Density Fluctuation Measurements in C-2W FRC Plasmas

In TAE Technologies’ current experimental device, C-2W (also called “Norman”) [1], record breaking, advanced beam-driven field reversed configuration (FRC) plasmas are produced and sustained in steady state utilizing variable energy neutral beams, advanced divertors, end bias electrodes, and an active plasma control system. Line-integrated electron density measurements from the multi-chord far-infrared (FIR) interferometer system provide high resolution, high bandwidth fluctuation measurements that can be used to probe the interactions of injected energetic particles with the FRC. Beam-induced instabilities like micro-bursts have been observed at frequencies above those observed for rotational instabilities (typically a few tens of kHz) [2]. For mode activity found above 100 kHz, measurements of the spatial structure and location of the instabilities are presented for different plasma conditions.

[1] H. Gota et al., Nucl. Fusion 61, 106039 (2021)

[2] B. H. Deng et al., Nucl. Fusion 58, 126026 (2018)