Comment on "Pressure dependence of wall relaxation in polarized He^3   gaseous cells." by W. Zheng, H. Gao, Q. Ye, and Y.Zhang
  The authors have demonstrated a strong linear pressure dependence of the longitudinal relaxation time for He^3 at room and cryogenic temperatures in a given experimental setup. They offer a theoretical explanation of the effect based on diffusion theory in the bulk and an unusual boundary condition. We question the physical basis of the boundary condition and suggest some alternate explanations of the observations. 
A. Petukhov, J. Chastagnier, C.M. Swank and R. Golub
physics.atom-ph cond-mat.other