强度平衡法测定^(138)Csγ射线发射概率

γ-ray emission probabilities measurement of ^(138)Cs using scheme balance method

短寿命裂变产物138Cs是测量裂变燃耗的重要核素,其半衰期为33.41min,经β-衰变到138Ba,共发射88条γ射线。根据母核衰变到子核基态上各种射线强度之和等于母核衰变活度的强度平衡法原理,用已标定好的峰效率曲线的HPGeγ谱仪准确测定了138Cs的γ射线发射概率,Pγ(1435.86keV)的测定结果为0.7599±0.0032。

The short-lived fission product ()^(138)Cs is one of the key nuclides in diagnosing fission burn-up, whose half life is 33.41 minutes and which trasits to ()^(139)Ba by β^- decay and emits about 88 γ-rays. This paper described scheme balance method and determined the main γ -ray emission probabilities of ()^(138)Cs using the calibrated efficiency curve. The result of 1435keV is 0.7599±0.0032.