Rotating plasma

Experimental and theoretical work on high-current impulsive discharges in crossed electric and magnetic fields is reviewed. Agreement between theory and experiment is considered, and attention is drawn to phenomena on which further experimentation is desirable. It is concluded, that, although good plasma containment and stability have been obtained, the temperatures and rotational energies are limited by impurity radiation and losses at the end plates. The highest recorded rotational velocities are about 6×107 cm/s, with estimated ion temperatures corresponding to 4×107 °K, under conditions where end-plate losses have been eliminated. Highest measured electron temperatures correspond to 18eV, and energy-decay times of up to 0.3 ms have been recorded. Unless impurities can be eliminated, the use of rotating-plasma devices for thermonuclear purposes must be ruled out, but there are possibilities of engineering applications for a device which changes its capacitance from picofarads to microfarads in a few microseconds.