Resonantly enhanced neutron intensity in a surface segregated polymer blend

We have formed a resonant cavity for a massive particle, the neutron, in an attractive potential between a surface segregated polymer film and its substrate. Standing waves occur when incident waves interfere with the waves reflected from the substrate. Multiple internal reflections lead to an enhanced intensity at resonant wave vectors below the wave vector for total reflection. At these resonant wave vectors the enhanced neutron intensity incoherently scatters from the hydrogen containing polymer of the potential well causing a marked decrease in the reflectivity. The position of the resonant dips provides an aid to fitting the reflectivity data by restricting the possible scattering length density profiles. This phenomena may find application in the study of in-plane correlations by enhancing off-specular scattering