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Edge and scrape-off layer temperature studies in the LTX-beta tokamak with lithium walls.

POSTER

Abstract

Two LLNL spectroscopic diagnostics are used in support of LTX-beta tokamak solid and liquid lithium wall studies using ohmic and NBI-heated 100+ kA limiter plasma discharges. Extreme ultraviolet spectra in the 2.5-20 nm range are used to analyze continuum, Li II and Li III series line intensities for edge electron temperature and lithium density estimates based on collisional-radiative modeling and the Inglis-Teller limit. Hydrogen 5-2 line Doppler broadening measurements are used with a two-Gaussian (two temperature) model to study Frank-Condon neutrals with few-eV temperatures (characteristic of gas fueling and recycling neutrals), and "hot", 20-120 eV, charge-exchange neutrals (characteristic of the low-collisionality scrape-off layer). Trends in these temperatures with the heating and fueling methods, recycling levels, as well as locations (inner or outer edge) are analyzed.

Presenters

  • Vlad Soukhanovskii

    Lawrence Livermore Natl Lab

Authors

  • Vlad Soukhanovskii

    Lawrence Livermore Natl Lab

  • Adam McLean

    Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab

  • Filippo Scotti

    Lawrence Livermore Natl Lab

  • Edward Magee

    Lawrence Livermore Natl Lab

  • Peter Beiersdorfer

    Lawrence Livermore Natl Lab

  • Dennis P Boyle

    PPPL

  • Anurag Maan

    PPPL

  • Ronald E Bell

    Princeton Plasma Physics Laboratory

  • Dick Majeski

    Princeton Plasma Physics Laboratory, Princeton University, PPPL, PPPL

  • Shigeyuki Kubota

    University of California, Los Angeles

  • William J Capecchi

    University of Wisconsin - Madison