English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The phenomenon of electric breakdown poses serious challenge to the design ofdevices that operate under high gradient environments. Experimental evidenceoften points towards breakdown events that are accompanied by elevatedtemperatures and dark current spikes, presumably due to high-asperitynano-structure formation that enhances the local electric field and triggers arunaway process. However, the exact mechanistic origin of such nano-structuresunder typical macroscopic operational conditions of electric gradient andmagnetic-field-mediated heating remains poorly understood. In this work, amodel is presented that describes the evolution of a typical copper surfaceunder the combined action of the electric fields and elevated temperatures.Using a mesoscale curvature-driven growth model, we show how the copper surfacecan undergo a type of dynamical instability that naturally leads to theformation of sharp asperities in realistic experimental conditions. Exploringthe combined effect of fields and temperature rise, we identify criticalregimes that allow for the formation of breakdown precursors. These regimesstrongly resonate with previous experimental findings on breakdown of copperelectrodes, hence suggesting surface diffusion to be a crucial breakdownprecursor mechanism.

Thermal and electric field driven breakdown precursor formation on metal surfaces