Dk. Walter et al., ESTIMATES OF THE RELATIVE MAGNITUDES OF THE ISOTROPIC AND ANISOTROPICMAGNETIC-DIPOLE HYPERFINE INTERACTIONS IN ALKALI-METAL-NOBLE-GAS SYSTEMS, Physical review. A, 58(5), 1998, pp. 3642-3653
We present a detailed theoretical analysis of the noble-gas nuclear-sp
in relaxation due to the anisotropic magnetic-dipole hyperfine interac
tion between the: noble-gas nucleus and alkali-metal valence electron
vis a vis the already well-understood (spin-conserving) isotropic magn
etic-dipole hyperfine interaction in alkali-metal-noble-gas systems. W
e find that, for all pairs in which the noble gas is not helium, the p
redicted spin-relaxation rate from the anisotropic interaction does no
t exceed 2.5% of the rate from the isotropic interaction, thereby not
appreciably limiting the maximum noble-gas nuclear polarization attain
able via spin-exchange collisions with polarized alkali-metal atoms. F
or alkali-metal-helium pairs, we predict that the anisotropic interact
ion has a slightly larger relative effect, perhaps limiting the nuclea
r polarization to similar to 95% of the electronic polarization in the
Rb-He-3 system; however, our confidence in the helium results is limi
ted by a lack of knowledge of the interatomic potentials necessary for
the calculation. [S1050-2947(98)00711-2].