Speaker
Description
A part of the FCC-hh design study explores different superconducting materials, which could be suitable to function as a coating on the beam screen, held at 50 K. Such a superconducting coating should be able to carry the beam image currents and lower the beam impedance in order to guarantee a high beam stability margin. Our study focuses on the still technologically unexploited thallium-based cuprates. For the development of the coating thin films of Tl-1223 are grown on untextured silver substrates. We present the microstructural analysis of these Tl-based films, performed with Scanning Electron Microscopy and Transmission Electron Microscopy where the chemical composition of the superconducting grains and especially the formation of the Tl-1223 phase is demonstrated. Furthermore, we present superconducting properties of the Tl-based films which are investigated by means of magnetization measurements and Scanning Hall Probe Microscopy. With magnetic field mapping we can investigate the global critical current homogeneity and compare microstructural features with the current distribution in superconducting grains and across grain boundaries.