# Numerical solution of the Fokker-Planck equation with a dc electric field

## Description

Abstract Using the IMSL package TWODEPEP, the full non-relativistic Fokker-Planck equation is solved numerically for the runaway electron distribution function in the presence of a dc electric field. A set of partial integro-differential equations derived from a Legendre expansion of the Fokker-Planck equation is solved simultaneously for the electron distribution parts up to f_3with f_0non-Maxwellian and including the full electron-electron collision operator. The runaway distribution function an... Title of program: FPLEGEND Catalogue Id: ACJA_v1_0 Nature of problem A code is presented that solves numerically the full non-relativistic Fokker-Planck equation using the IMSL package TWODEPEP, for the runaway electron distribution function in the presence of a dc electric field. Most other Fokker-Planck codes use a partially linearized form of this equation, which results in the wrong Spitzer conductivity. Here we aim to apply the full, rather than partially linearized, Fokker-Planck equation, which includes not only electron-electron collisions between the per ... Versions of this program held in the CPC repository in Mendeley Data ACJA_v1_0; FPLEGEND; 10.1016/0010-4655(92)90014-P This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)