An automatic beam alignment system based on relative reference points for Thomson scattering diagnosis system.

An automatic beam alignment system based on relative reference points is developed for the Thomson scattering system on Keda Torus eXperiment. Two critical apertures around the vacuum vessel are designed to shield stray light, and a probe beam is required to go through the centers of these two apertures, which are the reference points for alignment. Since these two apertures are coated with light absorbing materials, three fibers with glowing tips are employed to indicate the centers of two apertures.

Diagnostic capacity of electron cyclotron emission imaging system with continuous large observation area on EAST tokamak.

Electron cyclotron emission imaging on EAST provides direct measurements of the 2-D electron temperature dynamics in a continuous large observation area with high temporal and spatial resolution. Besides the normal MHD investigation, a system with a view field large enough to cover the core plasma region has been applied to extract more plasma information, such as the plasma center location, the deposition location of auxiliary heating, and the core toroidal rotation speed. These results solely based on electron cyclotron emission imaging (ECEI) data are consistent with the results of the equilibrium fitting (EFIT), numerical code, and other diagnostics, which indicate the powerful diagnostic capacity of this ECEI system.