The results of experiments and simulations of the transport of heat and particles in the Globus-M spherical tokamak are presented. Investigations were carried out in the ohmic mode in hydrogen and deuterium plasma. It is shown that in the phase of current growth under the same initial conditions, as long as the condition is met at which the minimum of the safety factor exceeds unity, two scenarios of discharge development are possible: with an electron temperature dive or with an electron density peak. After the safety factor reaches the value of 1, the differences are no longer observed. Modeling of transport processes using the ASTRA code showed that the dive of the electron temperature and density is a consequence of the decrease in the transport of heat and particles in the plasma core (i.e., the presence of internal transport barriers).
Experimental data indicating the influence of the magnetohydrodynamic tearing mode in the Globus-M spherical tokamak on the appearance of filamentary structures (filaments) are presented. The filaments were detected by the Doppler backscattering method. Filament groups localized in the toroidal direction were detected, the appearance of which turned out to be synchronized with the spreading of the tearing mode. The possible causes of the influence of low-frequency MHD oscillations on the occurrence of groups of filamentary perturbations are considered.
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