MAGNETIC COMPRESSION OF TOROIDAL PLASMA PART (I)

Abstract

The possibility of confining the plasma in a toroidal shape by means of axial magnetic field of high rate of rise has been examined in our laboratory. The plasma column was pre-heated with the induced axial current by' ohmic heating' before it is adiabatically compressed. The glass torus of 600 m/m, major and 120 mm minor diameters was used. The plasma machine was most carefully designed to provide high degree of uniformity of the electromagnetic field in the torus. The plasma of air and He was constricted to about 1/3 of the torus inner diameter, around the center axis for 10 to 20 μS, and after that the drift of the column due to the charge separation was observed to drive it toward the wall. The temperature was estimated from the plasma conductivity to attain as high as 100, 000 to 200, 000oK. Magnetic probe and spectroscopic disgnostics have also been applied. In part I, Discussions on the designing considerations about the plasma machine and the results of electrical measurements with streak photographs of the plasma appearance are given. The results of magnetic probe measurements and the spectroscopic investigations are now being prepared for publication and will be reported in part II.