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

Lunsford, R.; Rohde, Volker; Bortolon, Alessandro; Dux, Ralph; Herrmann, Albrecht; Kallenbach, Arne; McDermott, Rachael M.; David, Pierre; Drenik, Aleksander; Laggner, Florian; Maingi, Rajesh; Mansfield, D. K.; Nagy, Alexander; Neu, Rudolf; Wolfrum, Elisabeth

doi:10.1088/1741-4326/ab4095

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

Journal Article · Mon Oct 14 00:00:00 EDT 2019 · Nuclear Fusion

DOI:https://doi.org/10.1088/1741-4326/ab4095· OSTI ID:1562453

^[1]; Rohde, Volker ^[2]; ^[1]; Dux, Ralph ^[2]; Herrmann, Albrecht ^[2]; ^[2]; ^[2]; David, Pierre ^[2]; Drenik, Aleksander ^[2]; Laggner, Florian ^[1]; Maingi, Rajesh ^[1]; Mansfield, D. K. ^[1]; Nagy, Alexander ^[1]; Neu, Rudolf ^[2]; Wolfrum, Elisabeth ^[2]

Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Max-Planck-Institut fur Plasmaphysik, Garching (Germany)

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. Furthermore, 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.

View Accepted Manuscript (DOE)

Research Organization:: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)

Sponsoring Organization:: USDOE

Contributing Organization:: the ASDEX Upgrade team

Grant/Contract Number:: AC02-09CH11466

OSTI ID:: 1562453

Alternate ID(s):: OSTI ID: 22930036

Journal Information:: Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 12 Vol. 59; ISSN 0029-5515

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

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