Minimum Density Requirements for Critical Ionization Velocity in a Rapidly Rotating Plasma

Rapidly rotating plasmas show promise in applications such as fusion energy and large-scale x-ray generation because of their potential to confine plasma in a magnetic mirror configuration and the tendency of the shear velocity to mitigate instabilities from forming [1]. The Maryland Centrifugal Experiment (MCX) was a magnetized rapidly rotating plasma experiment that was able to reach the critical ionization velocity (CIV) at the midplane of the experiment's geometry [2]. CIV is the velocity, in this case the rotational velocity of the plasma, that when exceeded, a neutral traveling through a magnetized plasma will rapidly ionize [3]. A second generation of MCX is being built at the Air Force Research Laboratories (AFRL) to explore CIV phenomena further. One primary objective of this experiment is to pinpoint the neutral density needed for CIV to occur. There is no minimum density of neutral seed gas listed in the literature and this would be useful knowledge in the field of rapidly rotating plasmas. Preliminary results will be presented.