NUMERICAL-SIMULATION OF 2-PULSE NMR IN SUPERFLUID HE-3-B

Two-pulse NMR has been simulated numerically in the spatially uniform approximation in the Leggett-Takagi two-fluid model. In the particular configuration considered, the first rf pulse, at the Larmor frequency Omega(L), sends the system into the regime of the long-lived Brinkman -Smith mode. The next rf pulse, at the sum or difference frequency Ome ga(L)+/-Omega(Ld), creates nonequilibrium state. When a mechanism anal ogous to the mechanism of catastrophic relaxation operates, this noneq uilibrium state may lead to the destruction of the coherent induction signal. (C) 1994 American Institute of Physics.