Background: The Target-Moderator-Reflector System (TMRS) is the neutron source for nuclear physics experiments in the Lujan Neutron Scattering Center user facility. The TMRS is an assembly consisting of tungsten targets plus a network of moderators, reflectors and flight paths that deliver neutrons of specified energies and fluxes to surrounding experiments and detector stations. The second-generation TMRS (MK II), operational for 5 years, is scheduled for replacement in 2010. While many features of MK II will remain unchanged this paper describes the engineering design of important new features: 1) The tungsten components of the targets will be clad in tantalum to minimize erosion and consequent contamination of the water cooling system, and 2) A new liquid hydrogen moderator with a beryllium reflector/filter that doubles the neutron flux.
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.