An Anisothermal plasma is a plasma which thermal state can be approximated by more than one temperature for the different degrees of freedom of the plasma. The degrees of freedom refer to translation (

kinetic energy In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acc ...

), rotation, vibration of each particle type. Examples of anisothermal plasmas can be found among low-pressure plasmas that are excited by high frequency electric fields, see

frequency classification of plasmas Plasma () 1, where \nu_ is the electron gyrofrequency and \nu_ is the electron collision rate. It is often the case that the electrons are magnetized while the ions are not. Magnetized plasmas are ''anisotropic'', meaning that their properties ...

. They generally exhibit hot

electron The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no ...

s that are powered by the alternating electric field, and a neutral and

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

component, which is significantly colder due to the low efficiency of the energy transfer between light electrons and heavy neutrals and ions. The term nonthermal plasma includes anisothermal plasmas and means that the different degrees of freedom of the plasma are ''not'' in

thermal equilibrium Two physical systems are in thermal equilibrium if there is no net flow of thermal energy between them when they are connected by a path permeable to heat. Thermal equilibrium obeys the zeroth law of thermodynamics. A system is said to be i ...

See also