Modelling of the effect of ELMs on fuel retention at the bulk W divertor of JET. (May 2019)

• Record Type: Journal Article
• Authors: Heinola, K.; Ahlgren, T.; Brezinsek, S.; Vuoriheimo, T.; Wiesen, S.
• Is Part Of: Nuclear materials and energy. Volume 19(2019)
• Page Start: 397
• Page End: 402
• Publication Date: 2019-05
• Subjects: ELM -- Fuel retention -- Multi-scale computing -- JET; Nuclear energy -- Periodicals; Nuclear fuels -- Periodicals; Nuclear reactors -- Materials -- Periodicals; Radioactive substances -- Periodicals; 621.4833
• DOI: 10.1016/j.nme.2019.03.013
• Languages: English
• ISSNs: 2352-1791

Abstract

Highlights: Effect of ELMs on fuel retention at the bulk W target of JET-ILW was studied with multi-scale calculations. Energetic intra-ELM Deuterium particles get implanted and create near-surface defects up to depths of few tens of nm, which act as the main fuel trapping sites during ELMs. Inter-ELM Deuterium particles increase the filling levels of trapped fuel in defects. Clustering of vacancies was found to take place at high temperatures. Abstract: Effect of ELMs on fuel retention at the bulk W target of JET ITER-Like Wall was studied with multi-scale calculations. Plasma input parameters were taken from ELMy H-mode plasma experiment. The energetic intra-ELM fuel particles get implanted and create near-surface defects up to depths of few tens of nm, which act as the main fuel trapping sites during ELMs. Clustering of implantation-induced vacancies were found to take place. The incoming flux of inter-ELM plasma particles increases the different filling levels of trapped fuel in defects. The temperature increase of the W target during the pulse increases the fuel detrapping rate. The inter-ELM fuel particle flux refills the partially emptied trapping sites and fills new sites. This leads to a competing effect on the retention and release rates of the implanted particles. At high temperatures the main retention appeared in larger vacancy clusters due to increased clustering rate.