Extending the low-recycling regime to higher performance discharges and liquid lithium walls in the Lithium Tokamak Experiment-β

In order to extend the low-recycling regime first observed in the Lithium Tokamak Experiment to higher performance, steadier discharges with solid and liquid lithium wall coatings, and to study its unique physics in more detail, LTX was upgraded to the Lithium Tokamak Experiment-β. The upgrade improves the lithium evaporation system, roughly doubles the toroidal field and ohmic heating power supplies, adds neutral beam injection for heating and core fueling, and adds or improves numerous diagnostics. Recent experiments have extended the duration and performance of the low-recycling regime in ohmic discharges with solid and liquid Li walls, with record values of current, temperature, pressure, and confinement. Upcoming experiments will also investigate beam heating at high current.