Precise measurement of gamma ray emission probability by using a live-timed bi-dimensional data acquisition system

利用实时二维数据采集系统精确测量伽马射线发射概率

• 批准号: 63580174
• 负责人: MIYAHARA Hiroshi
• 金额: $ 0.96万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63580174/
• 关键词: 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 Emi

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 … More 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

1．采用高纯锗探测器和4pibeta加压正比计数器，采用实时二维数据采集系统，测量伽玛射线发射概率。2．当通过该系统测量通过β-粒子发射衰变的^ 60 Co和^ 134 Cs的分解速率时，结果与通过常规方法测量的结果一致。应用二维效率外推法可以很容易地测量通过电子俘获衰变的^ 57 Co的衰变速率。 3．进行 152 Eu 崩解速率的测量以确定伽马射线检测效率。 ^<152>Eu通过β-粒子发射和电子俘获而衰变，并伴随着相当一部分转换电子，这使标准化变得复杂，但可以通过二维效率外推法确定准确的衰变速率。4． ^<133>Ba 的崩解率稍微依赖于使用 NaI(T1) 闪烁体在 47pibeta-gamma 符合计数中设置的门。原因可能是大量的内部转换电子而不是 53 keV 伽马射线；因此，采用二维效率外推法。五种伽马射线组合均取得了良好的效果。5． ^ 42 K的1.52MeV伽马射线的发射概率被确定为0.1808±0.0009。当前结果的不确定性比过去的结果小两倍，并且该不确定性小到足以考虑可以从^<42>Ar.6“榨取”的^<42>K的应用。 ^ 86 Rb以大约0.9的概率直接跃迁到^ 86 Sr的地能级，并且在发射β射线之后以大约0.1的发射概率从激发能级发射1077keV伽马射线。为了确定伽马射线的发射概率，需要测量β分支比或衰变率和伽马射线强度。目前的工作显示出1077 keV伽马射线的发射概率为O.0888±O.0003.7的良好结果。 ^<103>Ru的大量跃迁经过40keV亚稳态能级，半衰期为56分钟，并且跃迁具有大的内转换系数。存在与 40 keV 能级或地能级的 β 跃迁有关的问题。目前的 497 keV 伽马射线发射概率结果表明，到地能级的 β 跃迁为 0.0072±0.0062，而到 40 keV 能级的 β 跃迁则为零。较少的

项目成果

宮原洋: "4πβ-γスペクトロスコピ-同時計数法による^<152>Euの絶対測定に対する二次元デ-タ集積システムの応用" Radioisotopes. 38. 252-254 (1989)

Hiroshi Miyahara：“应用二维数据采集系统通过 4πβ-γ 光谱-符合计数法绝对测量 ^<152>Eu”放射性同位素 38. 252-254 (1989)。

Hiroshi Miyahara: "Precision Measurement of the Emission Probability for the 1.52 MeV Gamma Ray of ^<42>K" Nuclear Instruments and Methods in Physics Research. A286. 519-522 (1990)

Hiroshi Miyahara：“^<42>K 1.52 MeV 伽马射线发射概率的精确测量”核仪器和物理研究方法。

H. Miyahara: "Precision Measurement of the Emission Probability for the 1.52 MeV Gamma Ray of ^<42>K" Nucl. Instr. and Meth., A286 (1990) 519-522.

H. Miyahara：“^ 42 K 1.52 MeV 伽马射线发射概率的精确测量”。

Hiroshi Miyahara: "Standardisation of ^<152>Eu by Two-Dimensional Extrapolation" Nuclear Instruments and Methods in Physics Research. A286. 497-501 (1990)

Hiroshi Miyahara：“通过二维外推法对 ^<152>Eu 进行标准化”物理研究中的核仪器和方法。

H. Miyahara: "A 4pibeta(ppc)-gamma(HPGe) Coincidence Apparatus Using A Live-timed Bi-dimensional Data Acquisition System and Its Application to Measurement of Gamma Ray Emission Probability" Appl. Radiat. Isotopes, 40 (1989) 343-345.

H. Miyahara：“使用实时二维数据采集系统的 4pibeta(ppc)-gamma(HPGe) 符合装置及其在伽马射线发射概率测量中的应用”