Plasmaphysikk

Plasmaphysikk is the study of plasmas, ionized gases in which a significant fraction of atoms are split into free electrons and ions. Plasmas are found throughout the universe, in laboratories, and in many technological applications. They exhibit collective behavior and are governed by electromagnetic fields, leading to phenomena such as Debye shielding, plasma oscillations, and magnetization.

Plasmas can be classified by temperature, ionization level, and state. Low‑temperature or non‑equilibrium plasmas are common in materials processing and lighting. High‑temperature plasmas approach thermal equilibrium and are central to fusion energy research. Space and astrophysical plasmas populate stars, planetary magnetospheres, the solar wind, and interstellar media.

Key concepts include plasma parameters (electron temperature and density, Debye length, plasma frequency), transport properties, and stability. Theoretical descriptions use fluid models like magnetohydrodynamics (MHD) for large‑scale behavior and kinetic models (Boltzmann, Vlasov equations) for detailed particle dynamics. Experimental and computational tools include Langmuir probes, spectroscopy, interferometry, Thomson scattering, and particle‑in‑cell simulations.

Applications of plasmaphysikk span science and industry. In fusion research, magnetic confinement devices aim to produce net energy. In industry, plasmas drive semiconductor manufacturing, surface modification, and lighting. Plasma propulsion, such as ion or Hall thrusters, offers alternative space travel concepts. Plasma processes also contribute to space science and astrophysics by modeling space weather and cosmic plasmas.

Historically, plasma physics emerged in the early 20th century with contributions from Irving Langmuir and others who developed diagnostic methods and foundational theory. Today it is an interdisciplinary field bridging physics, engineering, chemistry, and astronomy.