Experiments on the heating and energy balance of a reversed field pinch

Experiments were performed in the toroidal Eta-Beta device for the purpose of obtaining direct information on the energy balance of a stable reversed field pinch. The Eta-Beta device is described. Two different regimes were observed, a stable or low current regime, and an unstable or high current regime. For the stable case, the plasma energy remains practically constant during decay, which indicates an approximate balance between ohmic heating and losses. Loss mechanisms exceed the ohmic heating during decay in the high current case. Impurity line radiation is thought to be the main loss mechanism. Several plasma parameters are reported and discussed with reference to the diffusion of the pinch configuration.