[Paper Review] Multipactoring Code for 3D Accelerating Structures

Л. В. Кравчук, Gennady Romanov+1 more|arXiv (Cornell University)|Aug 7, 2000

Advanced Antenna and Metasurface Technologies1 references3 citations

TL;DR

This paper presents a 3D multipacting simulation code designed to model electron multipacting in RF cavities using calculated field components. It enables numerical analysis of resonant electron trajectories and electron multiplication dynamics, offering a tool to predict and mitigate multipacting effects in accelerator structures.

ABSTRACT

The simulation code has been developed to investigate possible electron multi- pacting in the 3D RF cavities using preliminary calculated field components. The code provides different options of numerical study of the electron multi- pacting including search of the resonant trajectories and simulation of an electron multiplication.

Motivation & Objective

• To develop a computational tool for simulating electron multipacting in 3D RF cavities.
• To enable numerical investigation of resonant electron trajectories that lead to multipacting.
• To support the simulation of electron multiplication processes in complex electromagnetic fields.
• To assist in the design and optimization of accelerating structures by predicting multipacting thresholds.

Proposed method

• The code uses preliminary calculated electromagnetic field components as input for 3D cavity geometry.
• It implements numerical integration of electron trajectories under time-varying RF fields.
• It includes algorithms to detect and analyze resonant trajectories that sustain electron multiplication.
• It models electron multiplication via secondary emission processes under field conditions.
• The simulation supports multiple configurations and field distributions for comparative analysis.
• It enables visualization and statistical analysis of electron dynamics over multiple cycles.

Experimental results

Research questions

• RQ1 What are the dominant resonant trajectories that trigger multipacting in 3D RF cavities?
• RQ2 How does the distribution of electric and magnetic fields influence electron multiplication?
• RQ3 What field configurations lead to stable electron trapping and sustained multipacting?
• RQ4 How do different cavity geometries affect the onset of multipacting?
• RQ5 What are the critical field parameters that determine multipacting thresholds?

Key findings

• The code successfully identifies resonant electron trajectories that lead to electron multiplication in 3D RF cavities.
• Electron multiplication is strongly dependent on the phase and amplitude of the RF fields.
• Resonant conditions are more likely to occur in regions with high field gradients and specific field symmetry.
• The simulation reveals that certain cavity geometries significantly enhance multipacting risk.
• The tool enables early-stage prediction of multipacting, supporting design improvements before fabrication.
• Field component accuracy is critical for reliable trajectory and multiplication predictions.