Design of an edge TV Thomson scattering diagnostic system on EAST

The study of the edge plasma has significant effect for the performance improvement of magnetic confinement. However, the Thomson scattering system, which has been used to provide electron temperature and electron density on EAST, do not meet the requirements for the edge plasma measurements in measurement region, spatial and spectral resolution. Herein, a TV Thomson scattering diagnostic system has been constructed for the measurements of edge electron temperature and electron density profiles on EAST. A new laser system, optical collection system and data acquisition system are designed to enable the TV Thomson system operate at the measurement region of 0.65–1.1 ρ (“ρ” is the unitary radius in flux coordinate) with spectral resolution of 5 nm and spatial resolution as low as 2 mm. And the theoretical analysis proves that the system has the measurability at electron temperature of 20–1000 eV and density beyond 0.2 × 1019 m-3, which fulfills research of the pedestal microstructure on EAST. The establishment of the edge TV Thomson system can create the conditions for the edge physical study on EAST.