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Saha equation

(Saha ionization equation, Saha-Langmuir equation)
(equation relating ionization to temperature)

The Saha equation (Saha ionization equation or Saha-Langmuir equation) yields information about the ionization of a sufficiently-thin plasma in thermodynamic equilibrium. It yields the ratio of number densities of ions at two successive states of ionization, i.e., those with i electrons missing verses those with i+1 electrons missing. It is used in stellar models. One form:

Ni+1   Zi+1  2
———— = ———— ———— (2π mekT)3/2ei/kT
 Ni     Zi  neh3

Further reading: equation

Referenced by pages:
Boltzmann equation
electron pressure
nuclear statistical equilibrium (NSE)
number density (n)
state of ionization