First result of boronization assisted by the ICWC on EAST with full metal wall

作者：Yue Guan, Guizhong Zuo, Wei Xu, Yaowei Yu, Zhen Sun, Zhe Wang, Rui Ding, Ling Zhang, Tao Zhang, Zhenwei Wu, Songtao Mao, Hailin Zhao, Tianqi Jia, Shouan Puyang, Lili Wang, T. Wauters, Xianzu Gong, Jiang Hu · 发表于：Nuclear Fusion · 年份：2025 · DOI：10.1088/1741-4326/adf75c · 被引用次数：5 · 研究领域：Fusion materials and technologies、Magnetic confinement fusion research、Particle accelerators and beam dynamics

Abstract Boron (B), a low-Z (atomic number) material, has been widely utilized in wall conditioning to improve plasma performance in fusion devices [1]. In 2023, boronization was successfully conducted on EAST featuring an ITER-like tungsten divertor and fully metallic first wall. The process employed predischarge coating with carborane (C2B10H12) as the working material, assisted by ion cyclotron wall conditioning (ICWC). After one time 12 g boronization, it was found the thickness of B film was approximately 120 nm. Post-boronization observations indicated that substantial hydrogen (H) release during initial plasma discharges compared with the consumed W/B wall, attributed to H co-deposition during the ICWC-boronization processing, which led to uncontrollable divertor neutral pressure and plasma density. The H/(H+D) ratio demonstrated a gradual reduction from ~85% to 30% over more than 1850 s of deuterium plasma, with a cumulative injected energy of 2325 MJ. The B coating significantly enhanced the stored energy in plasma and improved confinement performance. The stored energy in plasma showed an increase of about 20%, primarily due to a reduction in impurity radiation, including oxygen (O) and heavy impurities such as tungsten (W), iron (Fe), and copper (Cu). The effective ion charge (Zeff) decreased from 2.3 to 2.0. Following ICWC-boronization, the line-integrated radiation profile decreased by nearly 35% in the plasma core, plasma density and electron temperature exhibit...