Arbitrary Pulse Width in the Four-Pulse NMR Experiment

Abstract

Coherent averaging during rf irradiation can be utilized in the four-pulse nmr experiment in order to cancel the average dipolar interaction in solids. Thus an arbitrary pulse width can be used in the four-pulse experiment, leading to a total rotation angle β1 ≧ 90° of the rf pulses depending on the duty factor. Ideal timing is achieved in the classical Waugh, Huber, Häberlen sequence.