A short-length neutron transmission polariser for large beam cross-sections

A neutron spin polarisation device with a length of only 160 mm and a cross-section of 22×34mm2 is presented. Its design is specially suited to analyse large beams typically used for radiography with polarised cold neutrons. Characterisations show a polarisation efficiency of about 78% and a transmission of 44% for neutrons with a wavelength λλ of 5 Å. The compact size makes the device versatile and easily implementable for many purposes in neutron physics.