Parametric x-ray radiation and coherent bremsstrahlung from nonrelativistic electrons in crystals

A theoretical analysis of radiation spectra produced during the coherent interaction of nonrelativistic electrons with crystals has been carried out. The output intensity has been found to be the result of interference between two distinguishable phenomena, coherent Bremsstrahlung and parametric x-ray radiation. The latter is determined by a coherent summation of transition radiation from electrons interacting with successive crystallographic planes. The interference is shown to be considerable for the case of nonrelativistic electrons, and so allows us to describe quantitatively the experiments of Korobochko et al. (Zh. Eksp. Teor. Fiz. 48, 1248 (1965) [Sov. Phys. JETP 21, 834 (1965)]) and Reese et al. [Philos. Mag. A 49, 697 (1984)]. The conditions for possible application of coherent x-ray radiation, a comparison with synchrotron radiation, and the requirements for experimental setup are discussed.