Measurement of Tritium Distributions on Divertor Tiles used in JET-ITER Like Wall Experiments

2017 Fiscal Year Final Research Report

• Project/Area Number: 26289353
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Nuclear fusion studies
• Research Institution: University of Toyama
• Principal Investigator: Hatano Yuji 富山大学, 研究推進機構 水素同位体科学研究センター, 教授 (80218487)
• Co-Investigator(Kenkyū-buntansha): 大塚 哲平 近畿大学, 理工学部, 准教授 (80315118)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: プラズマ・核融合 / 放射線 / 水素 / 可視化 / タングステン

Outline of Final Research Achievements

ITER will use Be as a main chamber wall material and W as a divertor material. To examine the performances of these materials in tokamak environment, JET in EU has performed ITER-Like Wall (ILW) experimental campaigns with Be main chamber tiles and W-coated CFC divertor tiles. In this study, tritium (T) distributions on these tiles were examined using imaging plate (IP) technique and beta-ray induced X-ray spectrometry. Two retention mechanisms were found: (1) co-deposition with Be and other impurities, and (2) implantation into material bulk. T concentrations in Be deposition layers were lower than those in carbon deposition layers formed in previous campaigns with carbon tiles. Far less co-deposition of T on the sides of tiles was observed for ILW tiles compared with carbon tiles. Significantly reduced T retention was expected with Be and W walls in comparison with C walls. Technique to measure T retention in an individual dust particle using IP was also developed.

Free Research Field

核融合炉工学