Calculation of Self-consistent Radial Electric Field in Presence of Convective Electron Transport in a Stellarator

Abstract

Convective transport of supra‐thermal electrons can play a significant role in the energy balance of stellarators in case of high power electron cyclotron heating. Here, together with neoclassical thermal particle fluxes also the supra‐thermal electron flux should be taken into account in the flux ambipolarity condition, which defines the self‐consistent radial electric field. Since neoclassical particle fluxes are non‐linear functions of the radial electric field, one needs an iterative procedure to solve the ambipolarity condition, where the supra‐thermal electron flux has to be calculated for each iteration. A conventional Monte‐Carlo method used earlier for evaluation of supra‐thermal electron fluxes [1] is rather slow for performing the iterations in reasonable computer time. In the present report, the Stochastic Mapping Technique [2, 3] (SMT), which is more effective than the conventional Monte Carlo method, is used instead. Here, the problem with a local monoenergetic supra‐thermal particle source ...