Investigations on ASIC for Triple-GEM Detectors

Abstract: The main purpose of this work is to study the performance of the APV25 and VMM3a readout chips with regards to using them in the front-end readout system of a Triple-GEM detector. For the APV25, the Signal-to-Noise Ratio (SNR) was estimated with a cosmics measurement around 84.29 +/- 0.12. For the VMM3a, the noise of the chip was characterised in terms of the Equivalent Noise Charge (ENC) in the full parameter space and with increasing input capacitance. For the highest VMM gain and peaktime settings, the calculated ENC was about 300 electrons + 8 electrons/pF. Finally, a comparison was made between the two chips, based on their noise, while also the setup for future cosmics measurements with a VMM readout was prepared in order to also derive the VMM SNR ratio.