Details

Autor(en) / Beteiligte

• Rudakov, D.L.
• Abrams, T.
• Ding, R.
• Guo, H.Y.
• Stangeby, P.C.
• Wampler, W.R.
• Boedo, J.A.
• Briesemeister, A.
• Brooks, J.N.
• Buchenauer, D.A.
• Bykov, I.
• Chrobak, C.
• Doerner, R.P.
• Donovan, D.
• Elder, J.D.
• Fenstermacher, M.E.
• Guterl, J.
• Hinson, E.
• Hollmann, E.M.
• Lasnier, C.J.
• Leonard, A.W.
• McLean, A.G.
• Moyer, R.A.
• Nygren, R.E.
• Thomas, D.M.
• Unterberg, E.A.
• Watkins, J.G.
• Wong, C.P.C.

Titel

DiMES PMI research at DIII-D in support of ITER and beyond

Ist Teil von

• Fusion engineering and design, 2017-11, Vol.124, p.196-201

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2017

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• •Net erosion of high-Z PFC materials in DIII-D divertor is reduced by short scale re-deposition.•Positive electrical biasing locally suppresses erosion of high-Z PFC materials.•Local injection of methane gas suppressed Mo erosion by forming in-situ carbon coating.•Measurements of Mo and W erosion on DiMES samples are well reproduced by ERO-OEDGE modeling.•Migration of W in and out of DIII-D divertor was studied using DiMES and MiMES collector probes. An overview of recent Plasma-Material Interactions (PMI) research at the DIII-D tokamak using the Divertor Material Evaluation System (DiMES) is presented. The DiMES manipulator allows for exposure of material samples in the lower divertor of DIII-D under well-diagnosed ITER-relevant plasma conditions. Plasma parameters during the exposures are characterized by an extensive diagnostic suite including a number of spectroscopic diagnostics, Langmuir probes, IR imaging, and Divertor Thomson Scattering. Post-mortem measurements of net erosion/deposition on the samples are done by Ion Beam Analysis, and results are modelled by the ERO and REDEP/WBC codes with plasma background reproduced by OEDGE/DIVIMP modelling based on experimental inputs. This article highlights experiments studying sputtering erosion, re-deposition and migration of high-Z elements, mostly tungsten and molybdenum, as well as some alternative materials. Results are generally encouraging for use of high-Z PFCs in ITER and beyond, showing high redeposition and reduced net sputter erosion. Two methods of high-Z PFC surface erosion control, with (i) external electrical biasing and (ii) local gas injection, are also discussed. These techniques may find applications in the future devices.