arXiv subjects

P. I. Markov

Publications and source records attributed to P. I. Markov.

5 recordsLinked to original sources

arXiv2026

Wakefield Acceleration in a Layered Plasma Waveguide

Plasma wakefield accelerators (PWFA) represent one of the promising new accelerator concepts that are now being developed intensively for future applications in high-energy physics and industry. Among the unresolved problems of practical implementation of PWFA there are maintaining the required quality (emittance, size, energy spread of bunches) and stable transportation of drive and accelerated (witness) bunches over long acceleration distances. For improving the bunch transport, we propose to fill the bunch transport channel with the background plasma, the density of which is lower than the main plasma density building up an accelerating wake wave. We call this waveguide structure a layered plasma waveguide (LPW). The wakefield excitation by a regular sequence of electron bunches in the LPW of cylindrical configuration has been explored both analytically and numerically. The layered plasma has been modeled as a combination of a tubular plasma and a plasma column of significantly different densities. The plasma column has a lower density. The dispersion dependencies of the TM-modes of the LPW was obtained and analyzed, and it was found that there was a single TM wave resonant with the electron bunch. Based on the obtained analytical expressions, the structures of the axial and radial wakefield amplitudes have been numerically investigated for the cases of a single drive bunch and a regular train of bunches. It is shown that for certain density ratios of the outer and inner plasmas, it is possible both to accelerate and focus simultaneously the drive and witness bunches. The 2.5D particle-in-cell code was used to simulate the witness acceleration of an electron bunch by a wakefield created by drive electron bunches in a two-layer plasma wakefield accelerator. The simulation showed good agreement with the results of analytical calculations.

physics.acc-ph↗

arXiv2025

Theory of wakefield in a transversely inhomogeneous plasma waveguide

Theoretical studies have been made into the relativistic drive bunch generation of a wakefield in a cylindrical waveguide filled with a transversely inhomogeneous plasma. According to the model used, the transversely inhomogeneous plasma is considered as a combination of tubular plasma and the plasma background of different density. Analytical expressions have been derived for the excited radial and axial electric field components, and for the azimuthal magnetic field component. The dispersion of the plasma waveguide under study, as well as the topography of the electromagnetic field components of the TM-eigenwaves, resonant with the bunch, have been investigated. Longitudinal and transverse amplitude distribution structures of the axial and radial wakefields have been determined. Spectrum analysis of the longitudinal and transverse wakefields has been performed with the result that their frequency content has been determined.

physics.acc-ph↗

arXiv2023

Bunch-excited wakefield in dielectric waveguide with hollow plasma channel

Wakefield excitation by a single relativistic electron bunch in a plasma-dielectric accelerating structure has been studied both analytically and numerically. The structure represents a dielectric-loaded cylindrical metal waveguide, which has partially plasma-filled channel (the hollow plasma channel) to transport charged particles. Assuming the linear regime of excitation, analytical expressions have been derived for the longitudinal and radial wakefields generated by a finite-size electron bunch. Axial profiles of wakefield component amplitudes have been studied, and their mode and spectrum analyses have been performed. Furthermore, the electron bunch-driven wakefield excitation has been PIC-simulated numerically for the quasi-linear regime. The comparative analysis of the data resulting from analytical studies and the ones obtained by numerical simulation has demonstrated qualitative agreement between the results.

physics.acc-ph↗

arXiv2021

Acceleration and focusing of positron bunch in a dielectric waveguide accelerator with homogeneous plasma in transport channel

The paper presents the results of numerical PIC-simulation of positron bunch focusing when acceleration in a plasma dielectric wakefield accelerator. The wakefield was excited by drive electron bunch in quartz dielectric tube, embedded in cylindrical metal waveguide. The internal area of dielectric tube has been filled with radially homogeneous plasma having in general case the vacuum channel along waveguide axis. Results of numerical PIC simulation have shown that it is possible a simultaneous acceleration and focusing of test positron bunch in the wakefield. The dependence of transport and acceleration of positron bunch on size of vacuum channel and waveguide length is studied.

physics.acc-ph↗

arXiv2019

Focusing of Drive and Test Bunches in a Dielectric Waveguide Filled with Inhomogeneous Plasma

The paper presents the results of numerical PIC-simulation of accelerated and drive bunches dynamics in a dielectric waveguide filled with radially inhomogeneous plasma. The wakefield was excited by the electron bunch in a quartz (permittivity 3.75) dielectric tube with outer and inner diameters of 1.2 mm and 1.0 mm, respectively, which was nested into a cylindrical metallic waveguide. The drive bunch characteristics were chosen to be: 5 GeV for electron energy, 3 nC for the charge, 0.2 mm - the bunch length, 0.9 mm - the bunch diameter. The accelerated bunch had the same parameters, except for the charge, which was equal to 0.3 nC. The interior of the waveguide was filled with plasma having different transverse density profiles, viz., the density profile formed in the capillary discharge, and the radially nonuniform density profile with the vacuum channel along the waveguide axis. For all the cases under study the plasma density was low, so that the plasma frequency was lower than the fundamental dielectric mode frequency. The obtained PIC-simulation data have shown that the vacuum channel in the inhomogeneous plasma cylinder improves the accelerated bunch focusing. There is the optimum vacuum-channel size value, at which the focusing turns out to be the strongest. The improvement in the accelerated bunch focusing is accompanied by the decrease in the accelerating gradient as compared with the full plasma filling of the drift channel. The best acceleration takes place in the absence of plasma; however in that case the test bunch focusing does not occur.

physics.acc-ph↗