Xiao Shumei, Zang Qing, Han Xiaofeng, Wang Tengfei, Yu Jin, Zhao Junyu
Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei, Anhui 230031, People's Republic of China.
Academy of Opto-Electronics, Chinese Academy of Sciences, Beijing 100094, People's Republic of China.
Rev Sci Instrum. 2016 Jul;87(7):073506. doi: 10.1063/1.4959185.
Thomson scattering (TS) diagnostic is an important diagnostic for measuring electron temperature and density during plasma discharge. However, the measurement of Thomson scattering signal is disturbed by the stray light easily. The stray light sources in the Experimental Advanced Superconducting Tokamak (EAST) TS diagnostic system were analyzed by a simulation model of the diagnostic system, and simulation results show that the dump system is the primary stray light source. Based on the optics theory and the simulation analysis, a novel dump system including an improved beam trap was proposed and installed. The measurement results indicate that the new dump system can reduce more than 60% of the stray light for the diagnostic system, and the influence of stray light on the error of measured density decreases.
