Author: A. Ostaptchouk

Institution: Max-Planck-Institut fuer Physik, Munich

Co-Author: V.Bartheld, H.Kroha, S.Schael

A Novel Alignment System for Tracking Chambers

Abstract:

A novel optical monitoring system has been developed for precision alignment of particle tracking detectors. Collimated laser beams traversing transparent optical position sensors are used to measure the relative positions of the detector elements. Custom designed silicon strip photodiodes provide very high position resolution of order 1 micrometer for the incident laser beam and are semi- transparent at wave lengths in the red to infrared range emitted by laser diodes. Transmission rates up to more than 90% allow to align many stations along a common laser beam over long distances. The flexibility of the multi-point alignment system has lead to its application in several modern particle physics experiments which require high precision optical monitoring systems (The ATLAS muon spectrometer and the ATLAS inner detector, the CMS muon system and the CMS tracker, the HERA-B vertex detector and the HERA-B tracker, the AMS silicon tracker, the NOMAD calorimeter, the CHORUS emulsion target, the ZEUS vertex detector, the MAGIC telescope).