Recent Progress in Understanding Electron Thermal Transport in
NSTX
Authors: Y. Ren, E. Belova, N. Gorelenkov,
W. Guttenfelder, S.M. Kaye, E. Mazzucato, W.X. Wang, R.E. Bell,
B.P. LeBlanc
Abstract: The anomalous level of electron thermal
transport inferred in magnetically confined confirgurations is one
of the most challenging problems for the ultimate realization of
fusion power using toroidal devices: tokamaks, spherical tori and
stellarators. It is generally believed that plasma instabilities
driven by the abundant free energy in fusion plasmas are
responsible for the electron thermal transport. The National
Spherical Torus eXperiment (NSTX) [M. Ono et al., Nucl. Fusion 40
557, 2000] provides a unique laboratory for studying plasma
instabilities and their relation to electron thermal transport due
to its low toroidal field, high plasma beta, low aspect ratio and
large ExB ow shear. Recent findings on NSTX have shown that
multiple instabilities are required to explain observed electron
thermal transport, given the wide range of equilibrium parameters
due to different operational scenarios and radial regions in
fusion plasmas. Here we review the recent progresses in
understanding anomalous electron thermal transport in NSTX and
focus on mechanisms that could drive electron thermal transport in
the core region. The synergy between experiment and
theoretical/numerical modeling is essential to achieving these
progress. The plans for newly commissioned NSTX-Upgrade will also
be discussed.
Submitted to: Nuclear Fusion
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