COMPRESSION OF COMPACT TOROIDS IN CONICAL-COAXIAL GEOMETRY

Experiments to form, compress, and accelerate compact toroids are desc ribed. A 1-m-diam, two-stage, puffed gas, magnetic field embedded coax ial plasma gun is used. Emphasis is on conical compression. Discharges were in the several mega-ampere, few microsecond rise time range. Mag netic probe data suggest that 1/(r.deltar) compression of the toroid f ield is achieved, consistent with theoretical prediction. The magnetic field pulse and electron density pulse due to the compact toroid corr elate in space and time. The compact toroid species is the injected ga s species and precedes electrode plasma by several microseconds. The p oloidal magnetic field precedes the azimuthal magnetic field. The time of arrival of the axial magnetic field compared with the axial positi on is consistent with the mean current axial position trajectory obtai ned from inductance growth.