Speaker
Description
Helium is a byproduct of the DT fusion reaction and if not removed quickly enough will pose a real issue as a contaminant of the fusion plasma. Helium is difficult to remove and so finding ways of removing it sufficiently quickly is of importance. Recent results in HIDRA and MAGNUM-PSI have shown that liquid lithium can certainly do the pumping and the FLIER results from the early 2000’s show that flowing lithium can remove the helium. Thus, this possibly provides a path to removing helium. Experiments were performed in EAST where the LiMIT/FLiLi limiter plates that were developed between a US-China collaboration from 2016 – 2020 were reused and deployed in helium plasmas. The limiters were moved from 12 to 3 cm from the plasma edge with flowing lithium and the plasmas were 10 s long. Evidence shows that there was a reduction in the local helium pressure around the divertor where lithium that that interacts with the helium is deposited and co-deposition of helium in lithium occurs. Correlating the particle flow through gas puff balance, plasma density, plasma temperature and stored energy is important in trying to understand the effect of lithium on helium. This paper will compare results in EAST with similar experiments that have been performed in HIDRA and MAGNUM-PSI previously.