TY - JOUR
T1 - Impurity transport studies in NSTX neutral beam heated H-mode plasmas
AU - Delgado-Aparicio, L.
AU - Stutman, D.
AU - Tritz, K.
AU - Finkenthal, M.
AU - Kaye, S.
AU - Bell, R.
AU - Kaita, R.
AU - Leblanc, B.
AU - Levinton, F.
AU - Menard, J.
AU - Paul, S.
AU - Smith, D.
AU - Yuh, H.
PY - 2009
Y1 - 2009
N2 - The first experimental assessment of low-Z impurity transport in a neutral beam heated, high-confinement H-mode plasma sustained in a low-field, low-aspect ratio spherical tokamak, was performed at the National Spherical Torus Experiment (NSTX). The injected impurities penetrate to the core on a hundred millisecond time scale, indicating a low core particle diffusivity (≲1 m2 s-1) in good agreement with the values predicted by neoclassical transport theory. In addition, a fixed q-profile magnetic field scan that showed reduced impurity penetration at high fields is also reported. This result suggests that anomalous ion particle transport associated with turbulent long-wavelength electrostatic instabilities must be largely suppressed in the NSTX core.
AB - The first experimental assessment of low-Z impurity transport in a neutral beam heated, high-confinement H-mode plasma sustained in a low-field, low-aspect ratio spherical tokamak, was performed at the National Spherical Torus Experiment (NSTX). The injected impurities penetrate to the core on a hundred millisecond time scale, indicating a low core particle diffusivity (≲1 m2 s-1) in good agreement with the values predicted by neoclassical transport theory. In addition, a fixed q-profile magnetic field scan that showed reduced impurity penetration at high fields is also reported. This result suggests that anomalous ion particle transport associated with turbulent long-wavelength electrostatic instabilities must be largely suppressed in the NSTX core.
UR - https://www.scopus.com/pages/publications/70349086556
U2 - 10.1088/0029-5515/49/8/085028
DO - 10.1088/0029-5515/49/8/085028
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AN - SCOPUS:70349086556
SN - 0029-5515
VL - 49
JO - Nuclear Fusion
JF - Nuclear Fusion
IS - 8
M1 - 085028
ER -
