Current sheets in plasma: from theory to experiment

The main stages of experimental studies of the dynamics and evolution of current sheets formed in plasma in strong nonuniform magnetic fields are reviewed. These studies were initiated by Sergei Ivanovich Syrovatskii, who made an outstanding contribution to the creation of the MHD theory of current sheets. The experiments were developed in close interaction with the theory and under the influence of theoretical ideas and concepts. It was found that, in high-conductivity plasma, the formation of a current sheet leads to a concentration of magnetic energy, while during explosive destruction of the sheet, the magnetic energy is converted into the energy of plasma and accelerated electrons. It is shown that in many cases the rupture of the sheet is triggered by a rapid local increase in the plasma temperature and a violation of the transverse equilibrium within the current sheet. It has been proven that current sheets can develop in 3D magnetic configurations, and the range of such configurations has been determined. Reverse currents are found to play an important role in limiting the duration of plasma flows accelerated in current sheets.