First observation of Cherenkov rings with a large area CsI-TGEM-based RICH prototype

In this paper, we will present the results from a series of laboratory tests performed with this prototype carried out using UV light, 6 keV photons from 55Fe and electrons from 90Sr as well as recent results of tests with a beam of charged pions where for the first time Cherenkov Ring images have been successfully recorded with TGEM photodetectors. The achieved results prove the feasibility of building Cherenkov detector based on CsI coated TGEMs.