A mechanical velocity selector for the study of monochromatic neutrons in the range of energies below 0.3 ev is described.The instrument has been applied to the measurement of the cross section of boron, which is found to be 703 X 10~2 4 cm 2 for neutrons of 2200 meters per second velocity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.