Deuterium occupation of vacancy-type defects in argon-damaged tungsten exposed to high flux and low energy deuterium plasma

Content Provider	Scilit
Author	Zhu, Xiu-Li Zhang, Ying Cheng, Long Yuan, Yue Temmerman, Gregory De Wang, Bao-Yi Cao, Xingzhong Lu, Guang-Hong
Copyright Year	2016
Description	Journal: Nuclear Fusion Doppler broadening spectroscopy in the positron annihilation technique (DBS-PA) has been employed to investigate the defect properties in argon-damaged tungsten exposed to low-energy and high flux deuterium plasma. Argon ion irradiations with energy 500 keV are performed for tungsten samples with various levels of damage. The remarkable increment of the S parameter in DBS-PA indicates the introduction of vacancy-type defects in argon irradiated tungsten. An increase of ion fluence results in a continuous increase of the S parameter until saturation. Unexpectedly, a much higher fluence leads to a decrease of the S parameter in the near surface, and the (S,W) slope changes greatly. This should be associated with the formation of argon-vacancy complexes in the near surface produced by the excessive implanted argon ions. With deuterium plasma exposure, a significant decrease of the S parameter occurs in the pre-irradiated tungsten, suggesting the sharp reduction of the number and density of the vacancy-type defects. The thermal desorption spectroscopy results demonstrate that the argon-damaged tungsten, compared to the pristine one, exhibits an enhanced low-temperature desorption peak and an additional and broad high-temperature desorption peak, which indicates that deuterium atoms are trapped in both low-energy and high-energy sites. All these observations directly indicate the deuterium occupation of irradiation-induced vacancy defects in damaged tungsten, which is responsible for the remarkable increase of the deuterium retention in comparison with the pristine one.
Related Links	http://iopscience.iop.org/article/10.1088/0029-5515/56/3/036010/pdf
ISSN	00295515
e-ISSN	17414326
DOI	10.1088/0029-5515/56/3/036010
Journal	Nuclear Fusion
Issue Number	3
Volume Number	56
Language	English
Publisher	IOP Publishing
Publisher Date	2016-02-05
Access Restriction	Open
Subject Keyword	Journal: Nuclear Fusion Nuclear Energy and Engineering Vacancy Type Defects Argon Damaged Tungsten Low Energy and High
Content Type	Text
Resource Type	Article
Subject	Nuclear and High Energy Physics Condensed Matter Physics