Solar phenomena move about and can travel at a few hundred meters per second when they first appear. The solar wind is a stream of plasma released from the Sun's upper atmosphere. It consists of mostly electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in density, temperature and speed over time and over solar longitude. These particles can escape the Sun's gravity because of their high energy. The solar wind is divided into the slow solar wind and the fast solar wind. The slow solar wind has a velocity of about , a temperature
Plasma (physics) ionization formula_1, the electron-ion collision frequency can equal the electron-neutral collision frequency: formula_11 is the limit separating a plasma from being partially or fully ionized. Most of "technological" (engineered) plasmas are weakly ionized gases. Based on the relative temperatures of the electrons, ions and neutrals, plasmas are classified as "thermal" or "non-thermal" (also referred to as "cold plasmas"). A particular and unusual case of "inverse" nonthermal plasma is the very high temperature plasma produced by the Z machine, where ions are much hotter than electrons. Since plasmas are very good electrical conductors, electric potentials play an important role. The average