  THick Gas Electron Multipliers (THGEMs) are robust and high gain Micro
Pattern Gaseous Detectors which are economically manufactured by standard
drilling and etching of thin printed circuit boards. In this paper, we present
our recent simulation as well as experimental studies on THGEMs which have been
fabricated in India using local expertise. Two types of THGEMs have been
fabricated; one set has holes without any external rim and another set has
holes with rims. These detectors have been characterized using argon-carbon
dioxide and argon-isobutane gas mixtures. Electron transmission, effective
gain, energy resolution and optimized working range studies have been presented
for both the sets of THGEMs.
