Experimental and numerical simulation of a TPC like set up for the measurement of ion backflow

TL;DR

This paper presents an experimental and simulation study of ion backflow measurement in a TPC-like setup using bulk Micromegas detectors, introducing a novel measurement method with two drift meshes and optimizing field configurations.

Contribution

It introduces a new measurement approach for ion backflow fraction using two drift meshes and combines experimental data with Garfield simulations for accuracy.

Findings

Effective ion backflow suppression by bulk Micromegas

Optimized field configuration improves measurement accuracy

Simulation results align well with experimental data

Abstract

Ion backflow is one of the effects limiting the operation of a gaseous detector at high flux, by giving rise to space charge which perturbs the electric field. The natural ability of bulk Micromegas to suppress ion feedback is very effective and can help the TPC drift volume to remain relatively free of space charge build-up. An efficient and precise measurement of the backflow fraction is necessary to cope up with the track distortion due to the space charge effect. In a subtle but significant modification of the usual approach, we have made use of two drift meshes in order to measure the ion backflow fraction for bulk Micromegas detector. This helps to truly represent the backflow fraction for a TPC. Moreover, attempt is taken to optimize the field configuration between the drift meshes. In conjunction with the experimental measurement, Garfield simulation framework has been used to simulate the related physics processes numerically.