Neutron standing wave at total reflection and neutron bandpass filter using periodic superlattices

Abstract

The quantum mechanical phenomena of frustrated total reflection of neutrons in periodic ternary (Ti/Ni/Si) superlattices have been investigated using the polarized neutron reflectivity (PNR) technique. We have experimentally demonstrated that periodic ternary superlattices can efficiently produce a resonant enhanced coherent neutron source with a smaller cross-sectional size, which can probe large-scale inhomogeneities in condensed matter. Using PNR experiments and simulations, we have also studied the applications of periodic ternary superlattices for a possible neutron bandpass filter in the wavelength ranges of 1–10 Å. A comparison of neutron bandpass filter applications for the periodic ternary systems with periodic binary systems is also carried out. The PNR results revealed that the periodic ternary superlattices, which show quantum resonant behaviors, provide a smaller bandwidth for the neutron bandpass filter applications. Our measurements suggest that such periodic superlattices may, therefore, be used for making neutron beams suitable for applications in biochemical and nanoscience research, as well as for studying the fundamental quantum behaviors of neutron beams.