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Manuscript Title: GLOMAC: a one dimensional numerical model for steady state low pressure mercury-noble gas discharges.
Authors: G.G. Lister, S.E. Coe
Program title: GLOMAC
Catalogue identifier: ACLP_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 75(1993)160
Programming language: Fortran.
Computer: COMPAQ 386.
Operating system: DOS/VMS.
RAM: 186K words
Word size: 16
Keywords: Plasma physics, Diffusion, Glow discharge, Positive column, Low pressure, Discharge lamps.
Classification: 19.5.

Nature of problem:
A computer code for modelling low pressure mercury-noble gas discharges, with particular application to fluorescent lighting, is described. Diffusion equations are formulated for ground and excited states of mercury atoms, and also electrons and atomic and molecular mercury ions. All important inelastic processes involving mercury atoms and molecules are included. Allowance is also made for thermal conduction of noble gas temperature. The electron distribution function is computed from an analytic formula, which has been shown to give similar results to full Boltzmann calculations.

Solution method:
Iterative finite difference solution for coupled diffusion equations.

Convergence difficulties occur at "cool spot" (i.e. wall) temperatures below 20 degrees C. This is due to high electron temperatures, which would result in excitation of the noble gas atoms, an effect not included in the model. The model therefore becomes unphysical at these temperatures.

Running time:
24 seconds for Test Run 1 on the COMPAQ 386 (i.e. 4 seconds per iteration).