Design, Construction, and Performance of the New 148 mm Bore, 25 T Magnet Test Platform for HTS Cables at the CHMFL

Abstract To research and test the electromagnetic behavior of larger-size high-temperature superconducting cables under high magnetic fields(> 20 T), we are in urgent need of a new test platform with a larger bore and providing high background fields. Hence, the High Magnetic Field Laboratory of the Chinese Academy of Sciences (CHMFL) developed a 148 mm bore, 25 T test platform to reach it. A magnetic field of 25 T is a new world record for the 148 mm bore magnets. In this paper, we introduce the design and construction process of the unique test platform in detail. And the NMR method was adopted to measure the peak field, which can reach 25.159 T. Further, the first successful experiment for a long REBCO cable was carried out with the test platform. Moreover, the magnet leaves much space to improve the highest magnetic field in case of the necessity of the user's application for experimental requirements.