Photon - Axion Conversion Cross Sections in a Resonant Cavity

Photon - axion conversions in the resonant cavity with the lowest mode are considered in detail by the Feynman diagram method. The differential cross sections are presented and numerical evaluations are given. It is shown that there is a resonant conversion for the considered process, in which the conversion cross sections are much larger than those of the wave guide in the same conditions. Some estimates for experimental conditions are given from our results.