Thomson scattering diagnostics at the Globus-M2 tokamak

• Published in: Fusion engineering and design 2025-02, Vol.211, p.114753, Article 114753
• Main Authors: Zhiltsov, N.S., Kurskiev, G.S., Tolstyakov, S.Yu, Solovey, V.A., Koval, A.N., Tkachenko, E.E., Aleksandrov, S.E., Bakharev, N.N., Balachenkov, I.M., Bazhenov, A.N., Chernakov, P.V., Filippov, S.V., Gusev, V.K., Khromov, N.A., Kiselev, E.O., Kornev, A.F., Krikunov, S.V., Makarov, A.M., Minaev, V.B., Miroshnikov, I.V., Mukhin, E.E., Novokhatsky, A.N., Patrov, M.I., Petrov, Yu.V., Ponomarenko, A.M., Sakharov, N.V., Shchegolev, P.B., Shulyatiev, K.D., Skrekel, O.M., Solokha, V.V., Telnova, A.Yu, Tokarev, V.A., Tukhmeneva, E.A., Varfolomeev, V.I., Voronin, A.V., Yashin, A.Yu
• Format: Article
• Language: English
• Subjects: Electron temperature; Plasma diagnostics; Spectroscopy; Thomson scattering; Tokamak
• ISSN: 0920-3796
• DOI: 10.1016/j.fusengdes.2024.114753

•The new Thomson scattering diagnostics put in operation at Globus-M2 tokamak.•The diagnostics is built of ITER-grade components and satisfies the main requirements for Thomson scattering diagnostics in fusion reactor.•The paper describes design details of the new diagnostics system and demonstrates its performance in plasma experiment.•The first successful experiment on multi-colour Thomson scattering with nanosecond-scale delay between probing pulses is presented. The paper is devoted to the Thomson scattering (TS) diagnostics recently developed for the Globus-M2 spherical tokamak and prototyping the ITER divertor TS diagnostics. The distinctive features of the system are the use of spectrometers, acquisition system and lasers that meet the base requirements for ITER TS diagnostics. The paper describes the diagnostic system that allows precise measurements of TS signals, as well as the results of the first measurements of electron temperature and density in both the central region of the plasma column and the scrape-off layer. The system provides measurements of electron temperature Te in the range of 5 eV to 5 keV and density ne in the range of 5 × 1017÷3.25 × 1020 m-3. The use of two ITER-grade probing lasers of different wavelengths (Nd:YAG 1064.5 nm and Nd:YLF 1047.3 nm) allows reliable measurement of Te in multi-colour mode, i.e., assuming that spectral calibration is unknown.