Plot of the number of non-thermal particles as a function of energy. The energy distribution follows the power law F( E) = F ₀ E ^−δ with the electron spectral index, δ, set equal to 3 and a low energy cutoff of 15 keV. Each run consists of 2 × 10 ⁴ test particles. Each simulation is made from 50 runs yielding 1 × 10 ⁶ test particles in total.