Details

Autor(en) / Beteiligte

• Lunsford, R.
• Rohde, V.
• Bortolon, A.
• Dux, R.
• Herrmann, A.
• Kallenbach, A.
• McDermott, R.M.
• David, P.
• Drenik, A.
• Laggner, F.
• Maingi, R.
• Mansfield, D. K.
• Nagy, A.
• Neu, R.
• Wolfrum, E.

Titel

Active conditioning of ASDEX Upgrade tungsten plasma-facing components and discharge enhancement through boron and boron nitride particulate injection

Ist Teil von

• Nuclear fusion, 2019-10, Vol.59 (12), p.126034

Ort / Verlag

United States: IOP Publishing

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The injection of boron (B) and boron nitride (BN) powders into ASDEX Upgrade H-mode discharges have demonstrated effective control of tungsten influx in low density/collisionality operational regimes, similar to conventional boronization methods. Sub-mm powder particles are gravitationally accelerated into the upper edge of a lower single null H-mode plasma with a boundary shape roughly conforming to the shape of the poloidal midplane limiters. Visible spectroscopy measurements at one of the outer limiter showed increases in both B and N signal levels, as well as elevated B levels in the divertor, and an increase in total radiated power by greater than a factor of two during BN injection. Globally the BN injection improved energy confinement by 10%-20%, associated with improvements in pedestal performance similar to gaseous N injection. Following conditioning discharges with B powder injection, three low gas-fueling discharges with magnetic perturbations for ELM suppression were successfully conducted. These first results suggest that the application of B containing powders can be used to both improve plasma performance in real-time, and to improve overall wall conditions for subsequent discharges.