Methods suitable for the separation of monoenergetic neutrons in the low- energy field are not applicable to intermediate-range neutrons. Use of recoil proton spectrometers present experimental difficulties because both the energy and the angular separation of the recoil protons must be undertaken; however, one of these conditions may be eliminated if all the protons and the associated neutrons of a given energy are collected in a single point. Under certain conditions, the energy of the scattered neutrons is independent from the energy of the remaining neutrons or the scattering angle. Calculation of these conditions allowed an intermediate-range neutron selector to be designed. The neutron beam is used to release the recoil protons, a portion of which is recorded in a coincidence chamber, indicating that a neutron of the given energy is emitted from the scatterer and may be used for studying radiative or fission capture phenomena. The chief advantage of the scheme is its focusing'' of the recoil protons by means of a single, perpendicular magnetic field. (TTT)