  We study pion production from proton synchrotron radiation in the presence of
strong magnetic fields. We derive the exact proton propagator from the Dirac
equation in a strong magnetic field by explicitly including the anomalous
magnetic moment. In this exact quantum-field approach the magnitude of pion
synchrotron emission turns out to be much smaller than that obtained in the
semi-classical approach. However, we also find that the anomalous magnetic
moment of the proton greatly enhances the production rate about by two order
magnitude.
