Interpretation of effective gain variations with the drift electric field for a ceramic thick gas electron multiplier

Abstract The effective gain variations as a function of the drift electric field strength ( E d ) are measured in a ceramic thick gas electron multiplier (THGEM) and a standard GEM using the same experimental setup. Significant differences in the variations are observed between the THGEM and the standard GEM. The effective gain variations with E d are quantitatively reproduced by calculations via investigating the respective influence of E d change on the electron collection efficiency and the gain. The differences in the effective gain variation with E d between the THGEM and standard GEM are thus explained.