A detailed analysis is made in order to establish the multipactor breakdown threshold waveguide irises. The involves an analytical investigation based on conformal mapping technique and also extensive numerical simulations. Comparison with recent experimental results shows good agreement. main goal of work obtain charts for iris, i.e. voltage as a function frequency-gap product, different height width ratios iris.

Multipactor inside a rectangular waveguide is studied using both an analytical approach and numerical simulations. Particular attention given to analysis of the role such effects as velocity spread secondary emitted electrons action rf magnetic field on electron motion. Conventional resonance theory shown give correct predictions for multipactor threshold in cases where height very small first order dominates. In higher resonances, accurate prediction requires that normal component emission...

Theoretical considerations of the electron multipactor have mostly been restricted to simplified case plane-parallel geometry with a uniform field. However, nonuniform field may not only affect results quantitatively, but also lead qualitatively new effects. In present work, effects radiofrequency on properties initiation are analyzed in cylindrical coaxial transmission line. A useful approximate solution nonlinear differential equation motion for electrons is derived and simple analytical...

A plane parallel model of multipactor is studied in detail using both an analytical approach and numerical simulations. The analysis carried out within a widely exploited approximation, which assumes fixed value for the initial velocity secondary electrons. It shown that commonly accepted picture zones not quite complete should be modified by taking into account existence hybrid resonance modes important consequences emission yield significantly exceeds unity. Numerical simulations...

This paper presents a novel theory for describing the initial stage of single-surface multipactor discharge on dielectric surface in presence dc electric field, which returns secondary emitted electrons to surface. The calculations employ statistical method based an exact analytical solution probability density arrival times electrons. A general integral equation determining steady-state distribution emission phases and threshold growth is formulated. computer program has been developed...

The effects of nonuniform radiofrequency fields are analyzed for a cylindrical coaxial transmission line using particle-in-cell code. behavior predicted by the analytical analysis is confirmed this study. In addition, including an initial velocity spread and different maximum secondary electron yields, more elaborate performed. It found that in case high emission, increase velocities results overlapping multipactor zones both double single sided multipactor. other case, when emission low,...

This paper presents a concept of tunable cavity resonator composed resonating and dielectric perturber. is designed measured to prove the tuning mechanism obtained by varying angle rotation A from 0 90 produces ratio 1:1.25, i.e., range 22.2% around 11.5 GHz while maintaining an unloaded Q factor between 1500 2300. After this first experimental validation, third-order bandpass filter then using same base principle. Using single mechanical movement, all three resonators' perturbers are...

Radio-frequency (RF) systems used in vacuum can be damaged by electronic avalanches triggered the multipactor effect. This undesirable phenomenon appear for RF components space communication payloads as well experimental fusion devices, among others. To determine breakdown threshold, expensive tests made or simulations performed. second method uses Total Electron Emission Yield (TEEY) curve input and threshold predicted simulation highly depends on this curve. Consequently we decided to make...

A new global method for unambiguous detection of multipaction in microwave communication systems is presented. Theory as well experiments demonstrate the potential and usefulness method. short review existing methods given a background, order to illustrate advantages

Detailed numerical simulations of the two-sided multipactor have been carried out within a plane-parallel model. The main aim is to clarify uncertainty that still exists in literature concerning overlapping zones. Three different codes (Monte Carlo, particle-in-cell, and statistical) were used calculate charts wide range parameters such as spread initial velocities secondary electrons maximum value emission yield. It was found an increase results zones, provided high enough. In opposite...

A detailed theoretical as well experimental investigation has been made of the statistical properties rf corona breakdown thresholds, relevant to situations where no artificial electron seeding is used and avalanche initiated from weak naturally occurring seeding, primarily due cosmic radiation. Good qualitative quantitative understanding obtained concerning initiation process its consequences for observed threshold. Comparisons between predictions results show a good agreement.

Microwave discharge in vacuum a waveguide iris is analyzed under the approximation of uniform electric field over finite width iris. The analysis shows that random electron drift due to initial velocity secondary electrons leads significantly increased multipactor threshold as compared result predicted by (infinitely wide) parallel plate configuration. This increase determined value height-to-length ratio. For each fixed this ratio, susceptibility charts can be generated traditional...

Multipactor breakdown in a single waveguide iris is analyzed using the quasistatic approximation for spatial distribution of rf field iris. Based on conformal mapping approach, an analytical description given structure It shown that central part any with length to height ratio greater than approximately 0.5, close between two parallel plates. The multipactor threshold determined mainly by electron losses from where are due tangential component emission velocity secondary electrons. effective...

Detailed numerical simulations have been done to investigate the properties of multipactor breakdown in circular waveguides operating propagating fundamental TE11 mode. Main attention has given a comparison between two cases corresponding linear and polarizations, respectively, electromagnetic wave. It is found that polarization considerably more susceptible than polarization. The reason for this difference clarified by comprehensive study electron motion waveguide.

The electron emission under impact between 10 eV and 2 keV is investigated with a Monte Carlo (MC) code in aluminum, silver, silicon. based on the complex dielectric function theory to describe inelastic scattering uses Mott's model of partial waves elastic scattering. It takes into account both volume surface plasmon excitations. simulation results are compared experimental measurements yields (EEY) energy spectra low electrons performed ultrahigh vacuum Ar-etched bulk samples. Our MC...

A new multipactor saturation mechanism is presented for high power microwave devices in the presence of dielectrics. Recent measures have shown that positive charge deposited on a dielectric as consequence secondary electron emission causes reduction its yield. This work shows dynamics within partially filled parallel-plate waveguide where both decrease yield with and subsequent electrostatic field produced are taken into account. The results obtained show these two mechanisms predict well...

The polyphase multipactor, i.e. the non-resonant form of secondary electron emission rf discharges in vacuum, has been analysed and studied experimentally. multipactor discharge was observed an evacuated standard rectangular waveguide through which pulsed high-power microwave radiation decimeter wavelength range transmitted. power interval two-sided (between wide walls waveguide) appeared determined. It is found that there a characteristic delay time for onset breakdown as compared with at...

A particular software 'MuSLi' has been developed and applied for simulations of the multipactor effect in shielded microstrip lines with cross-sections that are partially filled dielectric material. The combines an electromagnetic field solver, determining electric structure line, a Monte Carlo algorithm, calculating corresponding electron trajectories taking into account spread initial velocity different secondary emission properties metal surfaces. were carried out number structures...

Single-surface multipactor on metal surfaces is studied in the case when microwave electric field superimposed a dc and permanent magnetic field. Based simple analysis of electron motion, it predicted that considerable reduction threshold possible cyclotron frequency equal to has proper orientation with respect surface. The prediction confirmed by numerical simulations, some experimental indications reduced are also presented.