Boris M. Bolotovskii

Application of the method of images in the problems of transition radiation in a dihedral angle

Application of the method of images to the description of transition radiation generated when a charged particle passes through a dihedral angle formed by perfectly conducting planes is considered. It is shown that the electromagnetic field generated when a charged particle passes through a dihedral angle of α = π/m is equivalent to the field generated when 2m charged particles (a given particle with charge q and 2m − 1 images with charges ± q of alternating signs) instantaneously start to move. Expressions are obtained that describe the field of transition radiation in the wave zone as a sum of the fields generated by the starting particles. The spectral-angular distributions of radiation in dihedral angles of α = 90°, 60°, 45°, 36°, and 30° are calculated. Specific features of this transition radiation are considered. It is suggested that this radiation can be used to diagnose the spatial distribution and the direction of motion of charged particles.

Transition radiation in a system of two cascaded gratings

Transition radiation that arises when a charged particle passes through two consecutive plane gratings is considered. The gratings are made up of parallel metal wires. The planes of the gratings are parallel to each other and perpendicular to the direction of motion of the particle. The conductors of one of the gratings are perpendicular to the conductors of the other. It is shown that the generated transition radiation has elliptic polarization; the ellipticity and the sign of rotation depend on the angle of radiation, the distance between the gratings, and the velocity of the charged particle.

Special features of the coherent transient radiation of an electron bunch accelerated in a microtron

The angular distribution of radiation generated by a relativistic electron bunch penetrating through a metal foil was experimentally measured at angles much greater than the characteristic angle γ−1. The experiments showed that the emission at large angles exhibits an asymmetric angular distribution with a pronounced maximum. The results of numerical calculations of the transient radiation of an electron bunch accelerated in a microtron agree with the experimental data.