TY - JOUR

T1 - Radiation of a Charge Intersecting a Boundary Between a Bilayer Area and a Homogeneous One in a Circular Waveguide

AU - Григорьева, Александра Андреевна

AU - Тюхтин, Андрей Викторович

AU - Воробьев, Виктор Викторович

AU - Antipov, Sergey

N1 - Funding Information: Manuscript received April 18, 2017; revised July 9, 2017; accepted July 19, 2017. Date of publication August 21, 2017; date of current version January 4, 2018. This work was supported by the Russian Foundation for Basic Research under Grant 15-02-03913. (Corresponding author: Aleksandra A. Grigoreva.) A. A. Grigoreva, A. V. Tyukhtin, and V. V. Vorobev are with the Laboratory of Electrodynamics of Nonstationary and Microwave Processes, Radiophysics Department, Saint Petersburg State University, 199034 Saint Petersburg, Russia (e-mail: aleksandra.a.grigoreva@gmail.com).

PY - 2018/1

Y1 - 2018/1

N2 - This paper is devoted to the analysis of electromagnetic field excited by a charge moving in a circular waveguide, which consists of two semi-infinite parts. The charge moves with a constant velocity along the waveguide axis from the partially dielectric section into the homogeneous one. It is assumed that Cherenkov radiation is generated in the bilayer section. The total field is represented as a sum of a known forced field that is the field of the charge in the infinite regular waveguide and a free field resulting from the presence of the transverse boundary. The infinite system of algebraic equations for amplitudes of the free-field modes is derived. The further analysis is conducted using numerical calculations. Special attention is given to the study of the so-called Cherenkov-transition radiation (CTR) within the homogeneous part of the waveguide volume. Typical distributions of CTR over frequencies and modes are presented for the case when the channel and the homogeneous area are free of medium. Analytical results obtained for the point charge are generalized for the charged bunch with an arbitrary profile and verified using direct simulations for the case of Gaussian bunch.

AB - This paper is devoted to the analysis of electromagnetic field excited by a charge moving in a circular waveguide, which consists of two semi-infinite parts. The charge moves with a constant velocity along the waveguide axis from the partially dielectric section into the homogeneous one. It is assumed that Cherenkov radiation is generated in the bilayer section. The total field is represented as a sum of a known forced field that is the field of the charge in the infinite regular waveguide and a free field resulting from the presence of the transverse boundary. The infinite system of algebraic equations for amplitudes of the free-field modes is derived. The further analysis is conducted using numerical calculations. Special attention is given to the study of the so-called Cherenkov-transition radiation (CTR) within the homogeneous part of the waveguide volume. Typical distributions of CTR over frequencies and modes are presented for the case when the channel and the homogeneous area are free of medium. Analytical results obtained for the point charge are generalized for the charged bunch with an arbitrary profile and verified using direct simulations for the case of Gaussian bunch.

KW - Cherenkov-transition radiation (CTR)

KW - mode transformation

KW - radiation of charged particle bunch

KW - waveguide with dielectric filling

UR - http://www.scopus.com/inward/record.url?scp=85028472169&partnerID=8YFLogxK

U2 - 10.1109/TMTT.2017.2738000

DO - 10.1109/TMTT.2017.2738000

M3 - Article

VL - 66

SP - 49

EP - 55

JO - IEEE Transactions on Microwave Theory and Techniques

JF - IEEE Transactions on Microwave Theory and Techniques

SN - 0018-9480

IS - 1

M1 - 8013704

ER -