The optical collection system designed for EAST edge TV Thomson scattering diagnostic

An optical collection system composed of a collection lens, fibers, and a mounting rack with high luminous flux, high transmission efficiency, and low optical losses has been designed and installed to collect sufficient scattered lights for the edge TV Thomson scattering diagnostic on the EAST tokamak. A collection lens with an on-axis optical structure, aspheric lens, and regular shaped image plane is designed to meet the system requirements in terms of field of view, spectral range, aberration, and assembly. A mounting rack is designed to fix the collection system. Fiber back-illumination and a location system are used to install the system to the designed position, and the measurement positions of each fiber are measured by using a portable laser tracker system. This optimized design of the optical collection system can facilitate the establishment of the edge TV Thomson scattering system on EAST, which verifies the feasibility of TV Thomson scattering used in large-scale fusion devices.