Optimising neutron polarizers—measuring the flipping ratio and related quantities

The continuing development of gaseous spin polarized 3He transmission filters for use as neutron polarizers makes the choice of optimum thickness for these filters an important consideration. The “quality factors” derived for the optimisation of transmission filters for particular measurements are general to all neutron polarizers. In this work optimisation conditions for neutron polarizers are derived and discussed for the family of studies related to measuring the flipping ratio from samples. The application of the optimisation conditions to 3He transmission filters and other types of neutron polarizers is discussed. Absolute comparisons are made between the effectiveness of different types of polarizers for this sort of work.