Transient oscillations under strongly mismatched Hartmann-Hahn conditions.

Based on the standard 2D Polarization inversion experiment, a new pulse sequence (PI-TAPF) is proposed. It represents a combination of Polarization Inversion and TAPF (time averaged precession frequency) sequences. The depolarization period consists of phase-alternating intervals of different duration in the I channel. The pulse sequence yields transient oscillations under the strongly mismatched HH conditions where the required power for the dilute spins is reduced by a factor of 5. Experimental results recorded for a sample of ferrocene powder are well reproduced by numerical simulations.