Construction and Performance of a Micro-Pattern Stereo Detector with Two Gas Electron Multipliers

TL;DR

This paper details the construction and evaluation of a micro-pattern gas detector with GEM foils, demonstrating high efficiency and precise position resolution in a muon beam test at CERN.

Contribution

It presents a novel micro-pattern stereo detector design with a two-layer readout and evaluates its performance in a high-energy physics setting.

Findings

Position resolution of 50 um and 1 mm for orthogonal coordinates

Muon detection efficiency of 96% for 2D space points

Successful construction and testing of a 40x10 cm² GEM-based detector

Abstract

The construction of a micro-pattern gas detector of dimensions 40x10 cm**2 is described. Two gas electron multiplier foils (GEM) provide the internal amplification stages. A two-layer readout structure was used, manufactured in the same technology as the GEM foils. The strips of each layer cross at an effective crossing angle of 6.7 degrees and have a 406 um pitch. The performance of the detector has been evaluated in a muon beam at CERN using a silicon telescope as reference system. The position resolutions of two orthogonal coordinates are measured to be 50 um and 1 mm, respectively. The muon detection efficiency for two-dimensional space points reaches 96%.