Studies of Dynamics of Neutral Component of Current Sheet Plasma, Based on Spectral Broadening of Helium Line He I 5876 Å

Spectroscopy methods were used for studying the dynamics of neutral plasma component in current sheets formed in two-dimensional (2D) and three-dimensional (3D) magnetic configurations during discharge in helium. It has been ascertained that when the current sheet is formed in the 2D magnetic field, flows of fast suprathermal helium atoms appear in it, which are directed along the current sheet width (the largest of the sheet transverse dimensions). It is shown that helium atoms can acquire the directed energy W x due to the resonance charge exchange of accelerated ions in the current sheet plasma. The energy of directed motion of helium atoms can reach W x ≈ (480 ± 120) eV, which is ~20 times higher than the temperature of helium atoms T a ≈ (20 ± 2) eV at the same times. During the current sheet formation in the 3D magnetic configuration, fast helium atoms were not observed.