PARAMETIC X-RADIATION IN A MOSAIC CRYSTAL OF PYROLYTIC

Anomalously high orders of parametric x-radiation of 900-MeV electrons in a crystal of pyrolytic graphite have been observed experimentally at the Tomsk synchrotron. This observation supports results found by F iorito et al. [Phys. Rev. Lett. 71, 704 (1993)] at an electron energy of 90 MeV. The angular distributions of the photons in the peaks of th e parametric x-radiation have been measured up to fourth order for the first time. The results are compared with the kinematic theory of par ametric x-radiation. (C) 1994 American Institute of Physics.