Innovation Progress and Collaborative Networks in China\u2019s Nuclear Fusion Technology: A Patent Analysis

Nuclear fusion has emerged as a global strategic priority, with China becoming a pivotal force. However, the internal mechanisms of its innovation ecosystem remain underexplored. This study analyzes 5,144 global patent data points (including 1,366 from China) using the Herfindahl-Hirschman Index (HHI), Latent Dirichlet Allocation (LDA), and Social Network Analysis (SNA) to unveil the system\u2019s structure and evolution. Results indicate: (1) Macro-structure: China\u2019s system exhibits a 'relative concentration' (HHI \u2248 456), significantly higher than the US 'dispersed' model (HHI \u2248 45), characterized by a unique 'Dual-Core' structure led by national institutes. (2) Technological Evolution: A clear strategic shift from \u201cfundamental physics\u201d to \u201cengineering breakthroughs\u201d is identified. (3) Network Structure: The collaborative network is sparse and fragmented, dominated by two \u201cNational Team\u201d clusters (HFIPS and SWIP). (4) Operational Mechanisms: This fragmentation reflects an \u201cordered division of labor\u201d, where research institutes act as system integrators, universities lead in basic science, and enterprises serve as specialized suppliers. Consequently, this study quantitatively characterizes the operational mode of China\u2019s \u201cWhole-of-Nation System\u201d as a mission-oriented, highly concentrated, and specialized division of labor system defined by \u201ccore-periphery\u201d clusters.