Analysis of the cool down related cavity performance of the European   XFEL vertical acceptance tests
  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. 
Marc Wenskat, J\"orn Schaffran
physics.acc-ph