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An Office of Science User Facility

Soft X-ray Materials Science (SXR)

This site is OBSOLETE as of 30 Oct. 2017
Please go to the new SXR site



Scientific Capabilities

Scientific Application Time-resolved spectroscopy and scattering with ultrafast and ultraintense soft X-rays at the LCLS
Techniques X-ray Emission Spectroscopy (XES)
X-ray Photoelectron Spectroscopy (XPS)
X-ray Absorption Spectroscopy (XAS)
Coherent Imaging and Fourier Transform Holography​
Reflectivity via Pump-Probe techniques
Resonant Inelastic X-ray Scattering (RIXS)
Sample Environment A wide range of experimental setups in UHV and HV conditions including liquid or highly ionized plasmas

Source Parameters

Repetition Rate 1 Hz, 10 Hz, 30 Hz, 60 Hz and 120 Hz, Burst Mode or Single Shot
Pulse Duration 60-200 fs for normal operation and ~10 fs for special low charge mode
Photons per Pulse 1 x 1013
​Polarization ​Linear in normal operation. Circular polarization with DELTA undulator possible with >1011 photons/pulse. Please contact the beamline scientist for details.
​Self-Seeding ​Available between 500-1000 eV, with λ/Δλ > 5000 and pulse energy up to 100 μJ. Please contact the beamline scientist for details.
​Two-Pulse Modes
​Possible two-pulse modes are described here. Please contact the beamline scientist for details.

Photon Beam Properties

Sample Configurations Pre-Mono Transmission Sample Chamber, white beam Endstation, white beam Endstation, mono
Focusing Capability (Kirkpatrick-Baez) 1x1 mm (unfocused at sample) = 2x2 um = 2x2 um
Energy Range 280-2000 eV grating 1
(100 lines/mm):
500-1500 eV
grating 2
(200 lines/mm):
800-2000 eV
Energy Resolution ~0.1 eV (500 eV) ~0.5 eV (500 eV) ~0.1 eV (500 eV)
~0.2 eV (1000 eV) ~1.0 eV (1000 eV) ~0.5 eV (1000 eV)
~0.6 eV (2000 eV) ~2.0 eV (2000 eV) ~0.6 eV (2000 eV)
Flux (ph/pulse) @ resolution limit 1 x 1012 (500 eV) 1 x 1011 (500 eV) 1 x 1010 (500 eV)
1 x 1013 (1000 eV) 1 x 1012 (1000 eV) 3 x 1012 (1000 eV)
1 x 1013 (2000 eV) 1 x 1012 (2000 eV) 2 x 1012 (2000 eV)

Optical Laser Properties

Sample Configurations Pre-Mono Transmission Sample Chamber Endstation
Laser Power 20 mJ at 800 nm 20 mJ at 800 nm
25 mJ at 800 nm

25 mJ at 800 nm (uncompressed)

4-5 mJ at 400 nm

4-5 mJ at 400 nm

1 mJ at 266 nm 1 mJ at 266 nm

~100 uJ at 4-10 microns

(~70 uJ for longer wavelengths and ~120 uJ for shorter)


~ 50 uJ at 10-17 microns 

(~ 40 uJ for longer wavelengths and ~ 70 uJ for shorter)


~ 15 uJ at 75-1500 microns (4 to 0.2 THz)

Using LiNbO3 and DAST we have measured energies up to 30 uJ for 0.6 THz peak field and 5 uJ for 2 THz peak fields, but note these are still being developed.

Laser Pulse Width 35-150 fs at 800 nm 35-150 fs at 800 nm
150 ps at 800 nm

150 ps at 800 nm (uncompressed)

50-100 fs at 400 nm 50-100 fs at 400 nm

50-100 fs at 266 nm

50-100 fs at 266 nm

100-200 fs at 4-10 microns


100-200 fs at 10-17 microns 



 ~ 1ps at 75-1500 microns (4 to 0.2 THz)

Focusing Capability 1mm (1/e2) 50µm (1/e2)


Approximate laser system pulse energies with wavelenth

laser numbers.png




Fast Shutter A fast shutter to quickly turn on or off the beam or to select individual LCLS x-ray pulses. Closes or opens in <8 ms. The fast shutter is up stream of the first experimental position.
Alignment Laser A class II alignment laser beam coaxial with the FEL beam at the Endstation Position, to facilitate the positioning of samples in the FEL beam.
Pop-In YAG Screens Along the instrument exist various pop-in YAG screens to observe the X-ray beam distribution with live video cameras.
Spectrometer Using the transmission sample system with thin samples, the spectrum can be viewed through a sample in transmission on a shot-by-shot basis.
Flux Monitor A thin transmissive film can be inserted before the KB system in situ for relative intensity monitoring.
Timing System The timetool measures the relative arrival times between the X-ray and optical pulses on a shot-to-shot basis and provides <100 fs timing resolution. Available when using the un-attenuated X-ray beam.
Gas Detector The gas detector provides shot to shot measurements of the number of photons in each pulse from 5 μJ to 5 mJ with 4-6% absolute uncertainty.


SLAC SLAC National Accelerator Laboratory, Menlo Park, CA
Operated by Stanford University for the U.S. Dept. of Energy