Experimental Analysis On Variation Of The Amount Of Particles Passing Through Traveling Wave Direct Energy Converter

Traveling wave direct energy converter (TWDEC) was proposed as an efficient energy recovery device for 14.7 MeV protons produced by D-3He fusion reaction. Protons are velocity-modulated and bunched up, then induce traveling wave field which traps and decelerates themselves. In simulation experiments, it was found that the amount of particles was larger during application of modulation/deceleration field in the condition providing high efficiency than other conditions. This paper treats the phenomenon and will present results of analytical experiments and discussion. We found that ions were scattered due to modulation, and variation of the number of ions was corresponding to variation of deceleration effect. The possible mechanism of the phenomenon is scattering of particles due to bunching and its suppression due to trapping by deceleration field. In other words, high efficiency would be obtained by suppression of scattering. (C) 2019 The Japan Society of Plasma Science and Nuclear Fusion Research