Ohmic-heating and plasma-compression experiments in the Tuman-3 tokamak

The principal systems of the Tuman-3 tokamak are described, and their characteristics are reported. Results of studies of ohmic heating in low toroidal fields (2.5--5 kG) at currents in the range 70--100 kA are reported. Under these conditions the safety factor is low, 2<q<3, beta is high, β/sub T/< or approx. =2%, and there are pronounced sawtooth oscillations in the density and other properties. The density oscillation reaches a relative magnitude of 30% at the center of the plasma column. The results of experiments on adiabatic compression of the plasma by an increasing toroidal field with a compression factor α = 2 are summarized. The observed increase in the density at the center of the plasma column and the ion heating agree with the adiabatic law. The outlook for the operation of this device is examined. The plasma parameters expected when the compression is combined with ion cyclotron heating are given