Speaker
Description
CERN has pioneered development of thin film superconducting radio-frequency cavities for particle accelerators. This technology has been applied in LEP II, LHC and more recently in HIE-ISOLDE. Many efforts are put in place at CERN in view of its potential implementation in the FCC machines. However, niobium thin film cavities historically feature a progressive degradation of performance by increasing the accelerating field.
A temperature mapping system has been developed and is currently used to detect the mechanisms responsible of performance degradation. Unlike most of the temperature mapping systems in operation, this system is specially designed for copper coated cavities. Since the thermal diffusivity of copper is noticeably high at liquid helium temperatures, the detection of heat losses in copper coated cavities turns out to be extremely challenging in comparison to that in bulk niobium cavities. We will report how we overcome this limitation in order to cope with our requirements. Furthermore, the first temperature maps of a niobium-copper 1.3 GHz cavity, tested at CERN, will be shown.
