China's CFETR Central Solenoid Model Coil achieves 12T with 48kA current

China achieved a major milestone in its nuclear fusion program with the successful first test campaign of the Central Solenoid Model Coil (CSMC), a critical subsystem of the Comprehensive Research Facility for Fusion Technology (CRAFT), completed in late 2024. The CSMC surpassed its design target by achieving a steady-state current of 48 kA (vs. 47 kA design) at a peak magnetic field of 12 T. This validates essential large-scale superconducting magnet technologies for fusion reactors. The coil, constructed using Nb 3 Sn and NbTi conductors, features a 1.5 m inner diameter, weighs 140 t, and stores 407.6 MJ of energy. Key challenges overcome include magnet design methodologies, complex manufacturing processes (winding, insulation, heat treatment, VPI, assembly, joints), and advanced testing/diagnostics (quench protection, cryogenic safety). Following cooldown to ∼4.5 K and subsystem checks, the coil demonstrated stable excitation to 48 kA. This success provides crucial technical support for the construction of the China Fusion Engineering Test Reactor (CFETR) and advances China's pursuit of practical fusion energy.