The Boltzmann equation allows a study of the effect of electron-electron scattering on the anisotropy of the electron distribution in a large electric field. An effective electron-electron scattering rate $\frac{1}{{\tau }_{\mathrm{ee}}}$ relates how the quadrupole moment of the distribution in velocity space relaxes, lower moments being preserved by electron-electron scattering. We report (1) calculated distribution functions and (2) the density and drift-velocity dependence of $\frac{1}{{\tau }_{\mathrm{ee}}}$ for realistic electron-electron scattering.

• Received 30 May 1986

DOI:https://doi.org/10.1103/PhysRevLett.57.1084