Calls for Proposals

The PSI User Office invites user proposals for the next user run at SwissFEL

  • We call for proposals for the Alvra, Bernina, and Cristallina-MX instrument at the Aramis hard X-ray line and for the Maloja and Furka instrument at the Athos soft X-ray line. The branch lines and instruments are described in detail below. Please take particular note of the available configurations described on the respective instrument tabs.
  • SwissFEL is being continuously developed but the proposals must be based on the parameters outlined below on this page. 
  • After the submission deadline the proposals are evaluated in terms of safety and technical feasibility. Then they are ranked in terms of scientific criteria by the international SwissFEL Proposal Review Committee (PRC). More information about the evaluation procedure is published on Evaluation. The result of this rating is the basis for the beamtime assessment made by SwissFEL.
  • The main proposers are informed by email about the result of the ranking and beamtime assessment.
  • The annual calendar for the proposal evaluation is as seen below.
  • Proposals can be submitted to the PSI User Office.

Schedule for Calls

We will open a call for proposals for SwissFEL in August 2024.

SwissFEL call schedule
Experimental Period01.02.2025 - 31.07.2025  
Submission deadline15.09.2024  
Start period01.02.2025  
End period31.07.2025  
21. - 23.10.2024  

Machine parameters

  • photon energy: 1.8-12.7 keV
  • typical bandwidth: 0.25% dE/E
  • typical pulse energies: up to 1000 µJ
  • repetition rate: single shot - 100Hz
  • X-ray pulse duration: 50 - 70 fs fwhm
  • X-ray-laser arrival-time jitter:  < 150 fs fwhm (for time tool options see instrument sections)

Advanced machine modes with lower operation experience are available on a best effort basis.

These include

  • large bandwidth mode (up to 2%)
  • short pulses mode (10-50 fs fwhm) with loss of pulse energies

Please contact the instrument teams for specific details that may help to enhance the technical feasibility of the proposed experiment. 

Experimental Endstations

For the new run the Alvra, Bernina and Cristallina-MX endstations are available with the following parameters:

The Alvra instrument specializes in ultrafast dynamics in chemical and biological systems, especially in solutions, liquids, or crystals in viscous media. Alvra is equipped for X-ray spectroscopy (absorption and emission), liquid scattering, and serial femtosecond crystallography measurements, as well as flexible user-provided setups. In Alvra there are two endstations available, the Alvra Prime chamber (vacuum and He environment) and Alvra Flex (in air) in the parameters described below.

For high time resolution experiments, a single pulse timing diagnostics, for jitter and drift corrections, can be used with pink FEL beam and Si-111 monochromatic on best effort basis (please contact instrument responsible).

We offer short and dedicated SFX beamtime slots for experiments in the following standard configuration: X-ray photon energy of 12 keV with standard bandwidth, femtosecond laser excitation between 500 nm - 600 nm or at 800 nm and at best 100 fsec time resolution, Jungfrau 4M detector, LCP injector. The max. beamtime length is 3 days (9 shifts) including setup. Indicate in the abstract of your proposal if it should be considered for the new standard SFX beamtime and add a detailed beamtime plan in the experimental description.

Alvra Prime
Photon energy range 2 keV – 12.4 keV, instrument fully commissioned over the full energy range
Beam profile
  • Measured focus <10 x 10 µm2 (fwhw) below 4.5 keV.
  • Measured focus  < 5 x 5 µm2 (fwhm) for energies > 6 keV
  • 1 x 1 µm2 (fwhm) achieved for 12 keV
  • Focus can be adjusted to meet experimental requirements
  • Unfocused beam: ~1 x 1 mm2 (fwhm) energy dependent
Bandwidth Monochromatic (Si(111), InSb(111), Si(311)) and pink beam (0.25% of fundamental); larger bandwidths of up to 2% are also possible (photon energy dependent)
Environment Vacuum (down to 5x10-4 mbar ) up to atmospheric pressure (He or N2)
Sample delivery Liquid jet:
  • Flat jet (100, 200, and 300 µm) with peristaltic pump
  • Round jet (25-200 µm) with HPLC pump

LCP injector (50-100 µm)
Solid samples

GDVN operation possible for user-supplied and operated injector

Detectors and Spectrometers
  • 16M Jungfrau forward scattering detector at a fixed 10 cm sample-detector distance
  • 2 x 2 crystal von Hamos dispersive X-ray emission spectrometer (1-12.4 keV)
  • Diodes for integrated x-ray absorption measurements
  • 4.2M PCO edge CMOS camera (flexible setup)
Alvra Flex
Photon energy range 5 keV – 12.4 keV
Beam profile Focused 100 x 100 µm2 (fwhm) from design
Unfocused beam 1 x 1 mm2 (fwhm) energy dependent
Bandwidth Monochromatic (Si(111), InSb(111), Si(311; commissioning 2019) and pink beam (0.25% of fundamental)
Environment Normal atmosphere
Sample delivery Liquid jet:
  • Flat jet (100, 200, and 300 µm) with peristaltic pump
  • Round jet (25-200 µm) with HPLC pump

Solid samples

Detectors and Spectrometers
  • 3 crystal von Hamos dispersive X-ray emission spectrometer with 0.5 M Jungfrau detector (75 µm pixels) or 0.5M Stripsel Jungfrau (25 x 225 µm pixels)
  • Diodes for x-ray absorption measurements
  • 4.2M PCO edge CMOS camera (flexible setup)

Alvra experimental laser infrastructure

Fundamental 800 nm, 35 fs (fwhm), 10 mJ (Ti:Sapphire)
Harmonics 800/400/266 nm branch available in parallel to OPA
OPA conversion 240 nm – 2.5 µm
Pulse energy at the sample position

Measured OPA pulse energies at the sample location vary with wavelength, ranging between 5 to 100 µJ. For specific pump wavelengths please inquire. Pulse durations are expected to be approximately 75 fs fwhm.

Harmonics branch allows for higher pulse energies at 800/400/266 nm with shorter pulse durations achievable. For current status please inquire.

Focus 50 x 50 – 500 x 500 µm2 (fwhm)


General information about the Alvra endstations can be found at: Alvra
For questions and further information about Alvra contact: Dr. Camila Bacellar

The Bernina Instrument is specialized on studying condensed matter systems by selective light excitation and selective X-ray probes. It is equipped with flexible but precise positioning hardware for diffraction on solid state samples, but also larger user-supplied hardware. The instrument can interchange two endstations, which can be configured for different sample and detector configurations. Bernina features versatile pump laser excitation from UV to single cycle THz pulses.

Endstation platforms

  • X-ray Diffractometer (XRD), equipped with a two circle detector arm,
  • General Purpose Station (GPS), with a multi-purpose horizontal 2-theta arm.

Sample platforms

  • Six degree of freedom (DOF) heavy load goniometer,
  • Two-circle surface diffractometer combination plus six DOF hexapod,
  • Kappa arm (6 DOF).

Standard setup options

  • Six circle kappa surface diffractometer, equipped with area detector on 2-circle detector arm (XRD). Sample in air or N2-cryostream atmosphere (80-500K stream temperature). Standard pump laser wavelengths from UV to near Ir. An optional polarisation analyzer can be used upon early request.
  • Vacuum chamber setup for low sample temperature (down to ~5K), high electric field THz pulse excitation, and tender X-ray range experiments. It is advised to explore the compatibility of proposed experiments with the chamber geometry before proposal submission. For details about the chamber please refer to
  • Resonant Inelastic X-ray Spectrometer (RIXS) with spherical Si(844) diced analyzer crystals is available upon early request. The spectrometer features a 1m arm following the Rowland geometry. Using the beamline double crystal Si-(333) monochromator, the reached energy resolution at the IR L-edge at 11.215keV is 130meV.

New developments

  • Visible short pulse pump (500 – 750 nm; ≤ 25 fs fwhm) by Non-Collinear Optical Parametric Amplifier (NOPA).

For high time resolution experiments, a single pulse timing diagnostics can be used at Si-111 monochromatic and the pink FEL beam.

Photon energy range 2 keV – 13.0 keV
Beam profile Focused down to 2x2 µm2 (fwhm, measured) to unfocused 1000x1000 µm2 (fwhm, photon energy dependent).
Bandwidth Monochromatic (Si(111) routinely used, InSb(111), Si(311) and pink beam (~0.2% of fundamental, transmissive single FEL pulse spectrometer available), special modes like broadband SASE operation possible.
Pulse length Standard SASE pulse length ~50 fs (fwhm), short pulse options at cost of pulse energy down to ~20 fs.
Environment He or ambient atmosphere, platform for user-supplied chambers, N2 and He based cryostream coolers down to ~80 K. Vacuum chamber available for low sample Temperature (<5 K), high field THz excitation, and tender X-ray range.
Sample systems

Solids: single crystals, powders, amorphous systems. Liquid/Gas only with user supplied equipment.

Detectors and Spectrometer
  • 1.5 M Jungfrau detector
  • 16 M Jungfrau detector
  • Diodes or single element (0.5 M) Jungfrau detectors for multi- purpose applications.
  • Resonant Inelastic X-ray spectrometer with spherical diced Si(844) analyzer crystals
  • Polarisation analyzer
  • Limited X-ray emission spectrometer options upon request
Bernina optical pump laser
Source type Wavelength range Pulse energy / max. Field Pulse length Comments
Primary pump source    800 nm 20 mJ

35 fs
or 100 fs

2nd and 3rd Harmonic (400 nm and 266 nm), as well as ~10 fs compressed fundamental 800 nm available upon request.
240 – 480 nm      10 – 100 uJ   ≤ 50 fs (fwhm) Pulse energy variation includes typical losses between source and sample.
480 – 780 nm 150 – 1000 uJ ≤ 50 fs (fwhm)
780 – 1160 nm 10 – 100 uJ ≤ 50 fs (fwhm)
1.16 – 1.58 µm

≤ 50 fs

1.58 – 2.4 um 500 – 1000 uJ ≤ 50 fs
NOPA 500 – 750 nm 10 – 70uJ
≤ 25 fs  

4.4 – 20 um  (70 15 THz)

1 – 20 µJ
≤ 300 fs  
Opt. rect. 2 – 5 THz single cycle >500 kV/cm  
LiNbO3 based

0.5 – 2 THz single cycle

>500 kV/cm  

General information can be found at: Aramis Bernina Experimental Endstations
For questions and further information about Bernina, please contact: Dr. Henrik Lemke

The first endstation the Cristallina-MX project to be commissioned is called SwissMX (Serial WIth Solid-Support MX), a fixed-target endstation designed for high-throughput SFX and SFX pump-probe. SwissMX has been commissioned with an in-air sample environment since May 2022 and is now ready for users.

The SwissMX has currently only been commissioned to accept two styles of fixed-target: the PSI MISP (MIcro-Structured Polymer) and the MPI SOS (Sheet-On-Sheet) chip (Doak et al., 2018). The MISP-chip is composed of an array of apertures in defined locations in a similar style to the Oxford (Horrell et al., 2021) and HARE chips (Mehrabi et al., 2020). The MISP-chips can be fabricated in either a clear or an opaque polymer, with the only latter being compatible with pump-probe measurements. The SOS chip by comparison is made by carefully sandwiching a sample between two sheets of polymer film and are ideal for samples of limited volume in viscous media such as LCP. Liquid-crystal samples will need to be embedded in a moderately viscous medium to be used effectively. Please indicate in the DUO which chip or both you would like to use.

The SwissMX is capable of both SFX and nanosecond resolution SFX pump-probe measurements. The endstation can be fibre-coupled to an EKSPLA nanosecond OPO and the pump-probe measurements have been commissioned using the opaque MISP chips. Pump-probe is only possible using these chips.

Our standard SFX beamtime configurations are: X-ray photon energy of 12 keV with standard bandwidth (0.15 % SASE), nano-second laser excitation between 410 nm - 700 nm (if required), Jungfrau 8M detector and either MISP or SOS chips. Max beamtime length will be 2 days (6 shifts). Please indicate if you would only like 0.5/1 shifts for non-pump-probe SFX measurements.

Photon energy range
  • 10 – 12.4 keV
  • SwissMX is currently only commissioned for in air measurements
  • Therefore, photon energy practically limited to >10 keV
  • The beam is caught by scatter guards before and after the sample position, giving a 15 mm of air window
Beam profile
  • Measured beam size to 1.5x1.5 µm2 (FWHM) at 12 keV
  • Larger beam profiles have been tested but not fully commissioned – please contact the beamline scientist if you have questions
  • Pink Beam with 0.25% of fundamental is standard; larger bandwidths of up to 2% are also possible (photon energy dependent)
  • SwissMX has only currently been commissioned for in air measurements


  • Small – 6,000 apertures
  • Large – 26,000 apertures
  • Aperture pitch = 120 µm (distance between adjacent apertures)
  • Typically sealed in two layers of film - 6 µm Mylar standard but thinner films are also possible.
  • Suitable for SFX and SFX pump-probe

MPI SOS chip

  • No apertures – crystals are embedded randomly in media and sandwiched between two pieces of film - 6 µm Mylar standard but thinner films are also possible.
  • User defined shot-spacing
  • 25x25 µm spacing commissioned with no radiation damage at 12 keV
  • Possible 250,000 images from 12.5x12.5 mm2
  • Not suitable for SFX pump-probe
  • 8 Mpixel JUNGFRAU (125 mm radius) on an 180 mm translation stage
  • Smallest sample detector distance = 110 mm
  • Please give a reasonable estimate of your desired resolution so the detector geometry can be properly determined prior to beamtime. See Cristallina-MX for a rough guide.
Optical pump laser
  • Pulse width = 3.2 ns at 450 nm
  • Laser is fibre-coupled to SwissMX
  • Maximum pulse energies are limit to 2 µJ
  • Only commissioned wavelength from 410-700 nm
  • Please contact beamline scientist if you wish to move outside of the visible spectrum
  • Focus 30x30 µm2 at 450 nm

General information can be found at the Cristallina-MX project page.
For questions and further information about Cristallina-MX, please contact: Dr. John Beale

Athos beam parameters:

Standard SASE:

  • Photon energies and pulse energies for circular polarization (linear polarization  30-40% less) : 
    • 350 - 1000eV with more than 2000μJ pulse energy
    • 1000 - 1300eV with more than 1000μJ pulse energy
    • 1300 - 1600eV with more than 250μJ pulse energy
  • Typical bandwidth ≤ 1 %
  • Repetition rate 100Hz
  • Standard X-ray pulse duration ≤ 100fs FWHM
  • Short X-ray pulses with tuneable pulse duration down to factor of x5 relative to standard SASE mode. Pulse energy directly proportional to pulse duration
  • Polarization adjustable: Circular +/- (delivers highest pulse energy), linear horizontal, linear vertical
  • Energy scan: feasible over +/- 10 % of fundamental energy

Advanced machine modes with lower operation experience are available on a best effort basis. These include:

  • Two colour X-ray mode: Two X-ray pulses with independently tuneable photon energies up to 1000eV, maximum delay between the pulses is 500fs and minimum delay is -50fs.

Please note, that advanced modes will result in overall reduced machine performance, like lower repetition rate and reduced pulse energy as compared to standard SASE operation. In case you plan to submit a proposal which requires an advanced mode, we advice to consult with the endstation contacts beforehand.

The Maloja instrument specializes on studying ultrafast processes in atomic, molecular, non-linear and chemical sciences. The flexible setup allows for a variety of spectroscopy and imaging approaches. For the current call only the following standard setups and parameters will be available:

Setup Configuration
Time resolved XPS
  • Hemispherical electron analyzer: Specs Phoibos 150 EP
  • Gas needle for sample delivery
  • Grating spectrometer after interaction point (Scienta XES350) for single shot spectral diagnostics
Pink beam XAS
  • Grating spectrometer after interaction point (Scienta XES350) in transmission geometry
  • Transmissive spectral characterization with electron spectrometer prior to sample (Specs Phoibos 150 EP)
  • Gas cell or solid sample support
Ion momentum spectroscopy
  • COLTRIMS spectrometer with short or long ion side
  • Hexagonal delay line anode for ion coincidence measurements
  • Quadratic delay line anode for ion recoil spectroscopy
  • Supersonic gas jet (Even-Lavie valve, room temperature to 100C heatable)
  • Setup is still under commissioning, please consult with Maloja contact for details
Single shot single particle imaging
  • 4M Jungfrau forward scattering detector, in standard configuration 34cm detector to sample distance
  • Pulsed supersonic gas jet (room temperature) or aerodynamic lens stack injectors, please consult with Maloja contact in case you plan to use the aerosol injector
  • Optional: ion time of flight spectrometer to be used with supersonic jet
Beam profile                                  
  • Tightest focus reaching 5um x 5um (FWHM)
  • Unfocused beam 3-7mm, depending on photon energy
  • Focus adjustable with bendable KB optics to meet experimental requirements                                                      
Optical laser
  • Fundamental wavelength: 800nm
  • Pulse energy 10mJ
  • Pulse duration 35fs
  • Harmonics of the fundamental at 400nm and 266nm are available
  • TOPAS to provide other wavelengths is under commissioning, if required for your experiment, please consult with the Maloja contact

Natural jitter between X-ray and optical pulse ~150fs (FWHM), which can be improved with an arrival time monitor.

Restrictions for hazardous samples apply, please consult with the Maloja contact before submission in case you plan to use such substances.

General information about the Maloja endstations can be found at: Maloja
For questions and further information about Maloja contact: Dr. Kirsten Schnorr

The Furka experimental endstation, located at the soft x-ray Athos beamline of the SwissFEL, is dedicated to the study of quantum materials using time-resolved Resonant Inelastic and Elastic X-ray Scattering (tr-RIXS and tr-REXS) as well as X-Ray Absorption (tr-XAS) spectroscopy.

The endstation is equipped with at 4-circles UHV diffractometer (Tmin=25 K), a set of x-ray detectors (APDs) rotating on two independent circles around the sample and 6 meter long RIXS spectrometer (200 meV min energy resolution).  Sample cleaving in the load lock (room temperature, vacuum 10-7 mbar) is available. The THz radiation is focused using a parabolic mirror mounted on a motorized manipulator (5 DOF) located inside the vacuum chamber.

Natural jitter between X-ray and optical pulses ~150fs (FWHM). For higher time resolution experiments, a single pulse timing diagnostics, for jitter and drift corrections, can be used (please contact instrument responsible for more info).

Setup Configuration
Time resolved XAS and REXS
  • Avalanche photodiode for FY detection (10x10 mm – 400 mm distance to sample position)
  • 2x10 mm photodiode for diffraction detection (400 mm distance to sample position)
  • Variable x ray polarization available (C+, C-, LV, LH)
Time resolved RIXS
  • sVLS Grating spectrometer
  • Energy resolution of  ≥ 200 meV for hv=500-1000 eV
  • Scattering angle 45-140 degrees. Angle variation under UHV conditions
  • CMOS detector 4MPixel (1 MPix @ 100 Hz acquisition), sensor size 1x1 inch2
Beam profile                                  
  • Tightest focus 10um x 10um (FWHM)
  • Unfocused beam 3-5mm, depending on photon energy
  • Focus adjustable with bendable KB optics to meet experimental requirements
  • Typical RIXS experiments focus 10 x (300-500) um
  • Vacuum baseline 1x10-8 mbar. For vacuum <1x10-8 mbar please contact instrument responsible 
Furka optical pump laser
Primary pump source    800 nm, 35 fs / 100 fs FWHM, 20 mJ (Ti:Sapphire)
Secondary pump sources with
35 fs 800 nm pulses
Wavelength range Pulse energy / max. Field Pulse length Comments
400 nm      200 uJ
~ 50 fs (fwhm)
266 nm 30 uJ
~ 50 fs (fwhm)
Secondary pump sources with
100 fs 800 nm pulses
240 – 780 nm   10 – 350 µJ ~ 100 fs (fwhm) Pulse energy depends highly on wavelength, for more information please contact the instrument responsible.
1.2 – 2.5 µm 200 – 500 µJ ~ 100 fs (fwhm)
~1 THz single cycle Up to 300 kV/cm
THz generation with nonlinear organic crystals, for mor information please contact the instrument responsible

General information about the Furka endstations can be found at: Furka
For questions and further information about Furka contact:  Dr Elia Razzoli

PSI User Office
Paul Scherrer Institute
Room WLGA/018
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Office hours:
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otherwise please contact us per email