66th Annual Meeting of the APS Division of Plasma Physics Poster Session VII: Turbulence and transport in fusion plasmas | ITER | MFE Heating and Energetic Particles | Self-organized configuration FRC, RFP, Spheromak (9:30 AM - 12:30 PM) Presentation Type: POSTER Polaris, Helion Energy's seventh generation field reversed configuration (FRC) prototype has the primary goal to demonstrate direct electricity recovery from fusion. Densities in the range of 1E21 – 1E23 m-3 are expected throughout the pulsed operation of the machine. A multichannel, 1550 nm fiber-based Michelson interferometer was developed to characterize the density distribution along multiple chords of the device. Telecommunication wavelengths in the C band are combined into common transmission fiber lines using dense wavelength division multiplexing (DWDM) and amplified with Erbium-doped fiber amplifiers (EDFA). View chords are radially centered and distributed axially along the machine. Corner-cube retroreflectors are used to streamline system integration while effectively boosting signal strength due to a double pass through the plasma. Initial data from an 8-channel version of this diagnostic fielded on Helion Energy's FRC formation optimization test bed are presented. Brian Henderson (Helion) Brian Henderson (Helion), Gustaf Downs (Helion), George Votroubek (Helion)