Identifying Density Fluctuation Modes with the FIR Interferometer System in C-2W FRCs

In the 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. The density profile measurements and characterization of fluctuations are made using the powerful 14 chords FIR interferometer system [2]. A variety of coherent density fluctuation modes are observed in different discharge stages and for a range of plasma parameters and machine settings. The attempts to identify these modes by comparing the mode spatial locations and frequencies with the theoretically predicted mode dispersion relation calculated from measured plasma parameters will be presented in this effort.

[1] H. Gota et al., Nucl. Fusion 59, 112009 (2019)

[2] B. Deng at al., Rev. Sci. Instrum. 89, 10B109 (2018)