Recent calculations of collisionless, Case-B, He I emissivities were performed by Bauman et al. (2005). The source code used in the calculation has been freely available online since that paper was published. A number of changes have been made to simplify the use of the code by third parties. Here I provide details on how to obtain, compile, and execute the program and interpret the results.
Cite
@article{arxiv.0705.1135,
title = {A He I Case-B Recombination Code},
author = {R. L. Porter},
journal= {arXiv preprint arXiv:0705.1135},
year = {2007}
}