Melt-layer ejection and material changes of three different tungsten materials under high heat-flux conditions in the tokamak edge plasma of TEXTOR
Melt-layer ejection and material changes of three different tungsten materials under high heat-flux conditions in the tokamak edge plasma of TEXTOR
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DOI：
10.1088/0029-5515/51/11/113020
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发表时间：
2011-11
期刊：
影响因子：
3.3
通讯作者：
J. Coenen;V. Philipps;S. Brezinsek;G. Pintsuk;I. Uytdenhouwen;M. Wirtz;A. Kreter;K. Sugiyama;H. Kurishita;Y. Torikai;Y. Ueda;U. Samm
中科院分区：
文献类型：
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作者：
J. Coenen;V. Philipps;S. Brezinsek;G. Pintsuk;I. Uytdenhouwen;M. Wirtz;A. Kreter;K. Sugiyama;H. Kurishita;Y. Torikai;Y. Ueda;U. Samm
已经在 TEXTOR 托卡马克的等离子体边缘研究了钨 (W) 面向等离子体的组件 (PFC) 的行为，以研究熔体层喷射、熔体层的宏观钨侵蚀以及材料特性的变化，例如晶粒尺寸和空隙或气泡的丰度。等离子体中暴露的钨瓦径向位置处的平行热通量范围约为 q‖∼ 45 MW m−2，导致样品以 35° 至 20–30 MW m−2 的冲击角暴露。局部温度高达 6000 K，高水平的蒸发和沸腾以连续细喷雾或液滴喷射的形式造成严重侵蚀。细喷雾钨的排放量在很大程度上取决于材料特性：对于钨钽合金，与普通钨甚至几乎没有喷雾的超高纯钨相比，即使在低温下，喷雾和液滴排放的效果也明显更高。材料成分、晶粒结构和尺寸的差异可能与宏观侵蚀的不同演化有关。此外，还研究了再凝固材料，并观察到再结晶晶粒尺寸以及晶粒结构和晶粒取向的演变方面的显着差异。已观察到大空隙的形成。
The behaviour of tungsten (W) plasma-facing components (PFCs) has been investigated in the plasma edge of the TEXTOR tokamak to study melt-layer ejection, macroscopic tungsten erosion from the melt layer as well as the changes of material properties such as grain-size and abundance of voids or bubbles. The parallel heat flux at the radial position of the exposed tungsten tile in the plasma ranges around q‖ ∼ 45 MW m−2 causing samples to be exposed at an impact angle of 35° to 20–30 MW m−2. Locally the temperature reached up to 6000 K, high levels of evaporation and boiling are causing significant erosion in the form of continuous fine spray or droplet ejection. The amount of fine-spray tungsten emission depends strongly on the material properties: in the case of the tungsten–tantalum alloy the effect of spraying and droplet emission is significantly higher at even low temperatures when compared with regular tungsten or even ultra-high purity tungsten which shows almost no spraying at all. Differences in the material composition, grain structure and size may be related to the different evolution of macroscopic erosion. In addition the re-solidified material is studied and strong differences in terms of re-crystallized grain size and evolution of the grain structure and grain orientation are observed. The build up of large voids has been observed.