Nonlinear Debye-Onsager-Relaxation-Effect
  The quantum kinetic equation for charged particles in strong electric fields is used to derive the nonlinear particle flux. The relaxation field is calculated quantum mechanically up to any order in the applied field provided a given Maxwellian plasma. The classical limit is given in analytical form. In the range of weak fields the deformation of the screening cloud is responsible for the Debye-Onsager relaxation effect. 
K. Morawetz