First prototype of MuCh second station GEM module: design, fabrication and testing for CBM experiment at GSI, Germany

Variable Energy Cyclotron Centre (VECC) is taking a leading role in the study of nuclear properties at high beam energies in Compressed Baryonic Matter (CBM) collaboration at GSI. CBM is a fixed target experiment which will explore the properties of nuclear matter under extreme density. This experiment will take place in the upcoming Facility for the Antiproton and Ion Research (FAIR) at Darmstadt, Germany. CBM will consist of four stations of Muon Chambers (MuCh) sandwiched between absorber layers and each station will consist of 3 layers of gaseous detectors. The first two stations of MuCh will consist of advanced gaseous detector made of Gas Electron Multiplying (GEM) technology capable of handling high event rates and the last two stations will be made of Resistive Plate Chamber (RPC) or any other suitable detectors. The first real size prototype of the second station GEM chamber has been designed and fabricated indigenously. The trapezoidal shaped readout PCB length is around 1 meter. Due to fabrication constraint of such large size multi layer single PCB by Indian industry, a PCB design involving a joint has been adopted. The detector was assembled at VECC clean room using three GEM foils, readout PCB, drift PCB and other necessary components. In this article the design, fabrication and testing of this module will be discussed in detail. The detector has been tested with cosmic muons and measured efficiency upto 98% with time resolution of 18 ns at VECC lab.