SELECTIVE DETECTION OF MULTIPLE QUANTUM TRANSITIONS IN NUCLEAR MAGNETIC RESONANCE

摘要

PATENT APPLICATION of RICHARD R. ERNST for SELECTIVE DETECTION OF MULTIPLE QUANTUM TRANSISTIONS IN NUCLEAR MAGNETIC RESONANCE Selected orders of multiple quantum transitions may be detected by preparing a statistical non-equilibrium state of an assembly of gyromagnetic resonators of selected phase with respect to a subsequent mixing pulse. After an evolution period, t1, a 90.degree. mixing pulse is applied and the free induction decay is sampled as a function of time, t2, The signal functions Si (t1 , t2, .PHI.i) is developed for systematically varied values of t1 and specially selected values of .PHI.i. Linear combinations of the signal functions Si yield, after Fourier transformation a two dimensioanl spectrum of multiple quantum transitions limited by the choice of phase and linear combination. In another embodiment, a magnetic gradient pulse is applied during the evolution period and resulting multiple quantum transitions yield spectral peaks of width dependent upon the order of such transitions. In particular, all spectral peaks may be removed from resulting spectra save only zero order transitions.