Neutron reflectometry by refractive encoding

Abstract

There is a great deal of interest in expanding the technique of neutron reflectivity beyond static structural measurements of layered structures to kinetic studies. The time resolution for kinetic studies is limited only by the available neutron flux. On a continuous source of neutrons, such as a reactor, many reflectometers use the time-of-flight technique involving low-transmission choppers. This paper describes a real measurement involving prism refraction to deduce the wavelength in place of choppers thus providing a large gain in useful neutron flux and hence open up the possibility of sub-second kinetics studies.