Spatial Resolution of a Micromegas-TPC Using the Charge Dispersion Signal

TL;DR

This paper investigates the spatial resolution of a Micromegas-based TPC using charge dispersion readout, demonstrating its potential to achieve high resolution with manageable pad sizes for collider detectors.

Contribution

It introduces and evaluates a charge dispersion readout method for Micromegas-TPCs, showing improved spatial resolution comparable to GEM-TPCs.

Findings

Micromegas-TPC with charge dispersion achieves high spatial resolution.

Resolution compares favorably with GEM-TPC and theoretical limits.

Charge dispersion enables using larger pads without sacrificing resolution.

Abstract

The Time Projection Chamber (TPC) for the International Linear Collider will need to measure about 200 track points with a resolution close to 100 $\mu$m. A Micro Pattern Gas Detector (MPGD) readout TPC could achieve the desired resolution with existing techniques using sub-millimeter width pads at the expense of a large increase in the detector cost and complexity. We have recently applied a new MPGD readout concept of charge dispersion to a prototype GEM-TPC and demonstrated the feasibility of achieving good resolution with pads similar in width to the ones used for the proportional wire TPC. The charge dispersion studies were repeated with a Micromegas TPC amplification stage. We present here our first results on the Micromegas-TPC resolution with charge dispersion. The TPC resolution with the Micromegas readout is compared to our earlier GEM results and to the resolution expected from electron statistics and transverse diffusion in a gaseous TPC.