ILL polarised hot-neutron beam facility D3

D3 is a very comprehensive polarised beam facility at the renewed hot neutron source of the Institut Laue-Langevin (ILL). In magnetic field up to 10T, it exploits the spin dependency of the neutron scattering cross-section for determining unpaired electron magnetisation in crystals. The technique applies very successfully to molecular compounds, heavy fermions, high-T c superconductors, transition metals and actinide alloys. Within the frame of the ILL Millennium Programme, we have recently added polarisation analysis by taking advantage of 3 He spin filters and built a dedicated third-generation Cryopad for carrying out spherical neutron polarimetry experiments. In the case of magnetic structures, this leads to the direct determination of the magnetic interaction vector. Hence, D3 has become one of the most powerful tool for solving complex AF structures that had proven to be intractable when employing other techniques. Moreover, when the magnetic and nuclear scattering occur at the same position in the reciprocal space, it allows a precise determination of the AF magnetisation distributions. D3 can also be used for many purposes other than diffraction experiments, e.g. the search for the T-odd asymmetry of light particle emission in 239 Pu ternary fission.