Compact neutron optical elements

Complete text of publication follows. The performance of neutron collimators and polarising benders is reported in which the neutrons transmit coated Si slabs with a thickness of 0.25mm. This offers the possibility of arranging the optically active coatings in new geometries compared to conventional devices. A compact polarising bender was tested with neutrons at wavelengths of 4.75 A and 2.4 A using either the neutrons reflected or transmitted at a supermirror coating. In reflection geometry a transmission through the bender of 65% of the spin up component with a polarisation of better than 95% was found for a wavelength of 4.75 A and of 42% and 97% respectively for a wavelength of 2.4 A. In transmission geometry first experiments gave values for transmission and polarisation of 39% and 90% for the wavelength of 4.75 A and of 47% and 78% respectively for 2.4 A. Using flat Si wafers coated with Gd, compact collimators could be realised with transmissions of 65%, 82% and 85% for collimations of 0.19 deg, 0.42 deg and 0.75 deg FWHM. The respective lengths of the wafers were only 75, 38 and 19 mm. (author)