Understanding core heavy impurity transport in a hybrid discharge on EAST
Understanding core heavy impurity transport in a hybrid discharge on EAST
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DOI：
10.1088/1741-4326/ac3e3b
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发表时间：
2021-11
期刊：
影响因子：
3.3
通讯作者：
S. Shi;Jiale Chen;C. Bourdelle;X. Jian;Tomáš Odstrčil;A. Garofalo;Yunxin Cheng;Y. Chao;
中科院分区：
文献类型：
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作者：
S. Shi;Jiale Chen;C. Bourdelle;X. Jian;Tomáš Odstrčil;A. Garofalo;Yunxin Cheng;Y. Chao;
分析了国际热核聚变实验堆类偏滤器EAST混合（高归一化β β N等离子体）方案堆芯重/高Z杂质钨（W）的行为。经常观察到W积聚，并严重降低等离子体性能（Gao等人，2017 Nucl. Fusion 57 056021）。考虑背景等离子体参数的同时演化，研究了混合放电中W积累过程的动力学。结果表明，体等离子体中心区域的环向旋转和密度峰通常较大，特别容易产生W的聚集。在W积累阶段的时间片建模，占新古典和湍流传输组件的W，通过近地天体与极向不对称效应引起的环形旋转，和TGLF，分别。该模型再现了W积累的实验观测结果，并确定了W的新古典向内对流/箍缩速度，由于大的密度峰值的体等离子体和环形旋转在中心区域的W积累的主要原因之一。此外，NEO + TGLF + STRAHL模型不仅可以预测核W密度分布，而且可以精确地重建实验中W主要产生的辐射信息。
The behavior of heavy/high-Z impurity tungsten (W) in the core of hybrid (high normalized beta β N plasmas) scenario on EAST with international thermonuclear experimental reactor-like divertor is analyzed. W accumulation is often observed and seriously degrades the plasma performance (Gao et al 2017 Nucl. Fusion 57 056021). The dynamics of the W accumulation process of a hybrid discharge are examined considering the concurrent evolution of the background plasma parameters. It is found that the toroidal rotation and density peaking of the bulk plasma are usually large in the central region, which is particularly prone to the W accumulation. A time slice during the W accumulation phase is modeled, accounting for both neoclassical and turbulent transport components of W, through NEO with poloidal asymmetry effects induced by toroidal rotation, and TGLF, respectively. This modeling reproduces the experimental observations of W accumulation and identifies the neoclassical inward convection/pinch velocity of W due to the large density peaking of the bulk plasma and toroidal rotation in the central region as one of the main reasons for the W accumulation. In addition, the NEO + TGLF + STRAHL modeling can not only predict the core W density profile but also closely reconstruct the radiated information mainly produced by W in the experiment.