Helium Ionization Fraction as Function of Density and Temperature
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The ionization fraction of helium is determined by the temperature and density of the plasma. At a particular density and temperature
, some fraction of helium will be neutral
, some fraction will be singly ionized
, and some fraction will be doubly ionized
. At the same time, the number of electrons per helium nucleus
is determined by charge neutrality. You can set
with
in cgs units (
to see the ionization fraction as temperature
varies from 40,000 K to 200,000 K.
Contributed by: Leo C. Stein (March 2011)
Open content licensed under CC BY-NC-SA