Speaker
Description
In the framework of classical electrodynamics, polarization radiation (PR) is created by a uniformly moving charge within or near a medium. In this scenario, sources of radiation are time-varying currents induced in the medium by the electromagnetic field of a charge. Several types of PR exist, including Cherenkov radiation, transition radiation, Smith-Purcell radiation, and parametric x-ray radiation. One of the key features distinguishing PR is that its spectral properties vary among different types depending on kinematic conditions. However, the shape of the PR spectrum is primarily determined by dielectric permittivity of the medium. Although most experimental studies have centered on the development of radiation sources based on PR. I.M. Frank was the first who propose a technique for measuring and evaluating the permittivity dispersion of metals utilizing PR spectra in the optical range. The application range of this approach can be easily extended to the absorption edge region, where inner electrons become sufficiently excited either to leave the atom or to be promoted to higher energy levels. In this report, we discussed the application of polarization radiation spectrum to determining the fine structure of the absorption edges of the medium. We considered the simple geometry of radiation, where a uniformly moving charge crosses a thin foil obliquely and showed how the spectrum and the photon yield depend on the dielectric permittivity.
