Lithium sputtering from lithium-coated plasma facing components in the NSTX divertor
2014; Elsevier BV; Volume: 463; Linguagem: Inglês
10.1016/j.jnucmat.2014.12.032
ISSN1873-4820
AutoresF. Scotti, V. Soukhanovskii, J.-W. Ahn, R. E. Bell, S. P. Gerhardt, Michael Jaworski, R. Kaita, H. Kugel, A. G. McLean, Eric Meier, M. Podestà, A. L. Roquemore,
Tópico(s)Superconducting Materials and Applications
ResumoLithium sputtering yields and gross impurity influxes from lithium-coated graphite and molybdenum plasma facing components (PFCs) have been analyzed for the first time in the National Spherical Torus Experiment (NSTX) divertor during H-mode NBI-heated discharges. Motivated by the beneficial effects of lithium conditioning on discharge performance and reproducibility, evaporative lithium coatings were the routine wall conditioning technique in NSTX. Neutral lithium sputtering yields from solid lithium coatings in NSTX were found to be consistent with values reported from test stand experiments from deuterium-saturated lithium (with sputtering yields YLi∼0.03–0.07). Temperature-enhanced lithium sputtering was observed on lithium-coated graphite and molybdenum as a result of PFC heating by both embedded heaters and incident plasma heat flux, leading to YLi∼0.1–0.2 for surface temperatures above the lithium melting point.
Referência(s)