Charge production in thin gap multi-wire chambers

Resistive cathode thin gap chambers (TGCs) have been used as particle detectors in high-energy physics experiments for more than a decade. A quantitative understanding of charge production mechanisms in TGCs has been developed and a simulation program produced to accurately describe the expected response from a chamber as a function of its design and operating parameters. This simulation is based upon a description of the processes of electron cluster production, drift and avalanche effects and space charge contributions from residual ions. Improved measurements of chamber performance are presented, and the parameters of the simulation have been fitted to these data yielding values consistent with estimates based on the physical mechanisms involved. Sensitivity of chamber timing and amplification properties to operating parameters is discussed.