arXiv subjects

Andrey Tyukhtin

Publications and source records attributed to Andrey Tyukhtin.

4 recordsLinked to original sources

arXiv2023

Diffraction of a symmetric TM mode at an open-ended deeply corrugated waveguide with a small period

We investigate the diffraction of a slow symmetric TM mode by an open-ended corrugated cylindrical waveguide with a flange. This mode can be generated, in particular, by a charged particle bunch moving along the waveguide axis. We analyze the so-called ''longwave'' range when the wavelengths and the waveguide radius are much greater than the corrugation period. In this case, the corrugated waveguide wall can be replaced with a smooth one on which the so-called equivalent boundary conditions (EBC) are fulfilled. Here, we also assume that the wall is deeply corrugated, i.e. the corrugation depth is of the same order as an inverse wavenumber. The approach applied uses the solution of the corresponding Wiener-Hopf-Fock equation. This solution is in turn utilized to construct an infinite linear system for reflection coefficients which can be solved numerically using the reduction technique. The dependences of the components of the electromagnetic field on the problem parameters are obtained and analyzed. Typical radiation patterns are presented.

physics.acc-ph↗

arXiv2022

Radiation of a charged particle bunch passing through a deeply corrugated structure with a relatively small period

We analyze electromagnetic radiation from a bunch passing through a corrugated conductive planar structure. The wavelengths of the radiation are assumed to be much greater than the corrugation period. Under this approximation, the corrugated structure can be replaced with a smooth surface on which the so-called equivalent boundary conditions (EBC) are fulfilled. Here, we also assume that the structure is deeply corrugated, i.e. the structure depth is of the same order as an inverse wavenumber. Using the EBC we obtain a general solution and investigate it asymptotically. It is shown that two types of radiation are generated: volume radiation and surface waves. Both types of the radiations are analyzed in detail. We demonstrate that the radiation is highly sensitive to the structure depth, which can be used, specifically, for generating the powerful surface radiation. The energy losses of the bunch by both volume and surface radiations are considered as well. In particular, the dependences of the energy density on the corrugation parameters are obtained and analyzed.

physics.acc-ph↗

arXiv2006

Studies of Particle Acceleration by an Active Microwave Medium

The PASER is potentially a very attractive method for particle acceleration, in which energy from an active medium is transferred to a charged particle beam. The effect is similar to the action of a maser or laser with the stimulated emission of radiation being produced by the virtual photons in the electromagnetic field of the beam. We have been investigating the possibility of developing a demonstration PASER operating at X-band. The less restrictive beam transport and device dimensional tolerances required for working at X-band rather than optical frequencies as well as the widespread application of X-band hardware in accelerator technology all contribute to the attractiveness of performing a PASER demonstration experiment in this frequency range. Key to this approach is the availability of a new class of active materials that exhibit photoinduced electron spin polarization. We will report on the status of active material development and measurements, numerical simulations, and progress towards a planned microwave PASER acceleration experiment at the Argonne Wakefield Accelerator facility.

physics.acc-ph↗

arXiv2006

Wakefields Generated by Electron Beams Passing Through a Waveguide Loaded With an Active Medium

The wakefields of a relativistic electron beam passing through a waveguide loaded with an active medium with weak resonant dispersion have been considered. For the calculations in this paper the parameters of the medium are those of a solution of fullerene (C60) in a nematic liquid crystal that exhibits activity in the X-band. It was shown that several of the TM accelerating modes can be amplified for the geometries under consideration; structures in which higher order modes are amplified exhibit essential advantages as PASERs. In particular, the amplification of the highest mode occurs in a structure loaded with a rather thick active medium layer that maximizes the energy stored by the active medium.

physics.acc-ph↗