Retractable Loop-Gap Resonators for Electron Paramagnetic Resonance Imaging with In Situ Irradiation Capabilities

A retractable split-top loop-gap resonator for both continuous wave and pulse electron paramagnetic resonance imaging of small animals with open, clam shell style design to allow convenient access to the sample for in situ animal irradiation is described. The resonator can be either rigidly attached to the animal support bed or floated independently from the bed to avoid communication of the mechanical vibrations of the bed to the resonator. Multiple split-top resonators for different animal sizes were built and tested. The characteristics of split-top resonators are comparable with those of loop-gap resonators used previously. The imaging experiments that involved the sham animal irradiation between pairs of images demonstrated very good maintenance of animal position between images. (C) 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 39B: 167-172, 2011