Larmor precession applications: magnetised foils as spin flippers in spin-echo SANS with varying wavelength

A new development in SESANS instrumentation will be discussed. Magnetised foils as π-flippers for neutron polarisation were discussed in previous papers as powerful tools for constructing a strong gradient in Larmor precession in some direction. Up to now, such foils could only be used with limited flipping power and only for monochromatic neutrons. In this paper, it will be shown that it is possible to use foils also as nearly perfect flippers and moreover that such foils can be used also for varying neutron wavelength