Abstract
Deuterium retention was measured in beryllium samples from the JET ITER-like wall limiter tiles that were in the JET vessel for one and three campaigns (in vessel during 2015–2016 and 2011–2016, respectively), using thermal desorption spectroscopy, ion beam analysis and secondary ion mass spectrometry. It was found that overall retention increases with time non-linearly but somewhat slower than a square root of plasma exposure time. Depth distribution of retained deuterium was observed to change with time, with near-surface content being variable and dependent on recent plasma exposure conditions, and bulk contribution progressively increasing. Desorption peaks were observed to shift to higher temperatures with time. Experimental evidence suggests that long-term deuterium accumulation in the Be limiter components in JET is diffusion-dominated, with observed changes as function of time being consistent with the correspondingly deeper diffusion due to the propagation of the diffusion front. Cleaning interventions are found to only slow down this propagation and not stop it.
| Original language | English |
|---|---|
| Article number | 101872 |
| Journal | Nuclear Materials and Energy |
| Volume | 42 |
| DOIs | |
| Publication status | Published - Mar 2025 |
| MoE publication type | A1 Journal article-refereed |
Funding
This work has been carried out within the framework of the EUROfusion Consortium, funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No 101052200 — EUROfusion). This work has been part-funded by the EPSRC Energy Programme (grant number EP/W006839/1). To obtain further information on the data and models underlying this paper please contact [email protected]. The research used UKAEA’s Materials Research Facility, which has been funded by and is part of the UK’s National Nuclear User Facility and Henry Royce Institute for Advanced Materials.
Keywords
- Beryllium
- Hydrogen retention
- IBA
- JET ITER-like wall
- SIMS
- TDS
