April 21, 2026
Room to move: how proteins behave in crowded environments
Neutron scattering shows how local density shapes motion within self-assembled protein structures
Spectroscopy
Neutron spectroscopy probes the dynamics of magnetic moments, molecules and lattices over length scales ranging from a few angstroms to tens of nanometers, and over timescales from tens of femtoseconds up to the microsecond.
Within neutron spectroscopy, there are 4 main techniques which use different methods to determine the energy of the incident and scattered neutrons and are adapted to different kinds of scientific studies. An overview of instrument parameters is provided in the instruments page.
Spectroscopy instruments
Various dynamic ranges of the Spin-echo, Back-scattering and Time-of-flight instruments at the ILL. Figure made by M. Appel.
Time-of-flight (TOF) spectrometers use the time-of-flight of neutrons through the spectrometer to determine the energies of the incident and scattered neutrons.
There are 3 dedicated time-of-flight (TOF) spectrometers. These instruments are optimised for different kinds of scientific studies, which depends mainly on their energy resolution and momentum transfer range.
IN5 Cold neutron multi-chopper TOF spectrometer
SHARPER Cold neutron time-focussing TOF spectrometer
PANTHER Thermal neutron TOF spectrometer
There is a range of triple-axis (TAS) spectrometers which use crystal monochromators and analysers to determine the incident and scattered neutron energies. TAS spectrometers are mainly used to study single crystal samples, focusing on specific regions of interest in reciprocal space. The TAS instruments are optmised for different kinds of scientific studies, which depends for example on the energy and flux of the incident neutron beam, polarised neutron capability and the availability of specific sample environments.
IN1 TAS/LAGRANGE Hot 3-axis spectrometer
IN8 High-flux thermal 3-axis spectrometer
IN12 Cold 3-axis spectrometer (CRG)
IN20 Polarized thermal 3-axis spectrometer
IN22 Polarized thermal 3-axis spectrometer (CRG)
ThALES Three Axis instrument for Low Energy Spectrometry
Neutron backscattering provides higher energy resolution than TOF or TAS by using crystal analysers that operate in a backscattering geometry. There are 2 dedicated spectrometers
IN16b Versatile high flux backscattering spectrometer
IN13 Thermal neutron backscattering spectrometer
IN16b is a very versatile instrument which includes a time-of-flight option to significantly increase the dynamic range.
Spin Echo Spectroscopy (NSE) achieves very high energy resolution using the change in polarization between the incident and scattered neutron beams to measure small energy changes due to the dynamics in the sample. The energy resolution is better than that of neutron backscattering and is expressed in Fourier times since the technique measures directly the intermediate scattering function I(Q,t).
There are 2 dedicated spectrometers, WASP and IN15, which differ essentially in terms of the detector coverage and therefore the count rate. IN15 holds the record for measuring the longest Fourier time – about 1 microsecond.
Instrument parameters
An overview of instrument parameters is provided here to help you choose the most suitable instrument. By clicking on the instrument, you can go directly to the dedicated instrument pages where more information can be found, including scientific highlights and contact details for the instrument scientists.
Recent science highlights
March 11, 2026
Designing Materials That Defy Heat Flow
Linking simple physical rules, machine learning and neutron spectroscopy to discover crystals with record-low thermal conductivity
Feb. 12, 2026
Cooling without gases: molecular design brings solid-state cooling closer to reality
A recent study shows that small molecular modifications can make barocaloric materials respond more reliably under pressure, supporting the development of solid-state cooling technologies without climate-damaging refrigerant gases.
Dec. 19, 2025
When antibodies attack: deciphering molecular mysteries of the immune system
A newly published study looks into the molecular motions of therapeutic antibodies and their ability to interact with their target molecules. The results provide crucial information for optimising design and formulations in future developments.
Dec. 15, 2025
Life in the cold: how microbes thrive - and die - at extreme temperatures
A new study based on neutrons provides valuable insights into the thermal vulnerability of different bacterial families. It shows that organisms adapted to very low temperatures are also surprisingly fragile: even a slight rise in temperature can be lethal, long before any structural damage appears.
Nov. 25, 2025
2025 operations: highlights
The ILL concluded 2025 operations at the end of October. In total, more than 1800 scientists came on site to perform close to 1400 experiments. The High-Flux Reactor will restart in late March 2026 for a year with 3 operating cycles in the programme.