Fabrication and testing of the upgraded GEM module for the station-1 of MuCh system of CBM experiment at FAIR, Germany

The CBM experiment is designed to investigate the properties of dense nuclear matter in nucleus-nucleus collision at an unprecedented interaction rate up to 10 MHz. CBM will consist of 4 stations of Muon- Chambers (MuCh) sandwiched between absorber layers and each station will consist of 3 layers of gaseous detectors. The two modules have been participating in the data taking since last 4 years and have undergone some hardware modifications as we approach towards the final version. In the earlier version of the drift PCB, some surface discharges were observed in the HV layout section, which resulted into link instability of the MuCh-XYTER readout electronics. In this report, we present the design modification of the drift PCB, fabrication of the detector and lab test results of the same. We prepared a cosmic muon coincidence setup and measured the efficiency of 96% corresponding to summed voltage of 1125 Volts. After a satisfactory lab test this module was installed in the mCBM cave