Separation capability of charged particles by Helmholtz-type direct energy converter with electrodes

The separation capability of charged particles is one of the most important requirements for direct energy converters (DEC) of D-3He fusion reactors. An alternative DEC using Helmholtz coils (Helmholtz DEC) is designed to reduce the self-induced electric field and to separate charged particles when the thermal input is large as 10 MW (8.8 MW/m2). Numerical analyses with a two-dimensional approximation have given the following results. (1) When both electrodes (collectors) are grounded, it can separate ions and electrons with 99.4% ion collection efficiency. (2) When the electric potential is applied to both electrodes as nine cases, the highest separation capability of the charged particles is about 95%. (3) When Cusp DEC, Cusp DEC with closer electrodes and Helmholtz DEC are compared, only Helmholtz DEC can separate the charged particles when the electric potential is applied to the anode