Plasma physics research. Technical progress report, 1 February 1979-30 September 1980

Progress during the 20-month period, Feburary 1, 1979 to September 30, 1980 on the University of Wisconsin Plasma Physics contract is described. Most of the work centers around two large experimental devices, the Levitated Octupole and Tokapole II. A major upgrade of the Octupole was begun to include 1.8 MW of neutral beam heating and 2 MW of ICRH. Meanwhile, gun optimization and low field operation has resulted in the attainment of 35% beta, a factor of 9 above the single fluid ballooning limit. The Tokapole has operated reliably for the past two years and has been used to study axisymmetric instability of dee, inverse dee, and square shaped plasmas. Low q (approx. 0.6) discharges with flat current profiles are obtained. ICRF heating studies were brought to a conclusion. The device is presently being used to study Alfven wave heating, ECRH startup, poloidal ohmic heating, and plasma ohmic heating, and plasma surface interactions. Smaller efforts on divertor simulation and plasma potential studies in a single ring device and plasma theory are also described