Tunneling reflection with polarized slow neutrons: polarized-neutron total frustrated reflection

This work describes the conditions required to observe the tunneling phenomenon in the grazing-angle reflection configuration of both polarized and unpolarized monochromatic neutron waves. According to the computed results, this neutron-tunneling phenomenon manifests itself by the existence of sharp resonances in the total reflection plateau. Their angular positions depend on the polarization state of the incident neutron waves. We treat the case where all these tunneling resonances (high and low orders) in the total-reflection plateau are observed. This can be achieved by using a Fabry-Perot cavity deposited onto an appropriate substrate. The substrate must be nonmagnetic, having a negative nuclear scattering-length density. The numbers of these resonances change mainly with the thickness of the spacer layer of the Fabry-Perot cavity, while their bandwidths are linked to the thicknesses of the reflecting layers.