Modelling the behaviour of microbulk Micromegas in Xenon/trimethylamine gas

Abstract

We model the response of a state of the art micro-hole single-stage charge amplication device (`microbulk' Micromegas) in a gaseous atmosphere consisting of Xenon/trimethylamine at various concentrations and pressures. The amplifying structure, made with photo-lithographic techniques similar to those followed in the fabrication of gas electron multipliers (GEMs), consisted of a 100 um-side equilateral-triangle pattern with 50 um-diameter holes placed at its vertexes. Once the primary electrons are guided into the holes by virtue of an optimized field configuration, avalanches develop along the 50 um-height channels etched out of the original doubly copper-clad polyimide foil. In order to properly account for the strong field gradients at the holes' entrance as well as for the fluctuations of the avalanche process (that ultimately determine the achievable energy resolution), we abandoned the hydrodynamic framework, resorting to a purely microscopic description of the electron trajectories as obtained from elementary cross-sections. We show that achieving a satisfactory description needs additional assumptions about atom-molecule (Penning) transfer reactions and charge recombination to be made.

References in corpus (9)

• Performance of Wavelength-Shifting Fibers for the Mu2e Cosmic Ray Veto Detector
• Radiopurity of Micromegas readout planes
• Characterisation of NEXT-DEMO using xenon K${}_{\alpha }$ X-rays
• Micromegas operation in high pressure xenon: charge and scintillation readout
• Electron transparency of a Micromegas mesh
• An improved measurement of electron-ion recombination in high-pressure xenon gas
• Directional dark matter by polar angle direct detection and application of columnar recombination
• Lessons from the operation of the "Penning-Fluorescent" TPC and prospects
• Measurement of scintillation and ionization yield with high-pressure gaseous mixtures of Xe and TMA for improved neutrinoless double beta decay and dark matter searches

Cited by in corpus (9)

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• Accurate gamma and MeV-electron track reconstruction with an ultra-low diffusion Xenon/TMA TPC at 10 atmospheres
• Electron Transport in Gaseous Detectors with a Python-based Monte Carlo Simulation Code
• Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives
• Directional dark matter by polar angle direct detection and application of columnar recombination
• Measurement of scintillation and ionization yield with high-pressure gaseous mixtures of Xe and TMA for improved neutrinoless double beta decay and dark matter searches
• Study of the loss of Xenon Scintillation in Xenon-Trimethylamine Mixtures
• Detectors and Concepts for sub-100 ps timing with gaseous detectors
• Lessons from the operation of the "Penning-Fluorescent" TPC and prospects