Bifurcation to Expanded H-mode Pedestal Width and Height with Lithium Dust Injection in DIII-D

Lithium (Li) aerosol injection into the SOL of the DIII-D tokamak has facilitated a rapid $\sim100\%$ expansion of the H-mode pedestal width in a class of ELMy discharges. ELM-free H-modes with $\tau_E$ increasing by $<60\%$ are observed; the radiated power held steady during ELM-free periods. The pedestal $T_e$ and $P_e$ doubled, while the $T_i$ increased by $\sim20\%$. Substantial $L_i$ density was observed in the core, reaching up to $15\%$ at the top of the pedestal. The onset of a continuous pedestal-localized instability measured on beam emission spectroscopy correlated with the pedestal expansion, which can occur on a $<$10 ms timescale. These enhanced pedestals are limited by onset of giant ELMs, which appear to be consistent with ideal stability calculations.