H-mode Pedestal Enhancement and Improved Confinement in DIII-D with Lithium Injection

Lithium has been injected into DIII-D discharges leading to larger density and temperature pedestal widths and pedestal pressure increases. The lithium injection allowed transitions from ELMing to ELM free \mbox{H-mode} with energy confinement improvements up to 70\%, compared to similar discharges without lithium. Lithium was injected directly into the plasma and SOL as an aerosol (44 $\mu$m dia particles) using a ``lithium dropper'' with no increase in radiated power. The lithium injection also led to density fluctuations of up to 8\% in the pedestal region in the frequency range $\approx$40 - 150 kHz, measured by the BES diagnostic [1]. We will discuss experiments to obtain ELM-free performance and enhanced pedestals with lithium, EPED modeling to determine proximity to the peeling-ballooning boundary, and conditions for obtaining reduced recycling. \\[4pt] [1] Z. Yan, et al., these proceedings