Photosensitive Strip RETHGEM

TL;DR

This paper introduces a novel photosensitive gaseous detector with a GEM-like structure, featuring layered electrodes and resistive strips for spark protection, suitable for UV imaging and Cherenkov detectors.

Contribution

It presents a new design of photosensitive gaseous detectors with layered electrodes and resistive layers, enhancing spark protection and high-gain operation.

Findings

Operates at high gains close to breakdown limit.

Effective in photosensitive gas mixtures with ethylferrocene or TMAE.

Suitable for large-area UV detection applications.

Abstract

An innovative photosensitive gaseous detector, consisting of a GEM like amplification structure with double layered electrodes (instead of commonly used metallic ones) coated with a CsI reflective photocathode, is described. In one of our latest designs, the inner electrode consists of a metallic grid and the outer one is made of resistive strips; the latter are manufactured by a screen printing technology on the top of the metallic strips grid The inner metallic grid is used for 2D position measurements whereas the resistive layer provides an efficient spark protected operation at high gains - close to the breakdown limit. Detectors with active areas of 10cm x10cm and 10cm x20cm were tested under various conditions including the operation in photosensitive gas mixtures containing ethylferrocene or TMAE vapors. The new technique could have many applications requiring robust and reliable large area detectors for UV visualization, as for example, in Cherenkov imaging devices.