液氩探测器的低温PMT性能测试

Low temperature PMT performance test for liquid argon detector

摘要:

中国暗物质实验(China dark matter experiment, CDEX)拟使用液氩探测器作为高纯锗探测器的反符合探测器, 其使用的光电倍增管（photomultiplier tube, PMT）需能长期稳定地工作在液氩温度（87.3 K）下. PMT在使用前, 须掌握其在低温下的性能情况. 文章中分别在室温和低温环境中测试了ETL 9357FLA型光电倍增管, 获得了单光电子响应、暗计数率以及低温环境中运行的稳定性等重要实验结果. 通过详细地对比和分析室温和低温环境中PMT的性能表现, 确认该型PMT能在低温环境中正常运行.

Abstract:

China dark matter experiment (CDEX) intends to use liquid argon detector as an anti-coincidence detector for high-purity germanium detectors. The photomultiplier tube used in the liquid argon detector needs to be able to work stably for a long time under the liquid argon temperature (87.3 K). Before using the PMT, we need to know its performance under low temperature. In this paper, the ETL 9357FLA photomultiplier tube was tested at room temperature and low temperature respectively, and important experimental results of single photoelectron response, dark count rate and stability in low temperature environment were obtained. According to the detailed comparison and analysis of PMT performance in the room temperature and low temperature environment, we confirmed that this type of PMT can work in low temperature environment.