Numerical solution of the electron distribution function in tandem-mirror thermal barriers

Abstract

The relativistic Fokker–Planck equation is solved with electron cyclotron resonance heating (ECRH) in a magnetic mirror for an assumed thermal barrier electrostatic potential profile. Two methods—a finite element technique and a Monte Carlo technique—give nearly the same results. Favorable comparison is made with recently obtained analytical expressions for the relation between axial density ratios and potential profile using parameters expected in the TMX-U and MFTF-B experiments.