Precise measurement of gamma ray emission probability by using a live-timed bi-dimensional data acquisition system
Project/Area Number |
63580174
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
Nuclear engineering
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Research Institution | Nagoya University |
Principal Investigator |
MIYAHARA Hiroshi Nagoya University, Department of Engineering, Associate Professor, 工学部, 助教授 (90023184)
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Project Period (FY) |
1988 – 1989
|
Project Status |
Completed (Fiscal Year 1989)
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Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1989: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1988: ¥900,000 (Direct Cost: ¥900,000)
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Keywords | Bi-Dimensional Data Acquisition System / Coincidence Apparatus / High Purity Germanium Detector / 4pibeta Pressurized Proportional Counter / Measurement of Activity / Two-Dimensional Efficiency Extrapolation Method / gamma Ray Spectroscopy / gamma Ray Emission Probability / 2パラメータ・データ集積システム / 同時計数装置 / 高純度Ge検出器 / γ線スペクトロメトリ / γ線放出率の精密測定 |
Research Abstract |
1. A high purity germanium detector and a 4pibeta pressurized proportional counter using a live-timed bi-dimensional data acquisition system were used for measurement of gamma-ray emission probability. 2. When the disintegration rate of ^<60>Co and ^<134>Cs, which decay by beta^- particle emission, were measured by this system, the results agreed with those measured by conventional method. The disintegration rate of ^<57>Co which decays by electron capture can be easily measured by application of two-dimensional efficiency extrapolation method. 3. Measurement of disintegration rate for ^<152>Eu was carried out for determination of gamma-ray detection efficiency. ^<152>Eu decays via beta^- -particle emission and electron capture accompanied by a substantial fraction of conversion electrons, which complicate standardization, but accurate disintegration rate can be determined by two-dimensional efficiency extrapolation method. 4. Disintegration rate of ^<133>Ba depended slightly on the gate
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set in the 47pibeta-gamma coincidence counting using a NaI(T1) scintillator. The reason is probably large internal conversion electrons instead of the 53 keV gamma-rays; therefore, two-dimensional efficiency extrapolation method was applied. Five combinations of gamma-rays gave good results. 5. The emission probability for the 1.52 MeV gamma-ray of ^<42>K was determined to be 0.1808<plus-minus>0.0009. The present result has an uncertainty smaller than the past results by factor of two, and that is small enough to consider the application of ^<42>K which can be "milked" from ^<42>Ar. 6. ^<86>Rb transits directly to the ground level of ^<86>Sr with probability of about 0.9, and the 1077 keV gamma-ray from the excited level is emitted following emission of beta-ray with about 0.1 of emission probability. To determine the emission probability of the gamma-ray, it is required the measurement of beta branching ratio or of the disintegration rate and gamma-ray intensity. The present work showed the good result for the emission probability of the 1077 keV gamma-ray, O.0888<plus-minus>O.0003. 7. A large amount transition from ^<103>Ru go through the 40 keV metastable level that has half-life of 56 min and the transition has a large internal conversion coefficient. There is a problem concerning with existence of beta transition to the 40 keV level or ground level. The present result for emission probability for the 497 keV gamma-ray showed that the beta transition to the ground level is 0.0072<plus-minus>0.0062 and that the beta transition to the 40 keV level is nothing. Less
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Report
(3 results)
Research Products
(13 results)