Theoretical and experimental study of microwave power absorption by a single-sided multipactor discharge on a dielectric

Sakharov, A.; Ivanov, V. A.; Tarbeeva, Yu. A.; Konyzhev, M. E.

doi:10.1134/s1063780x12080235

Cited by 5 publications

(3 citation statements)

References 14 publications

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“…3 shows a typical waveform of the reflected microwave power for a discharge on a NaCl crystal with an incident microwave power of P inc ≈ 1.6 MW and a straight breakdown channel. In the multipactor stage, less than 1% of the incident microwave power is absorbed by the discharge [18], [19]. The maximum microwave absorption (60%-70%) is achieved in the stage of filamentary discharge (t ≈ 1.25 μs).…”

Section: Methodsmentioning

confidence: 99%

Strong Local Interaction of Microwave Discharges With Solid Dielectrics in Vacuum

Ivanov

Sakharov

Konyzhev

2015

IEEE Trans. Plasma Sci.

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Excitation of microwave discharges by pulsed microwave radiation (≤2 MW, 1.95 GHz, 1-10 µs) on dielectric surfaces in vacuum (10 −6 torr) was studied experimentally. Different stages of a surface microwave discharge were observed: secondary-electron-emission microwave discharge (multipactor), surface microwave breakdown (filamentary microwave discharge), and plasma-flare microwave discharge. It is found that, in the stage of microwave breakdown (which lasts for ∼0.1 µs), ≥70% of the incident microwave power is absorbed by a dense plasma filament with a diameter of ∼100 µm, an electron density of up to 2 × 10 18 cm −3 , and an electron temperature of about 2 eV. Strong interaction of the dense plasma of the filamentary microwave discharge with the dielectric leads to local destruction of the dielectric surface in the form of a long thin erosion track (l ≈ 6 cm, d ∼ 100 µm). The coefficient of microwave power absorption by a plasma filament in a rectangular waveguide is calculated using an electrodynamic model that does not involve expansion in the waveguide modes and takes into account reflections of the scattered wave from the waveguide walls by introducing an array of filament mirror images. It is shown that the coefficient of microwave power absorption by the filamentary discharge plasma can reach 70% and more, which agrees well with the experimental data.

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Section: Methodsmentioning

confidence: 99%

Strong Local Interaction of Microwave Discharges With Solid Dielectrics in Vacuum

Ivanov

Sakharov

Konyzhev

2015

IEEE Trans. Plasma Sci.

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“…The linear-stage current is strongly influenced by externally applied magnetic field, indicating the existence of flying free electrons above the surface [172], and meanwhile, the X-ray confirms the presence of high-energy electrons from the acceleration of high electric field in the early stage of flashover and it is from the bremsstrahlung radiation generated by impacting electrons [74]. Neuber et al [173] observed the time-resolved spectroscopy of excited atomic hydrogen and ionic carbon that originally from water or F I G U R E 2 0 Dielectric multipactor thresholds [7] at frequencies from 2 to 11 GHz [106,[162][163][164] (hollow solid and dashed symbols) are compared with the data at 110 GHz (filled symbols). Data include parallel (to the surface) rf field geometry for fused quartz (diamonds) and alumina (squares) as well as perpendicular (to the surface) rf field geometry for alumina (circles).…”

Section: Fundamentalsmentioning

confidence: 95%

“… Dielectric multipactor thresholds [7] at frequencies from 2 to 11 GHz [106, 162–164] (hollow solid and dashed symbols) are compared with the data at 110 GHz (filled symbols). Data include parallel (to the surface) rf field geometry for fused quartz (diamonds) and alumina (squares) as well as perpendicular (to the surface) rf field geometry for alumina (circles).…”

Section: Recent Advances In Multipactor Prediction and Physicsmentioning

confidence: 99%

Recent advances in multipactor physics and mitigation

et al. 2023

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Recent progress made in the prediction, characterisation, and mitigation of multipactor discharge is reviewed for single‐ and two‐surface geometries. First, an overview of basic concepts including secondary electron emission, electron kinetics under the force law, multipactor susceptibility, and saturation mechanisms is provided, followed by a discussion on multipactor mitigation strategies. These strategies are categorised into two broad areas – mitigation by engineered devices and engineered radio frequency (rf) fields. Each approach is useful in different applications. Recent advances in multipactor physics and engineering during the past decade, such as novel multipactor prediction methods, understanding space charge effects, schemes for controlling multipacting particle trajectories, frequency domain analysis, high frequency effects, and impact on rf signal quality are presented. In addition to vacuum electron multipaction, multipactor‐induced ionization breakdown is also reviewed, and the recent advances are summarised.

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