Development of the flowing liquid lithium limiter for EAST tokamak

Lithium coating technology and liquid lithium limiter have been applied on HT-7 tokamak and many significant results were obtained. The study of exploring lithium as potential plasma facing material is being carried out on EAST tokamak. A flowing liquid lithium (FLiLi) limiter has been successfully tested in the EAST in 2014, and the in-vessel electromagnetic (EM) pump was validated to make liquid lithium circulate from the bottom collector to the distributor of the limiter, which realized the FLiLi operated under steady-state and also drastically reduced the total amount of lithium used in the experiment. To adapt to the plasma shape during discharge, the limiter can be moved along the guide rail into vacuum vessel to meet various plasma scenarios by the driving system. During the operation, the lithium can be easily controlled by adjusting the current of EM pump and the <0.1 mm thickness of lithium film and a mass flow rate ∼2 cm³/s were achieved. However, some problems were also exposed, which require improvement for the next generation of limiter. The current design, manufacturing and the latest results of the new EAST FLiLi limiter were introduced in this paper.