Collision effects on the saturated electrostatic potential along a magnetic field line

Abstract

The Coulomb collision effects on a saturated electrostatic potential ͑plug potential͒ formation in the end-mirror cell of a tandem mirror were investigated by a Monte Carlo simulation of ion orbits. A non-Maxwellian electron distribution function, which leads to a modified Boltzmann law, is assumed to obtain the electrostatic potential. An ion velocity distribution is determined by the Monte Carlo simulation of ions. It was found that a saturated electrostatic potential is formed in a wide range of the Coulomb collisionality. Especially, fewer Coulomb collisions were found to create a higher saturated electrostatic potential along a magnetic field, although the Coulomb collisions are necessary for a saturated electrostatic potential formation.

Neoclassical resonant transport of a mirror cell

“…The axial profiles of the magnetic field and the anticipated electrostatic potential are shown in Fig. 1͑d͒, where the axial profile of is assumed to be constant, except for the plug/ thermal barrier mirror cells [24][25][26][27][28][29][30] located at both ends of GAMMA10. The shape of the magnetic-flux tube and the names of the mirror cells in the nonaxisymmetric region are shown in Fig.…”