Improvement Of Electron Recovery Using A Magnetic Field With A Low Mirror Ratio In A Secondary Electron Direct Energy Converter Simulator

To recover the energy of fast protons created in D-He-3 fusion, a secondary electron (SE) direct energy converter was proposed, in which protons penetrated aligned metal foil electrodes, and their energy was converted into that of emitted SEs. Simulated experiments showed the problem of energy recovery of the SEs, which arose because of the magnetic mirror effect disturbing the arrival of SEs at collectors in the guiding magnetic field. To solve this problem, we propose the use of ring-type magnets to realize lower mirror ratio structures. As a result, better energy recovery is obtained for low mirror ratios because a larger part of the energy of the SEs is converted into components parallel to the magnetic field, which correspond to the direction normal to the surface of the collector. (C) 2020 The Japan Society of Plasma Science and Nuclear Fusion Research