(a) The reduced ion energy distribution for a 2d_i slice in the y-direction as a function of shock-normal direction and energy. (b)–(d) Ion distribution functions at the locations shown by the dashed lines in (a), scaled by ∣v − u∣². The distribution functions are plotted in the v_x, v_y plane and integrated over the v_z-direction. All the distribution functions are averaged in time over ﹩50{{\rm{\Omega }}}_{\mathrm{ci}}^{-1}﹩ at ﹩0.5{{\rm{\Omega }}}_{\mathrm{ci}}^{-1}﹩ intervals and are determined in the shock frame.