Analysis of testbeam data of irradiated silicon prototype sensors for the CMS tracker upgrade

CMS is working on identifying suitable radiation-hard silicon materials for the tracker upgrade in the high luminosity era of LHC. A large number 016 in. wafers made from p and n-type, float zone, Magnetic Czochralski and Epitaxial Silicon in thicknesses ranging from 50 to 320 mu m were ordered from Hamamatsu. The wafers contain many different test structures as well as strip sensors called Multi Geometry Silicon Strip Detector (MSSD), that feature pitches from 70 to 240 pm and different strip widths. The structures were irradiated to a fluence of 1.5 x 10(15) 1 MeV N-eq cm(-2) which corresponds to the fluence that the sensors will receive in a future tracker at a distance of 20 cm from the beam. This contribution will focus on the results obtained in various test beams with these strip sensors. The evolution of parameters such as resolution, signal and noise with increasing fluences will be addressed as well as the relation between geometry, thickness and technology. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved