Characteristic study of a quadruple GEM detector and its comparison with a triple GEM detector

A quadruple GEM detector has been assembled in a standalone configuration and operated using Ar and CO2 gas mixtures in proportions of 70:30 and 90:10. Detailed performance study of the detector has been made by using  106Ru-Rh β-source and X-ray spectrum of  55Fe source. Results of these measurements are presented in terms of gain, efficiency, energy and time resolutions and also compared with our earlier triple GEM results. The energy resolution has been found to be somewhat worse compared with that of the triple-GEM detector. Effect of drift field on electron transparency and time resolution has been studied in detail.