Tech-X presents a highly efficient method of predicting multipacting for RF design optimization with the FDTD PIC code VSim. Multipaction is a commonly encountered problem RF engineers face, that causes significant damage to RF structures, in which there are very often no analytical solutions. Therefore, often the only way to predict multipacting is by using numerical solvers.

The first simulation, in which the initial primary electrons were loaded uniformly inside a coax, successfully shows the multipacting effect. A second simulation shows how results can be generated much faster using primary electrons that are field-scaled. This a feature in VSim that allows for multiple RF field strengths to simultaneously exist in one simulation. As a result, the optimal conditions for the coax to multipact were measured, allowing for accurate multipacting predictions.

Webinar Outline

  • Introduction to Multipacting and its Importance in RF Engineering
  • Introduction to VSim: Capabilities and Applications
  • Simulating with Primary and Secondary Electrons in VSim, e.g., Field-Scaling, SEYs, etc.
  • Simulations: (1) with regular electrons, (2) with field-scaled electrons.
  • Simulation Results & Conclusions

Who Should Attend?

RF engineers that design cavities, traveling wavetubes, waveguides, magnetrons, accelerators, or other RF radiation generation devices.




Dr. Diana Cheatham

Application Engineer       
Tech-X Corporation   


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