Symmetrized pulse sequences in high resolution NMR in solids

Abstract

A systematic approach is developed for the improvement of the line narrowing efficiency of multipulse cycle sequences. This is based on the symmetrization of pulse cycles and exploits the useful properties of reflection symmetry subcycles. An example of a new pulse sequence is given which removes the dipolar interaction to third order in the time expansion of the logarithmic operator. Ways are discussed for compensating multipulse cycles for the effects of finite rf pulse width and rf inhomogeneity and a fully compensated version of the new pulse sequence is given.