The nonlinear theory of slow-wave electron cyclotron masers with inclusion of the beam velocity spread

Wang, Hongyu; Hou, Zhi‐Ling; Jin, Haibo; Du, Chao‐Hai

doi:10.1016/j.aop.2013.05.008

Cited by 3 publications

(1 citation statement)

References 21 publications

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“…Among other applications, dielectric-loaded waveguides have found applications in gyro-devices including gyrotron [2][3][4], gyro-TWT [5][6][7][8][9][10][11][12][13], CARM [14] and others [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. The gyro-devices usually employ RF structures with small structural nonuniformities.…”

Section: Introductionmentioning

confidence: 99%

Analogy Between Circular Core-Cladding and Impedance Waveguides and Their Membrane Functions

Shcherbinin¹,

Zaginaylov²,

Ткаченко³

2017

PIER M

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Abstract-One-side boundary conditions on the field inside core region are obtained for core-cladding waveguide with anisotropic cladding. The boundary conditions involve two functions acting as components of anisotropic surface impedance for cladding material. These functions are determined in relation to desired values for step-index waveguide and dielectric-lined waveguide with either perfectly or finitely conducting walls. With resulting surface impedance, the perfect analogy between corecladding and impedance waveguide is achieved. Using this analogy, independent eigenvalue problems are obtained for membrane functions of HE and EH waves of core-cladding waveguide. From this result some conclusions about electromagnetic properties of HE and EH waves are drawn.

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Section: Introductionmentioning

confidence: 99%

Analogy Between Circular Core-Cladding and Impedance Waveguides and Their Membrane Functions

Shcherbinin¹,

Zaginaylov²,

Ткаченко³

2017

PIER M

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A scheme to enhance the conversion efficiency of slow‐wave electron cyclotron masers in the large signal approximation

Zhang

Wang

et al. 2018

Contributions to Plasma Physics

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Based on the anomalous Doppler effect, we propose a scheme to improve the practicability of slow-wave electron cyclotron masers in the large signal approximation. This scheme simultaneously contains the tapered guiding magnetic field and tapered refractive index. Numerical calculations show that this scheme enables the conversion efficiency to reach a higher value within a shorter time than previous schemes. Besides, this scheme also works well in the cases of THz wave band and beam axial-velocity spread. KEYWORDSconversion efficiency, electron cyclotron maser, tapered guiding magnetic field, tapered refractive index INTRODUCTIONThe electron cyclotron maser (ECM), which is based on the stimulated cyclotron emission process involving energetic electrons in gyrational motion, has undergone a remarkably successful evolution from theoretical research to device implementation. Nowadays, ECM-based devices are important, coherent, high-power microwave sources, which have numerous applications in plasma diagnostics, particle accelerators, advanced radars, and industrial processing. [1][2][3][4][5][6][7][8] The resonance condition of the ECM is = k z v z + sΩ, in which , k z , v z , s and Ω = eB/m 0 c are the microwave angular frequency, axial wave number, axial velocity of electron, harmonic numbers, and relativistic electron cyclotron frequency, respectively. For the gyro-devices, resonance occurs at positive cyclotron harmonics (s > 0) in the normal Doppler effect. The gyrating electrons interact with a fast wave in the presence of a strong guiding magnetic field. The coherent radiation is produced by decelerating the rotational component of the electron beam velocity. It is applied to the coherent microwave or millimetre wave radiation sources. [9][10][11][12] Contrarily, for the resonance occurring at negative cyclotron harmonics (s < 0) in the anomalous Doppler effect, the axial velocity of the electrons exceeds the wave phase velocity, and the radiation is produced by decelerating the axial component of the electrons velocity. Due to this interaction mechanism, the slow-wave ECM has some distinctive advantages. Firstly, the initially rectilinear straight beam operated in the slow-wave ECM can be easily generated by a Pierce electron gun with a high-quality beam, as has been confirmed by the experiments. Secondly, there is no need for a strong guiding magnetic field, and the tolerance of the beam velocity spread is better than gyro-devices. Besides these reasons, the slow-wave ECM has the potential to induce a large frequency upshift with a moderate arrangement of the initial axial velocity of the beam and the guiding magnetic field, so the broadband width is attainable. The studies on the slow-wave ECM are highlighted. As the equations that describe the interaction between electrons and electromagnetic field are too complicated to be solved exactly, the large signal approximation method is applied. In this approximation method, the amplitude of the electric field in the electromagnetic wave is assumed to be large, ...

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Efficiency enhancement of anomalous-Doppler electron cyclotron masers with tapered magnetic field

Xie

Liu

et al. 2014

Physics of Plasmas

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The nonlinear theory of slow-wave electron cyclotron masers with inclusion of the beam velocity spread

Cited by 3 publications

References 21 publications

Analogy Between Circular Core-Cladding and Impedance Waveguides and Their Membrane Functions

Analogy Between Circular Core-Cladding and Impedance Waveguides and Their Membrane Functions

A scheme to enhance the conversion efficiency of slow‐wave electron cyclotron masers in the large signal approximation

Efficiency enhancement of anomalous-Doppler electron cyclotron masers with tapered magnetic field

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