Position A: example of electron which becomes ”trapped”. a) displays a zoomed view of the electron orbit (thick black line), which begins at the location shown by a green orb, and ends at the location shown by the blue orb, while black trapezoids indicate locations where the parallel velocity of the particle changes sign. The thin grey line indicates the locally interpolated B-field line based on the initial position (but almost exactly matches the particle orbit path). The red isosurface denotes where the parallel electric field changes sign (E_|| = 0). Orbit properties for this electron are displayed in b) and c); b) shows the change in kinetic energy (KE) and parallel electric field component (E_||) as a function of time, while c) shows the normalised parallel velocity (v_||/ max(v_||)) and magnetic field strength (| B |) for this orbit.