Collisionalradiative calculations
This type of theoretical work explains how many photons leave the working volume during plasma evolution. This in turn depends on (i) probability of photon emission by an atom, (ii) how many atoms present in the upper (initial) state of radiative transition, and (iii) how many emitted photons are lost during their travel to the plasma boundary.
The first of these problems is solved with pure atomic theory. The plasma environment does affect the atom properties; however, in many cases its influence on photon emission probability is rather small and can therefore be neglected. Obviously, an access to and/or possibility to produce the reliable transition probabilities is of highest importance in the CR calculations.
In order to determine the number of atoms in specific states, one has to know what the kinetic processes affecting the atom states are and how they depend on plasma conditions. The kinetic processes, which are typically accounted for in CR calculations, are:
 spontaneous transition:
 spontaneous radiative decay
 spontaneous radiative recombination
 autoionization
 dielectronic capture
 induced by an impact of free electron:
 excitation
 deexcitation
 ionization (including a removal of few electrons in one collision)
 threebody recombination
 induced by photon:
 photoexcitation
 photodeexcitation
 photoionization
 induced radiative recombination
 induced by an impact of atom:
 excitation
 deexcitation
 ionization
 charge exchange
The rates of these processes depend on electron and atom energy distribution functions (mostly but not necessarily Maxwellian), and particle densities (both electron and atom).
The transport of photons through plasma volume is generally described by complicated radiative transfer equations. More simple methods are often used in practical calculations, for example, the socalled escape factor approximation.
We apply collisionalradiative modeling to study behavior of very diverse plasmas, such as those in plasma opening switches, zpinches, xray lasers, etc.
References

Radiation transport and density effects in nonequilibrium plasmas

Radiation transport and density effects in nonequilibrium plasmas

Radiation transport and density effects in nonequilibrium plasmas
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Modified on: 20140120
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