Effect of progressively increasing lithium conditioning on
edge transport and stability in high triangularity NSTX H-modes
Authors: R. Maingia, J.M. Canikb, R.E.
Bella, D.P. Boylec, A. Dialloa, R. Kaitaa, S.M. Kayea, B.P.
LeBlanca, S.A. Sabbaghd, F. Scottie, V.A. Soukhanovskiie, and the
NSTX team
Abstract: A sequence of H-mode discharges with increasing
levels of pre-discharge lithium evaporation (‘dose’) was conducted
in high triangularity and elongation boundary shape in NSTX.
Energy confinement increased, and recycling decreased with
increasing lithium dose, similar to a previous lithium dose scan
in medium triangularity and elongation plasmas. Data-constrained
SOLPS interpretive modeling quantified the edge transport change:
the electron particle diffusivity decreased by 10-30x. The
electron thermal diffusivity decreased by 4x just inside the top
of the pedestal, but increased by up to 5x very near the
separatrix. These results provide a baseline expectation for
lithium benefits in NSTX-U, which is optimized for a boundary
shape similar to the one in this experiment.
Submitted to: Nuclear Materials and Energy
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