Cosine of pitch angle μ, normalized magnetic moment 2MB₀/γmu², and spatial displacement L_x/L_inj in the x-axis direction as a function of time τ. The results of the initially mirroring and scattering particles shown in panels a and b correspond respectively to the left and right particles in Fig. 1. The horizontal dashed lines represent ±μ_c in Table 1. The blue and red curves represent respectively the numerical result and the averaged result within one gyration period.