Thermal barrier potential and two-dimensional space-potential measurements with gold neutral-beam probes in GAMMA 10

Abstract
Gold neutral‐beam probes are used for the space‐potential measurements in the barrier and in the central cells of the GAMMA 10 tandem mirror. The thermal barrier potential depth is directly observed by simultaneous measurements of the on‐axis space potentials at both locations. Two‐dimensional space potentials in the barrier region are measured by sweeping the probing beams with different beam energies.