  The dominant emission from bare strange stars is thought to be
electron-positron pairs, produced through spontaneous pair creation (SPC) in a
surface layer of electrons tied to the star by a superstrong electric field.
The positrons escape freely, but the electrons are directed towards the star
and quickly fill all available states, such that their degeneracy suppresses
further SPC. An electron must be reflected and gain energy in order to escape,
along with the positron. Each escaping electron leaves a hole that is
immediately filled by another electron through SPC. We discuss the collisional
processes that produce escaping electrons. When the Landau quantization of the
motion perpendicular to the magnetic field is taken into account,
electron-electron collisions can lead to an escaping electron only through a
multi-stage process involving higher Landau levels. Although the available
estimates of the collision rate are deficient in several ways, it appears that
the rate is too low for electron-electron collisions to be effective. A simple
kinetic model for electron-quark collisions leads to an estimate of the rate of
pair production that is analogous to thermionic emission, but the work function
is poorly determined.
