Large area triple GEM chambers will be employed in the first two stations of the MuCh system of the CBM experiment at the upcoming Facility for Antiproton and Ion Research FAIR in Darmstadt/Germany. The GEM detectors have been designed to take data at an unprecedented interaction rate (up to 10 MHz) in nucleus-nucleus collisions in CBM at FAIR. Real-size trapezoidal modules have been installed in the mCBM experiment and tested in nucleus-nucleus collisions at the SIS18 beamline of GSI as a part of the FAIR Phase-0 program. In this report, we discuss the design, installation, commissioning, and response of these GEM modules in detail. The response has been studied using the self-triggered readout electronics. In free-streaming data, the first attempt on an event building based on the timestamps of hits has been carried out, resulting in the observation of clear spatial correlations between the GEM modules in the mCBM setup for the first time. Accordingly, a time resolution of ∼15 ns have been obtained for the GEM detectors. Gain uniformity & cluster characteristics have also been studied.

大面积三重 GEM 室将用于即将在德国达姆施塔特举行的反质子和离子研究 FAIR 设施的 CBM 实验的 MuCh 系统的前两个站。GEM 探测器的设计目的是在 FAIR 的 CBM 核-核碰撞中以前所未有的交互速率（高达 10 MHz）获取数据。作为 FAIR Phase-0 计划的一部分，实际尺寸的梯形模块已安装在 mCBM 实验中，并在 GSI SIS18 光束线的核-核碰撞中进行了测试。在本报告中，我们详细讨论了这些 GEM 模块的设计、安装、调试和响应。已经使用自触发读出电子设备研究了响应。在免费流数据中，已经进行了基于点击时间戳的事件构建的第一次尝试，导致首次观察到 mCBM 设置中 GEM 模块之间的明显空间相关性。因此，GEM 探测器的时间分辨率约为 15 ns。还研究了增益均匀性和集群特性。