Density Expansion for the Mobility of Electrons in Helium Gas
  We calculate the electron mobility for a quantum Lorentz model, which provides a realistic description of electrons in Helium gas, to second order in the gas density. We show that this provides sufficient theoretical information to allow for an experimental observation of the famous logarithmic term in the density expansion. Detailed predictions, and a discussion of a suitable parameter range, for such an experiment are given. 
K.I.Wysokinski, W.Park, D.Belitz, and T.R.Kirkpatrick