Transition radiation as a source of quasi-monochromatic X-rays

TL;DR

This paper demonstrates how collimated transition radiation from ultrarelativistic particles in a periodic N-foil stack can be used to generate quasi-monochromatic X-rays with tunable frequency and good spectral purity.

Contribution

It introduces a method to produce tunable, quasi-monochromatic X-rays using collimated transition radiation from a carefully designed N-foil radiator.

Findings

Peak frequency depends on plasma frequency and foil thickness.

Peak height scales with the number of foils N.

Collimation angle affects the spectral width and intensity.

Abstract

Transition radiation (TR) from ultrarelativistic particles is considered. It is shown that performing collimation of the TR from the periodic N-foil stack (parameters of which are selected in a appropriate manner) one obtains the spectrum of the TR which has a form of a peak position of which $\omega_1$ depends on the plasma frequency and the thickness of the radiator foils. The height and width of the peak depend on the collimation angle $\vartheta_c$. The height of the peak for given $\vartheta_c$ is proportional to N. Selecting parameters one can have the source of X-rays of desired frequency with rather good monochromaticity.