Development of Magnetic Field Components for the Polarisation Option of the Neutron Spectrometer FOCUS

L. Holitzner[1], U. Filges[1], J.P. Embs[2], T. Fennell[2], T. Panzner[1]
[1]Laboratory for Developments and Methods, Paul Scherrer Institut, Villigen, Switzerland
[3]Laboratory for Neutron Scattering, Paul Scherrer Institut, Villigen, Switzerland

We show a new, favourable space-saving method to host a neutron polarizer in the iron-containing monochromator shielding of a time-of-flight spectrometer for cold neutrons. In this poster you can learn e.g., how to create a robust, homogeneous, rectangular magnetic field (here realized by permanent magnet queues inside an iron tube).

The time-of-flight spectrometer FOCUS at the spallation neutron source SINQ at Paul Scherrer Institut can be extended by a polarisation option. Our current activities concentrate on the components for the primary polarisation: the polariser (to order the neutron spin), the magnetic guide field (to keep the beam polarised) and a spin flipper (which can invert the spin direction). These new components have to be implemented into the existing neutron spectrometer.