Single Event Upset Studies on the APV6 Front End Readout Chip

The microstrip tracker for the CMS experiment at the LHC will be read out using radiation hard APV chips. During high luminosity running of the LHC the tracker will be exposed to particle fluxes up to 10 cm s. This high rate of particles introduces a concern that the APV could occasionally suffer from Single Event Upset (SEU). In order to evaluate the expected upset rate the APV was run under controlled conditions in a heavy ion beam. The upset cross-sections of the main digital parts of the chip have been measured at two values of incident Linear Energy Transfer (LET). A theoretical prediction of both threshold LET and cross-section is presented along with the experimental measurements.