Spatial and temporal characteristics of energy deposition by protons and alpha particles in silicon

We present spatial and temporal distributions of energy deposition in silicon obtained from Monte Carlo simulations with Geant4. Detailed simulations are performed for protons and alphas over a wide energy range and include contributions from discrete /spl delta/-rays and nuclear reactions. The simulation technique we employ produces physically realistic complex track structures for which the plausibility is evaluated by comparison to the linear energy transfer, radial dose, and temporal characteristics described in previous works. The variability of events, including the distribution of energy deposition at varying distances from the ion track is discussed. Finally, we examine the temporal evolution of extreme events to investigate the physicality of the common assumption that energy deposition can be considered instantaneous.