Speaker
Description
It has been proposed that breakdown nucleation in high vacuum high field systems results from a critical transition linked to plastic activity in the surface of the metal exposed to the field [1]. It is also known that field emission is associated with, and generally considered to be a necessary precursor to, breakdown. Recently, a theoretical link was offered between the intensity and frequency of fluctuations in the pre-breakdown field emitted current and the ensuing breakdown nucleation event, and this link was investigated experimentally [2]. In fact, such a link is proposed to exist independent of the exact mechanism of breakdown, and the details of the fluctuations can serve to constrain models of the generative processes.
In this work, the field emitted current in high-field RF cavities has been monitored on a pulse-to-pulse basis leading up to the breakdown in an attempt to discern whether an observable evolution in the signal characteristics is present and whether a link between phenomena may be extracted. The challenges associated with this work are discussed, and the preliminary results are discussed.
[1] - "Theory of electric field breakdown nucleation due to mobile dislocations" Phys. Rev AB, 22 (2019) 083501
[2] - "Dark current spikes as an indicator of mobile dislocation dynamics under intense dc electric fields" Phys. Rev AB, 23 (2020) 123501
