Key points are not available for this paper at this time.
We have developed a theory for the effect of magnetic-field inhomogeneities on the spin relaxation of gases in cells with negligible relaxation at the walls. There is a characteristic pressure p^* at which the time ₃ required for an atom to diffuse across the cell is equal to the time ₋ required for the spin to precess by one radian in the mean magnetic field. For ``high pressures, '' pp^*, the longitudinal spin-relaxation time T₁ is inversely proportional to the pressure. This is the classic pressure dependence discussed in the literature. The new results reported in this paper are that at ``low pressures, '' pp^*, the pressure dependence changes and the longitudinal relaxation time becomes directly proportional to the pressure; that is, motional narrowing occurs. We show that the transverse relaxation time T₂ will ordinarily be proportional to the pressure at both low and high pressures, but with different coefficients. There is also a small, pressure-dependent shift of the Larmor frequency associated with the field inhomogeneity.
Cates et al. (Fri,) studied this question.