It was learned from the Institute of Metal Research, Chinese Academy of Sciences, that the research team led by Researcher Rong Lijian recently broke through the technical bottleneck of the metal substrate for the second-generation high-temperature superconducting tape (REBCO) used in controlled nuclear fusion, achieving the domestic preparation of this key core material for the "artificial sun." Fusion is the nuclear reaction principle that makes the sun shine and generate heat, and the "artificial sun" is a fusion device that simulates this process.