The ambipolar trap

Experimental studies between 1978 and 2004 on ambipolar (tandem) mirror traps are reviewed. Results on the formation of ambipolar ion-confining barriers and the formation of thermal barriers for thermally insulating electrons in ion barriers from plasma confined in a solenoid are discussed. Achievements on improving longitudinal plasma confinement and limiting transverse plasma losses in the trap are reviewed. The reasons for the limited density of solenoid plasma in TMX-U and GAMMA-10 machines are discussed. Some results on the MHD stabilization of plasma and on the suppression of plasma microinstabilities are reviewed. Prospects for constructing ambipolar fusion reactors are discussed