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Journal ArticleDOI

Mode competition and control in free electron lasers with one and two dimensional Bragg resonators

TL;DR: In this article, the authors present a time domain analysis of the transverse mode dynamics which occur in FEL oscillators using oversize microwave cavities, showing that both traditional one-dimensional and novel two-dimensional Bragg cavities can produce radiation at a single frequency with a one-mode azimuthal distribution, which corresponds to spatial synchronization of the electromagnetic radiation.
Abstract: We present a time domain analysis of the transverse mode dynamics which occur in FEL oscillators using oversize microwave cavities. It is shown that both traditional one-dimensional and novel two-dimensional Bragg cavities can produce radiation at a single frequency with a one-mode azimuthal distribution, which corresponds to spatial synchronization of the electromagnetic radiation. In one-dimensional system, electronic mode selection occurs via nonlinear mode competition. In contrast, electrodynamic mode selection occurs in two-dimensional Bragg cavities, resulting in the production of a single azimuthally-symmetric mode after the linear stage of evolution. The two-dimensional Bragg cavity is shown to retain its selectivity when its radius greatly exceeds the radiation wavelength.
Citations
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Journal ArticleDOI
TL;DR: In this article, the results of theoretical and experimental studies of 2D surface photonic band-gap structures are compared with theoretical results and good agreement between theory and experiment is demonstrated.
Abstract: Two-dimensional (2D) surface photonic band-gap (SPBG) structures can be obtained by providing a shallow corrugation of the inner surface of a waveguide wall. It can be used as a distributed mirror, a cavity, or a filter in integrated optics or microwave electronics. These structures can also be an alternative to conventional 2D PBG or 1D Bragg structures. In this article, we present the results of theoretical and experimental studies of 2D SPBG structures. Data obtained from experiments are compared with theoretical results and good agreement between theory and experiment is demonstrated. Comparison of a coaxial 2D SPBG structure with a conventional 1D Bragg structure is also presented.

45 citations

Journal ArticleDOI
TL;DR: In this article, the electrodynamical properties of a crystal-like artificial periodic structure (a photonic crystal) formed by a periodic structure built from the metallic threads (grid volume resonator) are considered.
Abstract: Spontaneous and induced parametric and Smith–Purcell radiation from electrons moving in periodic structures are considered. The electrodynamical properties of a crystal-like artificial periodic structure (a photonic crystal) formed by a periodic structure built from the metallic threads (“grid” volume resonator) is considered. The equation, which describes lasing of volume-free electron laser with a “grid” resonator (photonic crystal), are obtained.

25 citations

Journal ArticleDOI
TL;DR: In this paper, a 3D printed periodic structure was used in an electron beam driven sub-THz radiation source, which was constructed by additive manufacturing and used successfully in an EH radiation source.
Abstract: For the creation of novel coherent sub-THz sources excited by electron beams there is a requirement to manufacture intricate periodic structures to produce and radiate electromagnetic fields. The specification and the measured performance is reported of a periodic structure constructed by additive manufacturing and used successfully in an electron beam driven sub-THz radiation source. Additive manufacturing, or “3D printing”, is promising to be quick and cost-effective for prototyping these periodic structures.

21 citations


Cites background from "Mode competition and control in fre..."

  • ...both fast wave and slow wave interactions [3-12]....

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Journal ArticleDOI
TL;DR: In this article, the use of two-dimensional (2D) Bragg resonators of coaxial geometry is considered as a method of providing additional mode selection and producing spatially coherent radiation from oversized annular electron beams.
Abstract: The use of two-dimensional (2D) Bragg resonators of coaxial geometry, realising two-dimensional distributed feedback, is considered as a method of providing additional mode selection and producing spatially coherent radiation from oversized annular electron beams. The main goals of the project are to prove operability of a FEM using 2D Bragg structures and compare the performance of the FEM using the novel 2D Bragg resonators with conventional 1D Bragg resonators.

20 citations

Journal ArticleDOI
TL;DR: An FEL-oscillator with a new type of Bragg resonator was realized on the basis of linac LIU-3000 (JINR, Dubna) (0.8 MeV/200 A/200 N) as discussed by the authors.
Abstract: An FEL-oscillator with a new type of Bragg resonator was realized on the basis of linac LIU-3000 (JINR, Dubna) (0.8 MeV/200 A/200 ns). This resonator consists of two corrugated waveguide sections having a step of phase π between the corrugations at the point of connection. The selective properties of a resonator of this type are significantly improved in comparison with a traditional two-mirror Bragg resonator. The output power was about 50 MW at a frequency of 30.7 GHz with the optimal parameters of the resonator, which corresponds to the efficiency of 35%, which is the highest for millimeter wavelength FEL. Radiation at the fundamental mode and the two side modes with the frequencies coincided to the “cold” microwave testing was separately observed depending on the magnetic fields of the wiggler and solenoid.

18 citations

References
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Journal ArticleDOI
TL;DR: In this paper, a two-dimensional distributed feedback was proposed to realize spatial coherent radiation of ribbon relativistic electron beams with the transverse dimension essentially exceeding the wavelength, which can be provided in a Bragg resonator formed by two double-periodic corrugating metal plates.

42 citations

Journal ArticleDOI
TL;DR: In this paper, the authors studied the processes of oscillations build-up and spatial synchronization in FEL's with two-dimensional distributed feedback driven by a large size sheet and tubular relativistic electron beams.

40 citations