UK XFEL - Scientific Case Project
22 May 2019







Science Case - Final version published

STFC formally launched the process to create an updated science case for a UK based X-ray Free Electron Laser (UK-XFEL) in July 2019 at the Royal Society (more details of this event can be found here). The resulting draft document formed the basis of a consultation with the scientific community and comments received during this time have now been incorporated into a final version published in October. This final version of the science case was subject to a formal independent review in November.

​The science case can be downloaded in Full, or just the Executive Summary  (Final version published 5th October 2020)​.

​​The science case seeks to address:

  • Over the coming decades how will the technological and scientific opport​unities enabled by XFELs develop?
  • What specific impact might there be from a UK machine aimed at offering new capabilities and adding to the capacity available internationally.​ 

STFC, Prof Marangos and the Science Team are still actively soliciting feedback, Please send any comments or thoughts to

UK XFEL - Scientific Case Project - 2019 User Consultation exercise

This initial phase of the consultation process has now concluded. However details of the original science meetings including presentations by the various speakers from academia and industry can still be found here: UK XFEL - Scientific Case Project - 2019 User Consultation exercise

STFC hosted a series of live, discipline specific Webinars between July and mid-September 2020, where relevant members of the Science Team presented the key scientific, industrial and innovation opportunities. They were 90 mins long (45 min presentation; 45 min Q&A), and recordings are available through the following links: ​


SubjectDateTimeLive Webinar Link / Recording
Science Case Overview23 July
2 pmRecording available here
Life Sciences28 July
2 pm

Recording available here

Chemical and Material Sciences30 July2 pm
​Recording available here​
Physical and Extreme Conditions5 August
2 pm
Recording available here

Webinar Talks:

The process formally kicked off with a Town Meeting at the Royal Society on July 16th 2019. Details of this event can be found here - Town Meeting at the Royal Society - July 16th 2019

​​UK XFEL - Science Opportunities

High brightness ultra-fast x-ray pulses from an X-ray FEL allow the simultaneous imaging of atomic scale structure, electronic state and dynamics in a material. There is no other technology that can do that. The unique science opportunities that these machines can open-up include:

  • Access to structural dynamics: Dynamical phenomena can be probed on a time scale down to femtoseconds thus covering electronic dynamics, lattice dynamics and chemical bonds breaking/forming. This capability can be applied to: chemical reactions (for optimisation of e.g. catalysis, water-splitting, hydrogen storage mechanisms), energy materials (for optimisation of photovoltaics, battery technology), engineering materials (to understand/ mitigate mechanisms of corrosion, radiation damage, shock damage), and biochemistry (to unravel photosynthesis, light sensitive protein activity).

  • New modes of nanoscopic imaging: These can be used for seeing the nanoscopic arrangements in nanotechnology and life-sciences free from radiation damage and adverse effects of sample preparation (e.g. in situ imaging of the function of biomolecular assemblies at operating temperature).

  • Access to transient states: Matter can be probed under conditions which are only transiently achieved, such as: extreme pressure, high E & B fields, laser dressing and high energy density (important to astrophysics, planetary science, geophysics, defence and quantum materials).

  • The potential to capture rare events: In physical, chemical and biological systems critical processes often proceed through rare events arising from intrinsic fluctuations and an XFEL opens the possibility to directly visualize these (e.g. can capture natural chemical/biochemical reactions in the act).

These are broadly applicable capabilities that provide a completely new window into matter and dynamics with impact across a wide landscape of science and technology. They will be used alongside other modalities (optical, neutron, cryo EM, UED, synchrotron X-ray, NMR etc.) to increase our abilities to probe and control matter.

A unique UK X-ray FEL

An XFEL consists of a linear electron accelerator and undulators to generate very bright and ultra-short pulses of X-rays via the self-amplified spontaneous emission (SASE) process.  What is now needed is a machine with much better control of the X-ray properties than with the current generation of intrinsically noisy SASE machines. This will enable new classes of measurements. Building one of these in the UK would make us an international centre for the next generation of X-ray FEL science. Building a state-of-the-art SASE machine with a unique combination of end-station capability could also lead to compelling new science. The UK could also continue to invest substantially in the international array of X-ray FELs and use this as leverage to ensure those facilities, especially exciting new projects like Euro XFEL and LCLS II HE, are steered in directions that match best our science needs.

Contact our Science Team for further information:​

  • Matter in extreme conditions: Andy Higginbotham (York), Andy Comley (AWE), Malcolm McMahon (Edinburgh), Justin Wark (Oxford)

  • Nano/Quantum materials: Ian Robinson (UCL/Brookhaven), Anna Regoutz (IC), Simon Wall (ICFO)

  • Materials: David Rugg (RR), Sven Schroeder (Leeds), David Dye (IC)

  • Life sciences: Allen Orville (DLS), Jasper van Thor (IC)

  • Chemical sciences: Julia Weinstein (Sheffield), Russell Minns (Soton), Sofia Diaz-Moreno (DLS), Tom Penfold (Newcastle)

  • Ultrafast physics: Adam Kirrander (Edinburgh), Amelle Zair (KCL)
Contact: Green, James (STFC,RAL,CLF)