Speaker
Description
Vacuum arcs, also known as breakdowns (VBD), are a major limiting factor for various applications such as particle accelerators, fusion reactors, vacuum interrupters, X-ray sources, and space applications. However, the physical mechanisms underlying the very initiation of the phenomenon still remain unclear. Recent experimental evidence indicates that the distribution of electromagnetic power might be the main limiting factor of the arc initiation, instead of applied electric field and the cathode material as previously assumed. This work aims to understand the physics underlying the power supply limitation on the VBD initiation by developing computational models that predict its behavior, leading to reduced VBD occurrence or to higher operating fields in future applications.
The multi-physics code FEMOCS, used for VBD initiation modeling, now accounts for impedance based descriptions of external systems. Thus, connecting the full system’s circuit to local plasma initiation physics. This allows to directly investigate the effects of different circuit responses on the VBD initiation process. Comparison between different impedance functions are made. The effects of power flow during plasma initiation is investigated and preliminary conclusions outlined. Furthermore, the framework for direct comparison with experimental results is introduced.
