Abstract
Typical H-mode pedestal electron and ion temperature in NSTX range from 100-300 eV. A new operating regime termed the "Enhanced Pedestal" (EP) H-mode has been observed in which the pedestal ion temperature increases to ~600 eV in about 50ms, or one energy confinement time, resulting in a global confinement improvement. Ion temperature gradients as high as 30 keV/m are observed. The regime is correlated with a localized braking of edge toroidal rotation near the q=3 surface, in which case the pressure gradient term in the radial force balance becomes dominant over the toroidal and pololidal rotation terms. Coupled with increased rotation just inside the barrier, the radial electric field shear is also increased. An MHD trigger event is common to the formation of the EP H-mode phase, which can occur either during the Ip ramp-up or flat-top phases of discharges. The observed characteristics of this scenario are presented.