Plasmaström

Plasmaström, or plasma stream, is a flow of ionized gas in which electrons and ions move together under the influence of electromagnetic forces. The term is used in Swedish and international contexts to describe directed plasma plumes, jets, or outflows, often spanning laboratory devices and natural phenomena. In macroscopic descriptions the plasmaström is treated as a quasi-neutral fluid whose dynamics are described by magnetohydrodynamics (MHD) or kinetic theory, with magnetic fields guiding and confining the flow.

Natural plasmaströmmar occur in space: the solar wind is a continuous plasmaström emitted by the Sun, carrying magnetic fields into the solar system. Astrophysical jets from young stars, accreting black holes, or active galactic nuclei are highly collimated plasmaströmmar that transport energy across large distances and interact with ambient media.

Laboratory plasmaströmmar are produced by various devices such as plasma guns, pulsed-power setups, laser ablation, or discharges. They can be shaped, accelerated, or injected for experiments in basic plasma physics, material processing, or propulsion research. In propulsion contexts, plasma streams appear in Hall-effect thrusters, magnetoplasmadynamic thrusters, and related devices.

Key properties include density, velocity, temperature, and magnetic-field structure. Plasmaströmmar can exhibit instabilities and shocks and may emit radiation depending on temperature and composition. Diagnostics include spectroscopy, interferometry, and Thomson scattering to measure flow velocity and density.

See also: plasma physics, plasma jet, magnetohydrodynamics, solar wind, astrophysical jet, electric propulsion.