CRModel: a general collisional radiative modeling code. A. Hartgers, J. van Dijk, J. Jonkers, J.A.M. van der Mullen.

PROGRAM SUMMARY
Title of program: CRMODEL
Catalogue identifier: ADNK
Ref. in CPC: 135(2001)199
Distribution format: tar gzip file
Operating system: Linux 2.2 (SuSe 6.4), Windows 95
High speed store required: 3MK words
Number of lines in distributed program, including test data, etc: 53344
Keywords: Plasma physics, Atomic level population densities, Collisional-radiative ionization, Recombination rate coefficients, Atomic process.
Programming language used: C++
Computer: Pentium Workstation .

Nature of physical problem:
The program calculates atomic level population densities of atoms in low temperature plasmas. Collisional-radiative recombination and ionization rate coefficients, radiative energy losses, individual rate coefficients, and effective production and destruction flows between independent levels are also calculated.

Method of solution:
The radiative transition probabilities and collisional cross sections can be specified. These are used to construct a set of linear equations relating the level densities to each other. The number of considered levels can be significantly reduced through the use of a hybrid numerical/analytical cut off technique [1]. The set of linear equations is then solved by means of a matrix inversion. Restrictions: The only states that the model can consider are a ground state, the next ionized ground state and any number of excited states in between those. A further restriction is that the density of these excited states should be small compared to either the ground state density or the ionized state density. However, the total number of considered levels is only limited by available memory. References: [1] J.A.M. van der Mullen, Phys. Rep. 191, (2&3) (1990),109.