# RAD-TRAP 2, a program for the solution of the Holstein equation of radiation trapping

## Description

Abstract RAD-TRAP computes the solution of the Holstein equation of radiation trapping for three important geometries: plane-parallel slab, long cylinder, and sphere. The new version 2 offers the direct computation of the steady-state distribution of excited atoms and the computation of the emergent spectra; effects like self-reversal can now be studied. It also includes a new algorithm for a more efficient, highly accurate computation of the cylinder case. The new version also runs on IBM-PCs. ... Title of program: RAD-TRAP 2 Catalogue Id: ACLB_v2_0 [ACNX] Nature of problem Computation of the eigenvalues and eigenfunctions of the Holstein integral equation (describing radiation trapping in an atomic vapor) and the steady-state distribution of excited atoms in one-dimensional geometries. Versions of this program held in the CPC repository in Mendeley Data ACLB_v2_0; RAD-TRAP 2; 10.1016/0010-4655(93)90009-2 ACLB_v1_0; RAD-TRAP; 10.1016/0010-4655(93)90108-O This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)