Conveners
2.7 Microwave Plasma Interaction II
- John Verboncoeur (Michigan State University)
- John Leopold (Technion)
An experimental setup was designed and implemented for the study of the multipactor effect in a rectangular WR 284 waveguide geometry under high vacuum. Operated at S-Band frequencies the multipactoring electrons are directly detected via an Electron Multiplier Tube (EMT). The custom fabricated test section consists of a copper coated steel structure transitioning to standard WR 284 waveguide...
Multipactor [1] is a nonlinear phenomenon in which an electron avalanche driven by a high frequency rf field sustains itself by an exponential charge growth through secondary electron emission from surfaces. This work investigates the time dependent physics [2] of multipactor discharge on a single dielectric surface by a novel multiparticle Monte Carlo simulator [3] with adaptive time steps....
Multipactor is a much studied AC discharge [1,2] that is harmful to microwave components. There is substantial current interest on this topic because of its threat to satellite communications [3]. In this paper, we present an analytical transmission line model to assess the effects of multipactor, should it happen, on the distortion of a signal. Both planar and coaxial transmission lines will...
Multipactor breakdown is a cascade phenomenon that occurs in RF and microwave systems. It has been observed in microwave tubes, RF windows, coupling structures, transmission lines, and in accelerator structures. Multipactor can cause loading of microwave cavities, localized heating and detuning of signals. These effects can ultimately lead to inefficient operation and possible destruction of...
It is well known that single-surface multipactor discharges have a negative effect the electromagnetic wave transmission in high power microwave devices. In this work, we examine the single surface-multipactor dynamics under obliquely incident rf electric field, such as occurs in TM waveguide modes, using particle-in-cell simulation. The results show that the oblique angle, θ, between the...
Vacuum electronic communication devices, such as the traveling wave tube (TWT) and backward wave oscillator (BWO), can at times experience degraded performance up to complete failure due to the multipactor effect. This effect is tied to the production and acceleration of secondary electrons due to electron impact and coupling to the electromagnetic energy within the tube. As part of a...
Currently, the total power, performance and lifetime of high-power RF devices, like vacuum electron devices, RF space systems, and accelerators, are severely limited by a phenomena known as multipactor. This occurs when the electromagnetic field is in resonance with secondary electron emission leading to a runaway avalanche of electrons in the device, resulting in degraded operation and...
