RAMT

Authors

А. Rybikov ^1, ² , А. Eremkin ² , А. Komarov ² , V. Kuznetsov ² , А. Volodin ² , P. Piskarev ² , I. Bogdanov ² , V. Tanchuk ² , S. Grigoriev ² , M. Dorogov ¹ , N. Arkhipov ³

¹ Institute of Advanced Data Transfer Systems, ITMO University, Kronverkskiy pr., 49, lit. A, St. Petersburg, 197101, Russia

² JSC «NIIEFA» (Efremov Institute), Doroga na Metallostroy, 3, Metallostroy, St. Petersburg, 196641, Russia

³ Institution «Project Center ITER», Raspletina St., 11, bldg. 2, Moscow, 123182, Russia

10.17586/2687-0568-2025-7-3-184-197

Rev. Adv. Mater. Technol., 2025, vol. 7, no. 3, pp. 184–197

Abstract

The study presents the results of numerical simulation and experiments of thermal processes in the mock-ups of the ITER divertor dome plasma facing units (PFU). The divertor is a critical component subjected to extreme thermal loads which imposes high requirements on the reliability of its PFUs. The purpose of the study is to assess the impact of the parameters (geometry, size, localization) of defects in the brazed joint of tungsten-copper armour and bronze heat sink under heat loads qₛ = 1–6 MW/m2 . The simulation by the finite-element method was performed for the PFU configurations with defects of various shapes and sizes. The results were compared with the experimental data of thermal tests. It was found that an increase in the defect size leads to an increase in the armour temperature: at the maximum defect area (50% of the joint area), the local temperature increases by 55%, and the average temperature by 40% (qₛ = 6 MW/m2 ). The defect shape (rectangular/triangular) has a minor effect: deviations do not exceed 1.4% for the maximum and 10% for the average values. The longitudinal castellation (electrical discharge machining) of tiles in the model can affect the temperature distribution. The maximum armour surface temperature for all versions did not exceed 1200 °C. At loads ≤ 4 MW/m2 , cooling remains convective, while at the higher loads, local boiling zones occur without transition to a critical heat flux. The comparison between the calculated and experimental results has detected the similarity in the temperature distributions.

Keywords

Divertor dome; Plasma facing unit; Brazing defect; Thermal tests; Castellation

Foundings

Contract:17706413348240000190/55-24/01 of 20.06.2024 for R&D “Development of technology and pilot production of components for the Dome and First Wall panels and performance of thermal tests of divertor elements for the ITER reactor in 2024”

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Impact of Brazed Joint Defects on Operability of ITER Divertor Dome Plasma Facing Units

Authors

Abstract

Keywords

Foundings