Simulation of beam-induced backgrounds in comparison with data from the CMS pixel and other inner radii detectors

The response for pp-collisions and machine-induced background in CMS has been simulated with FLUKA. The pp-collisions lead to a background due to activation and excitation of the detector material, so that background particles many bunch crossings later than the initial collision are detected. The simulated results were compared to measured data, good qualitative agreement was found. The machine-induced background comes from three sources, of which the inelastic beam gas is the main contributor. The characteristics of the total background is shown and compared to pixel- and strip-tracker data. Good agreement was found in shape and rate. (C) 2010 Elsevier B.V. All rights reserved.