Attained continously through a gradual reduction of the edge particle influx from the plasma facing surfaces, the supershot regime is characterized by an energy confinement time strongly and inversely correlated with edge particle influx. Lithium injection reduces both the hydrogenic and carbon influxes, with improved confinement persisting over successive disharges. Core ion thermal diffusion nearly vanishes, leaving outward convection dominant, often producing flat-topped temperature profiles. Simulations of Li pellet recycling scans with constant edge temperature are presented. This limiter, L3, consists of a cylindrical body covered with stainless steel mesh.
Liquid lithium is supplied to the mesh surface via a flow tube from an in-situ reservoir.
Internal heaters permit operation of the limiter well above the lithium melting point. Results of these first experiments with L3 in CDX-U will be discussed.