A Resonance Guide for eV Neutrons

Neutron mirrors function like optical fibers, allowing for low-loss transport of neutrons over long distances. Multilayer supermirror neutron optics works very well for cold neutrons, but their transverse phase space acceptance is too small to make them useful for eV energy neutrons. In this talk we present some ideas for eV neutron guides which use the large imaginary part of the neutron optical potential for neutron reflection. We evaluate the performance of a neutron mirror made of boron carbide enriched in 10B. We also present some possibilities for a neutron guide made of a cocktail of heavy nuclei, where the neutrons  would bounce off of a "forest" of neutron-nucleus resonances.