Hot electrons as well as hot ions are a desirable feature of any fusion device. By particle simulations (in slab geometry) and simple theory, investigations are made on two variants of the Toroidal Cusp Experiment (TCX) with an eye to achieving hot electrons, while retaining its large direct ion heating feature. A toroidal field added to the TCX configuration, with cusp magnets arranged poloidally to partly cancel cusp trapping of the electrons, ensures electron flow across the cusps and electron heating. Helical winding of the cusp magnets around the torus with pitch θ ⪆ (m/M)1/2 allows trapped electron flow on average helical paths; however, ions can still flow across the cusps, and the · heating of ions and electrons can be varied at will.
Pre-ionization and pre-heat conditions for a compact toroidal plasma experiment in the millitorr pressure range