Planned Electron Density Measurements with a Multiple-Beam Interferometer for the Centrifugal Mirror Fusion Experiment

Plans, designs, and methods for interferometric density measurements at the Centrifugal Mirror Fusion Experiment (CMFX) are presented. We expect axially symmetric and reproducible plasmas; a single, and eventually multiple beam, 1310 nm NIR fiber-optic interferometer will be used at CMFX. The main interferometer components will be off-the-shelf, speeding up its design and implementation, reducing overall cost, and providing modularity to all measurement beams. Utilizing a rigid 2D mechanical alignment system, and CMFX’s many near-midplane ports, line integrated density measurements will be possible at multiple axial and radial locations inside the mirror. Using Abel inversion, radial density profiles will be calculated at midplane and near the mirror throat. Density measurements at midplane and near the mirror throat will help track cone losses and validate theoretical models for confinement and stability. Methods and considerations regarding testing, installation, data interpretation, and vibration mitigation will also be discussed.