Improvement of Structure of Traveling Wave Direct Energy Converter Simulator for Ion Flux with Wide Energy Spread

In D-³He fusion, most of fusion energy is carried by kinetic energy of created protons of 14.7 MeV. Concept of traveling wave direct energy converter (TWDEC) was proposed as an effective energy converter with less handling voltage. Although fundamental researches on TWDEC have been reported, the dependence on energy spread of flowing ions has not been investigated in spite of its significant effects against conversion efficiency. The paper treats this subject by an application of TWDEC simulator to GAMMA 10 tandem mirror whose end-loss flux has relatively wide energy spread. The energy distribution of the end-loss flux was measured, and a new structure of TWDEC simulator was designed according to the measured result. The conversion efficiency was estimated by one-dimensional numerical orbit calculations showing the designed structure had enough performance as TWDEC.