The collision operator in kinetic equation for a spin-polarized low-density electron gas

We derive the collision operator in kinetic equation for a low-density spin-polarized gas of fermions (electrons). We take into account the collisions between the fermions and the collisions with much heavier particles (ions), forming a randomly located stationary background (gas). An important new fact is that the scattering amplitude of the particles on each other is not assumed to be small, which could be obtained, for example, by the first-order Born approximation. The obtained collision operator can be used in the kinetic equation, including the case of relatively cold, low-density spin-polarized plasma.