Energy Loss from a Toroidal Pinch Discharge

Abstract

Most high-temperature plasma devices, and in particular pinch discharges, have energy-loss rates much larger than can be accounted for in terms of hydrogenic bremsstrahlung or quiescent plasma diffusion. This loss has been investigated for a toroidal pinch discharge machine with longitudinal stabilizing magnetic field, Perhapsatron S-4. It is found that the major energy dissipation is due to vacuum ultraviolet emission from partially stripped impurity ions. The impurity is predominantly oxygen liberated from the walls of the tube into the discharge after the pinch has been formed. Characteristics of this radiation are discussed, as well as a possible mechanism for the release of the impurity into the discharge. Comparisons between experimental results and theoretical predictions on the rate of radiation loss are given.