Editing Multipactor effect (section)

==Description==
[[File:Multipaction in coaxial connector.gif|thumb|Simulation of coxial multipactor. The electron cloud moves between the inner and outer conductor in resonance, causing an [[electron avalanche]]: in 5 nanoseconds, the number of electrons increases 150×.<ref>{{cite journal|title=Update on Multipactor in Coaxial Waveguides Using CST Particle Studio|first=Gennady|last=Romanov|url=https://accelconf.web.cern.ch/accelconf/PAC2011/papers/tup008.pdf|journal=Proceedings of 2011 Particle Accelerator Conference|year=2011|page=2|quote=Simulations  of  electron multipactor discharge in the coaxial waveguide have been performed using CST Particle Studio, with a primary goal to verify the effect of multi-particle approach combined with advanced probabilistic  emission model on the discharge thresholds. Most simulations agree with analytical results and the results from more simplified numerical codes}}</ref>|alt=|left]]
The multipactor effect occurs when electrons accelerated by [[radio-frequency]] (RF) fields are self-sustained in a [[vacuum]] (or near vacuum) via an [[electron avalanche]] caused by [[secondary emission|secondary]] electron emission.<ref name=Shem>
Valery D. Shemelin and Sergey A. Belomestnykh, Multipactor in Accelerating Cavities (Book 1 of a Series: Particle Acceleration and Detection) 1st ed. 
ISSN 1611-1052, Springer Nature Switzerland AG, 2020</ref> The impact of an electron to a surface can, depending on its energy and angle, release one or more [[secondary electrons]] into the vacuum. These electrons can then be accelerated by the RF fields and impact with the same or another surface. Should the impact energies, number of electrons released, and timing of the impacts be such that a sustained multiplication of the number of electrons occurs, the phenomenon can grow exponentially and may lead to operational problems of the RF system such as damage of RF components or loss or distortion of the RF signal.