排序方式: 共有35条查询结果,搜索用时 10 毫秒
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C. E. Aalseth F. T. Avignone III R. L. Brodzinski H. S. Miley J. H. Reeves 《Journal of Radioanalytical and Nuclear Chemistry》1998,233(1-2):119-125
A fast digital oscilloscope based pulse shape discrimination (PSD) system has been tested with intrinsic germanium detectors
large enough to allow ionizing events which generate localized electron-hole pairs at a single site to be segregated from
those depositing energy at several different sites in the crystal. Drift velocities of the electrons and holes result in pulses
several hundred nanoseconds long. Since the electric field varies by almost a factor of 10 between the outer and inner surfaces,
collection of electrons and holes can frequently be dinstinguished, and pulses due to multi-site events can be distinguished
from single site events. 相似文献
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R. L. Brodzinski 《Journal of Radioanalytical and Nuclear Chemistry》2005,264(1):139-143
Summary The Majorana project, a next-generation 76Ge neutrinoless double-beta decay experiment being undertaken by a large international collaboration, has the goal of measuring the neutrinoless double-beta decay rate by observing monochromatic events at 2039 keV in 500 kg of isotopically enriched 76Ge gamma-ray spectrometers. In order to achieve the desired sensitivity limit, the background in the 2037-2041 keV region must be reduced to <1 event per year in the entire germanium array. The effects of various background reduction techniques, and the combination thereof, to produce a huge 76Ge spectrometer array with virtually zero background are discussed. 相似文献
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E. A. Lepel W. K. Hensley R. L. Brodzinski J. E. Smart 《Journal of Radioanalytical and Nuclear Chemistry》2001,248(2):273-277
A pilot plant is being designed at the U. S. Department of Energy's Savannah River Site (SRS) to demonstrate the removal of 90Sr, 137Cs, and transuranics from a high-level liquid waste stream prior to encapsulation in a Saltstone Facility. In-line monitors are required to determine the concentration of all radionuclides on this processed waste stream. Calibration standards containing 60Co, 137Cs, and 90Sr were prepared and counted. Efficiency curves were generated. Strontium-90 is readily observable above the system background in the calibration standard count, and is observable at less than 3 nCi/ml in a mixed solution having the maximum allowable concentration of all other activities present in the proposed SRS effluent stream. 相似文献
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R. L. Brodzinski J. C. Langford M. T. Thomas O. K. Harling 《Journal of Radioanalytical and Nuclear Chemistry》1977,39(1-2):179-184
Interfering reactions in photon activation analysis are compiled and evaluated quantitatively; the results are based on experimentally
obtained data exclusively. All elements in the Periodic Table with few exceptions have been irradiated several times with
30 MeV bremsstrahlung produced by a linear electron accelerator. The element samples were measured many times to detect all
expected radionuclides and hence all possible interfering reactions. These reactions are listed and presented in Table 1. 相似文献
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H. S. Miley R. L. Brodzinski W. K. Hensley J. H. Reeves 《Journal of Radioanalytical and Nuclear Chemistry》1995,193(2):247-252
An implementation of the Electron Gamma Shower 4 code (EGS4) has been developed to allow convenient simulation of typical gamma ray measurement systems. Coincidence gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra for the purpose of extremely low-level assay. Monte Carlo calculations of this sort can be extremely successful since low background detectors are usually free of significant contributions from poorly localized radiation sources, such as cosmic muons, secondary cosmic neutrons, and radioactive construction or shielding materials. Previously, validation of this code has been obtained from a series of comparisons between measurements and blind calculations. An example of the application of this code to an exceedingly low background spectrum stripping will be presented.Pacific Northwest Laboratory is operated by Battelle Memorial Institute for the US Department of Energy under Contract DE-AC06-76RLO 1830. 相似文献
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A. O. Gattone D. Abriola F. T. Avignone R. L. Brodzinski J. I. Collar R. J. Creswick D. E. Di Gregorio H. A. Farach C. K. Gurard F. Hasenbalg H. Huck H. S. Miley A. Morales J. Morales S. Nussinov A. Ortiz de Solrzano J. H. Reeves J. A. Villar K. Zioutas The SOLAX Collaboration 《Nuclear Physics B - Proceedings Supplements》1999,70(1-3)
A new technique has been used to search for solar axions using a single crystal germanium detector. It exploits the coherent conversion of axions into photons when their angle of incidence satisfies a Bragg condition with a crystalline plane. The analysis of approximately 1.94 kg.yr of data from the 1 kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on axion-photon coupling of gαγγ < 2.7 × 10−9GeV−1, independent of axion mass up to 1 keV. 相似文献
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