Operation of the prospective beamline calorimeter in the high-radiation forward environment of the international linear collider

Results on electromagnetically-induced radiation damage to silicon diode sensors, obtained from the T506 experiment at SLAC, are used in concert with detailed shower simulations to project the effects of radiation damage on the proposed International Linear Collider Beamline Calorimeter (BeamCal) detector system. The study makes use of the FLUKA Monte Carlo to simulate electromagnetic showers in both the T506 apparatus and the prospective BeamCal detector system. Under the conservative assumption that damage leading to sensor leakage currents is dominated by the neutron component of the electromagnetic shower, and assuming that resulting leakage currents depend linearly on neutron fluence, the power consumption required to operate the BeamCal detector at a temperature of −10° C would be expected to increase by approximately 100 W per year of operation. Lowering the operating temperature to −30°C would be expected to reduce the growth in power consumption to approximately 10 W per year. Under other assumptions about the source of damage, the accumulated power draw would be expected to be significantly less. Results on fluences of both electromagnetic and hadronic particles in regions peripheral to the bulk of the BeamCal detector system, where front-end electronics would be mounted, are also presented.