Energetic neutral atom Energetic neutral atom Energetic neutral atom (ENA) imaging, often described as "seeing with atoms", is a technology used to create global images of otherwise invisible phenomena in the magnetospheres of planets and throughout the heliosphere, even to its outer boundary. This constitutes the far-flung edge of the solar system. The solar wind consists of ripped-apart atoms (called plasma) flying out of the Sun. This is mostly hydrogen, that is, bare electrons and protons, with a little bit of other kinds of nuclei, mostly helium. The space between solar systems is similar, but they come from other stars in our galaxy.
Anisothermal plasma Anisothermal plasma 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), 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. They generally exhibit hot electrons that are powered by the alternating electric field, and a neutral and ion component, which is significantly colder due the low efficiency of the energy transfer between light electrons