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, Cristallina-MX and Cristallina-Q instruments at the Aramis hard X-ray line and for the Maloja and Furka instruments at the Athos soft X-ray line. 
  • We also start offering Protein Crystal Screening (PCS) beamtimes with specific beam parameters and boundary conditions at the Alvra Prime and Cristallina-MX endstations. Please refer to the "Protein Crystal Screening" tab in the Aramis section below for details.
  • As a pilot project, we offer joint beamtime access to the Bernina endstation at SwissFEL and the ADDAMS surface diffractometer at the Swiss Light Source. Please refer to the "Bernina" tab in the Aramis section below for details of this joint call.

 

  • 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 via the DUO system of the PSI User Office.

For the description of the proposed experiments, please use one of the following templates. The "Research Proposal" template is also available in the DUO system. For other beamtime proposals, use the appropriate template from this page and upload the final pdf in the DUO system. The maximum file size is 3 MB. 

  • Regular research proposals have a maximum length of three pages. Download this wordfile or open this overleaf (Latex) project as template for the proposal structure.
  • Joint Bernina - ADDAMS proposals are similar to the regular research proposals for SwissFEL but include an additional page for the ADDAMS supportive experiment. Download this wordfile as template for the proposal structure.
  • Protein crystal screening beamtime proposals have a maximum length of one page and need to state a clear goal. Download this wordfile as template for the proposal structure.

If you have questions, please contact the appropriate instrument scientist as listed in the tabs below.

Schedule for Calls

We will open a call for proposals for SwissFEL in February 2025. 

SwissFEL call schedule
Experimental Period01.08.2025 - 31.12.2025  
Callapprox. 10.02.2025  
Submission deadline15.03.2025  
Start period01.08.2025  
End period31.12.2025  
EVALUATION
 		23. - 24.04.2025  

Aramis beam parameters

Regular SASE:

  • photon energy: 2 - 13 keV
  • polarization: linear horizontal
  • typical relative bandwidth (cumulated): 0.25% fwhm 
  • pulse energy: typically up to 1 mJ up to 12 keV
  • repetition rate: single shot - 100Hz  (accelerator at 100 Hz, rate reduction via fast shutter) 
  • pulse duration: 40-70 fs fwhm
  • X-ray pump-laser arrival-time jitter:  < 150 fs fwhm (for time tool options see instrument sections)

The following advanced machine modes are available on a best effort basis with lower operational stability:

  • Large bandwidth mode: relative bandwidth up to 2%
  • Short pulse mode: pulse length 10-40 fs fwhm, pulse energy scales with pulse length
  • Ultrashort pulse mode: pulse length < 1 fs fwhm, typical pulse energy 5 – 10 uJ

Please note, that advanced modes may result in overall reduced machine performance, including 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, please make sure to consult with the respective endstation contacts prior to proposal submission.

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

The Alvra instrument specializes in ultrafast dynamics in chemical and biological systems, specifically in solutions, liquids, or crystals in viscous media. Alvra is equipped for X-ray spectroscopy (XAS, XES, RIXS), liquid scattering, and serial femtosecond crystallography measurements, as well as flexible user-provided setups. The details are described below.

Alvra Prime
Photon energy range2 keV – 13 keV (fully commissioned over the full energy range)  
Beam profile
  • Typical focus <10 x 10 µm2 (fwhw) below 4.5 keV.
  • Typical 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 with KB benders
  • Unfocused beam: ~1 x 1 mm2 (fwhm) energy dependent
  
BandwidthMonochromatic (Si(111), InSb(111), Si(311)) and pink beam (0.25% of fundamental); larger bandwidths of up to 2% are also available (photon energy dependent) upon discussion  
EnvironmentTypically 200- 800 mbar of He atmosphere
Vacuum (down to 5x10-4 mbar ) up to atmospheric pressure (He or N2) possible		  
Sample delivery

Available Liquid jet setups:

  • Round jet (25, 50, 75, 100, 150 or 200 µm) with HPLC pump or syringe pump
  • Thin flat jets (5-30 µm, tunable) with HPLC pump
  • Flat jet (100, 200, and 300 µm) with peristaltic pump
  
Detectors and Spectrometers
  • 2 x 2 crystal von Hamos dispersive X-ray emission spectrometer (1-13 keV)
  • APD and PIPS diodes for integrated x-ray absorption (TFY) measurements
  
Alvra experimental laser infrastructure
Fundamental800 nm, 35 fs (fwhm), 10 mJ (Ti:Sapphire)  
Harmonics800/400/266 nm branch available in parallel to OPA  
OPA conversion240 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 50 µJ. For specific pump wavelengths please inquire. Pulse durations are expected to be approximately 75 fs fwhm. Possibility of further compression with chirp mirrors upon request.

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

  
Focus50 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

Bernina is equipped with flexible but precise positioning hardware for diffraction on solid state samples, which may also support user-supplied hardware. The instrument can interchange two endstations, which can be configured for different sample and detector degrees of freedom. Bernina features very versatile pump laser excitation from UV to single cycle THz pulses.

The  flexible Bernina endstation platform hosts following standard configurations

  • Six circle kappa surface diffractometer, equipped with area detector on a 2-circle detector arm (XRD). Sample in air or N2-cryostream atmosphere (80-500K stream temperature). Pump laser wavelengths from UV to THz. 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 https://doi.org/10.1088/1361-648X/ac08b5
  • Grazing incidence cryo vacuum chamber for pump/probe diffraction at low sample temperature (<10 K; 7.5 K shown at cold finger) and large diffraction angular range. The sample position is actively stabilized with respect to the FEL beam in grazing direction (<1µm). 

Experimental ideas, especially with needs for custom or special setups are encouraged to be cross-checked for feasibility with the instrument staff in good time before the proposal submission deadline.

New developments

  • New standard setup: Grazing incidence chamber GIC for pump/probe diffraction at low sample temperature and large diffraction angular range (see above).
  • Circularly polarized THz pulses at specific frequencies (opt.rect.), generated with monochromatic zero order l/4 waveplates.
  • Carrier envelope stabilized mid-Ir pulse laser source in 10–18 µm wavelength range (100-250 fs pulse length). 
  • Visible short pulse pump laser source (500 – 750 nm wavelength; ≤ 25 fs fwhm) by Non-Collinear Optical Parametric Amplifier (NOPA).
  • Load lock for High-field THz cryo chamber for quick sample exchange and transfer from inert atmosphere (under commissioning, usable upon request).

A single pulse timing diagnostics is typically used for time delay feedback and time delay measurement. The diagnostics works reliably at Si-111 monochromatic and pink FEL beam and typically provides pulse length limited time resolution (shown down to ~20 fs fwhm pulse lengths). 

Pilot joint call with Surface diffractometer at the Swiss Light Source 

With the ongoing restart of the SLS-2 Synchrotron facility at PSI, we are opening a new pilot option in this call for Bernina proposals, to express interest in an additional experiment at the Surface diffractometer of the ADvanced DiffrAction for Materials Science Beamline (ADDAMS). The instrument is comparable in X-ray diffraction geometry to the Bernina diffraction endstations and allows therefore to collect complementary static experimental data which should support the science case of the SwissFEL Bernina Proposal.  

Interest and justification for such an experiment should be expressed in the main proposal text. Additionally, a single-page proposal to ADDAMS needs to be added to the proposal.  Please follow this wordfile template and upload as pdf to the proposal (max. 3 MB filesize). 

The best Bernina proposals which benefit from a supporting ADDAMS experiment, will be considered for a short beamtime slot (~24h) during the pilot operation phase of Swiss Light Source (earliest 2nd half 2025).  

Bernina
Photon energy range2 keV – 13.0 keV, scannable up to 15% (e.g. 1 keV @ 7 keV) using undulator K (optionally with monochromator).  
Beam profileFocused down to 2x2 µm2 (fwhm, measured) to unfocused 1000x1000 µm2 (fwhm, photon energy dependent).  
BandwidthMonochromatic (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 lengthStandard SASE pulse length ~50 fs (fwhm), short pulse options at cost of pulse energy down to ~20 fs.  
EnvironmentHe 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 systemsSolids: 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 typeWavelength rangePulse energy / max. FieldPulse lengthComments 
Primary pump source   800 nm20 mJ35 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. 
OPA     
240 – 480 nm     10 – 100 uJ  ≤ 50 fs (fwhm)Pulse energy variation includes typical losses between source and sample.
 		 
480 – 780 nm150 – 1000 uJ≤ 50 fs (fwhm) 
780 – 1160 nm10 – 100 uJ≤ 50 fs (fwhm) 
1.16 – 1.58 µm≤ 50 fs  
1.58 – 2.4 um500 – 1000 uJ≤ 50 fs 
NOPA500 – 750 nm10 – 70uJ
 		≤ 25 fs  
OPA DFG4.4 – 20 um  (70 – 15 THz)1 – 20 µJ
 		≤ 300 fs  
CEP stabilized
10 – 18 um  (30 – 17 THz)		1 – 20 µJ≤ 250 fs  
Opt. rect.2 – 5 THz single cycle>500 kV/cm—Circularly polarized at specific frequencies 
LiNbO3 based0.5 – 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 Cristallina-MX experimental station is a fixed-target setup designed for high-throughput SFX and SFX pump-probe. 

We two styles of fixed-targets: the PSI MISP (MIcro-Structured Polymer) (Carrillo et al., 2023) and the MPI SOS (Sheet-On-Sheet) chip (Doak et al., 2024). An EKSPLA nanosecond OPO can be used for pump-probe measurements and has now been commissioned for both the MISP and SOS 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 280 nm - 700 nm (if required), Jungfrau 8M detector and either the MISP or SOS chips. For short (single-shift), non-pump-probe experiments please apply using the PCS proposal option described below.

SwissMX
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
  • Smallest measured beam size was 1.5x1.5 µm2 (FWHM) at 12 keV
  • Larger beam profiles are possible. Up to 20 µm have been attempted.
  
Bandwidth
  • Pink Beam with 0.25% of fundamental is standard; larger bandwidths of up to 2% are also possible (photon energy dependent)
  
Environment
  • SwissMX has only currently been commissioned for in air measurements
  
Fixed-targets

PSI MISP-chip

  • 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
  • Pump-probe experiments have been successfully demonstrated but please inquire if you would like to attempt this.
  
Detectors
  • 8 Mpixel JUNGFRAU (125 mm radius) on an 180 mm translation stage
  • Smallest sample detector distance = 111 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
  • EKSPLA NT230-100-SH/SF-ATTN/FC ns OPO
  • Pulse width = 3.2 ns at 450 nm
  • There are two coupling strategies:
    • on-axis to X-ray beam - only visible wavelengths
    • through-space coupling - principally for UV and IR
  • Pulse energies are limited in the fibre-coupling to 2 µJ
  • Commissioned wavelength from 350-700 nm
  • Please contact beamline scientist if you wish to move outside of the visible spectrum
  • Available time delays = 10 ns to 80 ms
  • Longer delays are currently being commissioned. Please ask the beamline scientist if you wish to use them.
  

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

The Cristallina-Q team has recently commissioned an experimental station named Ultralow-T Vectormagnet that enables resonant and non-resonant X-ray diffraction in high-magnetic fields and sub-Kelvin temperatures. It includes a dedicated cryostat with beryllium and mylar windows for the incident and the diffracted beams in the horizontal diffraction plane. The cryostat is installed on a heavy-load diffractometer to orient the sample with respect to the vertical axis (θ), as well as to position the detector at the Bragg angle (2θ) and at a suitable distance from the sample. The beam size on the sample can be varied by means of bendable KB focusing mirrors. The station can be placed at custom distances from the last KB mirror.

The ultralow-T sample environment requires mounting the sample and closing the cryostat at least 1 week before the beamtime start, to allow for cooling to the base temperature and offline tests. Depending on the requested measurement temperature and the sample properties, reduced repetition rates and/or high attenuation have to be used to ensure recovery of sub-Kelvin temperatures between subsequent X-ray pulses. Because of the latter, it is advantageous, although not mandatory, to operate the ARAMIS beamline in the ultrashort pulse mode such that that thermal and electronic modification of the sample can be outrun.

The capabilities of the Ultralow-T Vectormagnet are restricted in terms of the maximal θ range, due to mechanical limitations, and to higher photon energies to cope with in-air propagation and due to absorption of the X-ray windows.

Cristallina-Q Instruments
Photon energy range
  • ~5 keV – 13 keV
  
Repetition rate
  • 0.1 - 100 Hz;  the maximal rate is given by SwissFEL accelerator operation settings (normally 100 or 50 Hz), and can be reduced using the fast shutter.
  • Pulse on demand or custom pulse pattern possible via the fast shutter.
  
Beam profile on the sample
  • From focused down to < 2 x 2 µm2 (fwhm, measured) to unfocused 1 x 1 mm2 (fwhm, energy dependent).
  • Small beam size on the sample results in larger local sample heating.
  
Bandwidth
  • Pink beam (no monochromator) – 0.25% bandwidth.
  • Single-shot spectra are recorded with upstream transmissive spectrometer.
  
Pulse length & energy
  • Regular SASE mode: ~50 fs (fwhm), ~1 mJ/pulse.
  • Short pulse mode: ~10 fs (fwhm), ~200 µJ/pulse.
  • Ultra-short pulse mode: ~0.5 - 1 fs (fwhm), 5 - 10 µJ/pulse.
  
Temperature
  • 0.1 K - 2 K sample temperature (strongly linked to the beam intensity and the repetition rate, as well as sample properties).
  • Indicative sample temperatures at 1 Hz repetition rate: <100 mK at 0.1 uJ/pulse, <200 mK at 2 uJ/pulse, 500 mK at 150 uJ/pulse.
  
Magnetic field
  • 'Vertical mode': up to 5.2 T vertical field with up to 0.26 T horizontal field (2.5° tilt towards the horizontal plane in any direction).
  • 'Isotropic mode': up to 0.6 T field in any direction (full sphere).
  
Scattering geometry
  • Full access to horizontal scattering plane, as well as ±10° vertical scattering. 
  • In-situ sample rotation around the vertical axis (θ) restricted to Δθ = 20°.
  
Detectors
  • 1.5M Jungfrau detector.
  • Sample-detector distance: 250 - 700 mm with detector on the 2θ arm.
  

General information about the Cristallina-Q experimental station can be found at: Cristallina-Q.

Because of the novelty of this experimental station, the inherent challenges due to the ultralow-T environment, and operational limitations, proposers must contact the Cristallina-Q team well ahead of submission.

For these proposals, no optical pump laser will be offered and the beamlines will only operate with the following parameters: 

Parameter

Alvra

Cristallina

X-ray energy

12 keV*

12 keV*

X-ray focus

2 x 2 um*

2 x 2 um*

Maximum shift duration

Max 3 h**

Max 8 h**

Sample delivery method

High viscosity extruder

SOS chips

MISP chips

Sample environment

500-600 mbar helium*†

Air

Detector

4M Jungfrau

8M Jungfrau

Detector distance

95 mm (~1.4 Å resolution at edge)

112 mm* (~1.2 Å resolution at edge)

User participation

Users will be requested to send samples to PSI where the practical aspects of the experiments will be carried out by beamline staff in strong remote collaboration with the users.

Users may participate online and will have live access to data.

Maximum of 3 people onsite for the duration of the beamtime. Users will be expected to load their own samples after initial training. Viscous samples must use SOS chips.

Extra participants may follow online with live access to data.

 

Contact for further information

Dr. Emma Beale

Dr. John Beale

*Minor changes to these parameters may occur.

**Shift length is at the discretion of the beamline staff, but will not exceed this value.

Notes for proposal applications

  • Please apply using the standard application pipeline on DUO but with the protein crystal screening proposal word file template - please add ‘PROTEIN CRYSTAL SCREENING’ to the front of your proposal title.
  • Please include:
    • A representative image of protein crystals with a scale bar
    • Any available information about the unit cell dimensions, symmetry and diffraction quality of the crystals
  • In your proposal please indicate at least one of the following points that applies:
    • The project requires diffraction data from crystals that are too small and/or radiation sensitive to be measured at a synchrotron source.
    • The project aims to collect time-resolved diffraction data using fixed targets on the nanosecond to millisecond time-scale in future (Cristallina applications).
    • The project aims to collect time-resolved diffraction data using an HVE on the femtosecond to millisecond time-scale in future (Alvra applications).

Athos beam parameters

Standard SASE:

  • Photon energies and pulse energies for circular polarization (linear polarization  30-40% less) : 
    • 350 - 1000 eV with more than 2 mJ pulse energy
    • 1000 - 1300 eV with more than 1 mJ pulse energy
    • 1300 - 1600 eV with more than 250 μJ pulse energy
  • Typical bandwidth ≤ 1 %
  • Repetition rate 100 Hz
  • Standard X-ray pulse duration ≤ 100 fs FWHM
  • Polarization adjustable: Circular +/- (delivers highest pulse energy), linear horizontal, linear vertical
  • Energy scan: feasible over +/- 10 % of fundamental energy

The following advanced machine modes are available on a best effort basis with lower operational stability:

  • Two colour X-ray mode: Two X-ray pulses with independently tuneable photon energies up to 1000 eV, maximum delay between the pulses is 500 fs and minimum delay is -50 fs.
  • Short X-ray pulses with tuneable pulse duration down to factor of x10 relative to standard SASE mode. Pulse energy directly proportional to pulse duration
  • Ultrashort pulse mode with pulse length =< 1 fs fwhm, typical pulse energy 5 – 10 uJ

Please note, that advanced modes may result in overall reduced machine performance, including 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, please make sure to consult with the respective endstation contacts prior to proposal submission.

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. The following experimental capabilities are offered for this call as standard configurations. 

SetupConfiguration
Time-resolved XPS
  • Hemispherical electron analyzer: Specs Phoibos 150 EP
  • Gas needle or oven for sample delivery
  • Grating spectrometer after interaction point (Scienta XES350) for single shot spectral diagnostics in pink beam mode
  • Ion time-of-flight spectrometer upstream of interaction point used for Io for monochromatic X-rays
Time-resolved 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-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
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 in the UV and visible regime available

If your experiment requires significant modifications to these setups or if you plan on incorporating additional experimental capabilities, it is mandatory to discuss your plans and the feasibility with the instrument staff. 

The natural jitter between X-ray and optical pulses is ~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, a rotable Jungfrau 2D detector and a 6 meter long RIXS spectrometer. 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  in TR-XAS and TR-REXS (please contact instrument responsible for more info).

Furka
SetupConfiguration
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)
  • 40 mm × 80 mm  rotable Jungfrau 2D detector (280 mm distance to sample position)
  • Variable x ray polarization available (C+, C-, LV, LH)
Time resolved RIXS
  • sVLS Grating spectrometer
  • Energy resolution DE ≥ 150 meV for hv=500 eV and DE ≥ 200 meV for hv=1000 eV
  • Twin collecting mirrors to increase horizontal solid angle for TR-RIXS
  • Scattering angle 45-140 degrees. Angle variation under UHV conditions
  • CMOS detector 4MPixel (1 MPix @ 100 Hz acquisition), sensor size 1x1 inch2
Furka
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
Enviroment
  • 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 rangePulse energy / max. FieldPulse lengthComments
400 nm     200 uJ
(measured)  		~ 50 fs (fwhm)—
266 nm30 uJ
(measured)  		~ 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 µm200 – 500 µJ~ 100 fs (fwhm)
~1 THz single cycleUp to 300 kV/cm
(measured)		—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

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