Speaker
Description
The Compact Linear Accelerator for Research and Applications (CLARA) at Daresbury Laboratory has recently undertaken an upgrade of its photocathodes from using a copper emission surface to using caesium telluride (Cs\textsubscript{2}Te). During the conditioning of the first Cs\textsubscript{2}Te cathode a significant number of RF breakdowns were detected, and so that cathode was replaced; subsequent inspection of the cathode following removal identified a number of surface defects. To better study the second cathode, a diagnostic camera was used to collect images of the surface \textit{in situ} during RF conditioning; the frequent formation over time of surface defects was observed. In this paper we present a statistical analysis of the breakdown events and surface image data, utilizing cross-correlation of the signal derivatives to account for cumulative trends. The analysis reveals a correlation between the rate of defect formation and the incidence of RF breakdowns, with a Pearson coefficient of $r = 0.59$ at zero time lag. These results provide quantitative evidence that RF breakdown events are the likely driver of surface morphology changes on Cs\textsubscript{2}Te cathodes.
| Paper status | Resubmitted proceeding files received and assigned to an editor. Accepted by Submitter. |
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