Transmission properties of short curved neutron guides: Part I. Acceptance diagram analysis and calculations

A curved neutron guide is considered “short” if there are direct lines of sight through the device. Such guides have the disadvantage that they transmit high energy neutrons and γ-rays, which are generally unwanted, as well as the desired low energy neutrons. Nevertheless short curved guides have several uses at thermal neutron research facilities because they can be combined with sections of straight guide to produce composite guides through which there is no line of sight. We analyze the transmission properties of short curved neutron guides using the method of acceptance diagrams, and we present the results of several calculations of their performance.