Dust remobilization from rough planar surfaces in tokamak steady-state plasmas. (December 2018)

• Record Type: Journal Article
• Authors: Autricque, A.; Peillon, S.; Gensdarmes, F.; Sow, M.; Fedorczak, N.; Roche, H.; Pluchery, O.; Grisolia, C.
• Is Part Of: Nuclear materials and energy. Volume 17(2018)
• Page Start: 284
• Page End: 288
• Publication Date: 2018-12
• Subjects: Nuclear energy -- Periodicals; Nuclear fuels -- Periodicals; Nuclear reactors -- Materials -- Periodicals; Radioactive substances -- Periodicals; 621.4833
• DOI: 10.1016/j.nme.2018.11.013
• Languages: English
• ISSNs: 2352-1791

Abstract

Highlights: Adhesion forces distributions between tungsten spheroids and a tungsten roughness of tokamakrelevant roughness are measured using atomic force microscopy. The van der Waals-based Rabinovich model is shown to reasonably reproduce the mean adhesion force, while a fit (using a Biasi like function) for the spread is proposed. External forces applied on a dust particle located on a tokamak divertor are estimated using a simple sheath model. Typical tokamak tungsten dust is shown to be remobilizable by reasonable sheath electric fields. Abstract: The ability of tungsten (W) dust to be remobilized from rough tokamak plasma-facing surfaces is investigated in this study. Atomic Force Microscopy is used to evaluate the adhesion force distribution between W spheroids of ∼ 1 − 10 µm radius and a rough W substrate. Our results confirm that the Rabinovich model describes reasonably well the mean adhesion force in tokamak-relevant surface roughness regimes. The external (electric and ion drag) forces are estimated as well using a simplified sheath model. The results reveal that micron-size dust can be resuspended by attainable electric fields in tokamak conditions.