Expanding polarization bandwidth in neutron optics by eliminating the non-polarized low scattering vector region

Polarized neutron scattering is an important analysis technique offering valuable information in research fields such as magnetism and magnetic materials, condensed matter physics, and soft matter and biological systems. Enhancing these experiments relies on the performance of polarizing neutron optics to provide reflectivity and polarization at a variety of scattering vectors q z . State-of-the-art Fe/Si supermirror polarizers have an unpolarized q z - region below the critical vector q c of Si, while FeCoV/TiN supermirrors with a neutron absorbing Gd layer, can polarize at lower angles but cannot operate in transmission mode due to neutron beings absorbed. To address these challenges, the use of Co/Ti supermirrors on Ti substrates is proposed due to their favorable scattering length density characteristics and without using a neutron absorbing layer. This approach enables the possibility of a higher degree of design flexibility for e.g. transmission polarizers. It allows for the lowest possible high- q z limit (the m-value of the coating) for a given lower wavelength limit and beam divergence.