What is plasma
Plasma — partially or completely ionized gas composed of neutral atoms (or molecules) and charged particles (ions and electrons). The most important feature is its quasi-neutrality of the plasma, meaning that the bulk densities of the positive and negative charged particles, from which it is formed, are almost identical. Plasma is sometimes called the fourth (after solid, liquid and gaseous) state of matter.
The high-frequency plasma discharge in nitrogen.
The high-frequency plasma discharge in argon.
Plasma is divided into a high temperature (a highly-) and low-temperature, cold, equilibrium and non-equilibrium, isothermal and non-isothermal. Plasma varies by method of preparation, the composition and pressure of the gas, the method and the lifetime (retention).