Dynamics of nuclear spins at large polarizations

Equilibrium spin time auto- and cross-correlation functions, determining the rate of thermal mixing in the system of common and rare nuclear spins under high polarizations of common spins, are calculated within the framework of a spin-wave approximation. The properties of the correlation function obtained are studied. It is shown that the cross-correlational functions attenuate exponentially with an increase of distance between the nuclei. It is found that at low dipole temperatures the behaviour of auto-correlation function is of an oscillatory character. 23 refs., 3 figs