Ultrafine tungsten as a plasma-facing component in fusion devices: effect of high flux, high fluence low energy helium irradiation
Ultrafine tungsten as a plasma-facing component in fusion devices: effect of high flux, high fluence low energy helium irradiation
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DOI：
10.1088/0029-5515/54/8/083013
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发表时间：
2014-08-01
期刊：
影响因子：
3.3
通讯作者：
Allain, J. P.
中科院分区：
文献类型：
--
作者：
El-Atwani, O.;Gonderman, Sean;Allain, J. P.
这项工作讨论了超细晶钨材料对高通量、高通量、低能量纯氦辐照的响应。超细晶粒钨样品暴露在位于荷兰 Nieuwegein 的荷兰基础能源研究所 (DIFFER) 的 Pilot-PSI（Westerhout 等人 2007 Phys. Scr. T128 18）线性等离子体装置中。钨样品上的 He 通量范围为 1.0 x 10(23)-2.0 x 10(24) 离子 m(-2) s(-1)，样品偏压范围为负 (20-65) V，样品温度范围为 600-1500 摄氏度。对暴露样品的 SEM 分析清楚地表明，超细晶粒钨材料对绒毛的形成 增加了一个数量级或更多，支持了晶界在辐射损伤机制中起主要作用的猜想。解决了预绒毛损伤分析，如晶粒取向对结构形成的作用。 (1 1 0)和(1 1 1)取向的晶粒仅显示出孔的形成，而(0 0 1)取向的晶粒显示出装饰有孔的波纹(更高的结构)。在这种情况下还观察到晶界处的起泡。辐照过程中的原位 TEM 分析显示，晶界处形成了多面气泡，这可能是该位置起泡的原因。鉴于氦引起的损伤可能导致宏观灰尘排放到聚变等离子体中，该结果可能对未来的等离子体燃烧聚变装置产生重大影响。
This work discusses the response of ultrafine-grained tungsten materials to high-flux, high-fluence, low energy pure He irradiation. Ultrafine-grained tungsten samples were exposed in the Pilot-PSI (Westerhout et al 2007 Phys. Scr. T128 18) linear plasma device at the Dutch Institute for Fundamental Energy Research (DIFFER) in Nieuwegein, the Netherlands. The He flux on the tungsten samples ranged from 1.0 x 10(23)-2.0 x 10(24) ions m(-2) s(-1), the sample bias ranged from a negative (20-65) V, and the sample temperatures ranged from 600-1500 degrees C. SEM analysis of the exposed samples clearly shows that ultrafine-grained tungsten materials have a greater fluence threshold to the formation of fuzz by an order or magnitude or more, supporting the conjecture that grain boundaries play a major role in the mechanisms of radiation damage. Pre-fuzz damage analysis is addressed, as in the role of grain orientation on structure formation. Grains of (1 1 0) and (1 1 1) orientation showed only pore formation, while (0 0 1) oriented grains showed ripples (higher structures) decorated with pores. Blistering at the grain boundaries is also observed in this case. In situ TEM analysis during irradiation revealed facetted bubble formation at the grain boundaries likely responsible for blistering at this location. The results could have significant implications for future plasma-burning fusion devices given the He-induced damage could lead to macroscopic dust emission into the fusion plasma.