Analysis of the cool down related cavity performance of the European XFEL vertical acceptance tests

TL;DR

This paper investigates the impact of cool down dynamics on cavity performance during European XFEL production, focusing on how temperature changes near the critical temperature affect quality factors due to trapped flux.

Contribution

It provides the first analysis of cool down effects on cavity performance in the context of European XFEL production, highlighting the correlation with trapped flux.

Findings

Cool down dynamics influence cavity quality factors.

Temperature near T_c affects trapped flux levels.

Correlation observed between cool down and cavity performance.

Abstract

It has been reported that the cool down dynamics across $T_c$ has a significant influence on the observed quality factors $Q_0$ of a cavity, which is most likely due to trapped flux. In this document we show the results of the investigation if such a correlation can be observed during the European XFEL cavity production.