French contribution to the ESS instruments

Presentation of ESS

The ESS (European Spallation Source) is the next generation European spallation source currently under construction in Lund (Sweden). Using a long duration neutron pulse (2.86 ms compared to the usual 100 µs) clocked at 14 Hz, it will produce an integrated neutron flux equivalent to that of the ILL.

Vue d’artiste du site de l’ESS.
Artist's view of the ESS site

The pulsed character of the source allows to use the temporal structure of the neutron beam to determine the energy of the incident neutrons, eliminating the need for a monochromator for the vast majority of instruments. The usable flux at the sample position is thus naturally multiplied by the full use of the poly-chromatic beam.

Comparaison des pulses de neutrons de l’ESS et des sources à spallations en opération.
Comparison of expected neutron pulses from ESS and spallation sources in operation.

Two moderators, cold and thermal, will be installed giving users access to a neutron spectrum covering the range of 0.5 to 20 Å. The opening of the instruments to external users is planned for 2027, the installation of the essential components for the start-up of the source is in progress, and the instrumentation is in the detailed design phase.

French contribution

For the start of the ESS, 15 instruments have been selected for their ability to meet the needs of the European scientific community, as well as for their unique characteristics. These instruments are funded and built through in-kind contributions from the ESS partners. These in-kind contributions cover the design, component reception, installation, integration and cold commissioning phases. France contributes 8% of the total ESS construction budget (1843 M€) of which 35 M€ is dedicated to instrumentation.

Rendu 3D de la suite instrumentale en cours de développement.

In this framework, the LLB is involved in the construction of 6 instruments (3 diffractometers, 2 spectrometers and a SANS) and of part of the sample environment shared by the instruments. The IBS (Institut de Biologie Structurale, Grenoble) is also involved in the construction of an instrument. 


  • Type: polarized neutron diffractometer dedicated to the study of magnetic properties on single crystals.
  • Contributors: LLB ( 60%), JCNS ( 24%) and PSI ( 16%)
  • LLB staff involved: S. Klimko, T. Dupont, T. Robillard, A. Goukasov, X. Fabrèges
  • Capabilities: magnetic structure resolution, spin density, susceptibility/anisotropy/local magnetization, XYZ polarization and polarization analysis, high flux and small samples
  • Covered topics: multi-functional materials, superconductivity, spin-orbit coupling, fundamental magnetism, molecular magnetism, chirality, skyrmions, thin films and interface, quantum magnetism


  • Type : cold time-of-flight spectrometer with direct geometry.
  • Contributors : LLB (50%) and TUM (50%)
  • LLB staff involved: J. Guyon-le-Bouffy, G. Fabrèges, S. Longeville, Fernando Yamil Moreira
  • Capabilities: multi-scale (1 – 1000 Å and 10-14 – 10-10 s), small samples, pump/probe experiments, in-operando kinetics, high pressures, electric field measurements
  • Covered topics: soft matter, hydrogen/CO2 storage, catalysis, magnetism, batteries, life science, …, Fernando Yamil Moreira


  • Type : multi purpose spectrometer for small angle scattering.
  • Contributors : LLB ( 50%), JCNS ( 50%)
  • LLB staff involved: S. Désert, P. Lavie, Alexis Chennevière, J. Jestin
  • Capabilities: high wave vector dynamics (3 orders of magnitude simultaneously), very small angles, polarization, time-resolved studies, versatile sample environments.
  • Coverd topics : stimulable materials, biological systems, health, magnetic materials, energy materials, nano-materials, nano-composites, colloids and surfactants, mixed systems, …


  • Type : Non-polarized diffractometer dedicated to the study of structural (nuclear and magnetic) and microstructural properties on powders (single crystals possible)
  • Contributors : JCNS ( 76%) and LLB ( 24%)
  • LLB staff involved: S. Désert, B. Annighöfer, G. Fabrèges, A. Cazenave, F. Porcher
  • Capabilities: nuclear and magnetic structures by diffraction, PDF analysis, (SANS)
  • Covered topics: materials for energy, batteries, (multi-) functional materials, nano-materials, magnetism, superconductors, zeolite materials and MOFs,…


  • Type : Indirect geometry spectrometer with 50 analyzers/detectors covering 90° of scattering angle in the horizontal plane.
  • Contributeurs : DTU/KU ( 30%), PSI ( 27%), LLB ( 22%) and IFE ( 21%)
  • LLB staff involved: S. Rodrigues, P. Lavie, P. Bourges
  • Capabilities : parametric inelastic scattering measurements for the study of magnetic and phonon excitations and/or with extreme environments (strong magnetic field, high pressure,…), high flux and small samples.
  • Covered topics: multi-functional materials (phonons and magnetism), superconductivity, spin-orbit coupling, fundamental magnetism, quantum magnetism, materials for energy, thermoelectrics, geology (high pressure).


  • Type : quasi-Laue time-of-flight diffractometer.
  • Contributeurs : Wigner (38%), LLB/IBS (14%), UiB (12%), ESS (36%)
  • IBS staff involved (Grenoble) : J. L. Ferrer
  • Capabilities : large-mesh system, sub-mm samples, high resolution, signal-to-noise ratio, resolution of complex structures, hydrogen position.
  • Covered topics: biological systems, proteins, biomolecules, …

Sample environement

  • Magnets and low temperatures: superconducting magnet with large angular opening, warm-bore superconducting magnets, dilution inserts and 3He insert.
  • Hight pressure: liquid/gas cell, loading and pressurization system and Paris-Edinburgh cell.
  • LLB staff involved: B. Annighöfer, F. Maignen, X. Fabrèges