Far-infrared laser diagnostics in EAST

摘要

Structure, improvements and experiment results of a vertical three-channel far- infrared (FIR) hydrogen cyanide (HCN) laser interferometer, operated routinely in EAST to measure the electron density profile, are presented. Moreover, a five-channel deuterium cyanide (DCN) laser interferometer was developed successfully. Some key issues confronted in development, including the economization of working gas and the solution to atmospheric absorption, are resolved and described in detail.