साहा समीकरण
साहा समीकरण का विकाश सुप्रसिद्ध भारतीय खगोलविज्ञानी (एस्ट्रोफिजिसिस्ट्) मेघनाद साहा ने 1920 में किया था। इसके द्वारा वर्णपट्ट के आधार पर तारों के वर्गीकरण की व्याख्या की गई है। For a gas composed of a single atomic species, the Saha equation is written:

:formula_1

where:

* formula_2 is the density of atoms in the "i"-th state of ionization, that is with "i" electrons removed.
* formula_3 is the degeneracy of states for the "i"-ions
* formula_4 is the energy required to remove "i" electrons from a neutral atom, creating an "i"-level ion.
* formula_5 is the electron density
* formula_6 is the thermal de Broglie wavelength of an electron
::formula_7
* formula_8 is the mass of an electron
* formula_9 is the temperature of the gas
* formula_10 is the Boltzmann constant
* formula_11 is Planck's constant

In the case where only one level of ionization is important, we have formula_12 and defining the total density "n"  as formula_13, the Saha equation simplifies to:

:formula_14

where formula_15 is the energy of ionization.

The Saha equation is useful for determining the ratio of particle densities for two different ionization levels. The most useful form of the Saha equation for this purpose is

:formula_16, 

where "Z" denotes the partition function. The Saha equation can be seen as a restatement of the equilibrium condition for the chemical potentials:

:formula_17
Q668
भारतीय
LOC
Q377898
मेघनाद साहा
PER
Q2155
1920
TIME
None
वर्णपट्ट
UNK
Q523
तारों
Concept
None
degeneracy
UNK
None
electron density
UNK
None
thermal de Broglie wavelength
UNK
None
mass of an electron
UNK
None
temperature
UNK
None
Boltzmann constant
UNK
None
Planck's constant
UNK
None
partition function
UNK
None
chemical potential
UNK
Q12456737
साहा समीकरण
UNK
1920-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1920
DATE
+1920^^http://www.w3.org/2001/XMLSchema#decimal
1920
NUMBER
+1^^http://www.w3.org/2001/XMLSchema#decimal
1
NUMBER
+2^^http://www.w3.org/2001/XMLSchema#decimal
2
NUMBER
+3^^http://www.w3.org/2001/XMLSchema#decimal
3
NUMBER
+4^^http://www.w3.org/2001/XMLSchema#decimal
4
NUMBER
+5^^http://www.w3.org/2001/XMLSchema#decimal
5
NUMBER
+6^^http://www.w3.org/2001/XMLSchema#decimal
6
NUMBER
+7^^http://www.w3.org/2001/XMLSchema#decimal
7
NUMBER
+8^^http://www.w3.org/2001/XMLSchema#decimal
8
NUMBER
+9^^http://www.w3.org/2001/XMLSchema#decimal
9
NUMBER
+10^^http://www.w3.org/2001/XMLSchema#decimal
10
NUMBER
+11^^http://www.w3.org/2001/XMLSchema#decimal
11
NUMBER
+12^^http://www.w3.org/2001/XMLSchema#decimal
12
NUMBER
+13^^http://www.w3.org/2001/XMLSchema#decimal
13
NUMBER
+14^^http://www.w3.org/2001/XMLSchema#decimal
14
NUMBER
+15^^http://www.w3.org/2001/XMLSchema#decimal
15
NUMBER
+16^^http://www.w3.org/2001/XMLSchema#decimal
16
NUMBER
+17^^http://www.w3.org/2001/XMLSchema#decimal
17
NUMBER
country of citizenship