Electron trajectories under a double-hexapole magnetic field

Abstract

As a simulation to study the magnetic field properties of the ECR device at the NIP Plasma Physics Laboratory, electron trajectories were observed at different areas of the double hexapole magnetic field. The electrons were launched with an initial speed corresponding to energies of 3 eV. Initial locations of the electrons are: between the two hexapoles; at the middle of one hexapole; and at the area before the magnetic system. Reflection of electrons through magnetic mirrors was observed, as well as trapping of some electrons at magnetic cusps. The areas within each hexapole showed good confinement of electrons. However, the area between the two hexapoles has a relatively weak magnetic field gradient such that some of the electrons easily escaped.