An efficient energy-conserving numerical model for the electron energy distribution function in the presence of electron-electron collisions

An efficient algorithm to calculate the contribution of electron-electron collisions in the Boltzmann equation for free electrons, in the two-term approximation is presented. The electron-electron collision term must be energy-conserving, while, due to non-linearity, commonly used algorithms do not satisfy this requirement. The efficiency of the algorithm make feasible the use of a non-linear iterative solver to conserve electron energy in electron-electron collisions. The performance of the proposed algorithm has been compared with standard numerical schemes obtaining: 1) considerable gain in computational time: 2) the conservation of the total electron energy density in e-e collisions under the required tolerance. (C) 2010 Elsevier B.V. All rights reserved.