Computational investigation of incident ion angles and material erosion at rough graphite and silicon carbide divertor surfaces
Computational investigation of incident ion angles and material erosion at rough graphite and silicon carbide divertor surfaces
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粗糙石墨和碳化硅偏滤器表面的入射离子角和材料侵蚀的计算研究
DOI：
10.1063/5.0095155
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发表时间：
2022
影响因子：
2.2
通讯作者：
B. Koel
中科院分区：
文献类型：
--
作者：
S. Abe;C. H. Skinner;A. Liu;J. Garcia;Z. Lin;S. Bringuier;T. Abrams;B. Koel
我们提出了一个计算调查的依赖性材料侵蚀的入射离子角在粗糙的石墨和碳化硅偏滤器表面。通过跟踪鞘层离子轨迹的运动方程模型计算了NSTX-U和DIII-D偏滤器D等离子体的离子角分布。然后，有效的溅射产率和离子阴影面积分数计算的Monte Carlo微图案化和粗糙度代码，应用计算的IAD的表面形貌数据，从光学共聚焦显微镜的粗糙石墨和SiC偏滤器表面从NSTX-U和DIII-D实验。计算发现，有效的溅射产率，溅射图案，和阴影区域是由详细的表面拓扑结构，而不是均方根粗糙度RRMS，这表示从平坦表面的偏差。与光滑表面相比，粗糙表面的有效溅射产额的抑制是由平均局域离子入射角（LIIA）<$θ′ <$的变化引起的。发现平均表面倾角分布（SIAD）<$δ <$是一个有用的参数，以估计从计算的IAD的LIIA。本文给出了B场入射角α = 85°-89°的粗糙表面D等离子体的平均LIIA和主离子遮蔽面积分数随平均SIAD δ θ变化的经验公式。我们建议使用的平均LIIA <$θ′ <$估计溅射产额粗糙表面的角度依赖性的溅射产额。
We present a computational investigation of the dependence of material erosion on the incident ion angle at rough graphite and silicon carbide divertor surfaces. Ion angle distributions (IADs) for D plasmas at NSTX-U and DIII-D divertors were calculated by an equation-of-motion model that traces the ion trajectories in the sheath. Then, the effective sputtering yields and ion shadowed area fractions were calculated by a Monte Carlo micro-patterning and roughness code that applied the calculated IADs to surface topographic data that were obtained from optical confocal microscopy of rough graphite and SiC divertor surfaces from NSTX-U and DIII-D experiments. The calculations found that the effective sputtering yields, the sputtering pattern, and the shadowed area are determined by the detailed surface topology rather than the root mean square roughness RRMS, which represents deviations from a flat surface. The suppression of the effective sputtering yields for rough surfaces compared to the yield for a smooth surface was accounted for by the change of the mean local incident ion angle (LIIA) ⟨ θ′⟩. The mean surface inclination angle distribution (SIAD) ⟨ δ⟩ was found to be a useful parameter to estimate the LIIA from the calculated IADs. We report global empirical formulas for the mean LIIA and fraction of the area shadowed from the main ions for D plasmas for rough surfaces with B-field incident angles α = 85°–89° as a function of the mean SIAD ⟨ δ⟩. We propose the use of the mean LIIA ⟨ θ′⟩ to estimate the sputtering yield for rough surfaces from the angular dependence of the sputtering yield.
影响因子：
2.9
作者：
S. Abe;C. Skinner;I. Bykov;J. Guterl;A. Lasa;Y. Yeh;J. Coburn;D. Rudakov;C. Lasnier;H. Wang;A. Mclean;T. Abrams;B. Koel
通讯作者：
S. Abe;C. Skinner;I. Bykov;J. Guterl;A. Lasa;Y. Yeh;J. Coburn;D. Rudakov;C. Lasnier;H. Wang;A. Mclean;T. Abrams;B. Koel