Year: 2025
Type: article
Abstract: The kinetic stability of collisionless, sloshing beam-ion ( $45^\circ$ pitch angle) plasma is studied in a three-dimensional (3-D) simple magnetic mirror, mimicking the Wisconsin high-temperature superconductor axisymmetric mirror experiment. The collisional Fokker–Planck code CQL3D-m provides a slowing-down beam-ion distribution to initialize the kinetic-ion/fluid-electron code Hybrid-VPIC, which then simulates free plasma decay without external heating or fuelling. Over $1$ – $10\;\mathrm{\unicode{x03BC} s}$ , drift-cyclotron loss-cone (DCLC) modes grow and saturate in amplitude. The DCLC scatters ions to a marginally stable distribution with gas-dynamic rather than classical-mirror confinement. Sloshing ions can trap cool (low-energy) ions in an electrostatic potential well to stabilize DCLC, but DCLC itself does not scatter sloshing beam-ions into the said well. Instead, cool ions must come from external sources such as charge-exchange collisions with a low-density neutral population. Manually adding cool $\mathord {\sim } 1\;\mathrm{keV}$ ions improves beam-ion confinement several-fold in Hybrid-VPIC simulations, which qualitatively corroborates prior measurements from real mirror devices with sloshing ions.
Source: Journal of Plasma Physics
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,550
Funders: National Science Foundation, U.S. Department of Energy, Oak Ridge Associated Universities, Purdue University, Amazon Web Services, National Energy Research Scientific Computing Center, University of Cambridge, Advanced Research Projects Agency - Energy, Office of Science, Oak Ridge Institute for Science and Education, Advanced Research Projects Agency, Office of Advanced Cyberinfrastructure, Fusion Energy Sciences
Awards: G1453181110, G1615354355, Track 4: Advanced CI Coordination Ecosystem: Monitoring and Measurement Services, G2454646645, G2917895714, G3562386289, Track 1: ACCESS Resource Allocations Marketplace and Platform Services (RAMPS), G4010157413, ACO: An Open CI Ecosystem to Advance Scientific Discovery (OpenCI), G473123490, Track 3: COre National Ecosystem for CyberinfrasTructure (CONECT), G515206079, G5367127336, Co-Evolution of Cosmic Rays and Thermal Plasma in Galaxy Clusters, G5464919783, G601061201, G6017181652, G7619220232, Track 2: Customized Multi-tier Assistance, Training, and Computational Help (MATCH) for End User ACCESS to CI, G8570346810
OpenAlex ID: W4411004751