A HIGH-RESOLUTION EPR-CT MICROSCOPE USING CAVITY-RESONATORS EQUIPPED WITH SMALL-FIELD GRADIENT COILS

Cylindrical cavity resonators equipped with field gradient coils were developed for two-dimensional ERR-CT microscope systems. The field gra dient coils lie in four (or six) thin metal tubes placed along the dir ection of the microwave magnetic field in the cavity to minimize impac t on the resonator's quality factor. Two pairs of the tubes carry a 10 0 kHz current for magnetic field modulation. This cavity has high spin -detection sensitivity and can provide EPR images with submillimeter r esolution. In order to reconstruct better images from fewer projection s, we used an algebraic reconstruction technique (ART) for the two-dim ensional image reconstruction. The ART method may be suitable for not only spectral-spatial two-dimensional EPR imaging, but also spatio-tem poral EPR imaging in dynamic spin systems. Copyright (C) 1996 Elsevier Science Ltd