First test at ILL of a gaseous 3He neutron polarization filter

Abstract Polarized 3 He, a promising method for the filtering of the neutron spin, is becoming a reality owing to the development of optical pumping methods and new solid state lasers. We have used a fully polarized neutron beam of 0.84A wavelength to monitor the 3 He polarization in a Rb/ 3 He gas mixture pumped with a titanium-sapphire laser.