TY - JOUR

T1 - Theory of a beam-driven plasma antenna

AU - Timofeev, I. V.

AU - Volchok, E. P.

AU - Annenkov, V. V.

N1 - Funding Information: Russian Foundation for Basic Research (Grant No. 15-32-20432).?%blankline%?. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.

PY - 2016

Y1 - 2016

N2 - In this paper, we propose a theory describing generation of electromagnetic waves in a thin beamplasma system with a characteristic transverse size comparable with the radiation wavelength. In fact, a thin plasma column with a longitudinal density modulation works like a plasma antenna in which an electron beam can excite a superluminal wave of electric current. It has previously been shown that, if the period of this modulation coincides with the wavelength of the most unstable beam-driven mode, radiation at a frequency slightly below the plasma frequency is emitted transversely to the plasma column and generated in thin boundary layers. For the plasma thickness comparable with the skin-depth, generation of the terahertz radiation can reach high efficiency (∼10%) in such a scheme, but the absolute power of this radiation cannot be increased by increasing the transverse plasma size. In this paper, we study whether the power of such an antenna can be increased in the regime of oblique emission when the magnetized plasma is transparent to the radiated electromagnetic waves and the whole plasma volume may be involved in their generation.

AB - In this paper, we propose a theory describing generation of electromagnetic waves in a thin beamplasma system with a characteristic transverse size comparable with the radiation wavelength. In fact, a thin plasma column with a longitudinal density modulation works like a plasma antenna in which an electron beam can excite a superluminal wave of electric current. It has previously been shown that, if the period of this modulation coincides with the wavelength of the most unstable beam-driven mode, radiation at a frequency slightly below the plasma frequency is emitted transversely to the plasma column and generated in thin boundary layers. For the plasma thickness comparable with the skin-depth, generation of the terahertz radiation can reach high efficiency (∼10%) in such a scheme, but the absolute power of this radiation cannot be increased by increasing the transverse plasma size. In this paper, we study whether the power of such an antenna can be increased in the regime of oblique emission when the magnetized plasma is transparent to the radiated electromagnetic waves and the whole plasma volume may be involved in their generation.

UR - http://www.scopus.com/inward/record.url?scp=85019773327&partnerID=8YFLogxK

UR - https://www.elibrary.ru/item.asp?id=31040081

U2 - 10.1063/1.4961218

DO - 10.1063/1.4961218

M3 - Article

AN - SCOPUS:85019773327

VL - 23

JO - Physics of Plasmas

JF - Physics of Plasmas

SN - 1070-664X

IS - 8

M1 - 083119

ER -