The barrel region of the CMS pixel detector will be equipped with ``n-in-n'' type silicon sensors. They are processed on DOFZ material, use the moderated p-spray technique and feature a bias grid. The latter leads to a small fraction of the pixel area to be less sensitive to particles. In order to quantify this inefficiency prototype pixel sensors irradiated to particle fluences between 4.7×1013 and 2.6×1015\Neq have been bump bonded to un-irradiated readout chips and tested using high energy pions at the H2 beam line of the CERN SPS. The readout chip allows a non zero suppressed analogue readout and is therefore well suited to measure the charge collection properties of the sensors. In this paper we discuss the fluence dependence of the collected signal and the particle detection efficiency. Further the position dependence of the efficiency is investigated.
@article{arxiv.physics/0411214,
title = {Fluence Dependence of Charge Collection of irradiated Pixel Sensors},
author = {T. Rohe and D. Bortoletto and V. Chiochia and L. M. Cremaldi and S. Cucciarelli and A. Dorokhov and C. Hoermann and D. Kim and M. Konecki and D. Kotlinski and K. Prokofiev and C. Regenfus and D. A. Sanders and S. Son and T. Speer and M. Swartz},
journal= {arXiv preprint arXiv:physics/0411214},
year = {2008}
}
Comments
11 Pages, Presented at the 5th Int. Conf. on Radiation Effects on Semiconductor Materials Detectors and Devices, October 10-13, 2004 in Florence, Italy, v3: more typos corrected, minor changes required by the referee