We report an observation of robust suppression of edge-localized modes (ELMs) in the Experimental Advanced Superconducting Tokamak (EAST), enabled by continuous boron (B) powder injection. Edge harmonic oscillations appear during B powder injection, providing sufficient particle transport to maintain constant density and avoid impurity accumulation in ELM-stable plasmas. Quasi-steady ELM suppression discharges are demonstrated with modest energy confinement improvement and over a wide range of conditions: heating power and technique variation, electron density range over a factor ∼3.5, deuterium or helium ion species, and with either direction of the toroidal magnetic field. ELM suppression is observed above a threshold edge B intensity and ceases within 0.5 s of termination of the B injection. In contrast to ELM suppression accompanied by recycling reduction during Li powder injection in NSTX and EAST (Maingi et al 2018 Nucl. Fusion58 024003), reduced recycling due to hydrogenic species retention is unnecessary for the ELM suppression with B powder injection, paving the way for its consideration as an ELM control tool for future fusion devices.
我们在先进实验超导托卡马克（EAST）中观测到，通过连续注入硼（B）粉末，实现了对边缘局域模（ELMs）的稳健抑制。在硼粉末注入期间出现边缘谐波振荡，提供了足够的粒子输运，以维持恒定密度并避免ELM稳定等离子体中的杂质积累。准稳态ELM抑制放电得以实现，并伴有适度的能量约束改善，且覆盖了广泛的参数范围：加热功率与方式的改变、电子密度变化约3.5倍、氘或氦离子种类，以及环向磁场的两个方向。当边缘B强度超过阈值时，ELM抑制被观测到，并在B注入停止后0.5秒内消失。与锂（Li）粉末注入期间通过降低再循环来抑制ELM（见Maingi等人，2018年，《核聚变》58卷024015号）不同，在硼粉末注入实现ELM抑制时，氢同位素粒子滞留减少所导致的再循环降低并非必要因素。这为硼粉末注入作为未来聚变装置中ELM控制工具提供了依据。