Measurement of Flows in the HSX Stellarator Demonstrating the Importance of Momentum-Conservation in Neoclassical Flow Modeling

POSTER

Abstract

The flow velocity of carbon ions is measured using a Charge Exchange Recombination Spectroscopy (CHERS) system on the Helically Symmetric Experiment (HSX), a quasi-helically symmetric stellarator. Intrinsic parallel flow speeds of up to 20km/s have been measured. The parallel velocity is compared to the predictions of the PENTA code [1-2]. Multiple ion species, including the species used for the CHERS measurements, are included in the calculations. PENTA is a neoclassical code that includes the effects of momentum-conservation, which are often neglected for nonsymmetric stellarators. Without momentum conservation the parallel flow velocity in HSX is under-predicted by approximately an order of magnitude. Agreement is seen between the measured and calculated parallel flows when momentum conservation is included.\\[4pt] [1] D.A. Spong, Phys. Plasmas 12 (2005) 056114.\\[0pt] [2] J. Lore et al, Phys. Plasmas 17 (2010) 056101.

*Supported under DOE Grant DE-FG02-93ER54222.

Authors

  • A. Briesemeister

    • HSX Plasma Laboratory, University of Wisconsin, Madison, USA

  • Jeremy Lore

    • ORNL
    • ORNL/ORISE

  • K. Zhai

    • HSX Plasma Laboratory, University of Wisconsin, Madison, USA

  • D.T. Anderson

    • HSX Plasma Lab - UW Madison
    • HSX Plasma Lab, University of Wisconsin, Madison
    • HSX Plasma Lab, Univ. of Wisconsin, Madison, WI, USA
    • HSX Plasma Laboratory, University of Wisconsin, Madison, USA

  • F.S.B. Anderson

    • HSX Plasma Lab - UW Madison
    • HSX Plasma Laboratory, University of Wisconsin, Madison, USA

  • J.N. Talmadge

    • HSX Plasma Lab - UW Madison
    • HSX Plasma Laboratory, University of Wisconsin, Madison, USA