Some Efficiency Measurements of the Theta-Pinch

Abstract

A calorimeter technique has been developed to measure the transfer efficiency of the theta-pinch in converting capacitively stored electrical energy to plasma energy. Circuit-decay measurements show that the efficient theta-pinch circuit decay consists of a two-stage circuit decay and that the inefficient theta-pinch consists of a three-stage decay. With the use of the circuit decay data, a modified transfer efficiency measurement technique has been developed for a two-stage decay which is approximately as accurate as the calorimeter technique and very much quicker and easier to make. Measurements have been made to evaluate the transfer efficiency of the theta-pinch in argon at pressures of 2 and 5 Torr with different tube sizes and with different coupling impedances. These measurements show that within the present range of parameter values a transfer efficiency as high as 59% is possible.