Indexed by:Journal Papers

Date of Publication:2019-12-01

Journal:JOURNAL OF NUCLEAR MATERIALS

Included Journals:EI、SCIE

Volume:526

ISSN No.:0022-3115

Key Words:EAST; Plasma facing components; Impurity deposition; LIBS; Depth profile; EDX; Graphite tile

Abstract:Laser-induced breakdown spectroscopy (LIBS) has been applied for the depth-resolved identification of impurity deposited on EAST divertor tile. LIBS spectra show the presence of impurity elements (W, Mo, Li, Na, Ca, Cr) and tile material (C, Si, Ti) in the layer deposited on the graphite tile surface. The analysis of impurity deposition was performed in different positions on tile surface. The results indicate that the interaction of high heat plasma with plasma facing components (PFCs) leads to erosion of Mo from first wall and W from upper divertor. Depth profiling measurements show decay of impurity signals with successive laser shots and non-uniform impurity deposition in the different positions on tile surface. The impurity deposition was also measured at the different depths in the tile. The measurements show a non-uniform deposition at various depths in the deposition layer. Surface morphology and composition of tile were verified by SEM and EDX techniques. The study indicates that LIBS has potential to monitor the erosion and deposition of PFCs in fusion devices. The results obtained from LIBS technique are important for long pulse of H-mode plasma operation in EAST. (C) 2019 Elsevier B.V. All rights reserved.