Development Of High-Speed Vacuum Ultraviolet Spectroscopy Using A Modified Seya-Namioka Monochromator And Channel Electron Multiplier Detector In The Hl-2a Tokamak

A high-speed vacuum ultraviolet monochromator is developed for the HL-2A tokamak through the introduction of a novel channel electron multiplier in a modified Seya-Namioka spectrometer. A good signal to noise ratio of above 2000 is attained in the development phase of the system with typical operating parameters for observing routine HL-2A plasmas. The wavelength calibration is performed using characteristic line emissions from a hollow cathode light source with helium and argon discharges. The first measurement result of the monochromator at a sample rate of 60 kHz is presented in comparison with the visible D alpha signals. Published by AIP Publishing.