Test results of heavily irradiated Si detectors

A large use of silicon microstrip detectors is foreseen for the intermediate part of the CMS tracker. A specific research and development program has been carried out with the aim of finding design layouts and technological solutions for allowing silicon microstrip detectors to be reliably used on a high radiation level environment. As a result of this work single sided, AC-coupled, polysilicon biased, 300 mu m thick, p(+) on n substrate detectors were chosen. Irradiation tests have been performed on prototypes up to fluence 2 x 10(14) n/cm(2). The detector performances do not significantly change if the detectors are biased well above the depletion voltage. S/N is reduced by less than 20%, still enough to insure a good efficiency and space resolution. Multiguard structures has been developed in order to reach high voltage operation (above 500 V). (C) 1999 Published by Elsevier Science B.V. All rights reserved. RI Krammer, Manfred/A-6508-2010; Servoli, Leonello/E-6766-2012; Azzi, Patrizia/H-5404-2012