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用薄CaF_2(Eu)闪烁体与厚NaI(T1)辅助闪烁体(起保护作用)相组合,便可构成用于低本底β射线计数的层状探测器。在反符合计数线路中,采用CaF_2(Eu)与NaI(T1)结合的探测器能减少本底大约2倍。这是因为可以抑制康普顿散射,并且NaI(T1)晶体是一个有效的屏蔽层。如果探测器结构本身的放射性很低,采用薄CaF_2(Eu)则可减少本底,其降低值与探测器厚度成正比。概述如果两个闪烁体的闪烁衰减时间有明显差别,那么将两个层状闪烁体光学地耦合在一起,就可以分辨出不同闪烁体中产生的辐射事件。为此,采用一个普通的光电倍增管与这种层状复合闪烁体相组合,便可根据脉冲形状区
Combining a thin CaF 2 (Eu) scintillator with a thick NaI (T 1) auxiliary scintillator (protective) can form a layered detector for low background β-ray counting. In the anti-coincidence counting circuit, the detector using CaF 2 (Eu) combined with NaI (T1) can reduce the background by about 2 times. This is because Compton scattering can be suppressed and the NaI (T1) crystal is an effective shield. If the structure of the detector itself is very low, the background can be reduced with thin CaF 2 (Eu), with a decrease proportional to the thickness of the detector. Overview If the two scintillators have significantly different flicker decay times, then by optically coupling the two layered scintillators together, the radiation events generated in the different scintillators can be discerned. To this end, the use of a common photomultiplier tube in combination with such a layered composite scintillator, according to the pulse shape zone