MicroMegas-based detectors for time-of-flight measurements of neutron-induced reactions

F Gunsing,E Berthoumieux,E Ferrer-Ribas,F Belloni,E Dupont,M Diakaki

doi:10.1051/epjconf/202023917007

Abstract

MicroMegas detectors are versatile gaseous detectors which are used for ionizing particle detection. A MicroMegas detector consists of two adjacent gas-filled volumes. One volume acts as a drift region with an electric field operating in the ionization chamber regime, the second volume is the amplification region acting as a parallel-plate avalanche counter. The use of the microbulk technique allows the production of thin, radiation resistant, and low-mass detector with a highly variable gain. Such MicroMegas detectors have been developed and used in combination with neutron time-of-flight measurements for in-beam neutron-flux monitoring, fission and light-charged particle reaction cross section measurements, and for neutron-beam imaging. An overview of MicroMegas detectors for neutron detection and neutron reaction cross section measurements and related results and developments will be presented.

Highlights

Since the development of the first prototype, MicroMegas detectors [1] are used in many experiments in nuclear and particle physics
The MicroMegas was originally developed to cope with issues observed when existing gaseous detector families were used under high count rate
At present MicroMegas detectors are widely used in a variety of shapes [2]

Summary

Introduction

Since the development of the first prototype, MicroMegas detectors [1] are used in many experiments in nuclear and particle physics. The applicability of MicroMegas detectors for a diverse range of ionizing particles is due to the high range in possible gain, allowing to detect particles with very different energy deposits in the drift region. The field prevents the ions to recombine and the electrons drift to the micromesh, where they enter into the second gas volume This amplification region has a much stronger electric field which is in the avalanche or proportional counter regime, typically 100 kV/cm. The mesh-anode mounting is a critical step because of the strong forces due to the high electric field which may result in a varying meshanode distance and an inhomogeneous electric field Such problems are nowadays largely overcome by the use of the bulk technology [11]. The mesh structure and the anode readout strips or pixels are directly integrated in printed circuit board layers This has resulted in much more robust detector elements. The three voltages are chosen such that the electric fields form the ionization chamber and proportional counter regimes in the drift and amplification region respectively

Use of MicroMegas with pulsed neutron beams

Outlook