Department of Fusion Science,The Graduate University for Advanced Studies,SOKENDAI,322-6 Oroshi-cho,Toki 509-5292,Gifu,Japan;
Princeton Plasma Physics Laboratory,100 Stellarator Road,Princeton,NJ 08540,United States of America;
National Institute for Fusion Science,National Institutes of Natural Sciences,322-6 Oroshi-cho,Toki 509-5292,Gifu,Japan;
plasma spectroscopy; extreme ultraviolet; vacuum ultraviolet; magnetically confined fusion; impurity seeding; wall conditioning;