Wenskat, M.; Bate, C.; Jeromin, A.; Keller, T.; Knobloch, J.; Kugeler, O.; Köszegi, J.; Kramer, F.; Reschke, D.: Cavity Cut-out Studies of a 1.3 GHz Single-cell Cavity After a Failed Nitrogen Infusion Process. In: Peter Michel ... [Ed.] : SRF2019, Proceedings of the 19th International Conference on RF Superconductivity, Dresden, GermanyGeneve: JaCoW, 2019. - ISBN 978-3-95450-211-0, p. MOP025/87-89
http://accelconf.web.cern.ch/AccelConf/srf2019/papers/mop025.pdf
Open Access Version
Abstract:
R&D on the nitrogen infusion process at DESY produced at the beginning a series of 1.3 GHz single-cell cavities which have shown severe deterioration in the vertical cold test which was completely unexpected and could not be explained at the time. To investigate the origin of the deterioration, one of the cavities was optically inspected and a Temperature- and Magnetic Field-Mapping was done in collaboration with HZB. Together with 2nd Sound data, regions of interests were identified and cut from the cavity. Subsequent surface analysis techniques (SEM/EDX, SIMS, PIXE, EBSD) were applied in order to identify the reason for the deterioration. Especially the differences between hot and cold spots as well as quench spots identified by T-Mapping were investigated.