First evaluation of the Single Event Upset ( SEU ) risk for electronics in the CMS experiment

SEU error rates in the CMS tracker environment have been approximated with Monte Carlo simulations. The estimated upset rates for a submicron technology are 8.3 10-7 upsets/(bit s) at 4.9cm and 1.1 10-8 upsets/(bit s) at 49cm from the beam line, respectively. Comparison of simulation data with experimental proton irradiation benchmarks points to a tenfold underestimate of the actual rate. All these results have been obtained under the assumption of a 1Pm 3 sensitive volume and 1MeV energy threshold, and are very sensitive to the choice of these two parameters. The simulation indicates that mono-energetic proton beams are an effective tool for the SEU characterisation of ICs for the LHC radiation environment. Thermal neutrons might significantly contribute to the upset rate already in the outer parts of the tracker and in all the other parts of the experiment.