Forward diffracted parametric X radiation from a silicon single crystal

Experiments were performed with the 855 MeV electron beam of the Mainz Microtron MAMI which focused on still open questions in the X-ray emission process upon traversal of ultra relativistic electrons through single crystals. To elucidate the quest of kinematical versus dynamical production of PXR the radiation from silicon single crystal targets, emitted close to the electron direction, has been studied. The observed interference structures show that PXR is produced in a dynamical process.