Studies and Proposals for an Automatic Crystal Control System

This document presents the status of the studies for an Automatic Crystal COntrol System (ACCOS) performed since autumn 1995 for the CMS collaboration. Evaluation of a start‐stop method for light yield, light uniformity and decay time measurements of PbWO 4 crystals is presented, as well as the first results obtained with a compact double-beam spectrophotometer for transverse transmission. Various overall schemes are proposed for an integrated set-up including crystal dimension measurement. The initial financial evaluation performed is also given.