Thomson Scattering Diagnostics with Tangential Probing Geometry at the T-15MD Tokamak

Abstract

In 2023, the Thomson scattering diagnostics with tangential probing geometry was installed and put into operation at the T-15MD tokamak. The new system is based on a 100-Hz Nd:YAG laser with a pulse energy of up to 3 J at the first harmonic, λ = 1064 nm. The system allows measurements to be carried out throughout the plasma discharge with its duration of up to 10 s with a time interval of 10 ms. Laser radiation is introduced into the tokamak vessel in the equatorial plane, passing through the entire plasma volume from the inner to the outer periphery of the plasma. The scattered radiation acquisition system is located inside the equatorial port of the facility. The range of scattering angles is from 11° to 56°. The recording system is based on 10 polychromators on interference filters. Using this diagnostics, the electron temperature and density have been measured in the experimental campaign at the end of 2023. The system operation was demonstrated throughout the entire tokamak discharge in a wide temperature range and with a discharge duration of up to 2 s.