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Description
The baseline design of the FCC-hh beam screen is based on an octagonal shaped stainless-steel tube coated in its interior with copper. The surface impedance of the beam screen has a strong impact on the beam stability. In the foreseen operating temperature range from 40 K to 60 K the intended coating might not guarantee an impedance sufficiently low for a stable beam. This motivates the exploration of high-temperature superconducting coated conductor (HTS-CC) tapes as an alternative coating approach. It promises a lower surface impedance than copper under the required operating conditions. Therefore, we determine the suitability by validating the RF-performance of existing HTS-CCs as a function of temperature and magnetic fields, using a microwave non-contact dielectric loaded resonator technique and further, by developing a surface impedance measurement facility. First results will be discussed and compared to existing data for conventional metallic coating.
