Simulation of gas avalanche in a micro pixel chamber using Garfield++

Abstract

A micro pixel chamber (μ-PIC), the development of which started in 2000 as a type of a micro pattern gas detector, has a high gas gain greater than 6000 in stable operation, a large detection area of 900 cm2, and a fine position resolution of about 120 μm. However, for its development, simulation verification has not been very useful, because conventional simulations explain only part of the experimental data. On the other hand, some μ-PIC applications require precise understanding of the fluctuation of the gas avalanche and signal waveform for their improvement; therefore, there is a need to update the μ-PIC simulation. Hence, we adopted Garfield++, which is developed for simulating a microscopic avalanche in an effort to explain experimental data. The simulated avalanche size was well consistent with the experimental gas gain. Moreover, we calculated a signal waveform and successfully explained the pulse height and time-over-threshold. These results clearly indicate that the simulation of μ-PIC applications will improve and that Garfield++ simulation will easily facilitate the μ-PIC development.© 2013 IOP Publishing Ltd and Sissa Medialab srl.