Gain characteristics of a 100 micrometer thick GEM in Krypton-CO2 mixtures

TL;DR

This study evaluates the gain and energy resolution of a 100-micrometer thick GEM detector in krypton-CO2 mixtures, demonstrating high gain and good resolution suitable for imaging applications.

Contribution

It provides the first detailed characterization of a 100-micrometer GEM in krypton-CO2 mixtures, including gain and energy resolution measurements.

Findings

Achieved gains close to 10^4 in pure krypton.

Energy resolution of 22% (FWHM) at 5.9 keV in krypton.

Demonstrated stable operation suitable for imaging.

Abstract

The operation of a Micropattern Gaseous Detector (MPGD) comprising a cascade of two non-standard Gas Electron Multipliers (GEM) made from a 100 micrometer kapton foil was evaluated in pure krypton and in krypton-CO2 mixtures. The final avalanche charge was collected in a 2D strip readout, providing an active area of 10x10 cm2 for the entire detection system. For each mixture, the effective gain and energy resolution were measured as a function of the electric field in the drift, transfer and induction regions. Using X-rays from a 55Fe radioactive source (5.9 keV), gains close to 104 and energy resolution of 22% (FWHM) were achieved in pure krypton under stable conditions, showing the potential of the experimental setup for the following imaging studies.