Trajectories of an electron (panel a) and a proton (panel b) accelerated in similar magnetic islands. Panel c: Trajectory of an electron in the edge island as described by Eq. (20), which has an open field topology edge at |z| > 10. d = 2 m, ϵ = 0.3, k₀ = 1.0, ξ_y = 1. The sampled particles are all initialized at x = 0, z = 0 to reduce the computing time for the particle motion from the RCS boundaries. The orange lines present the magnetic field in the X−Z plane. Panel d: example of preferential ejection of electrons and protons from an RCS with multiple X-nullpoints.