Can Injected Lithium Granules Trigger ELMs?
POSTER
Abstract
Coating plasma facing components (PFCs) with lithium has eliminated ELMs in NSTX H-mode plasmas. Improved ELM-free confinement, however, leads to accumulation of high-Z impurities and uncontrolled radiation losses. Further, injecting solid deuterium pellets in other devices is known to trigger ELMs at frequencies approximating the injection frequency. Hence, one can pose the question:''can lithium granules (i.e. small pellets) injected at high frequency also trigger ELMs in fusion devices?'' Such a scheme might lead to the replacement of large amplitude Type-1 ELMs with small amplitude, high frequency (grassy) ELMs. These smaller ELMs would then reduce the power flux to PFCs (as compared to large ELMs) while \textit{perhaps} simultaneously purging the core of accumulated impurities. Such a technology, moreover, would not require cryogenics. The physics of this concept will be explored.
*Work supported by USDOE Contract DE-AC02-09CH11466.