Filling factor of a paramagnetic sample in a rectangular cavity: theory and application

A computational method is presented for calculating the filling factor of a n electron paramagnetic resonance (EPR) tube in a rectangular TE102 cavity. The algorithm employs the conventional finite element method. In addition to the filling factor, the algorithm allows to calculate the quality factor and the reflection coefficient of the loaded cavity. This method allows ca lculating very accurately the EPR signal intensities from which the spin co ncentration of paramagnetic samples can be determined. A comparison between the predicted EPR signal intensities to several experimental results was f ound to be satisfactory. The method also allows optimizing the EPR tube dim ensions and its glass quality to improve measurement sensitivity. (C) 2000 Elsevier Science B.V. All rights reserved.