A Study on Deuterium Retention Behavior of Plasma-Facing Materials for EAST

• Published in: IEEE transactions on plasma science 2018-06, Vol.46 (6), p.2198-2202
• Main Authors: Liu, Hao-Dong, Zhou, Hai-Shan, Zhao, Ming-Zhong, Wu, Jing, Xu, Yu-Ping, Wang, Jing, Zhang, Ying-Chun, Sun, Ning-Bo, Ding, Fang, Xu, Qian, Luo, Guang-Nan
• Format: Article
• Language: English
• Subjects: Coatings; Graphite; Plasma measurements; Plasma temperature; Surface morphology; Temperature measurement; tokamaks; tungsten
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/TPS.2018.2825234

To investigate the deuterium (D) retention behavior of plasma-facing materials (PFMs) in the Experimental Advanced Superconducting Tokamak (EAST), SiC-coated graphite, bulk W, and W coating were exposed to D plasmas employing the material and plasma evaluation system in EAST. A comparative study was performed in an electron cyclotron resonance (ECR) linear plasma facility as well. For the EAST experiments, the local electron temperature and density were T_{e}\approx 10-15 eV and n_{e}\approx (1-3) \times 10 18 m −3 , respectively. In the ECR facility, the plasma parameters were measured to be T_{e} \approx 2.4 eV and n_{e} \approx 1.5 \times 10^{17} m −3 . The surface morphology was examined by scanning electron microscopy, and D retention properties of various PFMs were examined by thermal desorption spectroscopy. No significant modification of the surface morphology was observed after tokamak exposure experiments. Bulk W and W coating exhibit similar D retention behavior, while D inventory in SiC-coated graphite has been found to be much larger than that in W materials.