Models of low-beta plasma expansion across magnetized vacuum

Detailed understanding of the microphysics associated with dynamic penetration of low-beta plasmas across magnetic fields has important implications for a number of applications including magnetic-fusion-energy (MFE), high-power transmission-lines, and charged-particle-beam diodes. Analytic models providing linear growth rates and characteristic wavelengths and frequencies for unstable modes at the interface between plasma and vacuum regions are presented and compared with detailed particle-in-cell simulations. The simulations treat both collisionless and collisional plasma regimes in a variety of configurations. Results of this combined theoretical analysis are compared with measurements from several experiments including magnetized electron-beam-diodes and high-power, magnetically-insulated transmission-lines. Potential applications of this modeling to MFE are discussed.