Collisional radiative models with multiple transport-sensitive levels-application to high electron density mercury discharges

Tijdschriftartikel

Dijk, van, J., Hartgers, A., Jonkers, J. & Mullen, van der, J.J.A.M. (2001). Collisional radiative models with multiple transport-sensitive levels-application to high electron density mercury discharges. Journal of Physics D: Applied Physics, 34(10), 1499-1509. In Scopus Cited 6 times.

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Abstract

 

In this paper some of the basic concepts in collisional radiative modelling of plasmas will be generalized. A mathematical framework is presented which is suitable for systems with an arbitrary number of transport sensitive and quasi-steady or local chemistry states.

The mathematical formulation presented here leads to straightforward extensions of quantities which have been previously introduced for systems in which only the atom and ion ground states were dealt with explicitly. These are the net coefficients of ionization and recombination, the effective specific emission coefficients, and the relative overpopulation coefficients. For a given set of transport-sensitive densities these quantities can be used to calculate the particle and radiation source terms and the atomic state distribution function.

Furthermore the use of matrix-vector calculus has led to concise, insightfull, yet general expressions. And although some explicit references will be made to plasmas which are governed primarily by processes involving electrons, most of the theory presented here can be carried over to other systems without great difficulty.

As an example, a collisional radiative model for mercury will be presented for discharges with electron temperatures between 0.75 eV and 2 eV and electron densities between 1018 m-3 and 1020 m-3. In the current model six transport-sensitive levels have been assumed. Another 13 excited mercury states are taken into account implicitly; ladderlike excitation and ionization will be shown to be of major importance for discharges in this parameter range. The model allows the incorporation of heavy-particle reactions and a full treatment of the transfer of resonant radiation.