Prospects of developing polarized neutron optics on the basis of new method for improving polarizing coatings

A method for improving polarizing neutron coatings by means of antibarrier interlayers has been suggested in PNPI, and the flip ratio for the reflected beam has been increased by an order as compared to prior coatings. In this paper the tasks to be solved for developing polarized neutron optics are formulated, and the factors that can restrict the efficiency of the polarizing devices on the basis of the improved coatings are discussed. The formulas for the polarizing efficiency which take account of the probabilities of both non-spin-flip (NSF) and spin-flip (SF) reflections are obtained, including the case of multiple reflections; the effect of scattering at magnetic inhomogeneities and that of non-collinearity of the magnetization to the magnetizing field are separated. In the case of multiple reflections the SF probability in the last reflection is shown to play a significant or even a primary role in determining the polarizing efficiency. New neutron instrumentation can be designed with improved polarizing devices, and the possibility to efficiently polarize and analyze very cold or even ultracold neutrons may appear. Thence arises the importance of studying oxidation kinetics and stability of Ti and Co nanolayers.