McTrap, a program for the computation of radiation trapping in 3-level atoms including bleaching effects Original Research Article

McTrap computes radiation trapping including bleaching effects and particle diffusion in a two-dimensional cylinder geometry. It combines Monte Carlo simulations of radiation trapping and analytical solutions of the diffusion equation for a highly efficient computation of the distribution of excited atoms. The spectral lineshapes can be freely chosen. Commonly occurring special cases, like two-level atoms, one-dimensional geometries (plane-parallel slab and infinite cylinder) etc. can also simulated. The program runs on workstations and on PCs.