γ辐射核素放射性活度测量标准装置

STANDARD APPARATUS FOR MEASURING ACTIVITY OF THEγ-RAY RADIONUCLIDES

该装置仅适用于γ射线发射体的活度检测，采用的是一种放射性活度相对测量方法。它由充以２．０ＭＰａ氩气的４πγ高气压电离室、小电流测量系统和镭参考源组成。电离室置于１０ｃｍ厚的全封闭屏蔽铅室中的典型本底电流为０．０６６±０．００３ｐＡ。用１７种放射性标准溶液刻度该装置，给出在此参考标准装置上，参考源对于每一种标准源的当量活度，可用于日后检测同种核素样品的活度。对电离室饱和损失、几何效率响应和能响特性予以讨论并给出刻度的总不确定度。

The apparatus applies only to activity testing of the γ-ray emitter.Arelative measurementmethod of radioactivity is adopted. The apparatus consists of a 4πγ high pressure chamber,whichis filled with argon of 2.0 MPa,small current measurement system,and a set of radium referencesources. When the chamber is placed in a house with a lead wall of 10 cm,the typical backgroundcurrent is 0.066±0.003pA. The apparatus is calibrated with 17 types of radioactive standardsolution,giving the equivalent activity of refer...