Test results of heavily irradiated Si detectors

A large use of silicon microstrip detectors is foreseen for the intermediat e part of the CMS tracker. A specific research and development program has been carried out with the aim of finding design layouts and technological s olutions for allowing silicon microstrip detectors to be reliably used on a high radiation level environment. As a result of this work single sided, A C-coupled, polysilicon biased, 300 mu m thick, p(+) on n substrate detector s were chosen. Irradiation tests have been performed on prototypes up to fl uence 2 x 10(14) n/cm(2). The detector performances do not significantly ch ange if the detectors are biased well above the depletion voltage. S/N is r educed by less than 20%, still enough to insure a good efficiency and space resolution. Multiguard structures has been developed in order to reach hig h voltage operation (above 500 V). (C) 1999 Published by Elsevier Science B .V. All rights reserved.