Liquid lithium divertor characteristics and plasma–material interactions in NSTX high-performance plasmas
Liquid lithium divertor characteristics and plasma–material interactions in NSTX high-performance plasmas
复制标题
DOI：
10.1088/0029-5515/53/8/083032
复制
发表时间：
2013-08
期刊：
影响因子：
3.3
通讯作者：
M. Jaworski;T. Abrams;J. Allain;M. Bell;R. Bell;A. Diallo;T. Gray;S. Gerhardt;R. Kaita
中科院分区：
文献类型：
--
作者：
M. Jaworski;T. Abrams;J. Allain;M. Bell;R. Bell;A. Diallo;T. Gray;S. Gerhardt;R. Kaita
液态金属等离子体组件（PFC）已被提议作为解决创建经济上可行的聚变反应堆所面临的几个问题的一种手段。迄今为止，这种方法在转向托卡马克装置中的演示很少，我们在这里概述了国家球形环面实验（NSTX）中的此类工作。使用蒸发涂层作为填充方法，在 2010 年运行活动中安装并运行了液态锂偏滤器 (LLD)。 LLD 由铜背衬结构和多孔钼正面组成。运行结束时，标称锂填充水平超过孔隙率 150%。尽管标称液位超过毛细管结构并且进入 PFC 的峰值电流密度超过 100 kA m−2，但没有观察到宏观喷射事件。此外，在达到表明锂芯的锂熔化温度后没有观察到基底线发射，并在钼多孔层上提供保护涂层。偏滤器发出的杂质表明，无论是否在 LLD 上偏滤，等离子体都会与受氧污染的锂相互作用。分析 LLD 放电数据库，以考虑在机器中沉积的锂总量范围内是否对放电产生净影响。对 H-97L 的检查表明，在整个运行过程中性能保持恒定，这与影响性能的是锂表面层的质量的假设一致。杂质的积累表明完全流动的液态锂系统可以在与 NSTX 相关的时间尺度上获得稳态 PFC。
Liquid metal plasma-facing components (PFCs) have been proposed as a means of solving several problems facing the creation of economically viable fusion power reactors. To date, few demonstrations exist of this approach in a diverted tokamak and we here provide an overview of such work on the National Spherical Torus Experiment (NSTX). The Liquid Lithium Divertor (LLD) was installed and operated for the 2010 run campaign using evaporated coatings as the filling method. The LLD consisted of a copper-backed structure with a porous molybdenum front face. Nominal Li filling levels by the end of the run campaign exceeded the porosity void fraction by 150%. Despite a nominal liquid level exceeding the capillary structure and peak current densities into the PFCs exceeding 100 kA m−2, no macroscopic ejection events were observed. In addition, no substrate line emission was observed after achieving lithium-melt temperatures indicating the lithium wicks and provides a protective coating on the molybdenum porous layer. Impurity emission from the divertor suggests that the plasma is interacting with oxygen-contaminated lithium whether diverted on the LLD or not. A database of LLD discharges is analysed to consider whether there is a net effect on the discharges over the range of total deposited lithium in the machine. Examination of H-97L indicates that performance was constant throughout the run, consistent with the hypothesis that it is the quality of the surface layers of the lithium that impact performance. The accumulation of impurities suggests a fully flowing liquid lithium system to obtain a steady-state PFC on timescales relevant to NSTX.