The presence of pertubing particles near an emitting atom will cause a broadening and possible shift of the emitted radiation.
There is two types impact and quasistatic
In each case you need the profile, represented by Cp as in C6 for Lennard-Jones potential
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Assume Maxwell-Boltzmann distribution for both cases.
From (Peach 1981, p. 387) harv error: no target: CITEREFPeach1981 (help)
For impact, its always Lorentzian profile
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- Broadening by linear Stark effect
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- Debye effects must be accounted for
- Broadening by ???
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- Broadening by quadratic Stark effect
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- Broadening by Van der Waals forces
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Quasistatic broadening
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From (Peach 1981, p. 408) harv error: no target: CITEREFPeach1981 (help)
For quasistatic, functional form of lineshape varies. Generally its a Levy skew alpha-stable distribution (Peach, page 408)
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- Broadening by linear Stark effect
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where K is of order unity. Its just an approximation.
- Broadening by quadratic Stark effect
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- (Peach1981 & Peach 1981, Eq 4.95) harv error: no target: CITEREFPeach1981Peach1981 (help)
where and are the static dipole polarizabilities of the i and j energy levels.
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- Broadening by Van der Waals forces gives a Van der Waals profile. C6 is the wing term in the Lennard-Jones potential.
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for
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0 otherwise.
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- (Peach 1981, Eq 4.101) harv error: no target: CITEREFPeach1981 (help)
- (Peach 1981, Eq 4.100) harv error: no target: CITEREFPeach1981 (help)
where K is of order 1.