Optics

The ILL's Neutron Optics Service produces neutron optical components for optimising neutron instruments. From monochromator and analyser crystals to converging guides, bandpass filters and polarising 3He spin-filters and supermirror devices, we provide know-how and in-house manufacturing capabilities. We develop and produce the neutron optical components required to maintain ILL's leading role in neutron scattering.

• Pierre COURTOIS
  Head of Service
  courtois(at)ill.eu
• Agnès Ratel
  Assistant
  ratela(at)ill.eu

The monochromator is the most important optical component in most reactor-source instruments. The ILL Monochromator group develops and produces crystals with a reproducible and well-controlled reflectivity and mosaic spread. We are world-leading in the production of large copper and Heusler alloy crystals for neutron monochromators. We also modify home-grown and commercially available germanium crystals. Our aim is to guarantee specific values of curvature and mosaic spread tailored to fit the neutron beam divergence and focusing requirements of the instrument.

The Monochromator Team
Jérémie Baudin-Cavallo,  Roland Hehn, Philipp Gausmann, Catherine Menthonnex, Benoît Mestrallet

The multilayer group specialises in the production of high-performance polarising supermirrors. These are built into reflection or transmission devices for polarising cold and thermal neutron beams. We run two magnetron sputtering machines for producing neutron supermirrors and other multilayers. These can be stacked together to form devices for focusing, collimating or polarising neutron beams. One of the best-known devices is the "Schärpf-type" bender for polarising cold-neutron beams, but many other types of device are possible, such as bandpass filters, converging/diverging guides and polarising cavities.

The Multilayers Team
Thierry Bigault, Guillaume Delphin, Amandine Vittoz

Neutron multilayers and supermirrors, the founding papers.

The spin-filter group operates a state-of-the-art polarised-³He filling station Tyrex-2 to supply ³He spin filters to ILL instruments. At up to 80% gas polarisation, we provide the highest level of ³He polarisation on the neutron beam in the world. Different types of magnetostatic cavities and spin-filter cells are used, optimised for each on-beam application. At the moment we provide beam polarisation or polarisation analysis capabilities for about 100 days of user experiments at the ILL every year.

The ³He Team
David Jullien - Nicolas Thiery - Philippe Chevalier
The team would like to pay here a tribute to Alexander Petoukhov