Table of Content
Calls for Proposals
- The PSI User Office invites user proposals for the first user run at SwissFEL.
- 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.
Schedule for Calls
We will open a call for proposals for SwissFEL on February 8, 2021.
| SwissFEL Call schedule | |||
|---|---|---|---|
| Experimental Period | 2021-II | ||
| Call | 08 February | ||
| Submission deadline | 15 March | ||
| Start period | 1 July | ||
| End period | 31 December | ||
| EVALUATION |
15 March - 30 April | ||
Status of SwissFEL ARAMIS
Machine parameters
- photon energy: 1.8-12.7 keV
- typical bandwidth: 0.25% dE/E
- typical pulse energies: 200-600 µJ
- repetition rate: single shot - 100Hz
- X-ray pulse duration: 50 - 100 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 (20-50 fs fwhm)
Please contact the instrument teams for specific details that may help to enhance the technical feasibility of the proposed experiment. Note that the facility resource requirements may be important criteria in this call due to the concurrent buildup of the ATHOS soft X-ray branch.
Experimental Endstations
For the new run the Alvra and Bernina endstations are available with the following parameters:
Alvra Instrument
The Alvra end station of SwissFEL specializes in measuring the ultrafast dynamics of photochemical and photobiological systems using a variety of X-ray scattering and spectroscopic techniques. For the Alvra branch, the Alvra Prime chamber and Alvra Flex in-air instruments will be available with the following parameters.
For high time resolution experiments, a single pulse timing diagnostics can be used at pink FEL beam, at Si-111 monochromatic on best effort basis (please contact instrument responsible).
| Alvra Prime | |||
|---|---|---|---|
| Photon energy range | 2 keV – 12.4 keV, instrument fully commissioned over the full energy range | ||
| Beam profile |
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| 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:
LCP injector (50-100 µm) GDVN operation possible for user-supplied and operated injector |
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| Detectors and Spectrometers |
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| 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 |
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| Bandwidth | Monochromatic (Si(111), InSb(111), Si(311; commissioning 2019) and pink beam (0.25% of fundamental) | ||
| Environment | Normal atmosphere | ||
| Sample delivery | Liquid jet:
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| Detectors and Spectrometers |
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| Alvra experimental laser | |||
|---|---|---|---|
| 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. |
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| 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. Christoph Bostedt
Bernina Instrument
The Bernina Instrument is specialized on studying condensed matter systems by selective light excitation and selective resonant 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 large endstations on rails transverse to beam direction. Two endstation platforms are permanently installed, which can be configured for different sample and detector degrees of freedom for varying loads of sample environment or detection schemes:
- X-ray Diffractometer (XRD), equipped with a two circle detector arm,
- General Purpose Station (GPS), with a multi-purpose horizontal 2-theta arm.
Both endstations can be completed with different sample platforms that allow a large range of of specialized sample environment being precisely positioned:
- Six degree of freedom (DOF) heavy load goniometer,
- Two-circle surface diffractometer combination plus six DOF hexapod,
- Kappa arm (6 DOF).
An additional 6 DOF robot arm can be used for flexible detector positioning.
For high time resolution experiments, a single pulse timing diagnostics can be used at Si-111 monochromatic and the pink FEL beam.
A newly commissioned Vacuum chamber sample environment is available for low sample temperature (down to 5K), high excitation THz field, and tender X-ray range experiments. It is advised to explore the compatibility of proposed experiments with the chamber geometry before proposal submission.
| Bernina | |||
|---|---|---|---|
| Photon energy range | 4 keV – 12.7 keV, 2 – 4 keV available at higher effort | ||
| 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). | ||
| 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. |
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| Detectors and Spectrometer |
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| Bernina optical pump laser | ||||
|---|---|---|---|---|
| Primary pump source | 800 nm, 35 fs FWHM, 20 mJ (Ti:Sapphire) | |||
| Secondary pump sources | Wavelength range | Pulse energy / max. Field | Pulse length | Comments |
| 240 – 400 nm | 10 – 30 uJ (measured) | 50 fs (fwhm) | ||
| 400 – 780 nm | 150 – 500 uJ | 50 fs (fwhm) | ||
| 1 – 2.5 µm | 150 – 500 uJ | 50 fs (fwhm) | ||
| 2.5 – 15 µm | 5 – 30 µJ | 250 fs (fwhm) | Pulse length and energy depend highly on wavelength | |
| ~1 THz single cycle | >300 kV/cm (measured) | — | ||
| 0.5 – 2.5 THz | >500 kV/cm (measured) | — | ||
General information can be found at: Aramis Bernina Experimental Endstations
For questions and further information about Bernina, please contact: Dr. Henrik Lemke