ESTIMATES OF THE RELATIVE MAGNITUDES OF THE ISOTROPIC AND ANISOTROPICMAGNETIC-DIPOLE HYPERFINE INTERACTIONS IN ALKALI-METAL-NOBLE-GAS SYSTEMS

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].