Host: The Japan Society of Vacuum and Surface Science
Trapped deuterium (D) in coated lithium layers was investigated in EAST. Depth profiles of deuterium retention in lithium layers were analyzed using glow discharge optical emission spectroscopy. Thick lithium layer of 7.2 micron was coated on tungsten specimen at the high field side during one experimental campaign of EAST, and deuterium was trapped in the lithium layer until interface. Higher oxygen intensities were counted in the lithium layers and it suggested that lithium forms oxide. From one day sample exposure, D was observed on the surface layer only and D intensities were about one order of magnitude lower than that of long term exposure. Hence, higher D trapping in lithium layer was performed by long term plasma-lithium interactions.
