Design and development of large size 8-layered sector shaped readout PCB for the GEM detector of CBM experiment

A GEM based detector system is being developed at VECC, Kolkata for use as muon tracker [1] in the Compressed Baryonic Matter (CBM) experiment. Due to high rate in the inner region near the beam pipe and relatively lower rate radially outwards, progressive pad geometry was chosen to optimize the rate versus number of channels per chamber, for the first two stations. Due to progressive pad geometry, there is relatively high density of pads in the inner ring and hence the design required an 8-layered PCB.