Repozytorium publikacji - Politechnika Gdańska

Unusual thermal self-focusing of two-dimensional beams in plasma which axis is parallel to the equilibrium straight magnetic field is considered. The equi- librium parameters of plasma determine scenario of a beam divergence (usual or unusual) which is stronger as compared with a flow without magnetic field. Nonlinear thermal self-action of a magnetosonic beam behaves differently in the ordinary and unusual cases. Damping of wave perturbations and normal defocusing in gases leads to reduction of the magnitude of initially planar per- turbations at the axis of a beam. Additional thermal self-focusing nonspecific for gases occurs in plasma under some condition which counteracts this reduc- tion. The theory and numerical examples concern thermal self-action of initially focused (defocused) magnetosonic beam. Dynamics of perturbations in a beam is determined by dimensionless parameters responsible for diffraction, damp- ing of the wave perturbations, initial radius of a beam’s front curvature, and the ratio of viscous to thermal damping coefficients.

Autorzy

• prof. dr hab. Anna Perelomova link otwiera się w nowej karcie