The very high momentum particle identification detector proposed for the ALICE upgrade is a focusing RICH using a C4F10 gaseous radiator. For the detection of Cherenkov photons, one of the options currently under investigation is to use a CsI coated Triple-Thick-GEM (CsI-TTGEM) with metallic or resistive electrodes. We will present results from the laboratory studies as well as preliminary results of beam tests of a RICH detector prototype consisting of a CaF2 radiator coupled to a 10x10 cm2 CsI-TTGEM equipped with a pad readout and GASSIPLEX-based front-end electronics. With such a prototype the detection of Cherenkov photons simultaneously with minimum ionizing particles has been achieved for the first time in a stable operation mode.
@article{arxiv.1009.2309,
title = {R&D results on a CsI-TTGEM based photodetector},
author = {A. Breskin and V. Peskov and A. Di Mauro and P. Martineng and D. Mayani Paras and L. Molnar and E. Nappi and G. Paic and J. van Hoorne},
journal= {arXiv preprint arXiv:1009.2309},
year = {2010}
}