^(182)Taγ射线发射概率的测定

Measurement of the Gamma-ray Emission Probabilities of ^(182)Ta

^(182)Ta发射低能和高能两组γ射线,半衰期适中,是HPGe探测器效率刻度的合适标准源之一。本工作通过反应堆活化得到了^(182)Ta放射源,制备了VYNS薄膜源。活度由4πβ+4πγ计数相加装置绝对测量,γ射线的发射率由已刻度效率曲线的HPGe探测器测量,从而得到了γ射线绝对发射概率,不确定度为0.6～1.5%。

^182Ta emits two groups Gamma-rays in the low and high energy range. And it has a moderate Long half-llfe, so that it is one of the suitable standard sources to calibrate the efficiency curve of HPGe detectors. ^182Ta is produced by thermal neutron in the reactor. In order to determine the Gamma-ray emission probabilities,the activities of 182Ta VYNS sources are measured using the 4πβ＋4πγ counting instrument, and the emission rates are determined by a calibrated HPGe detector in the meantime. The uneertalnties of the results vary from 0.6 % to 1.5 %.