Trajectories of the initially mirroring particle (left panel; initial pitch-angle cosine μ₀ = 0.15) and the initially scattering particle (right panel; μ₀ = 0.8). The magnetic field lines (black) extend to 1024 pixels in the x-axis direction. The trajectories of these two particles are color-coded by the time τ (normalized by the gyrofrequency Ω), as shown in the color bar. We note that for the sake of comparison, the right panel only shows a part of the trajectory in the range of τ<160. The Larmor radius of these two particles is R_g = 0.03L_inj. The simulations are from R2 listed in Table 1.