Distribution of Proton-Induced Transients in Silicon Focal Plane Arrays

Proton-induced energy deposition in a silicon P-i-N focal plane array is analyzed with Monte Carlo based simulations. These simulations include all physical processes, including events resulting from multiple particles incident on a single pixel, to describe the experimental data accurately. Post-processing of Monte Carlo simulations is done to account for the effects of pile up (multiple hits on a single pixel during one integration time) and non-radiation-induced noise in experiment. The results are compared with experimental data, and demonstrate how direct ionization dominates the cross section, yet fluctuations in dE/dx cause a broad range of energy depositions not addressed by an average LET calculation. An event rate is predicted for a full space proton flux and the dominance of direct ionization is shown and compared to computation using constant LET methods in CREME96. This comparison shows that at lower energies, CREME96 sufficiently predicts the event rate, but at higher energies a high fidelity simulation method is needed to capture the distribution.