【摘要】 液闪三双符合比(TDCR)方法采用3个光电倍增管对称放置的液闪计数器,利用三管符合和三对两管符合的计数计算液闪探测效率,从而得到放射性活度,不需要使用标准源对仪器进行效率刻度,是一种放射性活度绝对测量方法。由于具有无自吸收、制源简单、操作简便、一致性好等优点,已广泛应用于纯β衰变核素放射性活度的测量。介绍了液闪TDCR方法的基本原理和液闪TDCR活度测量装置,并绝对测量了纯β衰变核素99Tc放射性活度,测量不确定度小于0.3%。更多还原

【Abstract】 The triple- to- double coincidence ratio( TDCR) method is a kind of primary measurement method of radioactivity,requiring the use of a liquid scintillation counter equipped with of 3 photomultiplier tubes. The counting efficiency calculated through the triple coincidence count and 3 double coincidence counts. Due to its advantages in simple sample preparation,no self- absorption and good consistency,the TDCR method is a popular technique for the standardization of pure beta radionuclides. The principle of TDCR method is described in this paper. And a sample of99 Tc is calibrated in term of specify activity on the newly established TDCR system with uncertainty within 0. 3%.更多还原