Slotted resonator: principles and applications for high-frequency imaging and spectroscopy on electrically conducting samples.

The electric equivalent of an Alderman-Grant slotted resonator is analyzed in terms of two one-turn solenoids interconnected by a slotted cylinder resonator. The homogeneity of the magnetic RF field is probed using NMR imaging techniques and found to be comparable to that of a saddle-shaped coil. The dielectric losses of the slotted resonator are intrinsically low and much smaller than the inductive losses. Inductive losses are found to be proportional to the sample conductivity and to the fourth power of the sample diameter.