Estimation of Radiation Effects in the Front-End Electronics of an ILC Electromagnetic Calorimeter V. Bartsch, M. Postranecky, M. Warren, M. Wing University College London

very frontend electronics (VFE) based on ASICs frontend electronics (FE) based on FPGAs, 1 FPGA/slab HCAL ECAL, 30 slabs stacked on top each other, in z direction 25 slabs next to each other extends to |eta|=1.1 magnet Geometry

Single Event Upsets (SEUs) sensitive volume (can be guessed by irradiating with different ions with a different linear energy transfer, plus guessing the dephts of the device => Weibull fit which gives the cross sectional area of the sensitive region per node) critical energy ( depend on angle and entry point of the incident particle and its energy at each point of the volume) look for particles which deposit much charge in small area  p, , n

Physics processes Processno of events / hour generated events QCD(7-9)x  events (machine background) 4.1x other physics processes like ttbar, WW and Bhabhar scattering also studied but small in terms of SEUs pair production as another machine background studied but focussed on the very forward region

Event generation ProcessEvent generator QCDPYTHIA gg events (machine background) GUINEAPIG to generate  PYTHIA as a  collider with a variable energy device simulation in both cases done with MOKKA using the TESLA geometry model

energy spectrum at the FPGAs only n, p,  deposit enough energy for SEUs not every event causes a SEU

some FPGAs’ SEU cross sections D. Gingrich et al., IEEE Transactions on Nuclear Science, Vol. 50, No. 2, 2003 type of FPGA  SEU SEUs in ECAL/h Virtex II X-2V1008x Altera Stratix Xilinx XC4036XLA3x cross sections for SEU to occur vary for each FPGA values can be found in literature SEU rate in ECAL FPGAs small, but needs to be considered in choice of FPGA

additional studies studies are based on the generated MC samples for the SEU study, for the further studies all generated particles have been used occupancy for the barrel ECAL:  needs to be considered in the DAQ for the ECAL combined with occupancy resulting from noise ECAL radiation damage studies: expected fluence:2x10 6 (1 MeV n eq.)/(cm 2 *year) expected radiation: 0.13 Rad/year  fluence and radiation dose small enough not to cause damage to the FPGAs

conclusion  machine background and QCD physics background main contributor to protons, pions and neutrons crossing the ECAL Single Event Upset rate small for the ECAL FPGAs at the Linear Collider needs to be considered though for the final choice of the FPGA type