator, follows high resolution pulse height measurements of the gamma background carried out on the same instrument with the use of a high-purity germanium detector. In this experimental work, a mapping of the gamma background was attempted, trying to find the spatial distribution and degree of directionality of the different contributions identified in the previous study. It is found that the gamma background at low times is highly directional and mostly due to the gamma rays generated in the moderator-decoupler system. The other contributions, consistently to the findings of a previous experiment, are identified as a nearly isotropic one due to neutron absorption in the walls of the experimental hall, and a directional one coming from the beam dump.

γ-Ray background sources in the VESUVIO spectrometer at ISIS spallation neutron source

Science.gov (United States)

Pietropaolo, A.; Perelli Cippo, E.; Gorini, G.; Tardocchi, M.; Schooneveld, E. M.; Andreani, C.; Senesi, R.

2009-09-01

An investigation of the gamma background was carried out in the VESUVIO spectrometer at the ISIS spallation neutron source. This study, performed with a yttrium-aluminum-perovskite (YAP) scintillator, follows high resolution pulse height measurements of the gamma background carried out on the same instrument with the use of a high-purity germanium detector. In this experimental work, a mapping of the gamma background was attempted, trying to find the spatial distribution and degree of directionality of the different contributions identified in the previous study. It is found that the gamma background at low times is highly directional and mostly due to the gamma rays generated in the moderator-decoupler system. The other contributions, consistently to the findings of a previous experiment, are identified as a nearly isotropic one due to neutron absorption in the walls of the experimental hall, and a directional one coming from the beam dump.

An improved in situ method for determining depth distributions of gamma-ray emitting radionuclides

International Nuclear Information System (INIS)

Benke, R.R.; Kearfott, K.J.

2001-01-01

In situ gamma-ray spectrometry determines the quantities of radionuclides in some medium with a portable detector. The main limitation of in situ gamma-ray spectrometry lies in determining the depth distribution of radionuclides. This limitation is addressed by developing an improved in situ method for determining the depth distributions of gamma-ray emitting radionuclides in large area sources. This paper implements a unique collimator design with conventional radiation detection equipment. Cylindrically symmetric collimators were fabricated to allow only those gamma-rays emitted from a selected range of polar angles (measured off the detector axis) to be detected. Positioned with its axis normal to surface of the media, each collimator enables the detection of gamma-rays emitted from a different range of polar angles and preferential depths. Previous in situ methods require a priori knowledge of the depth distribution shape. However, the absolute method presented in this paper determines the depth distribution as a histogram and does not rely on such assumptions. Other advantages over previous in situ methods are that this method only requires a single gamma-ray emission, provides more detailed depth information, and offers a superior ability for characterizing complex depth distributions. Collimated spectrometer measurements of buried area sources demonstrated the ability of the method to yield accurate depth information. Based on the results of actual measurements, this method increases the potential of in situ gamma-ray spectrometry as an independent characterization tool in situations with unknown radionuclide depth distributions

Optical observations of Gamma-Ray Bursts

International Nuclear Information System (INIS)

Hjorth, J.; Pian, E.; Fynbo, J.P.U.

2004-01-01

We briefly review the status and recent progress in the field of optical observations of gamma-ray burst afterglows. We will focus on the fundamental observational evidence for the relationship between gamma-ray bursts and the final evolutionary phases of massive stars. In particular, we will address (i) gamma-ray burst host galaxies, (ii) optically dark gamma-ray burst afterglows, (iii) the gamma-ray burst-supernova connection, and (iv) the relation between X-ray flashes, gamma-ray bursts, and supernovae

Area specific stripping of lower energy windows for AGS and CGS NaI systems[Airborne Gamma Spectrometry; Carbone Gamma Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Korsbech, U.; Aage, H.K. [Technical Univ. of Denmark (Denmark); Bystroem, S.; Wedmark, M. [Geological Survey of Sweden (Sweden); Thorshaug, S. [Norwegian Radiation Protection Agency (Norway); Bargholz, K. [Danish Emergency Management Agency (Denmark)

2005-05-01

The report describes the results from a NKS (Nordic Nuclear Safety Research) project aiming at examining the possibilities for extracting stripping factors for Airborne Gamma-ray Spectrometry (AGS) data and Carborne Gamma-ray Spectrometry (CGS) data directly from the recorded set of data, i.e. without having to calibrate the detector systems on beforehand. The project 'NKS project ASSb' has been carried out between 1 August 2004 and 31 March 2005 by a research group composed of persons from Technical University of Denmark (DTU), Danish Emergency Management Agency (DEMA), Geological Survey of Sweden (SGU), and Norwegian Radiation Protection Authority (NRPA). The AGS and CGS data sets used for the project were recorded by SGU, DEMA, NGU (Geological Survey of Norway), and SSI (Swedish Radiation Protection Institute). Most of the project effort has been directed towards analysing AGS and CGS data with point source signals recorded at the Barents Rescue 2001 LIVEX exercise at Boden in Sweden. Possibilities and limitations for the method have been identified. (au)

The Gamma-ray Universe through Fermi

Science.gov (United States)

Thompson, David J.

2012-01-01

Gamma rays, the most powerful form of light, reveal extreme conditions in the Universe. The Fermi Gamma-ray Space Telescope and its smaller cousin AGILE have been exploring the gamma-ray sky for several years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge ga.nuna-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

The GSF anticoincidence-shielded Ge(Li) gamma-ray spectrometer and its application to the analysis of environmental samples

International Nuclear Information System (INIS)

Hoetzl, H.; Winkler, R.

1981-01-01

A high-efficiency gamma-ray spectrometer has been designed and built to provide simultaneous anticoincidence and coincidence spectrometry of low-level environmental samples. The spectrometer consists of a large-volume Ge(Li) detector as the main detector and a well-type NaI(Tl) guard detector. The Ge(Li) detector is a closed-end coaxial detector housed in a crystal of the vertical dip-stick type. Its relative photopeak efficiency is 27.5%. The guard counter is a 23-cm-dia. by 23-cm-long NaI(Tl) crystal with a 7.8-cm-dia. by 18-cm-deep centre well. The passive shield consists of a 10-cm lead shield with copper and cadmium lining. The electronics is designed to operate independently and simultaneously in the anticoincidence mode as well as in the coincidence or in the normal passive shield mode. When operating in the anticoincidence mode the Compton edge of 137 Cs is reduced by a factor of 7.7 to provide a peak-to-Compton edge ratio of 480:1. Bulk samples up to about 300 cm 3 can be measured on the top of the detector end cap inside the well of the NaI(Tl) crystal. The lower limit of detection (1000 min counting time, 95% confidence level) for 137 Cs is 1.6 pCi in a 3.8-cm-dia. by 3.5-cm-high sample geometry. The design of the spectrometer, its properties and the application to investigations on the migration of radionuclides in the soil, the analysis of radioactive emissions of coal-fired power plants and to fallout studies are described. (author)

Portable scintillation gamma-spectrometer for field measurement of radioactivity in extensive objects; Portativnyj stsintillyatsionnyj gamma-spektrometr dlya izmereniya radioaktivnosti ob''emnykh sred v polevykh usloviyakh

Energy Technology Data Exchange (ETDEWEB)

Besshejko, O. A. [Taras Shevchenko National University of Kyiv, Kyiv (Ukraine); Vishnevskij, I. N.; Denisenko, R. V.; Malyuk, I. A.; Petrosyan, Eh. E. [Institute for Nuclear Research, Kyiv (Ukraine); Karpenko, S. A.; Prijmak, V. N. [Ukrainian Association for Valves Industry, Dnepropetrovsk (Ukraine)

2011-07-01

The portable scintillated gamma-spectrometer for field measurement of radioactivity in the volume objects was designed. The crystal CdWO{sub 4} that has weak dependence of light yield from temperature in combination with PMT was applied as the gamma-rays detector. The design of the device provides the possibility for measuring radioactivity of the extensive objects in 4{pi}-geometry without background measurements. In this case the value of the efficiency needed for specific activity calculation in close approximation depends only from crystal geometry and density of measuring object and may be set as the device parameter without efficiency calibration procedure during the operation. The spectrometer does not have an auxiliary radio-active source and connecting cables in the composition. The smartphone operated under Windows Mobile is used as the control module. Bluetooth connection provides data exchange between smartphone and measurement head.

Lunar based gamma ray astronomy

International Nuclear Information System (INIS)

Haymes, R.C.

1985-01-01

Gamma ray astronomy represents the study of the universe on the basis of the electromagnetic radiation with the highest energy. Gamma ray astronomy provides a crucial tool for the understanding of astronomical phenomena, taking into account nucleosynthesis in supernovae, black holes, active galaxies, quasars, the sources of cosmic rays, neutron stars, and matter-antimatter annihilation. Difficulties concerning the conduction of studies by gamma ray astronomy are related to the necessity to perform such studies far from earth because the atmosphere is a source of gamma rays. Studies involving the use of gamma ray instruments in earth orbit have been conducted, and more gamma ray astronomy observations are planned for the future. Imperfections of studies conducted in low earth orbit could be overcome by estalishing an observatory on the moon which represents a satellite orbiting at 60 earth radii. Details concerning such an observatory are discussed. 5 references

Streaked, x-ray-transmission-grating spectrometer

International Nuclear Information System (INIS)

Ceglio, N.M.; Roth, M.; Hawryluk, A.M.

1981-08-01

A free standing x-ray transmission grating has been coupled with a soft x-ray streak camera to produce a time resolved x-ray spectrometer. The instrument has a temporal resolution of approx. 20 psec, is capable of covering a broad spectral range, 2 to 120 A, has high sensitivity, and is simple to use requiring no complex alignment procedure. In recent laser fusion experiments the spectrometer successfully recorded time resolved spectra over the range 10 to 120 A with a spectral resolving power, lambda/Δlambda of 4 to 50, limited primarily by source size and collimation effects

Compton Gamma-Ray Observatory

Science.gov (United States)

1991-01-01

This photograph shows the Compton Gamma-Ray Observatory (GRO) being deployed by the Remote Manipulator System (RMS) arm aboard the Space Shuttle Atlantis during the STS-37 mission in April 1991. The GRO reentered Earth atmosphere and ended its successful mission in June 2000. For nearly 9 years, the GRO Burst and Transient Source Experiment (BATSE), designed and built by the Marshall Space Flight Center (MSFC), kept an unblinking watch on the universe to alert scientists to the invisible, mysterious gamma-ray bursts that had puzzled them for decades. By studying gamma-rays from objects like black holes, pulsars, quasars, neutron stars, and other exotic objects, scientists could discover clues to the birth, evolution, and death of stars, galaxies, and the universe. The gamma-ray instrument was one of four major science instruments aboard the Compton. It consisted of eight detectors, or modules, located at each corner of the rectangular satellite to simultaneously scan the entire universe for bursts of gamma-rays ranging in duration from fractions of a second to minutes. In January 1999, the instrument, via the Internet, cued a computer-controlled telescope at Las Alamos National Laboratory in Los Alamos, New Mexico, within 20 seconds of registering a burst. With this capability, the gamma-ray experiment came to serve as a gamma-ray burst alert for the Hubble Space Telescope, the Chandra X-Ray Observatory, and major gound-based observatories around the world. Thirty-seven universities, observatories, and NASA centers in 19 states, and 11 more institutions in Europe and Russia, participated in the BATSE science program.

TRIUMF-ISAC Gamma-Ray Escape-Suppressed Spectrometer (TIGRESS): a versatile tool for radioactive beam physics

Science.gov (United States)

Ball, G. C.; Andreyev, A.; Austin, R. A. E.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Boston, H. C.; Chen, A.; Churchman, R.; Cifarelli, F.; Cline, D.; Cooper, R. J.; Cross, D. S.; Dashdorj, D.; Demand, G.; Dimmock, M. R.; Drake, T. E.; Finlay, P.; Gagon-Moisan, F.; Gallant, A. T.; Garrett, P. E.; Green, K. L.; Grint, A. N.; Hackman, G.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Leach, K. G.; Lee, G.; Maharaj, R.; Martin, J.-P.; Morton, A. C.; Mythili, S.; Nelson, L.; Newman, O.; Nolan, P. J.; Padilla-Rodal, E.; Pearson, C. J.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Roy, R.; Ruiz, C.; Savajols, H.; Sarazin, F.; Schumaker, M. A.; Scraggs, D. P.; Svensson, C. E.; Waddington, J. C.; Wan, J. M.; Whitbeck, A.; Williams, S. J.; Wong, J.; Wu, C. Y.

2007-05-01

TIGRESS is a new generation γ-ray spectrometer designed for use with radioactive beams from ISAC. This paper gives an overview of the project and presents results from the first radioactive beam experiment with TIGRESS, the Coulomb excitation of 20,21Na.

Method Validation for the Gamma-ray Spectrometric Determination of Natural Radioactive Nuclides in NORM Samples - Method Validation for the Gamma-ray Spectrometric Determination of Natural Radionuclides in raw materials and by-products

Energy Technology Data Exchange (ETDEWEB)

Ji, Young-Yong; Lim, Jong-Myoung; Jang, Mee; Kim, Chang-Jong; Chung, Kun Ho; Kang, Mun Ja; Choi, Geun-Sik [Environmental Radioactivity Assessment Team, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989, Yuseong, Daejeon, 305-353 (Korea, Republic of)

2014-07-01

It has established the 'Act on safety control of radioactive rays around living environment' in Korea, since 2011, to protect the public from natural occurring radioactive materials (NORM) and their by-products. The increasing concerns regarding the radioactivity of those materials therefore dictate many demands for the radioactive analysis for them. There are several methods to determine the concentration of natural radionuclides, such as {sup 235}U, {sup 238}U, {sup 226}Ra, {sup 232}Th, and so on, through a radiochemical analysis using an alpha spectrometer, mass spectrometer and liquid scintillation counter. However, gamma-ray spectroscopy still has an effect on the assessment of radioactive concentration for these nuclides and their progenies. To adapt a gamma spectrometer to the determination of natural radionuclides, the feasibility of their analysis methods should be first verified and validated with respect to accuracy and time and cost constraints. In general, one of the well-known processes in analyzing uranium with a gamma spectrometer is an indirect measurement using the secular equilibrium state with their progenies in a sample. This method, however, demands the time elapsed about 3 weeks to reach the equilibrium state between {sup 226}Ra and {sup 222}Rn and the sufficient integrity of a sample bottle to prevent the leakage of radon isotopes which is a form of noble gas. The simple and quick method is to directly measure a full energy absorption peak of 186.2 keV from {sup 226}Ra without the secular equilibrium state between {sup 226}Ra and {sup 222}Rn in the common sample bottle. However, this direct measurement also has difficulties about the interference with a full energy absorption peak of 185.7 keV from {sup 235}U. In this study, direct measurement with the interference correction technique, which uses several reference peaks for gamma-rays from {sup 235}U and {sup 234}Th, and indirect measurement, which means the identification of {sup

X-Ray-Driven Gamma Emission

International Nuclear Information System (INIS)

Carroll, J. J.; Karamian, S. A.; Rivlin, L. A.; Zadernovsky, A. A.

2001-01-01

X-ray-driven gamma emission describes processes that may release nuclear energy in a 'clean' way, as bursts of incoherent or coherent gamma rays without the production of radioactive by-products. Over the past decade, studies in this area, as a part of the larger field of quantum nucleonics, have gained tremendous momentum. Since 1987 it has been established that photons could trigger gamma emission from a long-lived metastable nuclear excited state of one nuclide and it appears likely that triggering in other isotopes will be demonstrated conclusively in the near future. With these experimental results have come new proposals for the creation of collective and avalanche-like incoherent gamma-ray bursts and even for the ultimate light source, a gamma-ray laser. Obviously, many applications would benefit from controlled bursts of gamma radiation, whether coherent or not. This paper reviews the experimental results and concepts for the production of gamma rays, driven by externally produced X-rays

ESA presents INTEGRAL, its space observatory for Gamma-ray astronomy

Science.gov (United States)

1998-09-01

more strange than the energetic radiation coming from the centre of distant galaxies are flashes of extremely powerful radiation that suddenly appear somewhere on the gamma-sky and disappear again after a short time. These gamma-bursts seem to be the biggest observed explosions in the Universe. But nobody knows their source. Integral will help to solve this long-standing mystery. ESA, the pioneer in gamma-ray astronomy The satellite as it can now be seen at ESA's test centre is five meters high and weighs more than four tonnes. Two main instruments observe the gamma-rays. An imager will give the sharpest gamma-ray images. It is provided by a consortium led by an Italian scientist. Gamma-rays ignore lenses and mirror, so INTEGRAL makes its images with so-called coded-masks. A coded-mask telescope is basically a pinhole camera, but with a larger aperture, i.e. many pinholes. A spectrometer will gauge gamma-ray energies extremely precisely. It is developed by a team of scientists under joint French-German leadership and will be a 100 times more sensitive than the previous high spectral resolution space instrument. It is made of a high-purity Germanium detector that has to be cooled down to minus 188 degree Celsius. These two gamma-ray-instruments are supported by two monitor instruments that play a crucial role in the detection and identification of the gamma-ray sources. An X-ray monitor developed in Denmark will observe X-rays, still powerful but less energetic than gamma-rays. An optical telescope provided by Spain will observe the visible light emitted by the energetic objects. Switzerland will host the Integral Science Data Centre which will preprocess and distribute the scientific data. The mission is conceived as an observatory led by ESA with Russia contributing the launcher and NASA providing tracking support with its Deep Space Network. Alenia Aerospazio in Turin, Italy is ESA's prime contractor for building INTEGRAL. Launch by a Russian Proton rocket from

Low energy x-ray spectrometer

International Nuclear Information System (INIS)

Woodruff, W.R.

1981-01-01

A subkilovolt spectrometer has been produced to permit high-energy-resolution, time-dependent x-ray intensity measurements. The diffracting element is a curved mica (d = 9.95A) crystal. To preclude higher order (n > 1) diffractions, a carbon x-ray mirror that reflects only photons with energies less than approx. 1.1 keV is utilized ahead of the diffracting element. The nominal energy range of interest is 800 to 900 eV. The diffracted photons are detected by a gold-surface photoelectric diode designed to have a very good frequency response, and whose current is recorded on an oscilloscope. A thin, aluminium light barrier is placed between the diffracting crystal and the photoelectric diode detector to keep any uv generated on or scattered by the crystal from illuminating the detector. High spectral energy resolution is provided by many photocathodes between 8- and 50-eV wide placed serially along the diffracted x-ray beam at the detector position. The spectrometer was calibrated for energy and energy dispersion using the Ni Lα 1 2 lines produced in the LLNL IONAC accelerator and in third order using a molybdenum target x-ray tube. For the latter calibration the carbon mirror was replaced by one surfaced with rhodium to raise the cut-off energy to about 3 keV. The carbon mirror reflection dependence on energy was measured using one of our Henke x-ray sources. The curved mica crystal diffraction efficiency was measured on our Low-Energy x-ray (LEX) machine. The spectrometer performs well although some changes in the way the x-ray mirror is held are desirable. 16 figures

Extragalactic Gamma-Ray Astrophysics

CERN Multimedia

CERN. Geneva

2016-01-01

During the last decades, various classes of radio-loud active galactic nuclei have been established as sources of high-energy radiation extending over a very broad range from soft gamma-rays (photon energies E~MeV) up to very-high-energy gamma-rays (E>100 GeV). These include blazars of different types, as well as young and evolved radio galaxies. The observed gamma-ray emission from such implies efficient particle acceleration processes taking place in highly magnetized and relativistic jets produced by supermassive black holes, processes that have yet to be identified and properly understood. In addition, nearby starforming and starburst galaxies, some of which host radio-quiet Seyfert-type nuclei, have been detected in the gamma-ray range as well. In their cases, the observed gamma-ray emission is due to non-thermal activity in the interstellar medium, possibly including also a contribution from accretion disks and nuclear outflows. Finally, the high-energy emission from clusters of galaxies remains elusive...

The use of gamma ray data to define the natural radiation environment

International Nuclear Information System (INIS)

1990-09-01

The natural radiation environment is the major source of radiation exposure to man and consists of both internal and external sources. The most significant internal sources are the radioactive elements 40 K and 222 Rn which are taken into the body. The external sources are cosmic rays and naturally occurring radioactive isotopes of the 40 K, 238 U, and 232 Th decay series, some or all of which can be found in the ground, in construction materials, and in the air. This report has been prepared to provide a guide for the use of existing gamma ray survey data to define the natural radiation environment, but will only be concerned with the gamma ray exposure resulting from radiation originating in geological materials. The type of data needed to produce maps are available as a result of airborne, carborne, and ground gamma ray surveys in many parts of the world. Although most of these data were acquired for uranium and other mineral exploration and geological mapping purposes, they can be used to provide background radioactivity information. Standardized survey data can be compiled to produce regional maps of gamma ray air dose rates as well as single radioelement maps. Compilation procedures may use either manual or computer techniques. Although this work will primarily be done as national compilations, it will open the possibility of the compilation of radioelement geochemical maps on a regional and global scale. 48 refs, figs and tabs

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

OpenAIRE

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

2012-01-01

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

Gamma-ray sources

International Nuclear Information System (INIS)

Hermsen, W.

1980-01-01

Results are presented from an analysis of the celestial gamma-ray fine-scale structure based on over half of the data which may ultimately be available from the COS-B satellite. A catalogue consisting of 25 gamma-ray sources measured at energies above 100 MeV is presented. (Auth.)

Environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system technology demonstration plan for use at the Savannah River Site F-Area Retention Basin

International Nuclear Information System (INIS)

Williams, C.V.; Lockwood, G.J.; Normann, R.A.; Gruebel, R.D.

1996-08-01

The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drillbit data during drilling operations. This demonstration plan presents information on the EMWD-GRS technology, demonstration design, Cs-137 contamination at the Savannah River Site F-Area Retention Basin, responsibilities of demonstration participants, and the policies and procedures for the demonstration to be conducted at the Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration will consist of continuously monitoring for gamma-radiation contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes will pass near previously sampled vertical borehole locations where concentrations of contaminant levels are known. Contaminant levels continuously recorded by the EMWD-GRS system during drilling will be compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples

Environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system technology demonstration plan for use at the Savannah River Site F-Area Retention Basin

Energy Technology Data Exchange (ETDEWEB)

Williams, C.V.; Lockwood, G.J.; Normann, R.A. [Sandia National Labs., Albuquerque, NM (United States); Gruebel, R.D. [Tech Reps, Inc., Albuquerque, NM (United States)

1996-08-01

The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drillbit data during drilling operations. This demonstration plan presents information on the EMWD-GRS technology, demonstration design, Cs-137 contamination at the Savannah River Site F-Area Retention Basin, responsibilities of demonstration participants, and the policies and procedures for the demonstration to be conducted at the Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration will consist of continuously monitoring for gamma-radiation contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes will pass near previously sampled vertical borehole locations where concentrations of contaminant levels are known. Contaminant levels continuously recorded by the EMWD-GRS system during drilling will be compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples.

Equipment for x- and gamma ray radiography

International Nuclear Information System (INIS)

Abd Nasir Ibrahim; Azali Muhammad; Ab Razak Hamzah; Abd Aziz Mohamed; Mohammad Pauzi Ismail

2004-01-01

The following topics related to the equipment for x - and gamma ray radiography are discussed in this chapter. The topics are x-ray source for Industrial Radiography: properties of x-ray, generation of x-ray, mechanism of x-ray production, x-ray equipment, power supply, distribution of x-ray intensity along the tube: gamma ray source for Industrial Radiography: properties of gamma rays, gamma ray sources, gamma ray projectors on cameras, source changing. Care of Radiographic Equipments: Merits and Demerits of x and Gamma Rays

Airborne gamma ray measurements conducted during an international trial in Finland

Energy Technology Data Exchange (ETDEWEB)

Sanderson, D.C.W.; Allyson, J.D.; McConville, P.; Murphy, S.; Smith, J. [Scottish Univ. Research and Reactor Centre, Glasgow, Scotland (United Kingdom)

1997-12-31

The Scottish Universities Research and Reactor Centre (SURRC) contributed to the Resume 95 exercise by developing the calibration site at Vesivehmaa, and by participating in the airborne gamma spectrometry (AGS) part of the study. This paper summarises the airborne survey results from the SURRC team. The AGS tasks included fallout mapping of a 6x3 km area in central Finland with nominal 150 m line spacing, and a time constrained search for an undisclosed number of hidden radioactive sources. Measurements at the calibration site were also taken to provide a basis for traceable cross comparison between each teams` quantification procedures at a single, well characterised, location. A full set of calibrated maps of Chernobyl deposition and natural radionuclides, together with overlays corresponding to topography, roads, rivers and lakes were finished during the survey and displayed at the end of the exercise. The main survey area (Area II) was found to have a mean {sup 137}Cs deposition of 64.4{+-}24.4 kBq m{sup -2}, based on the calibration appropriate to the Vesivehmaa site. The major point sources in Area III were discovered, although the collimated {sup 137}Cs and {sup 60}Co sources were not. Retrospective analysis has shown that sources Cs3 and Cs4 were not significantly above local environmental levels in our data set; whereas the low activity {sup 60}Co source Co3 was detected. This confirms the improved sensitivity of AGS source searches to nuclides which are not already present as environmental contaminants. The collimated {sup 192}Ir was found both using scattered radiation and from full energy lines detected with a Ge detector. The {sup 99m}Tc was located using a ratio of low energy integrals from the NaI spectra. (EG). 28 refs.

Airborne gamma ray measurements conducted during an international trial in Finland

International Nuclear Information System (INIS)

Sanderson, D.C.W.; Allyson, J.D.; McConville, P.; Murphy, S.; Smith, J.

1997-01-01

The Scottish Universities Research and Reactor Centre (SURRC) contributed to the Resume 95 exercise by developing the calibration site at Vesivehmaa, and by participating in the airborne gamma spectrometry (AGS) part of the study. This paper summarises the airborne survey results from the SURRC team. The AGS tasks included fallout mapping of a 6x3 km area in central Finland with nominal 150 m line spacing, and a time constrained search for an undisclosed number of hidden radioactive sources. Measurements at the calibration site were also taken to provide a basis for traceable cross comparison between each teams' quantification procedures at a single, well characterised, location. A full set of calibrated maps of Chernobyl deposition and natural radionuclides, together with overlays corresponding to topography, roads, rivers and lakes were finished during the survey and displayed at the end of the exercise. The main survey area (Area II) was found to have a mean 137 Cs deposition of 64.4±24.4 kBq m -2 , based on the calibration appropriate to the Vesivehmaa site. The major point sources in Area III were discovered, although the collimated 137 Cs and 60 Co sources were not. Retrospective analysis has shown that sources Cs3 and Cs4 were not significantly above local environmental levels in our data set; whereas the low activity 60 Co source Co3 was detected. This confirms the improved sensitivity of AGS source searches to nuclides which are not already present as environmental contaminants. The collimated 192 Ir was found both using scattered radiation and from full energy lines detected with a Ge detector. The 99m Tc was located using a ratio of low energy integrals from the NaI spectra. (EG)

Airborne gamma ray measurements conducted during an international trial in Finland

Energy Technology Data Exchange (ETDEWEB)

Sanderson, D C.W.; Allyson, J D; McConville, P; Murphy, S; Smith, J [Scottish Univ. Research and Reactor Centre, Glasgow, Scotland (United Kingdom)

1998-12-31

The Scottish Universities Research and Reactor Centre (SURRC) contributed to the Resume 95 exercise by developing the calibration site at Vesivehmaa, and by participating in the airborne gamma spectrometry (AGS) part of the study. This paper summarises the airborne survey results from the SURRC team. The AGS tasks included fallout mapping of a 6x3 km area in central Finland with nominal 150 m line spacing, and a time constrained search for an undisclosed number of hidden radioactive sources. Measurements at the calibration site were also taken to provide a basis for traceable cross comparison between each teams` quantification procedures at a single, well characterised, location. A full set of calibrated maps of Chernobyl deposition and natural radionuclides, together with overlays corresponding to topography, roads, rivers and lakes were finished during the survey and displayed at the end of the exercise. The main survey area (Area II) was found to have a mean {sup 137}Cs deposition of 64.4{+-}24.4 kBq m{sup -2}, based on the calibration appropriate to the Vesivehmaa site. The major point sources in Area III were discovered, although the collimated {sup 137}Cs and {sup 60}Co sources were not. Retrospective analysis has shown that sources Cs3 and Cs4 were not significantly above local environmental levels in our data set; whereas the low activity {sup 60}Co source Co3 was detected. This confirms the improved sensitivity of AGS source searches to nuclides which are not already present as environmental contaminants. The collimated {sup 192}Ir was found both using scattered radiation and from full energy lines detected with a Ge detector. The {sup 99m}Tc was located using a ratio of low energy integrals from the NaI spectra. (EG). 28 refs.

Gamma-ray burst polarimeter (GAP)

International Nuclear Information System (INIS)

Mihara, Tatehiro; Murakami, Toshio; Yonetoku, Daisuke; Gunji, Shuichi; Kubo, Shin

2013-01-01

The gamma-ray burst polarimeter (GAP: GAmma-ray burst Polarimeter), which had been almost handcrafted by scientists, has succeeded in working normally in interplanetary space, and in detecting the polarization of the gamma-ray from a mysterious astronomical object 'gamma-ray burst'. It is the first result of the detectors in the world exclusively aiming at detecting gamma-ray polarization. We mainly describe the hardware of our GAP equipment and show the method of preparing equipment to work in the cosmic space with a tight budget. The mechanical structure, the electronic circuits, the software on the equipment, the data analysis on the earth, and the scientific results gained by the observation just over one year, are presented after explaining the principle of gamma-ray polarization detection. Our design to protect equipment against mechanical shock and cosmic radiation may provide useful information for future preparation of compact satellite. (J.P.N.)

Future planetary X-ray and gamma-ray remote sensing system and in situ requirements for room temperature solid state detectors

CERN Document Server

Trombka, J I; Starr, R; Clark, P E; Floyd, S R

1999-01-01

X-Ray and gamma-ray remote sensing observations find important applications in the study of the development of the planets. Orbital measurements can be carried out on solar-system bodies whose atmospheres and trapped radiation environments do not interfere significantly with the emissions. Elemental compositions can be inferred from observations of these line emissions. Future planetary missions also will involve landing both stationery and roving probes on planetary surfaces. Both X-ray and gamma-ray spectrometers will be used for performing elemental analysis of surface samples. These future planetary missions will impose a number of constraints: the flight instruments must be significantly reduced in weight from those previously flown; for many missions, gravity assist will be required, greatly increasing mission duration, resulting in the passage of several years before the first scientific measurement of a solar system body. The detector systems must operate reliably after years of cosmic-ray irradiation...

Electron-ion-x-ray spectrometer system

International Nuclear Information System (INIS)

Southworth, S.H.; Deslattes, R.D.; MacDonald, M.A.

1993-01-01

The authors describe a spectrometer system developed for electron, ion, and x-ray spectroscopy of gas-phase atoms and molecules following inner-shell excitation by tunable synchrotron radiation. The spectrometer has been used on beamline X-24A at the National Synchrotron Light Source for excitation-dependent studies of Ar L-shell and K-shell photoexcitation and vacancy decay processes. The instrumentation and experimental methods are discussed, and examples are given of electron spectra and coincidence spectra between electrons and fluorescent x-rays

Gamma ray astronomy

International Nuclear Information System (INIS)

Hillier, R.

1984-01-01

The book reviews the development of gamma ray astronomy over the past twenty five years. A large section of the book is devoted to the problems of background radiation and the design of detectors. Gamma rays from the sun, the galactic disc, the galaxy, and extra galactic sources; are also discussed. (U.K.)

Time-of-flight spectrometer for the measurement of gamma correlated neutron spectra

International Nuclear Information System (INIS)

Andriashin, A.V.; Devkin, B.V.; Lychagin, A.A.; Minko, J.V.; Mironov, A.N.; Nesterenko, V.S.; Sztaricskai, T.; Petoe, G.; Vasvary, L.

1986-01-01

A time-of-flight spectrometer for the measurement of gamma correlated neutron spectra from (n,xnγ) reactions is described. The operation and the main parameters are discussed. The resolution in the neutron channel is 2.2 ns/m at the 150 keV neutron energy threshold. A simultaneous measurement of the time-of-flight and amplitude distributions makes it possible to study gamma correlated neutron spectra as well as the prompt gamma spectra in coincidence with selected energy neutrons. In order to test the spectrometer, measurements of the neutron spectrum in coincidence with the 846 keV gamma line of 56 Fe were carried out at an incident neutron energy of 14.1 MeV. (Auth.)

Scientific prospects for spectroscopy of the gamma-ray burst prompt emission with SVOM

Science.gov (United States)

Bernardini, M. G.; Xie, F.; Sizun, P.; Piron, F.; Dong, Y.; Atteia, J.-L.; Antier, S.; Daigne, F.; Godet, O.; Cordier, B.; Wei, J.

2017-10-01

SVOM (Space-based multi-band astronomical Variable Objects Monitor) is a Sino-French space mission dedicated to the study of Gamma-Ray Bursts (GRBs) in the next decade, capable to detect and localise the GRB emission, and to follow its evolution in the high-energy and X-ray domains, and in the visible and NIR bands. The satellite carries two wide-field high-energy instruments: a coded-mask gamma-ray imager (ECLAIRs; 4-150 keV), and a gamma-ray spectrometer (GRM; 15-5500 keV) that, together, will characterise the GRB prompt emission spectrum over a wide energy range. In this paper we describe the performances of the ECLAIRs and GRM system with different populations of GRBs from existing catalogues, from the classical ones to those with a possible thermal component superimposed to their non-thermal emission. The combination of ECLAIRs and the GRM will provide new insights also on other GRB properties, as for example the spectral characterisation of the subclass of short GRBs showing an extended emission after the initial spike.

The development for small scale soft X-ray spectrometer

International Nuclear Information System (INIS)

Sun Kexu; Jiang Shaoen; Yi Rongqing; Cui Yanli

2004-12-01

For the development of small-scale soft X-ray spectrometer, first, some small-scale soft X-ray detection elements are developed, it is included GaAs irradiated with neutron, GaAs irradiated with proton, multi-layer mirror, plane mirror and small scale X-ray diode et al. Soft X-ray spectrometers built of multi-layer mirror-GaAs (with neutron irradiation), and plane mirror-small-scale XRD, and plane mirror-GaAs (with proton irradiation) are prepared. These spectrometers are examined in Shen Guang-II laser facility, and some external estimation are given. (authors)

Space instrumentation for gamma-ray astronomy

Energy Technology Data Exchange (ETDEWEB)

Teegarden, B.J

1999-02-11

The decade of the 1990s has witnessed a renaissance in the field of gamma-ray astronomy. The seminal event was the launch of the Compton Gamma-Ray Observatory (CGRO) in April 1991. There have been a flood of major discoveries from CGRO including breakthroughs in gamma-ray bursts, annihilation radiation, and blazars. The Italian SAX satellite was launched in April 1996. Although not primarily a gamma-ray mission, it has added a new dimension to our understanding of gamma-ray bursts. Along with these new discoveries a firm groundwork has been laid for missions and new technology development that should maintain a healthy and vigorous field throughout most of the next decade. These include the ESA INTEGRAL mission (INTErnational Gamma-Ray Astrophysics Laboratory, to be launched in mid-2001) and the NASA GLAST mission (Gamma-Ray Large Area Space Telescope) with a likely launch in the middle of the next decade. These two missions will extend the observational capabilities well beyond those of CGRO. New technologies (to gamma-ray astronomy), such as cooled germanium detectors, silicon strip detectors, and CdTe detectors are planned for these new missions. Additional promising new technologies such as CdZnTe strip detectors, scintillator fibers, and a gamma-ray lens for future gamma-ray astronomy missions are under development in laboratories around the world.

Space instrumentation for gamma-ray astronomy

International Nuclear Information System (INIS)

Teegarden, B.J.

1999-01-01

The decade of the 1990s has witnessed a renaissance in the field of gamma-ray astronomy. The seminal event was the launch of the Compton Gamma-Ray Observatory (CGRO) in April 1991. There have been a flood of major discoveries from CGRO including breakthroughs in gamma-ray bursts, annihilation radiation, and blazars. The Italian SAX satellite was launched in April 1996. Although not primarily a gamma-ray mission, it has added a new dimension to our understanding of gamma-ray bursts. Along with these new discoveries a firm groundwork has been laid for missions and new technology development that should maintain a healthy and vigorous field throughout most of the next decade. These include the ESA INTEGRAL mission (INTErnational Gamma-Ray Astrophysics Laboratory, to be launched in mid-2001) and the NASA GLAST mission (Gamma-Ray Large Area Space Telescope) with a likely launch in the middle of the next decade. These two missions will extend the observational capabilities well beyond those of CGRO. New technologies (to gamma-ray astronomy), such as cooled germanium detectors, silicon strip detectors, and CdTe detectors are planned for these new missions. Additional promising new technologies such as CdZnTe strip detectors, scintillator fibers, and a gamma-ray lens for future gamma-ray astronomy missions are under development in laboratories around the world

Measurement of angularly dependent spectra of betatron gamma-rays from a laser plasma accelerator with quadrant-sectored range filters

Energy Technology Data Exchange (ETDEWEB)

Jeon, Jong Ho, E-mail: jhjeon07@ibs.re.kr; Nakajima, Kazuhisa, E-mail: naka115@dia-net.ne.jp; Rhee, Yong Joo; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Shin, Jung Hun; Yoo, Byung Ju; Jo, Sung Ha; Shin, Kang Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Kim, Hyung Taek; Sung, Jae Hee; Lee, Seong Ku; Choi, Il Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Advanced Photonics Research Institute, GIST, Gwangju 61005 (Korea, Republic of); Hojbota, Calin; Bae, Lee Jin; Jung, Jaehyung; Cho, Min Sang; Cho, Byoung Ick; Nam, Chang Hee [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 61005 (Korea, Republic of)

2016-07-15

Measurement of angularly dependent spectra of betatron gamma-rays radiated by GeV electron beams from laser wakefield accelerators (LWFAs) are presented. The angle-resolved spectrum of betatron radiation was deconvolved from the position dependent data measured for a single laser shot with a broadband gamma-ray spectrometer comprising four-quadrant sectored range filters and an unfolding algorithm, based on the Monte Carlo code GEANT4. The unfolded gamma-ray spectra in the photon energy range of 0.1–10 MeV revealed an approximately isotropic angular dependence of the peak photon energy and photon energy-integrated fluence. As expected by the analysis of betatron radiation from LWFAs, the results indicate that unpolarized gamma-rays are emitted by electrons undergoing betatron motion in isotropically distributed orbit planes.

NURE aerial gamma ray and magnetic reconnaissance survey, Thorpe area, Scranton NK18-8 Quadrangle. Volume I. Narrative report

International Nuclear Information System (INIS)

1978-02-01

A rotary wing combined airborne high sensitivity gamma-ray and magnetic survey of four 1:250,000 quadrangles covering portions of Pennsylvania, New Jersey, and New York was made. The results are given for the Scranton NK18-8 quadrangle

Apparatus for gamma ray radiography

International Nuclear Information System (INIS)

Kobayashi, Masatoshi; Enomoto, Shigemasa; Oga, Hiroshi

1979-01-01

This is the standard of Japan Non-Destructive Inspection Society, NDIS 1101-79, which stipulates on the design, construction and testing method of the apparatuses for gamma ray radiography used for taking industrial radiograms. The gamma ray apparatuses stipulated in this standard are those containing sealed radioactive isotopes exceeding 100 μCi, which emit gamma ray. The gamma ray apparatuses are classified into three groups according to their movability. The general design conditions, the irradiation dose rate and the sealed radiation sources for the gamma ray apparatuses are stipulated. The construction of the gamma ray apparatuses must be in accordance with the notification No. 52 of the Ministry of Labor, and safety devices and collimators must be equipped. The main bodies of the gamma ray apparatuses must pass the vibration test, penetration test, impact test and shielding efficiency test. The method of each test is described. The attached equipments must be also tested. The tests according to this standard are carried out by the makers of the apparatuses. The test records must be made when the apparatuses have passed the tests, and the test certificates are attached. The limit of guarantee by the endurance test must be clearly shown. The items to be shown on the apparatuses are stipulated. (Kako, I.)

Secondary-source energy-dispersive x-ray spectrometer

International Nuclear Information System (INIS)

Larsen, R.P.; Tisue, G.T.

1975-01-01

A secondary-source energy-dispersive x-ray spectrometer has been built and tested. In this instrument the primary source of x rays is a tungsten-target tube powered by a high-voltage (75 kV), a high-power (3.7 kW) generator from a wavelength spectrometer (G.E. XRD-6). The primary polychromatic x rays irradiate an elemental foil, the secondary source. Its characteristic essentially monochromatic x rays are used to irradiate the sample. Fluorescent x rays from the sample are detected and resolved by a lithium-drifted silicon detector, multichannel-analyzer system. The design of the instrument provides a convenient means for changing the secondary, and hence, the energy of the excitation radiation

High-resolution imaging gamma-ray spectroscopy with externally segmented germanium detectors

Science.gov (United States)

Callas, J. L.; Mahoney, W. A.; Varnell, L. S.; Wheaton, W. A.

1993-01-01

Externally segmented germanium detectors promise a breakthrough in gamma-ray imaging capabilities while retaining the superb energy resolution of germanium spectrometers. An angular resolution of 0.2 deg becomes practical by combining position-sensitive germanium detectors having a segment thickness of a few millimeters with a one-dimensional coded aperture located about a meter from the detectors. Correspondingly higher angular resolutions are possible with larger separations between the detectors and the coded aperture. Two-dimensional images can be obtained by rotating the instrument. Although the basic concept is similar to optical or X-ray coded-aperture imaging techniques, several complicating effects arise because of the penetrating nature of gamma rays. The complications include partial transmission through the coded aperture elements, Compton scattering in the germanium detectors, and high background count rates. Extensive electron-photon Monte Carlo modeling of a realistic detector/coded-aperture/collimator system has been performed. Results show that these complicating effects can be characterized and accounted for with no significant loss in instrument sensitivity.

Deep-water gamma-spectrometer based on HP(Ge) detector

International Nuclear Information System (INIS)

Sokolov, A.; Danengirsh, S.; Popov, S.; Pchelincev, A; Gostilo, V.; Kravchenko, S.; Shapovalov, V.; Druzhinin, A.

1995-01-01

Full text: For radionuclide monitoring of the sea bottom near underwater storage of high active waste of nuclear industries and near places of accidents with nuclear submarines the spectrometers of gamma-radiation, which allow to carry out the measurements on the great depth, are needed. Usually, these problems are solved with devices, which are cast down into the water, using the rope, and transmit the signals on the surface by the cable. However, the depth of immersion is limited by this construction and often the conditions of measurement are complicated. The deep water gamma-spectrometer based on HP(Ge) detector for the measurement on the depth up to 3000 m is developed. The spectrometer is completely autonomic and is put up in the selected place, using the manipulator of a deep-water apparatus. The spectrometer is created in two cylindrical cases with 170 mm diameter and 1100 mm length, bearing the high hydrostatic pressure. The part of the case around the detector is created from titanium and has especial construction with a thin wall for increasing the efficiency of registration in the region of low-energy gamma-radiation. The cooling of the semiconductor detector is provided by a coolant which supports the working temperature of the detector during more than 24 hours. The electronic system of the spectrometer includes high voltage supply f or the detector, preamplifier, analog processor, analog-digital converter and a device for collecting and storing information in flash memory. The power supply of the spectrometer is provided by a battery of accumulators, which can be recharged on the surface. The programming of the processor is carried out before immersion by connecting the spectrometer to personal computer using standard interface RS-232. During 24 hours the spectrometer provides registration of 16 spectrums each in 4096 channels. The reading of the information by the computer is carried out after lifting up the spectrometer on the surface in the same

Pilot study of the application of Tellus airborne radiometric and soil geochemical data for radon mapping

Energy Technology Data Exchange (ETDEWEB)

Appleton, J.D. [British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG (United Kingdom)], E-mail: jda@bgs.ac.uk; Miles, J.C.H.; Green, B.M.R. [Health Protection Agency (HPA) - Radiation Protection Division, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom); Larmour, R. [Environment and Heritage Service, Department of the Environment, Belfast BT7 2JA (United Kingdom)

2008-10-15

The scope for using Tellus Project airborne gamma-ray spectrometer and soil geochemical data to predict the probability of houses in Northern Ireland having high indoor radon concentrations is evaluated, in a pilot study in the southeast of the province, by comparing these data statistically with in-house radon measurements. There is generally good agreement between radon maps modelled from the airborne radiometric and soil geochemical data using multivariate linear regression analysis and conventional radon maps which depend solely on geological and indoor radon data. The radon maps based on the Tellus Project data identify some additional areas where the radon risk appears to be relatively high compared with the conventional radon maps. One of the ways of validating radon maps modelled on the Tellus Project data will be to carry out additional indoor measurements in these areas.

Gamma ray astronomy

International Nuclear Information System (INIS)

Broomhead, Laurent.

1980-01-01

The nuclear gamma astronomy is presented, in particular the Gamma Ray Observatory, an enormous eight tonnes machine fitted with gamma telescopes, scheduled for launching around 1985. It is thereby hoped to study the natural nuclear reactions which occur when stars explode [fr

Quantifying the benefits of ultrahigh energy resolution for Gamma-ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Drury, Owen B.; Terracol, Stephane F.; Friedrich, Stephan [Advanced Detector Group, Lawrence Livermore National Laboratory, L-270, Livermore CA 94550 (United States)

2005-03-01

Cryogenic Gamma-ray spectrometers operating at temperatures of {proportional_to}0.1 K provide an order of magnitude better energy resolution than conventional germanium detectors. Ultra-high energy resolution improves the accuracy of non-destructive analysis of nuclear materials, since a better separation of lines reduces statistical errors as well as systematic errors from background subtraction and efficiency correction. We are developing cryogenic Gamma-spectrometers based on bulk tin absorbers and superconducting molybdenum-copper sensors for nuclear forensics and non-proliferation applications. Here we quantify the improvements in accuracy for isotope analysis with cryogenic detectors in terms of detector performance for different cases of line separation, line intensity ratios and background levels. Precise measurements of isotope ratios are crucial in the context of nuclear attribution, since they provide signatures of composition, age, origin, intended purpose and processing history of illicit nuclear materials. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Time-of-flight spectrometer for the measurement of gamma correlated neutron spectra

International Nuclear Information System (INIS)

Andryashin, A.V.; Devlein, B.V.; Lychagin, A.A.; Minko, Y.V.; Mironov, A.N.; Nesterenko, V.S.

1986-01-01

A time-of-flight spectrometer for the measurement of gamma correlated neutron spectra form (n,xnγ) reactions is described. The operation and the main parameters are discussed. The resolution in the neutron channel is 2.2 ns/m at the 150 keV neutron energy threshold. A simultaneous measurement of the time-of-flight and amplitude distributions makes it possible to study gamma correlated neutron spectra as well as the prompt gamma spectra in coincidence with selected energy neutrons. In order to test the spectrometer, measurements of the neutron spectrum in coincidence with the 846 keV gamma line of 56 Fe were carried out at an incident neutron energy of 14.1 MeV. (author). 3 figs., 6 refs

Isomer-delayed gamma-ray spectroscopy of neutron-rich 166Tb

Directory of Open Access Journals (Sweden)

Gurgi L.A.

2017-01-01

Full Text Available This short paper presents the identification of a metastable, isomeric-state decay in the neutron-rich odd-odd, prolate-deformed nucleus 166Tb. The nucleus of interest was formed using the in-flight fission of a 345 MeV per nucleon 238U primary beam at the RIBF facility, RIKEN, Japan. Gamma-ray transitions decaying from the observed isomeric states in 166Tb were identified using the EURICA gamma-ray spectrometer, positioned at the final focus of the BigRIPS fragments separator. The current work identifies a single discrete gamma-ray transition of energy 119 keV which de-excites an isomeric state in 166Tb with a measured half-life of 3.5(4 μs. The multipolarity assignment for this transition is an electric dipole and is made on the basis internal conversion and decay lifetime arguments. Possible two quasi-particle Nilsson configurations for the initial and final states which are linked by this transition in 166Tb are made on the basis of comparison with Blocked BCS Nilsson calculations, with the predicted ground state configuration for this nucleus arising from the coupling of the v(1-/2[521] and π(3+/2 Nilsson orbitals.

Theory and optical design of x-ray echo spectrometers

Science.gov (United States)

Shvyd'ko, Yuri

2017-08-01

X-ray echo spectroscopy, a space-domain counterpart of neutron spin echo, is a recently proposed inelastic x-ray scattering (IXS) technique. X-ray echo spectroscopy relies on imaging IXS spectra and does not require x-ray monochromatization. Due to this, the echo-type IXS spectrometers are broadband, and thus have a potential to simultaneously provide dramatically increased signal strength, reduced measurement times, and higher resolution compared to the traditional narrow-band scanning-type IXS spectrometers. The theory of x-ray echo spectrometers presented earlier [Yu. Shvyd'ko, Phys. Rev. Lett. 116, 080801 (2016), 10.1103/PhysRevLett.116.080801] is developed here further with a focus on questions of practical importance, which could facilitate optical design and assessment of the feasibility and performance of the echo spectrometers. Among others, the following questions are addressed: spectral resolution, refocusing condition, echo spectrometer tolerances, refocusing condition adjustment, effective beam size on the sample, spectral window of imaging and scanning range, impact of the secondary source size on the spectral resolution, angular dispersive optics, focusing and collimating optics, and detector's spatial resolution. Examples of optical designs and characteristics of echo spectrometers with 1-meV and 0.1-meV resolutions are presented.

Cosmic gamma-ray burst

International Nuclear Information System (INIS)

Yamagami, Takamasa

1985-01-01

Ballon experiments for searching gamma-ray burst were carried out by employing rotating-cross modulation collimators. From a very long observation of total 315 hours during 1975 to 1979, three gamma-ray intensity anomalies were observed which were speculated as a gamma-ray burst. As for the first gamma-ray intensity anomaly observed in 1975, the burst source could be located precisely but the source, heavenly body, could not be specified. Gamma-ray burst source estimation was made by analyzing distribution of burst source in the celestial sphere, burst size distribution, and burst peak. Using the above-mentioned data together with previously published ones, apparent inconsistency was found between the observed results and the adopted theory that the source was in the Galaxy, and this inconsistency was found due to the different time profiles of the burst observed with instruments of different efficiency. It was concluded by these analysis results that employment of logN - logP (relation between burst frequency and burst count) was better than that of logN - logS (burst size) in the examination of gamma-ray burst because the former was less uncertain than the latter. Analyzing the author's observed gamma-ray burst data and the related published data, it was clarified that the burst distribution was almost P -312 for the burst peak value larger than 10 -6 erg/cm 2 .sec. The author could indicate that the calculated celestial distribution of burst source was consistent with the observed results by the derivation using the logN - logP relationship and that the burst larger than 10 -6 erg/cm 2 .sec happens about one thousand times a year, about ten times of the previous value. (Takagi, S.)

Determination of heavy metals concentrations in airborne particulates matter (APM) from Manjung district, Perak using energy dispersive X-ray fluorescence (EDXRF) spectrometer

Science.gov (United States)

Arshad, Nursyairah; Hamzah, Zaini; Wood, Ab. Khalik; Saat, Ahmad; Alias, Masitah

2015-04-01

Airborne particulates trace metals are considered as public health concern as it can enter human lungs through respiratory system. Generally, any substance that has been introduced to the atmosphere that can cause severe effects to living things and the environment is considered air pollution. Manjung, Perak is one of the development districts that is active with industrial activities. There are many industrial activities surrounding Manjung District area such as coal fired power plant, quarries and iron smelting which may contribute to the air pollution into the environment. This study was done to measure the concentrations of Hg, U, Th, K, Cu, Fe, Cr, Zn, As, Se, Pb and Cd in the Airborne Particulate Matter (APM) collected at nine locations in Manjung District area within 15 km radius towards three directions (North, North-East and South-East) in 5 km intervals. The samples were collected using mini volume air sampler with cellulose filter through total suspended particulate (TSP). The sampler was set up for eight hours with the flow rate of 5 L/min. The filter was weighed before and after sample collection using microbalance, to get the amount of APM and kept in desiccator before analyzing. The measurement was done using calibrated Energy Dispersive X-Ray Fluorescence (EDXRF) Spectrometer. The air particulate concentrations were found below the Malaysia Air Quality Guidelines for TSP (260 µg/m3). All of the metals concentrations were also lower than the guidelines set by World Health Organization (WHO), Ontario Ministry of the Environment and Argonne National Laboratory, USA NCRP (1975). From the concentrations, the enrichment factor were calculated.

Gamma-Ray Astronomy Technology Needs

Science.gov (United States)

Gehrels, N.; Cannizzo, J. K.

2012-01-01

In recent decades gamma-ray observations have become a valuable tool for studying the universe. Progress made in diverse 8re1lS such as gamma-ray bursts (GRBs), nucleosynthesis, and active galactic nuclei (AGNs) has complimented and enriched our astrophysical understanding in many ways. We present an overview of current and future planned space y-ray missions and discussion technology needs for- the next generation of space gamma-ray instruments.

Development and application of marine gamma-ray measurements: a review.

Science.gov (United States)

Jones, D G

2001-01-01

The development of instruments to measure gamma radiation in the marine environment, particularly on the sea floor, and the range of uses to which they have been put is reviewed. Since the first steps in the late 1950s, systems have been developed in at least 10 countries with the main thrust occurring in the 1970s. Development has continued up to the present, primarily in Europe and the USA. Marine gamma-ray spectrometers have been used for a range of applications including the mapping of rocks and unconsolidated sediments, mineral exploration (mainly for heavy minerals and phosphorites), sediment transport studies and investigations in relation to discharged and dumped nuclear wastes and at nuclear weapon test sites.

GRAP, Gamma-Ray Level-Scheme Assignment

International Nuclear Information System (INIS)

Franklyn, C.B.

2002-01-01

1 - Description of program or function: An interactive program for allocating gamma-rays to an energy level scheme. Procedure allows for searching for new candidate levels of the form: 1) L1 + G(A) + G(B) = L2; 2) G(A) + G(B) = G(C); 3) G(A) + G(B) = C (C is a user defined number); 4) L1 + G(A) + G(B) + G(C) = L2. Procedure indicates intensity balance of feed and decay of each energy level. Provides for optimization of a level energy (and associated error). Overall procedure allows for pre-defining of certain gamma-rays as belonging to particular regions of the level scheme, for example, high energy transition levels, or due to beta- decay. 2 - Method of solution: Search for cases in which the energy difference between two energy levels is equal to a gamma-ray energy within user-defined limits. 3 - Restrictions on the complexity of the problem: Maximum number of gamma-rays: 999; Maximum gamma ray energy: 32000 units; Minimum gamma ray energy: 10 units; Maximum gamma-ray intensity: 32000 units; Minimum gamma-ray intensity: 0.001 units; Maximum number of levels: 255; Maximum level energy: 32000 units; Minimum level energy: 10 units; Maximum error on energy, intensity: 32 units; Minimum error on energy, intensity: 0.001 units; Maximum number of combinations: 6400 (ca); Maximum number of gamma-ray types : 127

Development of Compton X-ray spectrometer for high energy resolution single-shot high-flux hard X-ray spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Kojima, Sadaoki, E-mail: kojima-s@ile.osaka-u.ac.jp, E-mail: sfujioka@ile.osaka-u.ac.jp; Ikenouchi, Takahito; Arikawa, Yasunobu; Sakata, Shohei; Zhang, Zhe; Abe, Yuki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Fujioka, Shinsuke, E-mail: kojima-s@ile.osaka-u.ac.jp, E-mail: sfujioka@ile.osaka-u.ac.jp; Azechi, Hiroshi [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Ozaki, Tetsuo [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Miyamoto, Shuji; Yamaguchi, Masashi; Takemoto, Akinori [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1205 (Japan)

2016-04-15

Hard X-ray spectroscopy is an essential diagnostics used to understand physical processes that take place in high energy density plasmas produced by intense laser-plasma interactions. A bundle of hard X-ray detectors, of which the responses have different energy thresholds, is used as a conventional single-shot spectrometer for high-flux (>10{sup 13} photons/shot) hard X-rays. However, high energy resolution (Δhv/hv < 0.1) is not achievable with a differential energy threshold (DET) X-ray spectrometer because its energy resolution is limited by energy differences between the response thresholds. Experimental demonstration of a Compton X-ray spectrometer has already been performed for obtaining higher energy resolution than that of DET spectrometers. In this paper, we describe design details of the Compton X-ray spectrometer, especially dependence of energy resolution and absolute response on photon-electron converter design and its background reduction scheme, and also its application to the laser-plasma interaction experiment. The developed spectrometer was used for spectroscopy of bremsstrahlung X-rays generated by intense laser-plasma interactions using a 200 μm thickness SiO{sub 2} converter. The X-ray spectrum obtained with the Compton X-ray spectrometer is consistent with that obtained with a DET X-ray spectrometer, furthermore higher certainly of a spectral intensity is obtained with the Compton X-ray spectrometer than that with the DET X-ray spectrometer in the photon energy range above 5 MeV.

High resolution solar soft X-ray spectrometer

International Nuclear Information System (INIS)

Zhang Fei; Wang Huanyu; Peng Wenxi; Liang Xiaohua; Zhang Chunlei; Cao Xuelei; Jiang Weichun; Zhang Jiayu; Cui Xingzhu

2012-01-01

A high resolution solar soft X-ray spectrometer (SOX) payload onboard a satellite is developed. A silicon drift detector (SDD) is adopted as the detector of the SOX spectrometer. The spectrometer consists of the detectors and their readout electronics, a data acquisition unit and a payload data handling unit. A ground test system is also developed to test SOX. The test results show that the design goals of the spectrometer system have been achieved. (authors)

Observation of solar gamma-ray by Hinotori

International Nuclear Information System (INIS)

Yoshimori, Masato; Okudaira, Kiyoaki; Hirashima, Yo; Kondo, Ichiro.

1982-01-01

The solar gamma-ray emitted by solar flare was observed. The gamma-ray is the electromagnetic radiation with the energy more than 300 keV. The line gamma-ray intensity and the time profile were observed. The gamma-ray detector CsI (Tl) was loaded on Hinotori, and the observed gamma-ray was analyzed by a multi-channel analyzer. The observed line gamma-ray was the radiation from Fe-56 and Ne-20. The line gamma-ray from C-12 and O-16 was also seen. These gamma-ray is the direct evidence of the nuclear reaction on the sun. The observed spectrum suggested the existence of the lines from Mg-24 and Si-28. The intensity of the 2.22 MeV gamma-line was small. This fact showed that the origin of this line was different from other nuclear gamma-ray. Two kinds of hard X-ray bursts were detected. The one was impulsive burst, and the other was gradual burst. There was no time difference between the hard X-ray and the gamma-ray of the impulsive burst. The impulsive burst may be explained by the beam model. The delay of time profile in the high energy gamma-ray of the gradual burst was observed. This means that the time when accelerated electrons cause bremsstrahlung depends on the electron energy. The long trapping of electrons at the top of magnetic loop is suggested. (Kato, T.)

Relativistic motion in gamma-ray bursts

International Nuclear Information System (INIS)

Krolik, J.H.; Pier, E.A.

1991-01-01

Three fundamental problems affect models of gamma-ray bursts, i.e., the energy source, the ability of high-energy photons to escape the radiation region, and the comparative weakness of X-ray emission. It is indicated that relativistic bulk motion of the gamma-ray-emitting plasma generically provides a solution to all three of these problems. Results show that, if the plasma that produces gamma-ray bursts has a bulk relativistic velocity with Lorentz factor gamma of about 10, several of the most troubling problems having to do with gamma-ray bursts are solved. 42 refs

Mapping methane emissions using the airborne imaging spectrometer AVIRIS-NG

Science.gov (United States)

Thorpe, A. K.; Frankenberg, C.; Thompson, D. R.; Duren, R. M.; Bue, B. D.; Green, R. O.

2017-12-01

The next generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG) has been used to survey large regions and map methane plumes with unambiguous identification of emission source locations. This capability is aided by real time detection and geolocation of gas plumes, permitting adaptive surveys and communication to ground teams for rapid follow up. We present results from AVIRIS-NG flight campaigns in Colorado, New Mexico, and California. Hundreds of plumes were observed, reflecting emissions from the energy sector that include hydraulic fracturing, gas processing plants, tanks, pumpjacks, and pipeline leaks. In some cases, plumes observed by AVIRIS-NG resulted in mitigation. Additional examples will be shown for methane from dairy lagoons, landfills, natural emissions, as well as carbon dioxide from power plants and refineries. We describe the unique capabilities of airborne imaging spectrometers to augment other measurement techniques by efficiently surveying key regions for methane point sources and supporting timely assessment and mitigation. We summarize the outlook for near- and longer-term monitoring capabilities including future satellite systems. Figure caption. AVIRIS-NG true color image subset with superimposed methane plume showing retrieved gas concentrations. Plume extends 200 m downwind of the southern edge of the well pad. Google Earth imagery with finer spatial resolution is also included (red box), indicating that tanks in the inset scene as the source of emissions. Five wells are located at the center of this well pad and all use horizontal drilling to produce mostly natural gas.

NURE aerial gamma ray and magnetic detail survey of portions of northeast Washington. Volume I. Data acquisition, reduction and interpretation. Final report

International Nuclear Information System (INIS)

1981-11-01

As part of the Department of Energy (DOE) National Uranium Evaluation Program a rotary wing detailed high sensitivity radiometric and magnetic survey was performed which encompassed 8 areas in the northeastern portion of Washington State. The total area surveyed consisted of approximately 9105 line miles. The survey was flown with a Sikorsky S58T helicopter equipped with a high sensitivity gamma ray spectrometer and magnetometer. The airborne spectrometer system was calibrated at the DOE calibration facilities at Walker Field in Grand Junction, Colorado and at the Dynamic Test Range at Lake Mead, Arizona. The radiometric data was corrected and normalized to 400 feet terrain clearance and identified as to rock type by correlating each sample with existing geologic map information. A multi-variate analysis was performed, which together with the radiometric and magnetic contour maps was utilized in the geochemical analysis of each area. The survey data is presented in the form of contour maps, stacked profiles, histograms and microfiche copies of the data listings. This graphic material is presented in the individual area reports. The results of the geologic and geochemical evaluation are presented as individual chapters of this narrative report

Gamma ray spectrometry results from core samples collected for RESUME 95

International Nuclear Information System (INIS)

Sanderson, D.C.W.; Allyson, J.D.; Toivonen, H.; Honkamaa, T.

1997-01-01

Field sampling of an airfield at Vesivehmaa, near Vaeaeksy, Finland (Area I) was carried out between 26-29 May 1995, to establish the radionuclide deposition and inventory of Chernobyl derived 137 Cs, and natural radionuclides. The objective was to establish a common calibration site for in-situ and airborne gamma spectrometers, for Exercise RESUME 95 conducted in August 1995. The report presents the sampling details, handling and treatment. The analyses are discussed with particular emphasis given to 137 Ca, 134 Cs, 40 K, 214 Bi and 208 radionuclides, and the quantification of their respective deposition and inventories. The results have been used to estimate the effective concentrations of nuclides at the calibration site for in-situ and airborne gamma spectrometry, and the depth distribution. For 137 Cs the weighted mean activity per unit area takes on values of 50.7±5.2 kBq m -2 at 1 m ground clearance, 51.1±6.9 kBq m -2 at 50 m height and 47.9±8.5 kBq m -2 at 100 m. The similarity of these values confirms the suitability of the Vesivehmaa site for comparison of in-situ and airborne results despite variations of a factor of two between results from individual cores. The mean α/ρ value for 137 Cs in Area I is 0.77±0.10 cm 2 g -1 (relaxation mass per unit area, β 1.31±0.15 gcm -2 ). Additional soil sampling across parts of Area II (a 6x3 km area selected for mapping Chernobyl deposition) was carried out. The mean level of 137 Cs activity from these samples was 92.4±63 kBq m -2 , a sample taken near Laihansuo showing the largest value obtained at 172 kBq m -2 . (EG)

Highlights of GeV Gamma-Ray Astronomy

Science.gov (United States)

Thompson, David J.

2010-01-01

Because high-energy gamma rays are primarily produced by high-energy particle interactions, the gamma-ray survey of the sky by the Fermi Gamma-ray Space Telescope offers a view of sites of cosmic ray production and interactions. Gamma-ray bursts, pulsars, pulsar wind nebulae, binary sources, and Active Galactic Nuclei are all phenomena that reveal particle acceleration through their gamma-ray emission. Diffuse Galactic gamma radiation, Solar System gamma-ray sources, and energetic radiation from supernova remnants are likely tracers of high-energy particle interactions with matter and photon fields. This paper will present a broad overview of the constantly changing sky seen with the Large Area Telescope (LAT) on the Fermi spacecraft.

Localization of Gamma-Ray Bursts Using the Fermi Gamma-Ray Burst Monitor

NARCIS (Netherlands)

Connaughton, V.; Briggs, M.S.; Goldstein, A.; Meegan, C.A.; Paciesas, W.S.; Preece, R.D.; Wilson-Hodge, C.A.; Gibby, M.H.; Greiner, J.; Gruber, D.; Jenke, P.; Kippen, R.M.; Pelassa, V.; Xiong, S.; Yu, H-F.; Bhat, P.N.; Burgess, J.M.; Byrne, D.; Fitzpatrick, G.; Foley, S.; Giles, M.M.; Guiriec, S.; van der Horst, A.J.; von Kienlin, A.; McBreen, S.; McGlynn, S.; Tierney, D.; Zhang, B..B.

2015-01-01

The Fermi Gamma-ray Burst Monitor (GBM) has detected over 1400 gamma-ray bursts (GRBs) since it began science operations in 2008 July. We use a subset of over 300 GRBs localized by instruments such as Swift, the Fermi Large Area Telescope, INTEGRAL, and MAXI, or through triangulations from the

Gamma-Ray Lenses for Astrophysics-and the Gamma-Ray Imager Mission GRI

DEFF Research Database (Denmark)

Wunderer, C. B.; Ballmoos, P. V.; Barriere, N.

2009-01-01

Observations of the gamma-ray sky reveal the most powerful sources and the most violent events in the Universe. While at lower wavebands the observed emission is generally dominated by thermal processes, the gamma-ray sky provides us with a view on the non-thermal Universe. Here particles are acc...

Gamma ray astronomy with COS-B

International Nuclear Information System (INIS)

Swanenburg, B.N.

1981-01-01

Observational results in the field of gamma-ray astronomy that have been obtained to date with the COS-B satellite are discussed and questions raised by these observations are summarized. Following a brief review of the instrumental characteristics of COS-B and the extent of COS-B gamma-ray coverage of the sky, particular attention is given to the questions raised by the discovery of many unidentified gamma-ray sources with no apparent optical, X-ray or radio counterparts and the detection of high-energy gamma radiation from the quasar 3C 273, which suggests the role of gamma-ray emission in the creation of other radiation

Inverse Compton gamma-rays from pulsars

International Nuclear Information System (INIS)

Morini, M.

1983-01-01

A model is proposed for pulsar optical and gamma-ray emission where relativistic electrons beams: (i) scatter the blackbody photons from the polar cap surface giving inverse Compton gamma-rays and (ii) produce synchrotron optical photons in the light cylinder region which are then inverse Compton scattered giving other gamma-rays. The model is applied to the Vela pulsar, explaining the first gamma-ray pulse by inverse Compton scattering of synchrotron photons near the light cylinder and the second gamma-ray pulse partly by inverse Compton scattering of synchrotron photons and partly by inverse Compton scattering of the thermal blackbody photons near the star surface. (author)

Levels in /sup 179/W studied in the /sup 181/Ta(p, 3n) reaction by on-line electron and gamma ray spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Meijer, B J; Konijn, J [Instituut voor Kernphysisch Onderzoek, Amsterdam (Netherlands); Klank, B; Jett, J H; Ristinen, R A [Colorado Univ., Boulder (USA)

1975-01-01

Levels in /sup 179/W have been deduced from in-beam gamma and conversion electron studies of the /sup 181/Ta(p, 3n)/sup 179/W reaction. The gamma-ray spectrum was studied with Ge(Li) detectors and a crystal diffraction spectrometer; the conversion electrons were measured with solenoid Si(Li) spectrometer. The multipolarities of some 50 transitions could be determined. Coriolis mixing of the Nilsson orbits with N = 6 was calculated.

The design and construction of a scintillation pair spectrometer for the detection of {gamma}-rays in the energy range 2-20 MeV; Realisation d'un spectrometre a scintillations et a paires pour la detection des rayonnements {gamma} d'energie comprise entre 2 et 20 MeV

Energy Technology Data Exchange (ETDEWEB)

Longequeue, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-15

The scintillation pair spectrometer is designed to allow the measurement of the energy of {gamma} rays in the range 2 to 20 MeV. Such an instrument is chosen because of its main features: high energy resolution and ease of working. Against this, however, the efficiency is low. It was possible to tolerate this low efficiency because of the facts that the {gamma}-rays studied emanated from (p, {gamma}) reactions and that the two electrostatic acceleration available could provide beams of 500 {mu}A having energy maxima at 300 and 600 keV. We used the {gamma} rays produced by the reactions {sup 23}Na (p, {gamma}) {sup 24}Mg, {sup 19}F (p, {alpha} {gamma}) {sup 16}O and {sup 7}Li (p, {gamma}) {sup 8}Be as well as the {gamma} rays emitted by sources of RTh and of {sup 24}Na. Under these conditions the spectrometer attained a resolving power of 6,5 {+-} 0,5 per cent at 6,1 MeV and it was able to separate the 14,8 and 17,6 MeV lines produced by the reaction {sup 7}Li (p, {gamma}) {sup 8}Be. As well as this, the efficiency which varied from 2.10{sup -4} to 1,7.10{sup -3} between 2 and 20 MeV was well above the efficiencies already obtained with this type of instrument. (author) [French] Le spectrometre a scintillations et a paires presente dans cette these a pour but de mesurer l'energie des rayonnements {gamma} dans la bande de 2 a 20 MeV. Le choix d'un tel appareil est du a ses caracteristiques essentielles: bonne resolution en energie et maniabilite. Par contre, son efficacite est faible. Nous avons pu tolerer cette faible efficacite car les rayonnements {gamma} que nous avons etudies provenaient de reactions (p, {gamma}) et les deux accelerateurs electrostatiques dont nous disposions pouvaient fournir des faisceaux de 500 {mu}A avec des energies maximum de 300 et 600 keV. Nous avons utilise les rayonnements {gamma} produits par les reactions {sup 23}Na (p, {gamma}) {sup 24}Mg, {sup 19}F (p, {alpha} {gamma}) {sup 16}O et {sup 7}Li (p, {gamma}) {sup 8}Be ainsi que les

Gamma-Ray Spectroscopy at TRIUMF-ISAC: the New Frontier of Radioactive Ion Beam Research

Science.gov (United States)

Ball, G. C.; Andreoiu, C.; Austin, R. A. E.; Bandyopadhyay, D.; Becker, J. A.; Bricault, P.; Brown, N.; Chan, S.; Churchman, R.; Colosimo, S.; Coombes, H.; Cross, D.; Demand, G.; Drake, T. E.; Dombsky, M.; Ettenauer, S.; Finlay, P.; Furse, D.; Garnsworthy, A.; Garrett, P. E.; Green, K. L.; Grinyer, G. F.; Hyland, B.; Hackman, G.; Kanungo, R.; Kulp, W. D.; Lassen, J.; Leach, K. G.; Leslie, J. R.; Mattoon, C.; Melconian, D.; Morton, A. C.; Pearson, C. J.; Phillips, A. A.; Rand, E.; Sarazin, F.; Svensson, C. E.; Sumithrarachchi, S.; Schumaker, M. A.; Triambak, S.; Waddington, J. C.; Walker, P. M.; Williams, S. J.; Wood, J. L.; Wong, J.; Zganjar, E. F.

2009-03-01

High-resolution gamma-ray spectroscopy is essential to fully exploit the unique scientific opportunities at the next generation radioactive ion beam facilities such as the TRIUMF Isotope Separator and Accelerator (ISAC). At ISAC the 8π spectrometer and its associated auxiliary detectors is optimize for β-decay studies while TIGRESS an array of segmented clover HPGe detectors has been designed for studies with accelerated beams. This paper gives a brief overview of these facilities and also presents recent examples of the diverse experimental program carried out at the 8π spectrometer.

Planetary gamma-ray spectroscopy: the effects of hydrogen absorption cross-section of the gamma-ray spectrum

International Nuclear Information System (INIS)

Lapides, J.R.

1981-01-01

The gamma-ray spectroscopy of planet surfaces is one of several possible methods that are useful in determining the elemental composition of planet surfaces from orbiting spacecraft. This has been demonstrated on the Apollos 15 and 16 missions as well as the Soviet Mars-5 mission. Planetary gamma-ray emission is primarily the result of natural radioactive decay and cosmic-ray and solar-flare-induced nuclear reactions. Secondary neutron reactions play a large role in the more intense gamma-ray emission. The technique provides information on the elemental composition of the top few tens of centimeters of the planet surface. Varying concentrations of hydrogen and compositional variations that alter the macroscopic thermal-neutron absorption cross section have a significant effect on the neutron flux in the planet surface and therefore also on the gamma-ray emission from the surface. These effects have been systematically studied for a wide range of possible planetary compositions that include Mercury, the moon, Mars, the comets, and the asteroids. The problem of the Martian atmosphere was also investigated. The results of these calculations, in which both surface neutron fluxes and gamma-ray emission fluxes were determined, were used to develop general procedures for obtaining planet compositions from the gamma-ray spectrum. Several changes have been suggested for reanalyzing the Apollos 15 and 16 gamma-ray results. In addition, procedures have been suggested that can be applied to neutron-gamma techniques in mineral and oil exploration

Smoke, Clouds and Radiation Brazil NASA ER-2 Moderate Resolution Imaging Spectrometer (MODIS) Airborne Simulator (MAS) Data

Data.gov (United States)

National Aeronautics and Space Administration — SCARB_ER2_MAS data are Smoke, Clouds and Radiation Brazil (SCARB) NASA ER2 Moderate Resolution Imaging Spectrometer (MODIS) Airborne Simulator (MAS)...

Gamma-ray Full Spectrum Analysis for Environmental Radioactivity by HPGe Detector

Science.gov (United States)

Jeong, Meeyoung; Lee, Kyeong Beom; Kim, Kyeong Ja; Lee, Min-Kie; Han, Ju-Bong

2014-12-01

Odyssey, one of the NASA¡¯s Mars exploration program and SELENE (Kaguya), a Japanese lunar orbiting spacecraft have a payload of Gamma-Ray Spectrometer (GRS) for analyzing radioactive chemical elements of the atmosphere and the surface. In these days, gamma-ray spectroscopy with a High-Purity Germanium (HPGe) detector has been widely used for the activity measurements of natural radionuclides contained in the soil of the Earth. The energy spectra obtained by the HPGe detectors have been generally analyzed by means of the Window Analysis (WA) method. In this method, activity concentrations are determined by using the net counts of energy window around individual peaks. Meanwhile, an alternative method, the so-called Full Spectrum Analysis (FSA) method uses count numbers not only from full-absorption peaks but from the contributions of Compton scattering due to gamma-rays. Consequently, while it takes a substantial time to obtain a statistically significant result in the WA method, the FSA method requires a much shorter time to reach the same level of the statistical significance. This study shows the validation results of FSA method. We have compared the concentration of radioactivity of 40K, 232Th and 238U in the soil measured by the WA method and the FSA method, respectively. The gamma-ray spectrum of reference materials (RGU and RGTh, KCl) and soil samples were measured by the 120% HPGe detector with cosmic muon veto detector. According to the comparison result of activity concentrations between the FSA and the WA, we could conclude that FSA method is validated against the WA method. This study implies that the FSA method can be used in a harsh measurement environment, such as the gamma-ray measurement in the Moon, in which the level of statistical significance is usually required in a much shorter data acquisition time than the WA method.

Gamma-ray Full Spectrum Analysis for Environmental Radioactivity by HPGe Detector

Directory of Open Access Journals (Sweden)

Meeyoung Jeong

2014-12-01

Full Text Available Odyssey, one of the NASA’s Mars exploration program and SELENE (Kaguya, a Japanese lunar orbiting spacecraft have a payload of Gamma-Ray Spectrometer (GRS for analyzing radioactive chemical elements of the atmosphere and the surface. In these days, gamma-ray spectroscopy with a High-Purity Germanium (HPGe detector has been widely used for the activity measurements of natural radionuclides contained in the soil of the Earth. The energy spectra obtained by the HPGe detectors have been generally analyzed by means of the Window Analysis (WA method. In this method, activity concentrations are determined by using the net counts of energy window around individual peaks. Meanwhile, an alternative method, the so-called Full Spectrum Analysis (FSA method uses count numbers not only from full-absorption peaks but from the contributions of Compton scattering due to gamma-rays. Consequently, while it takes a substantial time to obtain a statistically significant result in the WA method, the FSA method requires a much shorter time to reach the same level of the statistical significance. This study shows the validation results of FSA method. We have compared the concentration of radioactivity of 40K, 232Th and 238U in the soil measured by the WA method and the FSA method, respectively. The gamma-ray spectrum of reference materials (RGU and RGTh, KCl and soil samples were measured by the 120% HPGe detector with cosmic muon veto detector. According to the comparison result of activity concentrations between the FSA and the WA, we could conclude that FSA method is validated against the WA method. This study implies that the FSA method can be used in a harsh measurement environment, such as the gamma-ray measurement in the Moon, in which the level of statistical significance is usually required in a much shorter data acquisition time than the WA method.

Gamma Ray Bursts-Afterglows and Counterparts

Science.gov (United States)

Fishman, Gerald J

1998-01-01

Several breakthrough discoveries were made last year of x-ray, optical and radio afterglows and counterparts to gamma-ray bursts, and a redshift has been associated with at least one of these. These discoveries were made possible by the fast, accurate gamma-ray burst locations of the BeppoSAX satellite. It is now generally believed that the burst sources are at cosmological distances and that they represent the most powerful explosions in the Universe. These observations also open new possibilities for the study of early star formation, the physics of extreme conditions and perhaps even cosmology. This session will concentrate on recent x-ray, optical and radio afterglow observations of gamma-ray bursts, associated redshift measurements, and counterpart observations. Several review and theory talks will also be presented, along with a summary of the astrophysical implications of the observations. There will be additional poster contributions on observations of gamma-ray burst source locations at wavelengths other than gamma rays. Posters are also solicited that describe new observational capabilities for rapid follow-up observations of gamma-ray bursts.

About cosmic gamma ray lines

Science.gov (United States)

Diehl, Roland

2017-06-01

Gamma ray lines from cosmic sources convey the action of nuclear reactions in cosmic sites and their impacts on astrophysical objects. Gamma rays at characteristic energies result from nuclear transitions following radioactive decays or high-energy collisions with excitation of nuclei. The gamma-ray line from the annihilation of positrons at 511 keV falls into the same energy window, although of different origin. We present here the concepts of cosmic gamma ray spectrometry and the corresponding instruments and missions, followed by a discussion of recent results and the challenges and open issues for the future. Among the lessons learned are the diffuse radioactive afterglow of massive-star nucleosynthesis in 26Al and 60Fe gamma rays, which is now being exploited towards the cycle of matter driven by massive stars and their supernovae; large interstellar cavities and superbubbles have been recognised to be of key importance here. Also, constraints on the complex processes making stars explode as either thermonuclear or core-collapse supernovae are being illuminated by gamma-ray lines, in this case from shortlived radioactivities from 56Ni and 44Ti decays. In particular, the three-dimensionality and asphericities that have recently been recognised as important are enlightened in different ways through such gamma-ray line spectroscopy. Finally, the distribution of positron annihilation gamma ray emission with its puzzling bulge-dominated intensity disctribution is measured through spatially-resolved spectra, which indicate that annihilation conditions may differ in different parts of our Galaxy. But it is now understood that a variety of sources may feed positrons into the interstellar medium, and their characteristics largely get lost during slowing down and propagation of positrons before annihilation; a recent microquasar flare was caught as an opportunity to see positrons annihilate at a source.

Study of gamma ray multiplicity spectra for radiative capture of neutrons in 113,115In

International Nuclear Information System (INIS)

Georgiev, G.P.; Fajkov-Stanchik, Kh.; Grigor'ev, Yu.V.; Muradyan, G.V.; Yaneva, N.B.

1997-08-01

Neutron radiative capture measurements were performed for the enriched isotopes 113 In and 115 In on the neutron spectrometer at the Neutron Physics Laboratory of the Joint Institute for Nuclear Research employing the gamma ray multiplicity technique and using a ''Romashka'' multi-sectional 4p detector on the 500 m time base of the IBR-30 booster. The gamma multiplicity spectra of resolved resonances were obtained for the 20-500 eV energy range. The mean gamma ray multiplicity was determined for each resonance. The dependence of the ratio S of the low-energy coincidence multiplicity spectrum to the high-energy coincidence multiplicity spectrum on resonance energy exhibits a non-statistical structure. This structure was found to correlate with the local neutron strength function. (author). 10 refs, 6 figs, 2 tabs

Methods for fitting of efficiency curves obtained by means of HPGe gamma rays spectrometers; Metodos de ajuste de curvas de eficiencia obtidas por meio de espectrometros de HPGe

Energy Technology Data Exchange (ETDEWEB)

Cardoso, Vanderlei

2002-07-01

The present work describes a few methodologies developed for fitting efficiency curves obtained by means of a HPGe gamma-ray spectrometer. The interpolated values were determined by simple polynomial fitting and polynomial fitting between the ratio of experimental peak efficiency and total efficiency, calculated by Monte Carlo technique, as a function of gamma-ray energy. Moreover, non-linear fitting has been performed using a segmented polynomial function and applying the Gauss-Marquardt method. For the peak area obtainment different methodologies were developed in order to estimate the background area under the peak. This information was obtained by numerical integration or by using analytical functions associated to the background. One non-calibrated radioactive source has been included in the curve efficiency in order to provide additional calibration points. As a by-product, it was possible to determine the activity of this non-calibrated source. For all fittings developed in the present work the covariance matrix methodology was used, which is an essential procedure in order to give a complete description of the partial uncertainties involved. (author)

Lunar occultations for gamma-ray source measurements

Science.gov (United States)

Koch, David G.; Hughes, E. B.; Nolan, Patrick L.

1990-01-01

The unambiguous association of discrete gamma-ray sources with objects radiating at other wavelengths, the separation of discrete sources from the extended emission within the Galaxy, the mapping of gamma-ray emission from nearby galaxies and the measurement of structure within a discrete source cannot presently be accomplished at gamma-ray energies. In the past, the detection processes used in high-energy gamma-ray astronomy have not allowed for good angular resolution. This problem can be overcome by placing gamma-ray detectors on the moon and using the horizon as an occulting edge to achieve arcsec resolution. For purposes of discussion, this concept is examined for gamma rays above 100 MeV for which pair production dominates the detection process and locally-generated nuclear gamma rays do not contribute to the background.

Future prospects for. gamma. -ray astronomy

Energy Technology Data Exchange (ETDEWEB)

Fichtel, C [National Aeronautics and Space Administration, Greenbelt, MD (USA). Goddard Space Flight Center

1981-06-30

As ..gamma..-ray astronomy moves from the discovery to the exploratory phase, the promise of ..gamma..-ray astrophysics noted by theorists in the late 1940s and 1950s is beginning to be realized. In the future, satellites should carry instruments that will have over an order of magnitude greater sensitivity than those flown thus far, and, for at least some portions of the ..gamma..-ray energy range, these detectors will also have substantially improved energy and angular resolution. The information to be obtained from these experiments should greatly enhance our knowledge of several astrophysical phenomena including the very energetic and nuclear processes associated with compact objects, astrophysical nucleosynthesis, solar particle acceleration, the chemical composition of the planets and other bodies of the Solar System, the structure of our Galaxy, the origin and dynamic pressure effects of the cosmic rays, high energy particles and energetic processes in other galaxies especially active ones, and the degree of matter-antimatter symmetry of the Universe. The ..gamma..-ray results of the forthcoming programs such as Gamma-I, the Gamma Ray Observatory, the ..gamma..-ray burst network, Solar Polar, and very high energy ..gamma..-ray telescopes on the ground will almost certainly provide justification for more sophisticated telescopes. These advanced instruments might be placed on the Space Platform currently under study by N.A.S.A.

Differential cross sections for gamma-ray production by 14 MeV neutrons with several elements in structural materials

International Nuclear Information System (INIS)

Murata, Isao; Yamamoto, Junji; Takahashi, Akito

1988-01-01

Energy differential cross sections for the gamma-rays produced from the (n,xγ) reactions by 14 MeV neutrons were measured in the gamma-ray energy range from 700 keV to 10 MeV using an NaI spectrometer. Results were obtained for the 8 natural elements; C, Al, Si, Cr, Fe, Ni, Cu and Mo. For prominent discrete gamma-rays in the differential cross sections, the production cross sections were determined by measuring angular distributions with a Ge detector. The gamma-ray energy covered the range between 500 and 3000 keV. The energy distributions have been compared with the differential cross sections evaluated in the nuclear data files of JENDL-3T, ENDL and ENDF/B-IV. The evaluations in JENDL-3T agreed fairly well with the measurements concerning the continuum energy spectra for secondary photons. Discrepancies appeared, however, for Si, Cr and Ni at the energies where the discrete gamma-rays were dominant. The ENDL evaluations were largely deviated from the experimental data. The production cross sections for the discrete gamma-rays in ENDL and ENDF/B-IV were available for the comparison with some of the measured cross sections. Results are presented for C, Al and Si. (author)

A segmented detector for airbone gamma ray spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Burgada, G.; Iovene, A.; Petrucci, S.; Tintori, C., E-mail: g.burgada@caen.it [Costruzioni Apparecchiature Elettroniche Nucleari S.p.A. (CAEN), Viareggio (Italy); Alvarez, M.A.G., E-mail: malvarez@if.usp.br [Universidade de Sao Paulo (IF/USP), Sao Paulo, SP (Brazil). Instituto de Fisica; Baldoncini, M.; Xhixha, G.; Strati, V., E-mail: gerti.xhixha@unife.it [University of Ferrara, Department of Physics and Earth Sciences, Ferrara (Italy); Mantovani, F., E-mail: mantovani@fe.infn.it [Istituto Nazionale di Fisica Nucleare (INFN), Ferrara (Italy); Garosi, P.; Mou, L., E-mail: li.mou@libero.it [University of Siena (Italy); Alvarez, C. Rossi, E-mail: rossialvarez@pd.infn.it [Istituto Nazionale di Fisica Nucleare (INFN), Legnaro (Italy)

2014-07-01

The airborne gamma-ray spectrometry (AGRS) is widely acknowledged as a very efficient technique for large areas monitoring. The detector system mounted on a helicopter allows for an extensive survey in a single flight time, thus reducing the exposure risk for the operator. Results from AGRS techniques are exploited in many fields, from the geological research to the homeland security for the search of orphan radioactive sources, from the mining and hydrocarbon exploration to the construction industry. The new generation of compact digital data acquisition and online processing equipment allows for faster airborne survey campaigns, and enhances the flexibility of operations. In addition, the algorithm for the extrapolation of the nuclide concentrations from the acquired gamma spectra is a challenging step of the entire technique. We are going to present a new device for advanced AGRS measurements, with an innovative detector configuration and data processing algorithms for optimizing the source localization and the on-line response capabilities. The new compact structure makes the system easily portable by a single operator, and rapidly mountable on most common helicopters. Preliminary feasibility studies have been performed to test the mechanics and the hardware of the whole system, which is intended to work without any human attendance. The first flights are planned by the end of 2014, with the aim of detecting artificial point sources having intensities on the order of 10^8 Bq and natural enriched fields already monitored. (author)

A segmented detector for airbone gamma ray spectroscopy

International Nuclear Information System (INIS)

Burgada, G.; Iovene, A.; Petrucci, S.; Tintori, C.; Alvarez, M.A.G.; Mantovani, F.; Garosi, P.; Mou, L.; Alvarez, C. Rossi

2014-01-01

The airborne gamma-ray spectrometry (AGRS) is widely acknowledged as a very efficient technique for large areas monitoring. The detector system mounted on a helicopter allows for an extensive survey in a single flight time, thus reducing the exposure risk for the operator. Results from AGRS techniques are exploited in many fields, from the geological research to the homeland security for the search of orphan radioactive sources, from the mining and hydrocarbon exploration to the construction industry. The new generation of compact digital data acquisition and online processing equipment allows for faster airborne survey campaigns, and enhances the flexibility of operations. In addition, the algorithm for the extrapolation of the nuclide concentrations from the acquired gamma spectra is a challenging step of the entire technique. We are going to present a new device for advanced AGRS measurements, with an innovative detector configuration and data processing algorithms for optimizing the source localization and the on-line response capabilities. The new compact structure makes the system easily portable by a single operator, and rapidly mountable on most common helicopters. Preliminary feasibility studies have been performed to test the mechanics and the hardware of the whole system, which is intended to work without any human attendance. The first flights are planned by the end of 2014, with the aim of detecting artificial point sources having intensities on the order of 10^8 Bq and natural enriched fields already monitored. (author)

The Airborne Visible / Infrared Imaging Spectrometer AVIS: Design, Characterization and Calibration

Directory of Open Access Journals (Sweden)

Wolfram Mauser

2007-09-01

Full Text Available The Airborne Visible / Infrared imaging Spectrometer AVIS is a hyperspectralimager designed for environmental monitoring purposes. The sensor, which wasconstructed entirely from commercially available components, has been successfullydeployed during several experiments between 1999 and 2007. We describe the instrumentdesign and present the results of laboratory characterization and calibration of the system’ssecond generation, AVIS-2, which is currently being operated. The processing of the datais described and examples of remote sensing reflectance data are presented.

Radio Observations of Gamma-ray Novae

Science.gov (United States)

Linford, Justin D.; Chomiuk, L.; Ribeiro, V.; project, E.-Nova

2014-01-01

Recent detection of gamma-ray emission from classical novae by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope surprised many in the astronomical community. We present results from radio observations, obtained using the Karl G. Jansky Very Large Array (VLA), of three gamma-ray novae: Mon2012, Sco2012, and Del2013. Radio observations allow for the calculation of ejecta masses, place limits on the distances, and provide information about the gamma-ray emission mechanism for these sources.

The Gamma-Ray Imager GRI

Science.gov (United States)

Wunderer, Cornelia B.; GRI Collaboration

2008-03-01

Observations of the gamma-ray sky reveal the most powerful sources and the most violent events in the Universe. While at lower wavebands the observed emission is generally dominated by thermal processes, the gamma-ray sky provides us with a view on the non-thermal Universe. Here particles are accelerated to extreme relativistic energies by mechanisms which are still poorly understood, and nuclear reactions are synthesizing the basic constituents of our world. Cosmic accelerators and cosmic explosions are major science themes that are addressed in the gamma-ray regime. ESA's INTEGRAL observatory currently provides the astronomical community with a unique tool to investigate the sky up to MeV energies and hundreds of sources, new classes of objects, extraordinary views of antimatter annihilation in our Galaxy, and fingerprints of recent nucleosynthesis processes have been discovered. NASA's GLAST mission will similarly take the next step in surveying the high-energy ( GeV) sky, and NuSTAR will pioneer focusing observations at hard X-ray energies (to 80 keV). There will be clearly a growing need to perform deeper, more focused investigations of gamma-ray sources in the 100-keV to MeV regime. Recent technological advances in the domain of gamma-ray focusing using Laue diffraction and multilayer-coated mirror techniques have paved the way towards a gamma-ray mission, providing major improvements compared to past missions regarding sensitivity and angular resolution. Such a future Gamma-Ray Imager will allow the study of particle acceleration processes and explosion physics in unprecedented detail, providing essential clues on the innermost nature of the most violent and most energetic processes in the Universe.

Mapping the terrestrial air-absorbed gamma dose rate based on the data of airborne gamma-ray spectrometry in southern cities of China

International Nuclear Information System (INIS)

Xiong Shengqing; Fan Zhengguo; Wu Qifan; Wan Jianhua; Wang Nanping; Chu Xingming; Pei Shaoying; Zeng Lihui

2012-01-01

An environmental radioactivity survey by Airborne Gamma-ray Spectrometry (AGS) on a large scale was undertaken in Zhuhai Zone (ZZ) and Shenzhen Zone (SZ), which include major cities in southern China, covering areas of 3800 km 2 and 4660 km 2 , respectively. The estimated dose rates by AGS have been compared with observed results by ionization chamber and portable dosemeter. Maps of the terrestrial dose rate at 1m above ground level have been calculated based on the data of AGS. The mean dose rates are 84.37 ± 51.69 and 82.10 ± 32.98 nGy/h in ZZ and SZ, and the maximum rates are 343.11 and 368.36 nGy/h, respectively. Dose rates in some places are above 180 nGy/h; the areas covered where 149 km 2 in ZZ and 43 km 2 in SZ. The dominant geological conditions that evidently contribute to the radioactive anomalies are outcrops of Middle and Late Jurassic and Cretaceous biotitic-granite. The growth of industrialization and urbanization has dramatically altered radiation background. Stone mining results in the increase of radiation levels with maximum dose rates approaching 368.36 nGy/h in an open pit. The investigation results provide valuable background data and give a good example for mapping nationwide natural radiation terrestrial dose rates in China by AGS. (author)

Observation of gamma-ray bursts with GINGA

International Nuclear Information System (INIS)

Murakami, Toshio; Fujii, Masami; Nishimura, Jun

1989-01-01

Gamma-ray Burst Detector System (GBD) on board the scientific satellite 'GINGA' which was launched on Feb. 5, 1987, was realized as an international cooperation between ISAS and LANL. It has recorded more than 40 Gamma-Ray Burst candidates during 20 months observation. Although many observational evidences were accumulated in past 20 years after the discovery of gamma-ray burst by LANL scientists, there are not enough evidence to determine the origin and the production mechanism of the gamma-ray burst. GBD consists of a proportional counter and a NaI scintillation counter so that it became possible to observe energy spectrum of the gamma-ray burst with high energy resolution over wide range of energy (1.5-380 keV) together with high time resolution. As the result of observation, the following facts are obtained: (1) A large fraction of observed gamma-ray bursts has a long X-ray tail after the harder part of gamma-ray emission has terminated. (2) Clear spectral absorption features with harmonic in energy was observed in some of the energy spectrum of gamma-ray bursts. These evidences support the hypothesis that the strongly magnetized neutron star is the origin of gamma-ray burst. (author)

Gamma ray astronomy from satellites and balloons

International Nuclear Information System (INIS)

Schoenfelder, V.

1986-01-01

A survey is given of gamma ray astronomy topics presented at the Cosmic Ray Conference. The major conclusions at the Cosmic Ray Conference in the field of gamma ray astronomy are given. (1) MeV-emission of gamma-ray bursts is a common feature. Variations in duration and energy spectra from burst to burst may explain the discrepancy between the measured log N - log S dependence and the observed isotropy of bursts. (2) The gamma-ray line at 1.809 MeV from Al(26) is the first detected line from a radioactive nucleosynthesis product. In order to understand its origin it will be necessary to measure its longitude distribution in the Milky Way. (3) The indications of a gamma-ray excess found from the direction of Loop I is consistent with the picture that the bulk of cosmic rays below 100 GeV is produced in galactic supernova remnants. (4) The interpretation of the large scale distribution of gamma rays in the Milky Way is controversial. At present an extragalactic origin of the cosmic ray nuclei in the GeV-range cannot be excluded from the gamma ray data. (5) The detection of MeV-emission from Cen A is a promising step towards the interesting field of extragalactic gamma ray astronomy

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-09-01

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

Synoptic view of the different domains of application of airborne radiometric and spectrometric surveys in egypt

International Nuclear Information System (INIS)

Fouad, K.M.

1998-01-01

Airborne radiometric survey has been applied for more than three decades in egypt. Experience gained from the acquired data over different geological environments has revealed the importance of this geophysical tool in: 1. disclosure of anomalies of potential uranium deposits, 2. geological mapping, 3. environmental monitoring of natural radiometric background around nuclear facilities, as well as the detection of nuclear fallout resulting from local or foreign nuclear activities. The advent of recording of the discriminated gamma ray energies in the airborne 256-channel spectrometer has eventually resulted in the quantitative detection of uranium, thorium, and potassium and their elemental ratios in the rocks. This has greatly widened the scope of geophysical and geochemical application. When this type is coupled with airborne magnetometry, the geological and structural configuration is appreciably revealed in three dimensions. The important role played by the statistical method of analysis is also shown. Case histories from the eastern desert, and sinai peninsula, are exhibited to help manifest the wide variety of applications of radiometric and spectrometric surveys

{gamma} ray spectroscopy of neutron rich nuclei around N=20; Spectroscopie {gamma} des noyaux riches en neutrons autour de N=20

Energy Technology Data Exchange (ETDEWEB)

Gelin, M

2007-09-15

There is an island of inversion around {sup 32}Mg (12 protons, 20 neutrons) in contradiction with a shell closure N=20. It means a coexistence of spherical and deformed shapes. This work is devoted to the study of {gamma}-ray spectroscopy for nuclei in this region, based on an experiment done at GANIL with a composite secondary beam produced by fragmentation. The originality of the method used here lies in the possibility to study simultaneously several nuclei, and for each of them to explore several reaction channels. The VAMOS spectrometer was used for the identification of the ejectiles. The {gamma}-rays were detected with EXOGAM, a germanium clover array. The detectors used before and after the target allowed for a unique identification and a selection of the reaction channel: inelastic scattering, transfer and fragmentation reaction. In this thesis the following nuclei were studied: {sup 28}Ne, {sup 30-32}Mg {sup 31-34}Al, {sup 33-35}Si, {sup 35}P. New {gamma}-rays have been observed. The {gamma}-ray angular distributions and {gamma}-{gamma} angular correlations have been measured for some transitions. Assignment of spins and parities has been proposed for some states. In particular, in {sup 34}Si, the 3{sup -} assignment is confirmed and a new candidate for the second 0{sup +} has been proposed. In {sup 32}Mg, the state at 2.321 MeV, for which conflicting assignment existed, is deduced from the present data as a 4{sup +}, and a 6{sup +} state is proposed. (author)

X-ray and gamma radiography devices

International Nuclear Information System (INIS)

Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

2008-01-01

When we are using this technique, we also must familiar with the device and instrument that used such as gamma projector, crawler, x-ray tubes and others. So this chapter discussed detailed on device used for radiography work. For the x-ray and gamma, their characteristics are same but the source to produce is a big different. X-ray produced from the machine meanwhile, gamma produce from the source such as Co-60 and IR-192. Both are electromagnetic waves. So, the reader can have some knowledge on what is x-ray tube, discrete x-ray and characteristic x-ray, how the machine works and how to control a machine, what is source for gamma emitter, how to handle the projector and lastly difference between x-ray and gamma. Of course this cannot be with the theory only, so detailed must be learned practically.

Determination of correction and conversion factor of exposure rate generated Gamma spectrometer GR-320 to Victoreen data

International Nuclear Information System (INIS)

Supardjo-AS; Mappa, Djody-Rachim; Nasrun-Syamsul; Syamsul-Hadi

2000-01-01

Exposure rate data of Muria Peninsula were generated from Victoreen-491 measurement and calculation of radioelement content in soil which were measured by Exploranium GR-320, using IAEA formula. However those data are not be comparable so the exposure rate calculated from Gamma Spectrometer data necessarily to be corrected. The correction factor was determinate by measuring the exposure rate of at the NMDC's back yard selected location using Victoreen-491 and Gamma Spectrometer Exploranium GR-320 . Correction factor was created by comparing mean exposure rate data that calculated from 30 data measured by Gamma Spectrometer instrument and to those Victoreen's exposure rate. Conversion factor was gained from comparing of total count data of Gamma Spectrometer Exploranium GR-320 to Victoreen's exposure rate data. The correction factor of Exploranium GR-320's exposure rate is 0.34 μR/hours, and the conversion factor of total count is 0.0092 μR/hours per c/m. Deviation Victoreen 491 = 4.7 % and Gamma Spectrometer Exploranium GR-320 8.6 %

High intensity line source for x-ray spectrometer calibration

International Nuclear Information System (INIS)

Thoe, R.S.

1986-06-01

A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 μ x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10 4 ) time-resolved cyrstal spectrometer, will be discussed in detail

Processing of gamma-ray spectrometric logs

International Nuclear Information System (INIS)

Umiastowski, K.; Dumesnil, P.

1984-10-01

CEA (Commissariat a l'Energie Atomique) has developped a gamma-ray spectrometric tool, containing an analog-to-digital converter. This new tool permits to perform very precise uranium logs (natural gamma-ray spectrometry), neutron activation logs and litho-density logs (gamma-gamma spectrometric logs). Specific processing methods were developped to treate the particular problems of down-hole gamma-ray spectrometry. Extraction of the characteristic gamma-ray peak, even if they are superposed on the background radiation of very high intensity, is possible. This processing methode enables also to obtain geological informations contained in the continuous background of the spectrum. Computer programs are written in high level language for SIRIUS (VICTOR) and APOLLO computers. Exemples of uranium and neutron activation logs treatment are presented [fr

A link between prompt optical and prompt gamma-ray emission in gamma-ray bursts.

Science.gov (United States)

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

2005-05-12

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

The Study of Radiation of Gamma-Ray Background at Sedimentology Laboratorium, P3TIR, BATAN, Using Gamma Spectrometry

International Nuclear Information System (INIS)

Lubis, Ali Arman; Aliyanta, Barokah; Darman

2002-01-01

The measurement of background radiation of gamma-ray has been done at Sedimentology Laboratory, SDAL building, P3TIR, BATAN using gamma spectrometer. The measurement was done without shielding with the range of energy between 50 keV and 1500 keV. The identified radiations are coming from environmental radionuclide and man-made radionuclide as well with 32 energy peaks. The environmental radionuclides are from Uranium series, Thorium series, and 4 0 K having dose rate of 12.510 ± O.980, 36.408 ± 3.243, 9.455 ±O.016 n Sv/day, respectively, whilst man-made radionuclide is 6 O C o having dose rate of O.136 ±O.078 n Sv/day

Stellar Sources of Gamma-ray Bursts

OpenAIRE

Luchkov, B. I.

2011-01-01

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

The full automation of a Philips 1220 x-ray spectrometer

International Nuclear Information System (INIS)

Austen, C.E.

1976-01-01

A Philips 1220 X-ray spectrometer (semi-automatic) was fully automated by the addition of a custom-built automatic sample-loader constructed at the National Institute for Metallurgy and a Texas 980 A mini-computer. The mini-computer was interfaced to the existing control circuits of the X-ray spectrometer through a custom-built logic-circuit unit that controls the automatic sample-loader and X-ray spectrometer on instructions received from the mini-computer. The controlling software is written in BASIC

SMM observation of a cosmic gamma-ray burst from 20 keV to 100 MeV

Science.gov (United States)

Share, G. H.; Matz, S. M.; Messina, D. C.; Nolan, P. L.; Chupp, E. L.

1986-01-01

The Solar Maximum Mission gamma-ray spectrometer has detected an intense gamma-ray burst that occurred on August 5, 1984. The burst originated from a source in the constellation Hydra and lasted about 45 s. Its integral fluence at 20 keV was 0.003 erg/sq cm. Spectral evolution similar to other bursts detected by SMM was observed. The overall shape of the spectrum from 20 keV to 100 MeV, on timescales as short as 2 s, is relatively constant. This shape can be fitted by the sum of an exponential-type function and a power law. There is no evidence for narrow or broadened emission lines.

Physical constraints on models of gamma-ray bursters

International Nuclear Information System (INIS)

Epstein, R.I.

1985-01-01

This report deals with the constraints that can be placed on models of gamma-ray burst sources based on only the well-established observational facts and physical principles. The premise is developed that the very hard x-ray and gamma-ray continua spectra are well-established aspects of gamma-ray bursts. Recent theoretical work on gamma-ray bursts are summarized with emphasis on the geometrical properties of the models. Constraints on the source models which are implied by the x-ray and gamma-ray spectra are described. The allowed ranges for the luminosity and characteristic dimension for gamma-ray burst sources are shown. Some of the deductions and inferences about the nature of the gamma-ray burst sources are summarized. 67 refs., 3 figs

Microwave-gamma ray water in crude monitor

International Nuclear Information System (INIS)

Paap, H.J.

1984-01-01

A microwave-gamma ray water-in-crude monitoring system measures the percent quantity of fresh water or salt water in crude oil flowing in a pipe line. The system includes a measuring cell arranged with the pipe line so that the crude oil flows through the measuring cell. A microwave transmitter subsystem and a gamma ray source are arranged with the measuring cell so that microwave energy and gamma rays are transmitted through the measuring cell. A microwave receiving subsystem and a gamma ray detector provide signals corresponding to received microwave energy and to the received gamma rays, respectively. Apparatus connected to the microwave receiver and to the gamma ray detector provides an indication of the percentage of water in the crude oil

Multilayer x-ray mirrors for the objective crystal spectrometer on the Spectrum Roentgen Gamma satellite

DEFF Research Database (Denmark)

Louis, E.; Spiller, E.; Abdali, S.

1995-01-01

with Kr+- and Ar+- ions of 300, 500, and 1000 eV. We examined the effect of different polishing parameters on the smoothening of the Co- and Ni-layers. The in-situ reflectivity of lambda equals 3.16 nm during deposition and the ex-situ grazing incidence reflectivity of Cu-K(alpha ) radiation (lambda...... multiplied by 6 cm2 Si (111) crystals for the Objective Crystal Spectrometer on the Russian Spectrum Rontgen Gamma satellite. The coatings on the flight crystals have a period Lambda of 3.95 plus or minus 0.02 nm and a reflectivity of more than 8% averaged over s- and p-polarization over the entire...

Educational Testing of an Auditory Display of Mars Gamma Ray Spectrometer Data

Science.gov (United States)

Keller, J. M.; Pompea, S. M.; Prather, E. E.; Slater, T. F.; Boynton, W. V.; Enos, H. L.; Quinn, M.

2003-12-01

A unique, alternative educational and public outreach product was created to investigate the use and effectiveness of auditory displays in science education. The product, which allows students to both visualize and hear seasonal variations in data detected by the Gamma Ray Spectrometer (GRS) aboard the Mars Odyssey spacecraft, consists of an animation of false-color maps of hydrogen concentrations on Mars along with a musical presentation, or sonification, of the same data. Learners can access this data using the visual false-color animation, the auditory false-pitch sonification, or both. Central to the development of this product is the question of its educational effectiveness and implementation. During the spring 2003 semester, three sections of an introductory astronomy course, each with ˜100 non-science undergraduates, were presented with one of three different exposures to GRS hydrogen data: one auditory, one visual, and one both auditory and visual. Student achievement data was collected through use of multiple-choice and open-ended surveys administered before, immediately following, and three and six weeks following the experiment. It was found that the three student groups performed equally well in their ability to perceive and interpret the data presented. Additionally, student groups exposed to the auditory display reported a higher interest and engagement level than the student group exposed to the visual data alone. Based upon this preliminary testing,we have made improvements to both the educational product and our evaluation protocol. This fall, we will conduct further testing with ˜100 additional students, half receiving auditory data and half receiving visual data, and we will conduct interviews with individual students as they interface with the auditory display. Through this process, we hope to further assess both learning and engagement gains associated with alternative and multi-modal representations of scientific data that extend beyond

A new approach for the high-precision determination of the elemental uranium concentration in uranium ore by gamma-ray spectrometry

International Nuclear Information System (INIS)

Nagel, W.; Quik, F.

1993-01-01

A new approach for the determination of elemental uranium in uranium bearing ore, using high resolution gamma-ray spectrometry, was applied. Using a variant of the enrichment meter technique an agreement of better than 1% has been obtained between gamma-ray measurement results and the certified value obtained by other analytical methods. For the calibration of the gamma-ray spectrometer uranium reference samples have been used which are made available jointly in Europe and the USA as Certified Reference Materials for Gamma-ray Spectrometry (EC NRM 171 and NBS SRM 969, respectively). The measured ore has been put in a special designed container which ensured in all directions seen from the radiation window a uniform degree of infinite thickness of about 95%. The measurement results can be taken as an example for the applicability of gamma-ray spectrometry when high accuracy is required and under conditions where homogeneous distributed elemental uranium is embedded in a larger amount of matrix material. (author). 8 refs., 10 figs., 2 tabs., 2 appendices

Development of a gamma ray spectroscopy capability at LANSCE

International Nuclear Information System (INIS)

Nelson, R.O.; Strottman, D.D.; Sterbenz, S.M.

1998-01-01

This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project was to explore an upgrade to the GEANIE high-resolution gamma-ray spectrometer at the Los Alamos Neutron Science Center (LANSCE) to help build additional experimental capabilities. The improvements identified have significantly added to the capabilities of GEANIE and made the facility more attractive for studies supporting the core national security mission as well as for use by outside collaborators. These benefits apply to both basic and applied studies

Multifrequency Observations of Gamma-Ray Burst

OpenAIRE

Greiner, J.

1995-01-01

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

Gamma-rays from deep inelastic collisions

International Nuclear Information System (INIS)

Stephens, F.S.

1981-01-01

My objective in this talk is to consider the question: 'What can be learned about deep inelastic collisions (DIC) from studying the associated gamma-rays'. First, I discuss the origin and nature of the gamma-rays from DIC, then the kinds of information gamma-ray spectra contain, and finally come to the combination of these two subjects. (orig./HSI)

Soft x-ray emission from gamma-ray bursts observed with ginga

International Nuclear Information System (INIS)

Yoshida, Atsumasa; Murakami, Toshio; Itoh, Masayuki

1989-01-01

The soft X-ray emission of gamma-ray bursts below 10 keV provides information about size, location, and emission mechanism. The Gamma-ray Burst Detector (GBD) on board Ginga, which consists of a proportional counter and a scintillation detector, covers an energy range down to 1.5 keV with 63 cm 2 effective area. In several of the observed gamma-ray bursts, the intensity of the soft X-ray emission showed a longer decay time of 50 to 100s after the higher energy gamma-ray emission had ended. Although we cannot rule out other models, such as bremsstrahlung and thermal cyclotron types, due to poor statistics, the soft X-ray spectra are consistent with a blackbody of 1 to 2 keV in the late phase of the gamma-ray bursts. This enables us to estimate the size of the blackbody responsible for the X-ray emission. (author)

The high intensity {gamma}-ray source (HI{gamma}S) and recent results

Energy Technology Data Exchange (ETDEWEB)

Tonchev, A.P. [Duke University and TUNL, Triangle University Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 0308 (United States)]. E-mail: tonchev@tunl.duke.edu; Boswell, M. [University of North Carolina at Chapel Hill and TUNL, Chapel Hill, NC 27599 (United States); Howell, C.R. [Duke University and TUNL, Triangle University Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 0308 (United States); Karwowski, H.J. [University of North Carolina at Chapel Hill and TUNL, Chapel Hill, NC 27599 (United States); Kelley, J.H. [North Carolina State University and TUNL, Raleigh, NC 27695 (United States); Tornow, W. [Duke University and TUNL, Triangle University Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 0308 (United States); Wu, Y.K. [Duke University and Duke Free Electron Laser Laboratory, Durham, NC 27708-0319 (United States)

2005-12-15

The high intensity {gamma}-ray source (HI{gamma}S) utilizes intra-cavity backscattering of free electron laser photons from the Duke electron storage ring to produce a unique monoenergetic beam of high-flux {gamma}-rays with high polarization and selectable energy resolution. At present, {gamma}-ray beams with energies from 2 to 58 MeV are available with intensities as high as 10{sup 5}-5 x 10{sup 6} {gamma}/s, energy spreads of 3% or better, and nearly 100% linear polarization. The quality and intensity of the {gamma}-ray beams at HI{gamma}S are responsible for the unprecedented performance of this facility in a broad range of research programs in nuclear structure, nuclear astrophysics and nuclear applications. Recent results from excitation of isomeric states in ({gamma}, n) reactions and parity assignments of dipole states determined via the ({gamma}, {gamma}') reaction are presented.

Gamma-ray spectroscopy applications in radiation control and environmental monitoring

Energy Technology Data Exchange (ETDEWEB)

Manushev, B [Sofia Univ. (Bulgaria). Fizicheski Fakultet; Koleva, K [National Metrology Centre, Sofia (Bulgaria)

1996-12-31

A method for stabilization of gamma-ray spectrometers energy calibration is proposed. It is based on recalibration of the spectrum by numerical filtration. The possibility of efficiency auto-calibration is considered in the case when a reference source with appropriate shape is unavailable. The method is tested by estimation of the effective thickness of a lead plate (self-absorption). Potential applications include the evaluation of surface pollution infiltration depth as well as the development of pure beta sources (e.g. Sr-90) using the registration of their Bremsstrahlung. 6 refs.

Gamma-ray Output Spectra from 239 Pu Fission

International Nuclear Information System (INIS)

Ullmann, John

2015-01-01

Gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239 Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. A dependence of the gamma-ray spectrum on the gamma-ray multplicity was also observed. Global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution

Hyper-filter-fluorescer spectrometer for fusion x-ray diagnostics

International Nuclear Information System (INIS)

Wang, C.L.

1981-01-01

The filter-fluorescer spectrometer (FFS) is a powerful tool for measuring x-ray spectrum from high fluence x-ray sources. However, this technique is limited to energies less than 120 keV, because there are no practical absorption edges available above this energy. In this paper, we present a new method of utilizing the filter-fluorescer system for x-ray spectral measurement above 120 keV. The new apparatus is called hyper-filter-fluorescer spectrometer

Discuss the technology for decrease the detection limit of NaI(Tl) gamma spectrometer

International Nuclear Information System (INIS)

Guo Xiaobin; Qu Guopu; Liu Zhiying; Wang Hongyan; Wang Lieming

2011-01-01

The radioelement species is complex and quantity is few after nuclear explosion, thus it is hard to tell the difference when using the Nal (TI) Gamma spectrometer detection due to several kinds of the peak of nuclide overlapped in the scattering region. So there is a high demand for spectrometer stability, energy resolution, solution spectrum and minimum detective activity. The paper analysed the influenced factors to Nal (TI) Gamma spectrometer and the measures of detection limit decrease by experiments and MCNP simulation, which proposed the methods to reduce background through shielding in order to improve minimum detective activity. The experiment shows that choosing reasonable shielding can reduce the background effectively and improve the spectrometer low level radioactive detect ability. (authors)

X-ray and. gamma. -ray sources: a comparison of their characteristics

Energy Technology Data Exchange (ETDEWEB)

Freund, A K [Institut Max von Laue - Paul Langevin, 38 - Grenoble (France)

1979-11-01

A comparison of the various source characteristics, in particular the available fluxes of radiation in the X-ray/..gamma..-ray region from (1) high power rotary anode X-ray generators, (2) radioactive ..gamma..-ray sources and (3) high energy electron storage rings is presented. Some of the specific characteristics and possible applications of synchrotron radiation as a source are discussed in detail, together with problems associated with the monochromatization of the continuous radiation in the X-ray/..gamma..-ray region. The new high energy machines PEP at Stanford, the 8 GeV storage ring CESR at Cornell and the PETRA storage ring in Hamburg, which will soon come into operation provide a spectrum of high intensity radiation reaching well above h..gamma..sub(photon)=100 keV. The possibilities of using ondulators (wigglers), and laser-electron scattering for constructing high repetition rate tunable ..gamma..-ray sources are also discussed. Finally the potentials of using the powerful spontaneous emission of ..gamma..-quanta by relativistic channeled particles are mentioned.

Gamma-Ray Bursts

Science.gov (United States)

Pellizza, L. J.

Gamma-ray bursts are the brightest transient sources in the gamma-ray sky. Since their discovery in the late 1960s, the investigation of the astrophysical sys- tems in which these phenomena take place, and the physical mechanisms that drive them, has become a vast and prolific area of modern astrophysics. In this work I will briefly describe the most relevant observations of these sources, and the models that describe their nature, emphasizing on the in- vestigations about the progenitor astrophysical systems. FULL TEXT IN SPANISH

Design and Performance of the GAMMA-400 Gamma-Ray Telescope for Dark Matter Searches

Science.gov (United States)

Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu V.;

Integration and evaluation of a position sensor with continuous read-out for use with the Environmental Measurement-While-Drilling Gamma Ray Spectrometer system

International Nuclear Information System (INIS)

Normann, R.A.; Lockwood, G.J.; Williams, C.V.; Selph, M.M.

1998-02-01

The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides real-time environmental and drill bit data during drilling operations. The EMWD-GRS technology was demonstrated at Savannah River Site (SRS) F-Area Retention Basin. The EMWD-GRS technology demonstration consisted of continuously monitoring for gamma-radiation-producing contamination while drilling two horizontal boreholes below the backfilled waste retention basin. These boreholes passed near previously sampled locations where concentrations of contaminant levels of cesium had been measured. Contaminant levels continuously recorded by the EMWD-GRS system during drilling were compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples. The results show general agreement between the soil sampling and EMWD-GRS techniques for Cs-137. The EMWD-GRS system has been improved by the integration of an orientation sensor package for position sensing (PS) (EMWD-GRS/PS). This added feature gives the capability of calculating position, which is tied directly to EMWD-GRS sensor data obtained while drilling. The EMWD-GRS/PS system is described and the results of the field tests are presented

Thermal neutron capture gamma-rays

International Nuclear Information System (INIS)

Tuli, J.K.

1983-01-01

The energy and intensity of gamma rays as seen in thermal neutron capture are presented. Only those (n,α), E = thermal, reactions for which the residual nucleus mass number is greater than or equal to 45 are included. These correspond to evaluations published in Nuclear Data Sheets. The publication source data are contained in the Evaluated Nuclear Structure Data File (ENSDF). The data presented here do not involve any additional evaluation. Appendix I lists all the residual nuclides for which the data are included here. Appendix II gives a cumulated index to A-chain evaluations including the year of publication. The capture gamma ray data are given in two tables - the Table 1 is the list of all gamma rays seen in (n,#betta#) reaction given in the order of increasing energy; the Table II lists the gamma rays according to the nuclide

Material inhomogeneities in Cd1-xZnxTe and their effects on large volume gamma-ray detectors

International Nuclear Information System (INIS)

Scyoc, J.M. Van; Lund, J.C.; Morse, D.H.

1997-01-01

Cadmium zinc telluride (Cd 1-x Zn x Te or CZT) has shown great promise as a material for room-temperature x-ray and gamma-ray detectors. In particular, polycrystalline material grown by the High Pressure Bridgman method with nominal Zn fraction (x) from 0.1 to 0.2 has been used to fabricate high resolution gamma-ray spectrometers with resolution approaching that of cooled high-purity Ge. For increased sensitivity, large areas (> 1 cm 2 ) are required, and for good sensitivity to high energy gamma photons, thick detectors (on the order of 1 cm) are required. Thus there has been a push for the development of CZT detectors with a volume greater than 1 cm 3 . However, nonuniformities in the material over this scale degrade the performance of the detectors. Variations in the zinc fraction, and thus the bandgap, and changes in the impurity distributions, both of which arise from the selective segregation of elements during crystal growth, result in spectral distortions. In this work several materials characterization techniques were combined with detector evaluations to determine the materials properties limiting detector performance. Materials measurements were performed on detectors found to have differing performance. Measurements conducted include infrared transmission (IR), particle induced x-ray emission (PIXE), photoluminescence (PL), and triaxial x-ray diffraction (TAXRD). To varying degrees, these measurements reveal that poor-performance detectors exhibit higher nonuniformities than spectrometer-grade detectors. This is reasonable, as regions of CZT material with different properties will give different localized spectral responses, which combine to result in a degraded spectrum for the total device