Plasma-wall interaction on the divertor tiles of JET ITER-like wall from the viewpoint of micro/nanoscopic observations
Plasma-wall interaction on the divertor tiles of JET ITER-like wall from the viewpoint of micro/nanoscopic observations
复制标题
从微/纳米观察的角度看类JET ITER壁偏滤器瓦片上的等离子体-壁相互作用
DOI：
10.1016/j.fusengdes.2018.01.051
复制
发表时间：
2018
影响因子：
1.7
通讯作者：
JET Contributors
中科院分区：
文献类型：
--
作者：
M. Tokitani ;M. Miyamoto;S. Masuzaki;R. Sakamoto;Y. Oya;Y. Hatano;T. Otsuka;M. Oyaidzu;H. Kurotaki;T. Suzuki;D. Hamaguchi;K. Isobe;N. Asakura;A. Widdowson;K. Heinola;M. Rubel;JET Contributors
利用多种材料分析技术对具有ITER样壁的喷气托卡马克装置(JET-ILW)第一次战役(2011-2012年)中使用的偏滤器瓦片表面进行了微纳观察。来自内部偏滤器的先前结果分别针对1、3和4号瓦片的单个极向段，即上部、垂直和水平目标。在1号和4号瓷砖上形成了较厚的层状混合料沉积层，并在3号瓷砖上形成了侵蚀。这项研究主要集中在外部偏滤器：磁片6、7和8。与内部磁片相比，垂直靶片(磁片7和8)没有观察到明显的表面修饰，在那里溅射侵蚀和杂质沉积几乎是平衡的。只有位于排气通道附近的瓷砖6(水平靶)的特定部分被一层(类似地质的)混合物质沉积层所覆盖，该混合层主要包括厚度为∼2 μm的Be和Ni。该混合层的特点是在该层中明显检测到一定量的氮。由于N的浓度随深度位置的不同而不同，这取决于在射流实验过程中为等离子体边缘冷却而喷出的气体的量。除了外部偏滤器外，本文还报道了局部侵蚀和沉积效应的一个非常有趣的特征。
Micro/nanoscopic observations on the surface of the divertor tiles used in the first campaign (2011–2012) of the JET tokamak with ITER-like Wall (JET ILW) have been carried out by means of several material analysis techniques. Previous results from the inner divertor were reported for a single poloidal section of the tile numbers 1, 3 and 4, i.e., upper, vertical and horizontal targets, respectively. The formation of the thick stratified mixed-material deposition layer on tiles 1 and 4, and erosion on tile 3 were identified. This study is mostly focused on the outer divertor: tiles 6, 7 and 8. In contrast to the inner tile, remarkable surface modifications have not been observed on the vertical target (tiles 7 and 8) where sputtering erosion and impurity deposition would have been almost balanced. Only a specific part of tile 6 (horizontal target) located near the exhaust channel was covered with a stratified (“geological-like”) mixed-material deposition layer which mainly included Be and Ni with the thickness of ∼2 μm. Special feature of this mixed layer was that a certain amount of nitrogen (N) was clearly detected in the layer. Since the concentration of N varied with the depth position, it could be depended on the amount of that gas puffed for plasma edge cooling during the JET experimental campaign. In addition to the outer divertor tiles, a very interesting feature of the local erosion and deposition effects is reported in this paper.