Определение параметров филаментов на сферическом токамаке Глобус-М2 с помощью метода допплеровского обратного рассеяния

In improved confinement (in H-mode) in the Globus-M2 tokamak, the development of edge-localized modes (ELMs) is accompanied by the appearance of filament structures. The use of the Doppler backscattering (DBS) method allowed to determine filament parameters both during ELMs triggered by sawtooth crashes and during independent ELMs. It is shown that the number of filaments observed during synchronized ELMs is greater and their area of observation is wider. The velocity of the filaments during all types of ELMs observed on Globus-M2 ELM is higher than on the previous tokamak Globus-M. Filaments developing immediately before an ELM burst are characterized by smaller amplitudes and velocities. Comparing the results of two diagnostic techniques, DBS and poloidal correlation Doppler reflectometry, to determine the velocity of such filaments, shows a similarity of the measured values, which may indicate linear scattering off these filaments.