Close This Window

Please download official ILL logos here


For using on the web or on a screenFor printing in high resolutionWhite version, for dark backgrounds

Download PNG

Download AI

Download white PNG

Download JPG


Download white AI


The ILL has firmly established itself as a pioneer in neutron science and technology. Neutron beams are used to carry out frontier research in diverse fields.

Back to ILL Homepage
English French Deutsch 

Neutron technology at ILL


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)

Agnès Ratel - Assistant: ratela(at)

The Neutron Optics Service focuses on three main areas of development:

Monochromator crystals

The monochromator is the first and most important optical component of most reactor-source instruments. The 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.

Multilayer devices

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.

3He spin-filters

The spin-filter group operates a state-of-the-art polarised-3He filling station 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.