IPAC2015 - List of Authors (Grigoreva, A.A.)

Paper	Title	Page
MOPTY036	Radiation of a Bunch Moving in the Presence of a Bounded Planar Wire Structure	1007
	V.V. Vorobev, S.N. Galyamin, A.A. Grigoreva, A.V. Tyukhtin Saint-Petersburg State University, Saint-Petersburg, Russia
	Three-dimensional* and planar periodic structures can be used for non-destructive diagnostics of charged particle bunches. Here we consider the semi-infinite planar structure comprised of thin conducting parallel wires. If the period of the structure is much less than the typical wavelength of the electromagnetic field, then the structure's influence can be described with help of the averaged boundary conditions. We study radiation of a charged particle bunch with small transversal size and arbitrary longitudinal one in two cases: (i) the bunch moves orthogonally to the grid at some distance from the edge and (ii) it moves along the edge of the grid. The problems are solved analytically. In both cases the bunch generates a surface wave which contains the information about the size of the bunch. The shape of the surface waves is similar to the radiation generated in the presence of 3D periodical wire structures, however planar structure is simpler for use in accelerating system. Some typical numerical results for bunches of various shapes are given. * V.V. Vorobev et al., Phys. Rev. Let., 108, 184801 (2012); A.V. Tyukhtin et al., Phys. Rev. ST AB (in press). * M.I. Kontorovich et al., Electrodynamics of Grid Structures (Moscow, 1987).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY036
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WEPWA037	Beam-Driven Terahertz Source Based on Open Ended Waveguide with a Dielectric Layer: Rigorous Approach	2578
	S.N. Galyamin, A.A. Grigoreva, A.V. Tyukhtin, V.V. Vorobev Saint-Petersburg State University, Saint-Petersburg, Russia
	Funding: Grant of the President of Russian Federation (No. 6765.2015.2) and Russian Foundation for Basic Research (No. 15-32-20985, 15-02-03913). Terahertz frequency radiation (0.1-10 THz) is a promising tool for a number of scientific and practical applications. One promising scheme to obtain powerful and efficient THz emission is usage of beam-driven dielectric loaded structures [1]. Recently we have considered the problem where the microbunched ultrarelativistic charge exits the open end of a cylindrical waveguide with a dielectric layer and produces THz waves in a form of Cherenkov radiation [2]. To investigate the applicability of utilized approximations, we analyze here the case of orthogonal end of a waveguide with continuous filling. However, presented rigorous approach can be generalized for waveguide with vacuum channel. We use the combination of Wiener-Hopf technique and tailoring technique. The infinite linear system for magnitudes of reflected waveguide modes is obtained and solved numerically. We present typical field distributions over the aperture and typical radiation patterns in the Fraunhofer zone. * S. Antipov et al., Appl. Phys. Lett. 100, 132910 (2012). ** S.N. Galyamin et al., Opt. Express. 22(8), 8902 (2014).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA037
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WEPWA038	Mode Transformation in Waveguide with Transversal Boundary Between Vacuum and Partially Dielectric Area	2581
	A.A. Grigoreva, T.Yu. Alekhina, S.N. Galyamin, A.V. Tyukhtin Saint-Petersburg State University, Saint-Petersburg, Russia
	We consider the mode transformation in a circular waveguide with a transversal boundary between a vacuum part and a part with a cylindrical dielectric layer and a vacuum channel. It is assumed that an incident mode can be both propagating and evanescent. Analysis is carried out with the using the mode decomposition technique. Numerical algorithm for calculating the mode transformation at an arbitrary channel radius is also developed. Typical dependences for the reflection and transmission coefficients on the channel radius are presented and discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA038
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Paper

Title

Page

Radiation of a Bunch Moving in the Presence of a Bounded Planar Wire Structure

1007

V.V. Vorobev, S.N. Galyamin, A.A. Grigoreva, A.V. Tyukhtin
Saint-Petersburg State University, Saint-Petersburg, Russia

Three-dimensional* and planar** periodic structures can be used for non-destructive diagnostics of charged particle bunches. Here we consider the semi-infinite planar structure comprised of thin conducting parallel wires. If the period of the structure is much less than the typical wavelength of the electromagnetic field, then the structure's influence can be described with help of the averaged boundary conditions***. We study radiation of a charged particle bunch with small transversal size and arbitrary longitudinal one in two cases: (i) the bunch moves orthogonally to the grid at some distance from the edge and (ii) it moves along the edge of the grid. The problems are solved analytically. In both cases the bunch generates a surface wave which contains the information about the size of the bunch. The shape of the surface waves is similar to the radiation generated in the presence of 3D periodical wire structures*, however planar structure is simpler for use in accelerating system. Some typical numerical results for bunches of various shapes are given.
* V.V. Vorobev et al., Phys. Rev. Let., 108, 184801 (2012);
** A.V. Tyukhtin et al., Phys. Rev. ST AB (in press).
*** M.I. Kontorovich et al., Electrodynamics of Grid Structures (Moscow, 1987).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY036

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WEPWA037

Beam-Driven Terahertz Source Based on Open Ended Waveguide with a Dielectric Layer: Rigorous Approach

2578

S.N. Galyamin, A.A. Grigoreva, A.V. Tyukhtin, V.V. Vorobev
Saint-Petersburg State University, Saint-Petersburg, Russia

Funding: Grant of the President of Russian Federation (No. 6765.2015.2) and Russian Foundation for Basic Research (No. 15-32-20985, 15-02-03913).
Terahertz frequency radiation (0.1-10 THz) is a promising tool for a number of scientific and practical applications. One promising scheme to obtain powerful and efficient THz emission is usage of beam-driven dielectric loaded structures [1]. Recently we have considered the problem where the microbunched ultrarelativistic charge exits the open end of a cylindrical waveguide with a dielectric layer and produces THz waves in a form of Cherenkov radiation [2]. To investigate the applicability of utilized approximations, we analyze here the case of orthogonal end of a waveguide with continuous filling. However, presented rigorous approach can be generalized for waveguide with vacuum channel. We use the combination of Wiener-Hopf technique and tailoring technique. The infinite linear system for magnitudes of reflected waveguide modes is obtained and solved numerically. We present typical field distributions over the aperture and typical radiation patterns in the Fraunhofer zone.
* S. Antipov et al., Appl. Phys. Lett. 100, 132910 (2012).
** S.N. Galyamin et al., Opt. Express. 22(8), 8902 (2014).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA037

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPWA038

Mode Transformation in Waveguide with Transversal Boundary Between Vacuum and Partially Dielectric Area

2581

A.A. Grigoreva, T.Yu. Alekhina, S.N. Galyamin, A.V. Tyukhtin
Saint-Petersburg State University, Saint-Petersburg, Russia

We consider the mode transformation in a circular waveguide with a transversal boundary between a vacuum part and a part with a cylindrical dielectric layer and a vacuum channel. It is assumed that an incident mode can be both propagating and evanescent. Analysis is carried out with the using the mode decomposition technique. Numerical algorithm for calculating the mode transformation at an arbitrary channel radius is also developed. Typical dependences for the reflection and transmission coefficients on the channel radius are presented and discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA038

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)