Fusion programs in applied plasma physics and development and technology, fiscal 1984

The GA programs in Applied Plasma Physics and Development and Technology have registered substantial accomplishments during fiscal 1984. Theoretical work in the MHD area has contributed to further understanding of the physics governing low-g, high-(BETA) tokamak discharges, including the effects of a cold plasma mantle and an edge-temperature pedestal. The unviersal scaling law for the maximum (BETA) stable to ideal-MHD modes has been verified for Doublet III and has also been validated for JET, DIII-D, and a Double Dee configuration. Experimental work in Applied Plasma Physics included the development of two new high-energy diagnostics, one for gamma rays and one for tritons (or, in a reactor, alpha particles), both of which can yield essential physics information that is not readily obtainable from the panoply of existing diagnostic instruments. The development of current-density profile diagnostic continued, and it was found that the instrument could also be used to obtain relative density profiles throughout a tokamak discharge. And tests of an ergodic magnetic limiter scheme indicated that the configuration has the potential to create a stable, radiating boundary layer while reducing the heat load to the walls in future high-power devices. The work carried out in the area of Development and Technology included a group of reactor systems design studies that bring into focus some of the challenges that will be faced by the engineers of fusion power equipment. Closer to realization are advanced rf equipment and superconducting magnet developments, both under design in the area of plasma technologies. Technological developments that apply directly to current experiments as well as to future devices comprise the rest of the GA D and T program.