Design and construction of a high homogeneity rf coil for solid-state multiple-pulse NMR

Abstract A prescription is given for construction of a coil having an optimal rf homogeneity desired, especially, in multiple-pulse solid-state NMR. The approach is to use a coil with variable pitch. The field in a helical coil and in the coil with variable pitch are compared. The field distribution across the sample and some experimental aspects associated with the nonuniformity of the rf field are also discussed.