Control of the Operation Mode of a Relativistic &lt;italic&gt;Ka&lt;/italic&gt;-Band Backward-Wave Oscillator

Boltachev, G. Sh.; Rostov, V. V.; Sharypov, K. A.; Shunaĭlov, S. A.; Shpak, V. G.; Ul’maskulov, M. R.; Yalandin, M. I.

doi:10.1109/tps.2015.2446502

Cited by 10 publications

(2 citation statements)

References 44 publications

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“…The second series of experiments with coaxial electron beams was performed using SR BWO operating in a 38 GHz band [10]. Gap D was reduced to 6 mm, and an external beam current increased to ≈2.2 kA.…”

Section: Experimental Scheme and Formation Of Coaxial Beamsmentioning

confidence: 99%

High-gradient acceleration of electron beam by superradiative microwave pulse

Sharypov¹,

Shpak²,

Shunaĭlov³

et al. 2022

8th International Congress on Energy Fluxes and Radiation Effects

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For high-gradient acceleration of electron bunches by microwave superradiance pulses, a scheme is considered in which devices for the radiation generation and particle acceleration are combined. Two electron beams from coaxial cathodes powered by a single voltage pulse (–300 kV; 1.5 ns) are used. Outer tubular beam excites a relativistic superradiant Ka-band backward-wave oscillator (BWO), and paraxial beam is accelerated in a “pill-box” cavity positioned at the input of the BWO slow-wave structure. Formation of such beams is studied with the use a model cathode system. In calculations by particles-in-cells method, the rate of electron acceleration of up to 400 MeV/m was obtained and the role of nonsynchronous microwaves-to-bunches interaction was shown.

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Section: Experimental Scheme and Formation Of Coaxial Beamsmentioning

confidence: 99%

High-gradient acceleration of electron beam by superradiative microwave pulse

Sharypov¹,

Shpak²,

Shunaĭlov³

et al. 2022

8th International Congress on Energy Fluxes and Radiation Effects

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“…When α increases, several axisymmetric modes at the required frequency could appear together in the corrugated waveguide. According to the previous research, the coupling impedance and the growth rate of the lowest axisymmetric mode TM 01 are always much larger than those of other higher axisymmetric ones thus resulting in the dominance in the mode competition [24], [25]. Therefore, TM 01 always works as the operation mode in RBWO [11], [26].…”

Section: Introductionmentioning

confidence: 99%

Theoretical Research on Properties of Spatial Harmonics in Corrugated Waveguide

Teng

Wang

et al. 2019

IEEE Access

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This paper investigates the dependence of the properties of the spatial harmonics on the overmoded ratio of the corrugated waveguide operating in TM 01 at 30 GHz with the consideration of the effects of the ripple shape. It is found that as the overmoded ratio grows, the electric fields concentrate towards the ripple surface, which weakens the enhancement of the power handling capacity caused by augmentation of the overmoded ratio. As the overmoded ratio grows, the ratio between the field amplitudes of the −1st spatial harmonic and the fundamental harmonic increases monotonically. Therefore, the total electric fields composed of the spatial harmonics become the spatial beating-wave with the single frequency, whose amplitudes vary along z-axis with the spatial period determined mainly by the −1st spatial harmonic and the fundamental harmonic. Researches on coupling impedances show that with the same overmoded ratio, the corrugated waveguide consisting of the improved rectangular ripples provides better synchronous coupling for the wave-beam interaction than that of the sinusoidal ripples does. Moreover, it is better to choose the fundamental harmonic close to the light line as the synchronous wave for the wave-beam interaction in the low magnetic field. In that case, even if the electron beam keeps far away from the ripple surface, the synchronous wave still provides strong enough coupling for the electron beam. INDEX TERMS Corrugated waveguide, coupling impedance, field distribution, high power microwave generation, overmoded ratio.

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