Deuterium retention in tungsten and tungsten–tantalum alloys exposed to high-flux deuterium plasmas
Deuterium retention in tungsten and tungsten–tantalum alloys exposed to high-flux deuterium plasmas
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DOI：
10.1088/0029-5515/52/10/103021
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发表时间：
2012-10
期刊：
影响因子：
3.3
通讯作者：
Y. Zayachuk;M. 't Hoen;P. Zeijlmans van Emmichoven;I. Uytdenhouwen;G. Van Oost
中科院分区：
文献类型：
--
作者：
Y. Zayachuk;M. 't Hoen;P. Zeijlmans van Emmichoven;I. Uytdenhouwen;G. Van Oost
用热脱附谱(TDS)直接比较了钨和两种钨-钽合金-W-1%Ta和W-5%Ta在等离子体发生器等离子体(离子通量∼1024m−2 S−1，偏置靶处的离子能量∼50 eV)中的氢保留。在钨和钨-钽中的总保留量没有系统性差异。每个等级的测量保留值与暴露在相同条件下的三个等级的平均值的偏差不超过24%。与W靶相比，W-Ta样品的TDS谱中没有出现额外的脱附峰，说明W与Ta的合金化没有引入额外类型的陷阱。在实验过程中，将相同的样品多次暴露在相同的等离子体条件下，结果表明，与以前没有暴露的样品相比，在所研究的条件下，具有先前暴露历史的样品产生的氚保留率最高增加了130%。我们认为这是所考虑的材料暴露在能量低于置换阈值的离子中产生额外的氘陷阱的证据。对于W和W-Ta，由这些陷阱引起的释放峰的位置是相似的，这表明对应的陷阱是同类的。
A direct comparison of deuterium retention in samples of tungsten and two grades of tungsten–tantalum alloys—W–1% Ta and W–5% Ta, exposed to deuterium plasmas (ion flux ∼1024 m−2 s−1, ion energy at the biased target ∼50 eV) at the plasma generator Pilot-PSI was performed using thermal desorption spectroscopy (TDS). No systematic difference in terms of total retention in tungsten and tungsten–tantalum was identified. The measured retention value for each grade did not deviate by more than 24% from the value averaged over the three grades exposed to the same conditions. No additional desorption peaks appeared in the TDS spectra of the W–Ta samples as compared with the W target, indicating that no additional kinds of traps are introduced by the alloying of W with Ta. In the course of the experiment the same samples were exposed to the same plasma conditions several times, and it is demonstrated that samples with the history of prior exposures yield an increase in deuterium retention of up to 130% under the investigated conditions compared with the samples that were not exposed before. We consider this as evidence that exposure of the considered materials to ions with energy below the displacement threshold generates additional traps for deuterium. The positions of the release peaks caused by these traps are similar for W and W–Ta, which indicates that the corresponding traps are of the same kind.