Erosion and deposition in tokamaks

Journal Article · Wed May 01 04:00:00 EDT 1985 · J. Vac. Sci. Technol., A; (United States)

DOI:https://doi.org/10.1116/1.573125· OSTI ID:5544719

Staudenmaier, G

The flow of metal impurities from the wall and limiter to the plasma, and back towards the wall, is investigated using surface collection probes and subsequent surface analysis in order to understand impuritiy generation and impurity transport. Impurity fluxes and their scrapeoff lengths have been investigated for several years in a large number of tokamaks. The results are summarized and discussed. Erosion exceeding deposition was first observed to occur at limiterlike structures closest to the plasma edge. Recently, a new probe has been developed to measure quantitatively the erosion in ASDEX. Subsequent quantitative surface analysis is performed in situ by electron induced x-ray analysis. Erosion caused either by ions (limiter) or charge exchange neutrals (wall) can be investigated separately. The erosion at the wall is about two orders of magnitude smaller than the erosion at limiterlike structures, which is of the order of one monolayer per discharge. Simultaneous measurements of deposition and erosion have been performed to elucidate net values of deposition and erosion.

• Research Organization: Max-Planck-Institut fuer Plasmaphysik, EURATOM-Association, D-8046 Garching/Muenchen, Federal Republic of Germany
• OSTI ID: 5544719
• Journal Information: J. Vac. Sci. Technol., A; (United States), Journal Name: J. Vac. Sci. Technol., A; (United States) Vol. 3:3; ISSN JVTAD
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700209* -- Fusion Power Plant Technology-- Component Development & Materials Testing
ASDEX TOKAMAK
CLOSED PLASMA DEVICES
EROSION
FIRST WALL
IMPURITIES
LIMITERS
NEUTRAL-PARTICLE TRANSPORT
RADIATION TRANSPORT
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTOR WALLS
TOKAMAK DEVICES