PICOSEC-Micromegas : Robustness measurements and study of different photocathode materials

Abstract

Detectors with a time resolution of 20-30 ps and a reliable performance in highparticles flux environments are necessary for an accurate vertex separation in future HEPexperiments. The PICOSEC-Micromegas detector concept is a Micro-Pattern Gaseous Detector(MPGD) based solution addressing this particular challenge.The PICOSEC-Micromegasconcept is based on a Micromegas detector coupled to a Cherenkov radiator and a photocathode.In this detector concept, all primary electrons are initiated in the photocathode and the timejitter fluctuations are reduced. Different resistive anode layers have been tested with thegoal of preserving a stable detector operation in a high intensity pion beam. One importantcharacteristic of a gaseous detector in a high flux environment is the ion backflow (IBF). Thatcan cause damage to more fragile photocathode materials like CsI. Various types of photocathodematerials have been tested in order to find a robust solution against IBF bombardment.