ST-FRC Hybrid Steady-State Fusion Core: A Conceptual Design

This preprint presents an independent conceptual design of a compact steady-state fusion core based on a hybrid spherical tokamak (ST) and field-reversed configuration (FRC) configuration. The design adopts a high-beta ST (aspect ratio 1.4–1.8, toroidal field 3–5 T, plasma beta 20%–40%) as the primary confinement body, with an embedded 5–10 cm thin FRC layer serving as an edge buffer to intercept 30%–50% of parallel heat flux and suppress Type-I ELM drive. All dominant confinement loss channels—ITG/ETG micro-turbulence, large ELMs, neoclassical tearing modes, alpha-particle orbit loss, and FRC interface reconnection—are systematically analyzed and matched with experimentally validated mitigation strategies. Engineering challenges including ST-FRC magnetic topology matching, RMP field penetration, and long-pulse steady-state operation are reviewed with known mitigation pathways. No insurmountable physical obstacles are identified at the conceptual level. This preprint establishes academic priority. The full technical report, including detailed parameter optimization and structured engineering data, is available upon request to the author.