physical quality quality factor Dimensionless factor developed for purposes of radiation protection and assessing health risks in general terms that accounts for the relative biological effectiveness of different radiations in producing stochastic effects and is used to relate absorbed Jack Miller Neutrons have a high quality factor compared to photons. NCRP Glossary (https://ncrponline.org/wp-content/themes/ncrp/PDFs/NCRP-Composite-Glossary.pdf)