Investigation of plasma confinement 1 = 1 torsatron Vint-20

From 3rd international symposium on toroidal plasma confinement; Garching, Germany (26 Mar 1973). The toroidal l = 1 torsatron Vint-20'' with a spatial magnetic axis, as distinguished from the stellarator classical scheme, has only one helical winding with a modulated winding angle, this winding producing both longitudinal and helicoidal magnetic fields. Investigations of magnetic field structure by means of the electronbeam method showed the working volume to be limited by the helical corragated magnetic surface with the spatial magnetic axis. Preliminary experiments on plasma confinement in Vint-20'' were made at quasi-stationary magnetic field strengths up to approximately 2 kOe. Plasma was produced by a titanium injector placed close to the last magnetic surface. For measuring plasma parameters and confinement time, moving electric probes and multimode resonator methods were used. These measurements showed that the maximum density of trapped plasma was approximately 1 x 10/sup 10/ cm/sup -3/ , and its boundary agreed with dimensions of the last closed magnetic surface. (GE)