Refraction as a means of encoding wavelength for neutron reflectometry

Neutron reflectometry is a well-established technique used to analyze the structure of interfaces as a function of depth normal to the surface. On a continuous source of neutrons, such as a reactor, the measurement can be done at a fixed incident angle and a white beam with the neutron wavelength encoded by the use of choppers to measure the time of flight. Although providing a certain flexibility in wavelength resolution, choppers have low transmission. This paper explores the possibility of using refraction to encode neutron wavelength opening the possibility of reactor sources to use almost the full-time-averaged neutron flux available and hence, increase the performance of neutron reflectometers by orders of magnitude.