On neutrino-atom scattering in searches for neutrino magnetic moments
  In the experimental searches for neutrino magnetic moments using germanium detectors one studies the ionization channel in the neutrino-atom scattering. We find that the so-called stepping approximation to the neutrino-impact ionization is exact in the semiclassical limit, and that the deviations from this approximation are very small. 
Konstantin A. Kouzakov, Alexander I. Studenikin, and Mikhail B.   Voloshin
hep-ph hep-ex