Evaluation of fine pitch p-onp and n-on-n irradiated silicon microstrip sensors for the LHCb experiment

Abstract

The Vertex Locator (VELO) of the LHCb experiment has to operate its silicon microstrip sensors in a harsh and non-uniform radiation environment. Irradiated prototype n-on-n and p-on-n silicon microstrip detectors have been evaluated in a testbeam while being read out at 40 MHz. Measurements of the efficiency of these prototypes are presented. The particular dangers of p-on-n detectors are outlined and the n-on-n technology choice for LHCb is motivated.