Electrode biasing system in C-2W

In TAE Technologies’ current experimental device, C-2W (also called “Norman”) [1], record breaking, advanced beam-driven field reversed configuration (FRC) plasmas [2] are produced and sustained in steady state utilizing variable energy neutral beams (15 –- 40 keV, total power up to 20 MW), advanced divertors, end bias electrodes, and an active plasma control system. The end bias electrode system provides stabilization and heating of the high-beta axisymmetric plasmas by inducing azimuthal plasma rotation via the application of radial electric fields [3]. The bias electrodes and limiters are designed for high voltage operation and were tested for up to 15 kV in vacuum. The bias voltage of -2 kV (on the device axis) with the total current through the electrodes of 5-7 kA were proven sufficient for stabilization of the C-2W plasmas. The details of the electrode-biasing system, protection and measurement circuits, as well as experimental results will be presented. \newline [1] H. Gota \textit{et al}., Nucl. Fusion \textbf{59}, 112009 (2019).\newline [2] M.W. Binderbauer \textit{et al}., AIP Conf. Proc. \textbf{1721}, 030003 (2016).\newline [3] A.D. Beklemishev \textit{et al}., Fusion Sci.Technol. \textbf{57}, N4, 351 (2010).