Relation between the ionization state of a gas and the temperature and pressure
In physics, the Saha ionization equation is an expression that relates the ionization state of a gas in thermal equilibrium to the temperature and pressure.[1][2] The equation is a result of combining ideas of quantum mechanics and statistical mechanics and is used to explain the spectral classification of stars. The expression was developed by physicist Meghnad Saha in 1920.[3][4] It is discussed in many textbooks on statistical physics and plasma physics.[5]