Radiative divertor behavior and physics in Ar seeded plasma on EAST

Chen Jingbo^{1, 2}, Duan Yanmin¹, Yang Zhongshi^{1, 2, †}, Wang Liang¹, Wu Kai^{1, 2}, Li Kedong^{1, 2}, Ding Fang¹, Mao Hongmin¹, Xu Jichan^{1, 2}, Gao Wei¹, Zhang Ling¹, Wu Jinhua¹, Luo Guang-Nan^{1, 2}, EAST Team

(color online) Impurities in the upper divertor region observed by div-W spectroscopy without Ar seeding (4.8 s) and with Ar seeding (5.2 s). In this L-mode discharge, a small amount of tungsten sputtered from the divertor target, which causes a rapid increase of core radiation.