Speaker: Carlos Rovero-Talamas, University of Maryland, Baltimore County
Abstract: The Centrifugal Mirror Fusion Experiment (CMFX), a research effort led by UMBC in partnership with the University of Maryland, College Park, has been funded since 2020 by ARPA-E to test the physics of centrifugal mirrors and demonstrate magnetic confinement at parameters relevant to sustained fusion production. The CMFX is the second-generation centrifugal mirror at Maryland, but the first one in the world to use superconducting coils, with a maximum field of 3-T. It is also the first one to achieve sustained operation (limited only by the passive cooling of components). Temperatures, densities, and momentum confinement times in CMFX are now high enough to produce small amounts of fusion energy when experimenting with deuterium plasmas. The applied voltages result in supersonic E x B rotation, with velocities in the azimuthal direction exceeding 1,700 km/s in deuterium plasmas. The high velocities also generate flow shear and heating, resulting in total sustained neutron productions estimated at 10^7 neutrons per second. These neutron rates indicate plasma temperatures must be around 1 keV for plasma densities of 2 – 4 x 10^18 m^-3. Neutral gas can be added in bursts during plasma discharges, leading to an increase in density and neutron production that slowly decays with confinement times of tens to hundreds of milliseconds. Experiments are underway with two He-3 detectors to time-resolve the neutron production with respect to applied voltage, and to spatially resolve the plasma region producing the neutrons.