Diffracted transition radiation of relativistic electrons in an artificial periodic structure

Abstract

A theory concerning the coherent X ray radiation of relativistic electrons crossing an artificial periodic medium in Laue scattering geometry has been constructed. Expressions describing the spectral angular characteristics of radiation in the Bragg scattering direction have been obtained and studied. Radia tion is considered in analogy with that in the crystal medium as a result of the coherent summation of the con tributions of two radiation mechanisms, in particular, parametric X ray radiation (PXR) and diffracted tran sition radiation (DTR). It is shown that the DTR yield from a layered target can exceed the particle radiation yield in a single crystal radiator by one order or more under similar conditions.

Coherent X-ray radiation excited by a diverging relativistic electron beam in a single crystal

“…1) analogous to those mentioned in [19,20], we can obtain the following expressions for the specu lar and angular densities of PXR and DTR taking into…”

“…Coherent scattering of X rays emitted by a relativ istic electron in a crystal was described in [17][18][19][20] using the dynamic theory of diffraction of X ray waves. In these publications, the dynamic theory of coherent X rays emitted by a relativistic electron in a crystal was constructed for the general case of reflection of the electron field for a system of parallel reflecting layers of a target placed at any angle relative to the target sur face.…”

Diffracted transition radiation of a relativistic electron in a three-layer structure

“…The emission and diffraction of X-ray waves in the crystal layer in direction kg can be described in the two-wave approximation of dynamic diffraction the ory [24] analogously to [22,25] Considering the emission process in a three-layer structure analogously to emission in a two-layer struc ture [23] and using the apparatus of dynamic theory of diffraction of X-ray waves in the crystal wafer described in [22,25], we obtain the following expres sion for radiation amplitude ^)Rad in the direction of Bragg scattering, which can be written as the sum of the amplitudes of diffracted transition radiation and parametric X-ray radiation: j4s)RcLd _ 2 " ^DTR ^PXR? (3a) …”