标题： 光子探测系统在LHCb RICH升级中的高速测试 显示英文标题

标题： High rate tests of the photon detection system for the LHCb RICH Upgrade

摘要： LHCb RICH升级的光子探测系统由一组多阳极光电倍增管（MaPMTs）组成，通过定制的模块化电子设备进行读出。 在整个链路的行为在CERN使用脉冲激光进行了研究。 为了研究高事件率和不同光子强度下的MaPMT脉冲高度谱，进行了阈值扫描。 结果表明，当事件率从100 kHz增加到20 MHz时，在900 V偏置电压下光子探测效率有所降低，单光子峰高度减少了20%。 在1000 V偏置电压下未观察到这种减少。 显示英文摘要

摘要： The photon detection system for the LHCb RICH Upgrade consists of an array of multianode photomultiplier tubes (MaPMTs) read out by custom-built modular electronics. The behaviour of the whole chain was studied at CERN using a pulsed laser. Threshold scans were performed in order to study the MaPMT pulse-height spectra at high event rates and different photon intensities. The results show a reduction in photon detection efficiency at 900 V bias voltage, marked by a 20 % decrease in the single-photon peak height, when increasing the event rate from 100 kHz to 20 MHz. This reduction was not observed at 1000 V bias voltage.