Abstract
The autocorrelation function of the transversal magnetic moment is investigated in the presence of dipole-dipole interaction. For that purpose an integrodifferential equation is derived which is exact in all orders of the perturbation. The resulting equation is simplified with the aid of a linearity and Gaussian assumption and is solved numerically. Good agreement is thereby found with the experimental situation. In particular, it is shown that the physical nature of the oscillations found in the free-induction-decay experiments of Lowe and Norberg can be understood as a precession around an average internal magnetic field.