title: Continuous improvement of H-mode discharge performance with progressively increasing lithium coatings in the National Spherical Torus Experiment.
abstract: Lithium wall coatings have been shown to reduce recycling, improve energy confinement, and suppress edge localized modes in the National Spherical Torus Experiment. Here, we show that these effects depend continuously on the amount of predischarge lithium evaporation. We observed a nearly monotonic reduction in recycling, decrease in electron transport, and modification of the edge profiles and stability with increasing lithium. These correlations challenge basic expectations, given that even the smallest coatings exceeded that needed for a nominal thickness of the order of the implantation range.
authors: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors: R
authors: R
authors: Maingi
authors: S M
authors: SM
authors: Kaye
authors: C H
authors: CH
authors: Skinner
authors: D P
authors: DP
authors: Boyle
authors: J M
authors: JM
authors: Canik
authors: M G
authors: MG
authors: Bell
authors: R E
authors: RE
authors: Bell
authors: T K
authors: TK
authors: Gray
authors: M A
authors: MA
authors: Jaworski
authors: R
authors: R
authors: Kaita
authors: H W
authors: HW
authors: Kugel
authors: B P
authors: BP
authors: LeBlanc
authors: D K
authors: DK
authors: Mansfield
authors: T H
authors: TH
authors: Osborne
authors: S A
authors: SA
authors: Sabbagh
authors: V A
authors: VA
authors: Soukhanovskii