IMPACT RECONSTRUCTION IN PAD CHAMBERS .1. SIMULATION STUDIES

Using the simple electrostatic model initiated by Endo et al., we prop ose 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 fro m pad and strip chambers. This model allows for the definition of new algorithms to find the avalanche location with good accuracy and no (o r nearly no) bias in contrast with the standard centroid method. The q uality of the impact reconstruction is studied within a chamber geomet ry which highly favours small size clusters (two and three strips reco nstructed from pads). We show that an accuracy of 100 mum is easily ac hieved (compared with a pad pitch of 4.5 mm) and this limit is intimat ely related with the level of the white noise. Other consequences of t he model are also studied.