The ionization of H, He or Ne atoms using neutrinos or antineutrinos at keV energies

We calculate the ionization cross sections for H, He or Ne atoms using νe and ν̄e scattering at keV energies. Such cross sections are useful for e.g., ν̄e-oscillation experiments using a tritium source. Using realistic atomic wave functions, we find that for Eν≲10 keV the atomic ionization cross sections, normalized to one electron per unit volume, are smaller than the corresponding free electron ones, and that they approach it from below as energies of 20 keV are reached.