Experimental and theoretical studies of a coaxial free-electron maser based on two-dimensional distributed feedback

Journal Article · Thu Nov 15 00:00:00 EST 2007 · Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics

DOI:https://doi.org/10.1103/PHYSREVE.76.056406· OSTI ID:21076275

Konoplev, I V; Cross, A W; Phelps, A D. R.; He, W; Ronald, K; Whyte, C G; Robertson, C W; MacInnes, P; Ginzburg, N S; Peskov, N Yu; Sergeev, A S; Zaslavsky, V Yu; Thumm, M ^[1]

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1. SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

The first operation of a coaxial free-electron maser (FEM) based on two-dimensional (2D) distributed feedback has been recently observed. Analytical and numerical modeling, as well as measurements, of microwave radiation generated by a FEM with a cavity defined by coaxial structures with a 2D periodic perturbation on the inner surfaces of the outer conductor were carried out. The two-mirror cavity was formed with two 2D periodic structures separated by a central smooth section of coaxial waveguide. The FEM was driven by a large diameter (7 cm), high-current (500 A), annular electron beam with electron energy of 475 keV. Studies of the FEM operation have been conducted. It has been demonstrated that by tuning the amplitude of the undulator or guide magnetic field, modes associated with the different band gaps of the 2D structures were excited. The Ka-band FEM generated 15 MW of radiation with a 6% conversion efficiency, in good agreement with theory.

• OSTI ID: 21076275
• Journal Information: Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, Vol. 76, Issue 5; Other Information: DOI: 10.1103/PhysRevE.76.056406; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-651X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ELECTRON BEAMS
ELECTRONS
ENERGY GAP
FEEDBACK
FREE ELECTRON LASERS
LASER CAVITIES
LASER MIRRORS
MAGNETIC FIELDS
MASERS
MICROWAVE RADIATION
PERIODICITY
PERTURBATION THEORY
PLASMA SIMULATION
RESONATORS
TWO-DIMENSIONAL CALCULATIONS
WAVEGUIDES
WIGGLER MAGNETS