Microwave Multipactor Breakdown Between Two Cylinders

Rasch, Joel; Anderson, D.; Johansson, J.; Lisak, M.; Puech, J.; Rakova, E.; Semenov, V. E.

doi:10.1109/tps.2010.2052372

Cited by 10 publications

(20 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The electrons that are not short range will drift away from the surface, and will only return due to some external force, for example the ponderomotive force of an electric inhomogeneity 10,19,29 . These are the long range electrons.…”

Section: A Electron Emissionmentioning

confidence: 99%

“…8. Silver has W 1 = 30 eV, and σ max = 2.22 29,30,32 , and the act of solving for the breakdown threshold consists in finding the electric field strength ratio E 0 /E 1 which produces a steady state impactemission density for a given ratio W e /W 1 . The two dashed lines indicate the approximations corresponding to non-resonant (Eq.…”

Section: B Solutionsmentioning

confidence: 99%

“…The choice of parameters corresponds to silver, and is the same as in our previous recent publications 29,30 , making the results easy to compare. But as is seen in Fig.…”

Section: B Solutionsmentioning

confidence: 99%

“…The inhomogeneity of the electric field can be incorporated using the concept of the ponderomotive force, which affects the electron drift velocity 10,20,[28][29][30] , and the concept of geometrical spreading can be used to model curved surfaces by diluting the electron density appropriately 29 .…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Non-resonant multipactor—A statistical model

Rasch

Johansson

2012

Physics of Plasmas

View full text Add to dashboard Cite

High power microwave systems operating in vacuum or near vacuum run the risk of multipactor breakdown. In order to avoid multipactor, it is necessary to make theoretical predictions of critical parameter combinations. These treatments are generally based on the assumption of electrons moving in resonance with the electric field while traversing the gap between critical surfaces.Through comparison with experiments, it has been found that only for small system dimensions will the resonant approach give correct predictions. Apparently, the resonance is destroyed due to the statistical spread in electron emission velocity, and for a more valid description it is necessary to resort to rather complicated statistical treatments of the electron population, and extensive simulations. However, in the limit where resonance is completely destroyed it is possible to use a much simpler treatment, here called non-resonant theory. In this paper we develop the formalism for this theory, use it to calculate universal curves for the existence of multipactor, and compare with previous results. Two important effects that leads to an increase in the multipactor threshold in comparison with the resonant prediction are identified. These are the statistical spread of impact speed, which leads to a lower average electron impact speed, and the impact of electrons in phase regions where the secondary electrons are immediately reabsorbed, leading to an effective removal of electrons from the discharge.

show abstract

Section: A Electron Emissionmentioning

confidence: 99%

Section: B Solutionsmentioning

confidence: 99%

“…The choice of parameters corresponds to silver, and is the same as in our previous recent publications 29,30 , making the results easy to compare. But as is seen in Fig.…”

Section: B Solutionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Non-resonant multipactor—A statistical model

Rasch

Johansson

2012

Physics of Plasmas

View full text Add to dashboard Cite

show abstract

“…When the distance between the wires becomes large compared to the wire radii, the corresponding electric field becomes strongly inhomogeneous and significant deviations from the plane parallel plate predictions can be expected. A first qualitative analysis of this problem was recently made 16 where the electron motion in the electromagnetic field between two wires was analyzed by separating the motion into a slowly varying drift velocity (driven by the ponderomotive force due to the electric field inhomogeneity) and a rapidly oscillating part (driven by the oscillating electric field). The curvature of the cylindrical surfaces of emission was shown to give rise to a spreading out of the emitted secondary electrons, which implied a dilution of the electron density equivalent to a loss of electrons.…”

Section: Introductionmentioning

confidence: 99%

Simulations of Multipactor Breakdown Between Two Cylinders

Rasch

Semenov

Rakova

et al. 2011

IEEE Trans. Plasma Sci.

View full text Add to dashboard Cite

Simulations have been performed to determine the multipactor breakdown threshold in a microwave structure comprised of two parallel cylinders, chosen to be an approximate model of an open helix microwave antenna system. The electromagnetic field between the cylinders is available in closed analytical form and a Monte Carlo software has been developed to calculate the 2D electron trajectories and to simulate the multipactor avalanche in this inhomogeneous electric field for different ratios of cylinder radius and distance of separation between the cylinders. The results are compared with those of a recently published analytical theory and show a qualitatively good agreement. In particular, it is confirmed that for given distance between cylinders, there exists a smallest cylinder radius below which no two-sided multipactor breakdown can occur. The basic physical explanation is a loss mechanism for secondary emitted electrons that is caused by the curvature of the cylinder surfaces together with the strong electric field at the surfaces. The results imply that the breakdown threshold in realistic open helix antennas is significantly higher than those predicted using extrapolations based on resonance theory and the classical two parallel plate model.

show abstract

Enhanced dynamics simulation and threshold analysis of multipaction in the ferrite microwave component

Cui

et al. 2017

Physics of Plasmas

View full text Add to dashboard Cite

Multipactor discharge between dielectric and metal was investigated and experimentally verified for the first time. Moreover, multipaction electron evolution laws in the complex ferrite component were revealed, and discharge breakdown threshold was analyzed. Through reasonable approximation and by establishing the equivalent analytical model, the effects of the external static magnetic field and charge accumulation were investigated, and transient electronic trajectory was obtained. Based on the electromagnetic particle-in-cell technology, the three dimensional simulation method of electron evolution in complex ferromagnetic microwave components was implemented. The discharge threshold was obtained through the long term evolution of field to electron and electron to field interactions and verified by multipactor measurement on the circulator for the first time. Instead of the steady field condition, the steady particle condition was proposed for the threshold prediction, exhibiting great potential in the space industry application. It is demonstrated that for ferrite dielectric-metal multipaction, the phase focusing process was prolonged, and the traditional prediction criteria for the threshold analysis were invalid due to the existence of the external magnetic field and highly inhomogeneous field distribution.

show abstract

Microwave Multipactor Breakdown Between Two Cylinders

Cited by 10 publications

References 21 publications

Non-resonant multipactor—A statistical model

Non-resonant multipactor—A statistical model

Simulations of Multipactor Breakdown Between Two Cylinders

Enhanced dynamics simulation and threshold analysis of multipaction in the ferrite microwave component

Contact Info

Product

Resources

About