CSR外靶实验终端中CsI（Tl）晶体的测试

为测量重离子加速器冷却储存环（HIRFL-CSR）的外靶实验终端上不同能量的γ射线，一种用于探测γ射线的高能量分辨的探测装置正在中国科学院近代物理研究所建设，该探测器由中国科学院近代物理研究所自行生长的铊激活的碘化铯CsI（Tl）晶体组成。与日本Hamamatsu公司生产的S8664-1010型雪崩光二极管（APD）耦合，测试其光输出的非均匀性和能量分辨，从测试结果给出了所需CsI（Tl）晶体合格的标准。目前已完成该γ探测球计划的六分之一，所提供的晶体合格率达94%以上。

Test of CsI(Tl) Crystal at External Target Experimental Terminal of Cooling Storage Ring

In order to detect gamma rays with different energy at the external target experimental terminal of the Cooling Storage Ring (CSR) of Heavy Ion Research Facility of Lanzhou, a gamma ray detector with perfect energy resolution is being constructed at Institute of Modern Physics, Chinese Academy of Sciences. It is made of CsI(Tl) crystal grown at IMP. The light output of non-uniformity and energy resolution of CsI(Tl) crystal were tested after CsI(Tl) crystal coupled with the Hamamastu S8664-1010 avalanche photodiode (APD). From the result of test, standard of CsI(Tl) crystal qualified was obtained. At present, one-sixth of the detectors was finished. The test result indicates that 1 024 pieces are good enough, and the percent of pass is over 94%.