Surface analysis studies for plasma-wall interactions in torus devices

Yamashina, Toshiro; Mohri, Mamoru

doi:10.1016/0022-3115(84)90354-4

Cited by 9 publications

(1 citation statement)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In tokamaks, collection probes have been used(l,2) to measure the impurity fluxes in the scrapeoff layer (SOL) plasma. Limiter componcnts (3)(4)(5)(6)(7)(8)(9)(10)(11) and samples placed on or near the walls have been analyzed after extended exposure to plasma discharges. This provides data on the erosion and redistribution of the materials in the tokamak.…”

Section: Introductionmentioning

confidence: 99%

Erosion and redeposition experiments in the PISCES facility

Goebel¹,

Hirooka²,

Conn³

et al. 1986

View full text Add to dashboard Cite

The modfication of surfaces during exposure to plasma bombardment is a critical issue in the development of limiter and wall materials for fusion confinement experiments. Controlled studies of the erosion and redeposition of materials during high flux and fluence plasma exposure are now possible in the PISCES facility. PISCES is a continuously operating plasma device which has achieved hydrogen plasma densities of over 10 13 cm" 3 and electron temperatures of 5 to 24eV over large areas. Ion fluxes of 10 17 to 10 19 cm" 2 sec 1 and fluences of up to 10 23 cm* 2 have been used to bombard biased samples inserted into the plasma. The plasma parameters can be selected to produce simple sputtering, or redeposition by the ionization and recycling of the sputtered target materials. Collaborative studies on the performance of Cu and Cu-Li alloys (with ANL), stainless steel (with SNLL), and graphite (with IPP at Garching, and SNLL) have been undertaken. Surface topography modification is always observed after a sufficient fluence is achieved-The net erosion rate is significantly lower during redeposition than one would expect from classical sputtering yields. The transport and deposition of different materials by the plasma to the samples during redeposition conditions results in greatly modified surface composition and morphology. Chemical sputtering of graphite during low energy, high flux (>10 18 cm" 2 sec" 1 ) plasma bombardment is observed. Chemically formed hydrocarbons are relatively easily redeposited compared to sputtered carbon. The performance of these materials, the surface morphology evolution, and the characteristics of the redeposited materials are discussed.

show abstract

Section: Introductionmentioning

confidence: 99%

Erosion and redeposition experiments in the PISCES facility

Goebel¹,

Hirooka²,

Conn³

et al. 1986

View full text Add to dashboard Cite

show abstract

Erosion and redeposition experiments in the pisces facility

Goebel

Hirooka

Conn

et al. 1987

Journal of Nuclear Materials

View full text Add to dashboard Cite

The modfication of surfaces during exposure to plasma bombardment is a critical issue in the development of limiter and wall materials for fusion confinement experiments. Controlled studies of the erosion and redeposition of materials during high flux and fluence plasma exposure are now possible in the PISCES facility. PISCES is a continuously operating plasma device which has achieved hydrogen plasma densities of over 10 13 cm" 3 and electron temperatures of 5 to 24eV over large areas. Ion fluxes of 10 17 to 10 19 cm" 2 sec 1 and fluences of up to 10 23 cm* 2 have been used to bombard biased samples inserted into the plasma. The plasma parameters can be selected to produce simple sputtering, or redeposition by the ionization and recycling of the sputtered target materials. Collaborative studies on the performance of Cu and Cu-Li alloys (with ANL), stainless steel (with SNLL), and graphite (with IPP at Garching, and SNLL) have been undertaken. Surface topography modification is always observed after a sufficient fluence is achieved-The net erosion rate is significantly lower during redeposition than one would expect from classical sputtering yields. The transport and deposition of different materials by the plasma to the samples during redeposition conditions results in greatly modified surface composition and morphology. Chemical sputtering of graphite during low energy, high flux (>10 18 cm" 2 sec" 1) plasma bombardment is observed. Chemically formed hydrocarbons are relatively easily redeposited compared to sputtered carbon. The performance of these materials, the surface morphology evolution, and the characteristics of the redeposited materials are discussed.

show abstract