Анализируются спектрально-угловые характеристики поляризованного черенковского излучения релятивистских частиц в кварцевом стекле в ультрафиолетовом, оптическом и терагерцовом спектральных диапазонах при наклонном влете в мишень. Излучение, генерируемое в тонких кварцевых мишенях, может найти применение как для создания монохроматических направленных источников излучения в различных спектральных диапазонах, так и для диагностики угловых характеристик пучков ускоренных релятивистских частиц. Ключевые слова: черенковское излучение, переходное излучение, релятивистские частицы, кварцевое стекло.

It is shown that the breaking of azimuthal symmetry during the oblique entry of relativistic particles into a thin target leads to oscillations of the spectral-angular density of polarized Cherenkov radiation along the azimuthal angle. The effect of modulation of the angular distribution of Cherenkov radiation can be observed in quartz glass on individual spectral lines in the optical and near ultraviolet ranges. The interference maxima have a small angular width not exceeding 10 –2 rad. The effect can be used in the diagnostics of the angular characteristics of beams of accelerated relativistic particles.

The spectral-angular characteristics of transition and Cherenkov radiation arising during the passage of fast charged particles through an absorbing medium at grazing incidence angles to the interface are considered. When particles escape from a target in this geometry, radiation is polarized both in the radiation plane and orthogonal to it. With an increase in the emission angle relative to the normal to the surface, the angular distribution of the radiation becomes asymmetric, the intensity of the Cherenkov-radiation component with longitudinal polarization increases significantly, and the angular width decreases. Since in the X‑ray region near absorption the spectral density of Cherenkov radiation has a pronounced maximum, the effect of radiation at grazing incidence angles of particles from the target has serious prospects for becoming an important tool in the creation of sources of polarized oriented hard electromagnetic radiation.

The spectral-angular characteristics of the electromagnetic radiation produced during the propagation of fast charged particles through an absorbing medium with finite dimensions are considered using equations of macroscopic electrodynamics. The change in its angular distribution is studied after achievement of the Vavilov–Cherenkov radiation threshold. The yield of the transition radiation produced at high particle energies and the spectral characteristics of the Vavilov–Cherenkov radiation in the X-ray frequency range are analyzed.

На основе уравнений макроскопической электродинамики рассмотрены спектрально-угловые характери-стики электромагнитного излучения, возникающего при прохождении быстрых заряженных частиц через погло-щающую среду конечных размеров. Исследовано изменение углового распределения излучения при переходе через порог излучения Вавилова – Черенкова, проанализирован вклад возникающего переходного излучения при высоких энергиях частиц и спектральные характеристики излучения Вавилова – Черенкова в рентгеновском диа-пазоне частот. DOI: 10.17223/00213411/62/3/31

Based on the equations of macroscopic electrodynamics, the spectral-angular characteristics of electromagnetic radiation are considered, which is generated during the passage of fast, charged particles through a finite-size absorbing medium. The variation in the angular distribution of the radiation overcoming the Cerenkov radiation threshold is investigated, the contribution from the generated transition radiation is analyzed at high particle energies and so are the spectral characteristics of the Cerenkov radiation within the X-ray frequency range.