Potential formation due to plasma injection along converging magnetic field lines

Using a two-and-half-dimensional electrostatic particle simulation code, potential formation in a high-speed plasma flow along converging magnetic mirror field lines has been investigated. When a plasma flows into the converging magnetic field region, a large potential jump with φ>Ts/e (Ts: electron temperature, e: electronic charge) is formed along the magnetic field lines, increasing with an increase in the mirror ratio or the plasma flow speed. The results are compared with those in the previous theoretical analyses and particle simulations for a one-dimensional configuration. The simulation is found to yield a good agreement with the results observed in the Q-machine experiment [N. Sato et al., Phys. Rev. Lett. 61, 1615 (1988)]. copyright 1995 American Institute of Physics