Thallium-1223, a superconductor with high critical temperature (Tc ∼ 120 K) and high irreversibility line is a promising alternative to copper layers as a low surface impedance material in particle accelerator components. In the existing design of the Future Circular Collider (FCC-hh), for reasons of cryogenic efficiency and vacuum stability, the beam screen that shields the dipoles from synchrotron radiation has to stay at best in the temperature range between 40 and 60 K, in which copper surface resistance might be too high to prevent beam instabilities due to wakefields. This paper reports the progress on the realization of thallium-1223 based high temperature superconducting (HTS) coatings realized by electrochemical deposition. The study of the Tl-1223 phase has been carried out on precursor-pellets and films. Transport characterization revealing a very high irreversibility line and also high local critical currents obtained from Scanning Hall Probe Microscopy (SHPM) measurements will be shown. A first analysis of compatibility in vacuum has been carried out and the generation of secondary electrons (SEY) has been investigated as well. The encouraging results, although not conclusive, will state that thallium-based phase could be suitable for the proposed application.

中文翻译：

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未来的圆形对撞机光束屏幕：Tl-1223 HTS 涂层的进展

铊 1223 是一种具有高临界温度 (Tc ∼ 120 K) 和高不可逆线的超导体，作为粒子加速器组件中的低表面阻抗材料，是铜层的有前途的替代品。在未来圆形对撞机 (FCC-hh) 的现有设计中，出于低温效率和真空稳定性的原因，屏蔽偶极子免受同步辐射的光束屏必须在 40 到 60 K 的温度范围内保持最佳状态，在哪个铜表面电阻可能太高以防止由于尾流场引起的光束不稳定性。本文报道了通过电化学沉积实现基于铊 1223 的高温超导 (HTS) 涂层的进展。Tl-1223 相的研究是在前体颗粒和薄膜上进行的。传输特性揭示了非常高的不可逆线以及从扫描霍尔探针显微镜 (SHPM) 测量获得的高局部临界电流。已经对真空中的相容性进行了第一次分析，并且还研究了二次电子 (SEY) 的产生。令人鼓舞的结果虽然不是决定性的，但表明铊基相可能适用于拟议的应用。