Abstract

A detector concept based on a two-stage Micromegas coupled to a Cherenkov radiator with a photocathode (hereafter named PICOSEC) has been developed to provide precise timing information needed for high rate experiments in High Energy Physics (HEP). Single channel prototypes of this detector have demonstrated an excellent resolution, of 24 ps, for timing the arrival of particles in the minimum ionizing regime (MIPs). The PICOSEC timing characteristics have been extensively studied with laser beams and have been understood in terms of detailed simulations and phenomenological models. An analysis technique, based on the comparison of the charge distribution of the PICOSEC response signal to UV light and muons, has been developed to consistently estimate the photoelectron yield of the photocathode, a parameter which affects critically the PICOSEC timing resolution. Towards the development of this detector concept for practical applications, a multi-channel PICOSEC has been recently tested in muon beam, resulting to a uniform timing resolution of 25 ps for each pad. Due to the fact that ion backflow in the drift region damages the CsI photocathode, alternative photocathode materials have been investigated. Following an introduction of the PICOSEC concept, this talk presents data analysis techniques and results on estimating the photoelectron yield of various photocathodes, and it focuses on the methods and results concerning the multi-channel PICOSEC prototype performance.