Call for Proposals

There is no call for Proposals open at the moment.

Information from the latest call for Proposals:

The European X-Ray Free-Electron Laser Facility (European XFEL) encourages the scientific community worldwide to submit proposals for User Experiments via the User Portal to the European XFEL (UPEX) until Wednesday 11 December 2019 16:00 (local Hamburg / Schenefeld time – Central European Time CET)

Beamtime at EuXFEL

Beamtime will be allocated to successful proposals from July to November 2020 at the following instruments:

See also the instrument overview.

Instrument conditions

The scientific instruments are at different stages of advancement. Please check with the relevant instrument team about feasibility conditions for this call before submitting a proposal. Please also inquire with the instrument team for more information about planned user community projects. Contact:

All proposals submitted in this call will be reviewed for their scientific quality by panels of international experts and, in addition, checked for safety and feasibility conditions.

Proposals shall consider the specific conditions expected for this allocation period. Verification about specific feasibility conditions with the instrument teams is nevertheless required.

6th Call for Proposals - specific conditions (7/2020 – 11/2020)
Photon energy [keV]
5 – 24
0.5 – 3.0
Max. mean pulse energy *[mJ]
0.2 – 4
1 – 10
Bunch duration [rms fs]
10 – 25
10 – 25
Max. intra-train frequency [MHz]
Typ. number of pulses* *

* Pulse energy depends on bunch charge, electron energy and photon energy.

** Bunch distribution: 400 X-ray pulses per instrument assume equal distribution at 2.25 MHz operation. This number additionally depends on specific conditions of operation, e.g. by radiation safety for the instrument hutches. Higher or smaller numbers will follow from higher/smaller intra-train frequency. Max. 2250 electron bunches within 500 µs are available for distribution to the instruments (4.5 MHz).


  1. The above parameters correspond to the standard SASE operation mode.
  2. The following special modes are available, but require more tuning and are less reliable:
    1. Hard X-ray Self-Seeding (SASE2; 8- 10 keV);
    2. Hard X-ray 2-color w. variable delay (SASE2; 6 – 10 keV; 0 –  0.5 ps).
      Experiments requesting these special modes should address the development of new techniques and fields and are expected to involve large communities and facility staff. If included in final schedule, then continued (24-hour shift) operation will be planned.
  3. Pulse energy depends on bunch charge (higher -> more), electron energy (higher -> more) and photon energy (higher -> less).  For operation with x-rays above 20 keV photon energies more tuning time will be needed, pulse energies will depend on the status of FEL tuning and will be (significantly) less than 1 mJ. Due to the complexity, continued (24-hour shift) operation will be planned.

User pages

More practical information for users can be found on the user pages.

Travel funding to users

  • Travel funding and living subsistence is available for a specified number of users affiliated with organizations based in the member countries of European XFEL. Further details are available on funded user travel.
  • Also for this call, limited funding for scientists from organizations in non-member countries is also available through the EU support programme CALIPSOplus (

User office contact