Excitation and amplification of hybrid modes in circular-elliptic combined plasma waveguides including relativistic electron beam

Document Type : Original Article

Authors

1 PhD student, Faculty of Physics, Kashan University, Kashan, Iran

2 Assistant Professor, Faculty of Physics, Kashan University, Kashan, Iran

3 Associate Professor, Faculty of Physics, Kashan University, Kashan, Iran

Abstract

The dispersion relation and the growth rate of the hybrid electromagnetic waves propagating in the two types of combined waveguides with complete conductor walls including isotropic cold plasma column that powered by relativistic electron beam, have been studied.The conducting wall cross section of the first waveguide is elliptical that plasma column with circular cross section is located in its core and the rest of interior regions is filled with dielectric material from the plasma boundary to the waveguide boundary. But the second waveguide has acircular cross section that elliptical plasma column is situated in its center. Electron beams as source energy are injected inside it coaxially with plasma column. By calculation of electromagnetic fields components in each of regions in the considered configurations, applying the boundary conditions, operating frequency and growth rate are obtained. The results of numerical computations are graphically presented.

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[1]    B. Shokri and B. Jazi, "Spatial growth rate and field profiles of symmetric mode in a rod dielectric Čerenkov maser with a magnetized plasma column," Phys. Lett. A, vol. 336, no. 6, pp. 477-489, 2005
[2]    J. Zheng, C. Yu, Z. Zheng, and K. Tanaka, "Cherenkov radiation generated by a beam of electrons revisited," Phys. Plasmas, vol. 12, no. 9, pp. 93-105, 2005.
[3]    P. D. Coleman and C. Enderby, "Megavolt electronics Cerenkov coupler for the production of millimeter and submillimeter waves," J. Appl. Phys, vol. 31, no.9,  pp. 1695-1696, 1960.
[4]    B. Jazi, Z. Rahmani, E. Heidari-Semiromi, and A. Abdoli-Arani, "Time growth rate and field profiles of hybrid modes excited by a relativistic elliptical electron beam in an elliptical metallic waveguide with dielectric rod," Phys. Plasmas, vol. 19, no. 10, pp. 102-110, 2012.
[5]    A. Malakzadeh and M. Ahmadi, "Analytical Design and Simulation of a Corrugated Rectangular Waveguide Based on the Principles of the Backward-Wave Oscillator for Communication Band of THz Regime to Work in Troposphere," Scientific Journal of Applied Electromagnetics, vol. 7, no. 2, pp. 25-32, 2020. (In Persian)
[6]    M. Rouhani and B. Maraghechi, "Wave-mode dispersions in a relativistic electron beam with ion-channel guiding," Phys. Plasmas, vol. 13, no. 8, pp. 083-101, 2006.
[7]    L. Shenggang, Y. Yang, M. Jie, and D. M. Manos, "Theory of wave propagation along a waveguide filled with moving magnetized plasma," Phys. Rev. E, vol. 65, no. 3, p. 036411, 2002.
[8]    R. Bhatt and C. Chen, "Theory and simulation of nonrelativistic elliptic-beam formation with one-dimensional Child-Langmuir flow characteristics," Phys. Rev. ST Accel. Beams, vol. 8, no. 1, p. 014201, 2005.
[9]    S. J. Russell, Z.-F. Wang, W. B. Haynes, R. M. Wheat, Jr., B. E. Carlsten, L. M. Earley, S. Humphries, Jr., and P. Ferguson, "First observation of elliptical sheet beam formation with an asymmetric solenoid lens," Phys. Rev. ST Accel. Beams, vol. 8, no. 8, pp. 080401, 2005.
[10] R. J. Bhatt, "Inverse problems in elliptic charged-particle beams," Massachusetts Institute of Technology, 2006.
[11] J. Zhou, R. Bhatt, and C. Chen, "Cold-fluid theory of equilibrium and stability of a high-intensity periodically twisted ellipse-shaped charged-particle beam," Phys. Rev. ST Accel. Beams, vol. 9, no. 3, pp. 034401, 2006.
[12] G. Caryotakis, A. Krasnykh, M. Neubauer, R. Phillips, G. Scheitrum, D. Sprehn, R. Steele, A. Jensen, and D. Smithe, "Design of a 11.4 GHz, 150-MW, Sheet Beam, PPM-Focused Klystron," AIP Conference Proceedings, vol. 691, no. 1, pp. 22-33, 2003.
[13] B. E. Carlsten, "Modal analysis and gain calculations for a sheet electron beam in a ridged waveguide slow-wave structure," Phys. Plasmas, vol. 9, no. 12, pp. 5088-5096, 2002.
[14] H. Freund and T. Abu-Elfadl, "Linearized field theory of a Smith-Purcell traveling wave tube," IEEE Trans. Plasma Sci., vol. 32, no. 3, pp. 1015-1027, 2004.
[15] A. E. Brainerd, C. Chen, and J. Zhou, "Space-charge waves on relativistic elliptic electron beams," J. Appl. Phys, vol. 106, no. 2, pp. 023310, 2009.
[16] B. Jazi and B. Shokri, "Excitation of electromagnetic   surface waves by an annular electron beam in a plasma waveguide with a dielectric rod and a magnetized plasma column," Plasma Phys. Controlled Fusion, vol. 47, no. 1, pp. 37-47, 2005.
[17] M. A. K. n. M. Birau, M.V. Kuzelev, A.A. Rukhadze, "Topicals Problems," Phys.-Usp., vol. 40, pp. 975-992, 1997.
[18] N. W. McLachlan, "Theory and Applications of Mathieu Functions", Dover, New York, 1964.
[19] Z. Rahmani, E. Heidari-Semiromi, and S. Safari, “Excitation of THz hybrid modes in an elliptical dielectric rod waveguide with a cold collisionless unmagnetized plasma column by an annular electron beam,” Phys. Plasmas, vol. 23, no. 6, pp. 062113,  2016.