Neutron spectra unfolding codes. Appendix 7

The determination of energy spectra by the multiple foil activation technique is a rather universal and well establish method. It is of advantage for measuring the spectral fluence in harsh radiation environments, at high temperatures and in compact volumes, where other detectors and methods are not applicable. Many codes, each employing different models and algorithms, have been developed during the last decades for unfolding an energy spectrum from measured reaction rates. Based on published reference documents and manuals, we would like to give a short overview of used methods, computing environment and availability of the most popular neutron spectra unfolding or adjustment codes.