Rotating magnetic field oscillator system for current drive in the translation, confinement, and sustainment experiment

The experimental setup and test results for the similar to 125 MW rotating magnetic field current drive system of the Translation, Confinement and Sus tainment Experiment at the University of Washington are described. The osci llator system, constructed at Los Alamos National Laboratory, drives two ta nk circuits (15 kV(peak) potential, 8.5 kA(peak) maximum circulating curren t in each tank to date) operated 90 degrees out of phase to produce a 54 G rotating magnetic field with a frequency of 163 kHz (omega = 1.02 x 10(-6) s(-1)). Programmable waveform generators control "hot deck" totem pole driv ers that are used to control the grid of 12 Machlett 8618 magnetically beam ed triode tubes. This setup allows the current to be turned on or off in le ss than 100 ns (similar to6 degrees). Both tank circuits are isolated from the current source by a 1:1 air core, transmission line transformer. Each t ank circuit contains two saddle coils (combined inductance of 1.6 muH), and radio frequency capacitors (580 nF). Test results are presented for three conditions: no external load, a resistive external load, and a plasma load. A SPICE model of the oscillator system was created. Comparisons between th is model and experimental data are given. (C) 2001 American Institute of Ph ysics.