Impact reconstruction in pad chambers Part I: Simulation studies

Abstract

Using the simple electrostatic model initiated by Endo et al., we propose a model for pad chambers valid when pads have a rectangular shape. The result gives the framework of a realistic Monte Carlo simulation. We show that this model exhibits all the properties already known from pad and strip chambers. This model allows for the definition of new algorithms to find the avalanche location with good accuracy and no (or nearly no) bias in contrast with the standard centroid method. The quality of the impact reconstruction is studied within a chamber geometry which highly favours small size clusters (two and three strips reconstructed from pads). We show that an accuracy of 100 μm is easily achieved (compared with a pad pitch of 4.5 mm) and this limit is intimately related with the level of the white noise. Other consequences of the model are also studied.