Percentage of total particles (+) reaching current sheet at z = z_η from the external region (R = 1 in the inflow quadrant), and the mean time taken (*), for different values of η, B_s and λ. Each data point is from a many particle simulation with initial Maxwellian distribution (T = 86 eV) of 5000 protons. The set-up is the same as that in Fig. 7. a) For different values of η with fixed B_s = α = 5, λ = 0.75. The solid line is a least squares fit to the points. b) For different values of B_s (with B_s = α) for fixed η = 10^-8, λ = 0.75. The solid line is a least squares fit. c) For different λ with fixed B_s = α = 5, η = 10^-8. No curve was fit.