Fundamentals of Gas Micropattern Detectors

TL;DR

This paper systematically studies the gain and rate characteristics of micropattern gaseous detectors under various conditions, revealing fundamental operational limits and suggesting improvements and alternatives like RPCs for enhanced performance.

Contribution

It presents new systematic measurements of micropattern detectors at different pressures, gas mixtures, and irradiation conditions, discovering fundamental limits and proposing performance enhancements.

Findings

Identified fundamental operational limits of micropattern detectors.

Discovered new effects influencing detector performance.

Suggested RPCs as a viable alternative in some applications.

Abstract

We performed a new series of systematic studies of gain and rate characteristics of several micropattern gaseous detectors. Extending earlier studies, these measurements were done at various pressures, gas mixtures, at a wide range of primary charges and also when the whole area of the detectors was irradiated with a high intensity x-ray beam. Several new effects were discovered, common to all tested detectors, which define fundamental limits of operation. The results of these studies allow us to identify several concrete ways of improving the performance of micropattern detectors and to suggest that in some applications RPCs may constitute a valid alternative. Being protected from damaging discharges by the resistive electrodes, these detectors feature high gain, high rate capability (10^5 Hz/mm^2), good position resolution (better than 30 micrometer) and excellent timing (50 ps sigma).