High-harmonic Fast Wave Heating and Current Drive Results for Deuterium H-mode Plasmas in the National Spherical Torus Experiment
Authors: G. Taylor, P.T. Bonoli, R.W. Harvey, J.C. hosea, E.F. Jaeger, B.P. LeBlanc, C.K. Phillips, P.M. Ryan, E.J. Valeo, J.R. Wilson, J.C. Wright, and the NSTX Team
Abstract:
A critical research goal for the spherical torus (ST) program is to initiate, ramp-up, and
sustain a discharge without using the central solenoid. Simulations of non-solenoidal plasma
scenarios in the National Spherical Torus Experiment (NSTX) [1] predict that high-harmonic
fast wave (HHFW) heating and current drive (CD) [2] can play an important roll in enabling
fully non-inductive (fNI ~ 1) ST operation. The NSTX fNI ~ 1 strategy requires 5-6 MW of
HHFW power (PRF) to be coupled into a non-inductively generated discharge [3] with a
plasma current, Ip ~ 250-350 kA, driving the plasma into an HHFW H-mode with Ip ~ 500 kA,
a level where 90 keV deuterium neutral beam injection (NBI) can heat the plasma and provide
additional CD. The initial approach on NSTX has been to heat Ip ~ 300 kA, inductively
heated, deuterium plasmas with CD phased HHFW power [2], in order to drive the plasma
into an H-mode with fNI ~ 1.
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Presented at: 38th European Physical Society Conferene on Plasma Physics, Strasbourg, France (June 2011)
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Download PPPL-4647 (pdf 1.31 MB 4 pp)
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