The momentum distributions of plasma ions (dotted lines), plasma electrons (dashed lines), and CRs (solid lines) in the plasma ion rest frame, for monenergetic (top) and power-law (bottom) CRs with similar ξ ≈ 66. The colors represent distributions at different times. Heating of plasma species (nonthermal tails and shifts in thermal peaks) and changes in CR distributions are observed at later times. The higher-energy CRs in the power-law distribution are essentially undisturbed.