Excitation of terahertz radiation by an electron beam in a dielectric lined waveguide with rippled dielectric surface

Journal Article · Sat Sep 15 00:00:00 EDT 2012 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4751457· OSTI ID:22086158

Tripathi, Deepak; Uma, R ^[1]; Tripathi, V K ^[2]

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1. Center for Energy Studies, Indian Institute of Technology Delhi, New Delhi 110016 (India)
2. Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India)

A relativistic electron beam propagating through a dielectric lined waveguide, with ripple on the dielectric surface, excites a free electron laser type instability where ripple acts as a wiggler. The spatial modulation of permittivity in the ripple region couples a terahertz radiation mode to a driven mode of lower phase velocity, where the beam is in Cerenkov resonance with the slow mode. Both the modes grow at the expanse of beam energy. The terahertz frequency increases as the beam velocity increases. The growth rate of the instability goes as one third power of beam density.

• OSTI ID: 22086158
• Journal Information: Physics of Plasmas, Vol. 19, Issue 9; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAM PROFILES
BEAM TRANSPORT
CHERENKOV RADIATION
DIELECTRIC MATERIALS
ELECTRON BEAMS
EXCITATION
FREE ELECTRON LASERS
MODULATION
PERMITTIVITY
PHASE VELOCITY
PLASMA INSTABILITY
RELATIVISTIC RANGE
RESONANCE
WAVEGUIDES