High-power nanosecond laser (Ultra High-Pressure Science)
By combining XFEL with a 100J-class high-power nanosecond laser, ultra-fast diagnostics of ultra-high-pressure materials created by high-power lasers is possible. This page introduces high-power nanosecond laser experiments at BL3 EH5.
※The high-power nanosecond laser equipment was mainly developed by Osaka University.
※ This experimental system was developed in collaboration with a user group for high-power nanosecond lasers. The sophistication of some systems is being upgraded by the SACLA Basic Development Program (representative: associate professor Norimasa Ozaki, Osaka University).
References:
Y. Inubushi et. al., Appl. Sci. 10, 2224 (2020).
Basic Performance and Results
Shock-compressed corundum X-ray diffraction measurements
X-ray diffraction data of polycrystalline corundum is shown as an example for the measurements. It is used to observe the compressed state of the high-power nanosecond laser irradiation.
By using a flat panel detector that can be installed in the sample chamber, the measurements are possible over a wide angle range (Diffraction angle: 18–78°, azimuthal angle: +/-60°).

X-ray diffraction from polycrystalline corundum
Laser focusing and pressure generation conditions
A typical laser focused spot size is approximately 200-300 µm, with an irradiation intensity of ~1 × 1013 W/cm2, and a solid sample can generate a pressure of several hundred GPa.
Experimental Equipment
Sample chamber
For high-power nanosecond laser experiments, the vacuum sample chamber permanently installed in the experimental hutch EH5, which is downstream of SACLA BL3, can be used. Experiments are conducted by irradiating the sample placed in the sample chamber with XFEL and high-power nanosecond lasers.

Sample chamber

Inside the sample chamber
The driving mechanisms for the sample and the sample holder
A multi-axis stage for aligning the sample is permanently installed in the sample chamber.
The standard sample holder system consists of a strip-shaped sample plate (100 mm × 10 mm) that secures the sample and a frame that holds the sample plate. The frame is connected to the drive mechanisms by a magnetic kinematic base. The sample holder system can be modified to suit the experiment.
Driving mechanisms inside of the sample chamber
Details of the driving mechanism A inside of the sample chamber
Operating Parameters (EH5@BL3)
XFEL parameters
Photon energy (fundamental wave) |
4-20 keV |
Pulse energy |
To photon energy (see figure below) |
Energy width(ΔE/E) |
~0.5%(without a two crystal spectrometer) |
Repetition rate |
30 Hz(BL2&3 simultaneous operation) |
References:
M. Yabashi et al., J. Synchrotron Rad. 22, 477 (2015).
K. Tono et al., J. Synchrotron Rad. 26, 595 (2019).
(Reference) The relationship between photon energy and pulse energy / number of photons (for BL3)

X-ray focusing characteristics
To ensure the resolution of X-ray diffraction, adjust the focusing size of the XFEL according to the experiment by using the following KB mirror optical system designed to have a vertical divergence angle of 1 mrad or less. In addition, X-ray can be focused in one direction by using only one side of the mirror.
The typical non-focused XFEL beam diameter is 600 µm (full width at half maximum), and can be adjusted to any size with the four-quadrant slit.
Optical parameters (KB mirrors) |
Vertical |
Horizontal |
Surface coating |
Rhodium |
Rhodium |
Substrate size |
300 × 50 × 50 mm |
400 × 50 × 50 mm |
Glancing angle |
4.0 mrad |
3.7 mrad |
Focal length |
1200 mm |
800 mm |
Distance from source |
~260 m |
~260 m |
Spatial acceptance |
> 1.2 mm |
> 1.4 mm |
Divergent angle |
~1 mrad |
~2 mrad |
Typical focal size @10keV |
~430 nm FWHM |
~480 nm FWHM |
References:
Y. Inubushi et. al., Appl. Sci. 10, 2224 (2020).
Optical laser characteristics
|
High-Power Nanosecond Laser |
Wavelength |
532 nm |
Pulse Energy (Max.) |
~60 J(10 ns rectangular wave)* |
Pulse Duration |
3-10 ns |
Rep. Rate |
0.1 Hz |
* The maximum energy depends on the pulse waveform
Standard Experimental Arrangement
Examples of X-ray measurement methods and experimental arrangements
X-ray diffraction
・Wide-angle X-ray diffraction measurements for a sample irradiated with a high-power nanosecond laser using XFEL as a probe
・A flat panel detector (scintillation CMOS camera) can be installed inside the sample chamber, or a Dual-MPCCD can be installed outside of the chamber to be used as the detector
・When using a flat panel detector, it is possible to measure in both reflection and transmission arrangements

X-ray diffraction reflection arrangement

X-ray diffraction transmission arrangement

X-ray diffraction detector
Small-angle X-ray scattering
- Small-angle X-ray scattering measurements from samples irradiated with a high-power nanosecond laser using XFEL as the probe
- ・A detector is installed downstream of the sample chamber
X-ray imaging
- ・Imagine measurements of a sample irradiated with a high-power nanosecond laser using XFEL as a probe
- ・A detector is installed downstream of the sample
Examples of optical measurement methods and experimental arrangements
Velocity interferometer measurements (VISAR)
- ・Velocity measurements for a sample irradiated with a high-power nanosecond laser using an optical laser as a probe
- ・The optical systems installed on the rotation stage(Circle stage, θx)of the diffractometer can be used
Radiance thermometer (SOP)
- ・Self-luminous thermometer measurements from a sample irradiated with a high-power nanosecond laser
- ・The optical system installed on the rotation stage(Circle stage, θx)of the diffractometer can be used
Adjustments before the Measurement
What the SACLA staff do before the beam time:
- ・Introduce the high-power nanosecond laser into the sample chamber
- ・Set up the facility equipment and perform the initial alignments
- ・Adjust and focus the XFEL spectrum and the optical axis
- ・Rough space matching between the XFEL and the high-power nanosecond laser
- ・Time matching of the XFEL and the high-power nanosecond laser using high-speed PD
What the user does after the start of the beam time:
- ・Precise space matching between the XFEL and the high-power nanosecond laser
- ・Precise alignment of the permanent equipment
- ・Precise alignment of user provided equipment
- ・Precise time matching between the XFEL and high-power nanosecond laser instruments
- ・Sample alignment
- ・XFEL and high-power nanosecond laser irradiation
- ・Operate the measurement equipment
Measurement Procedure
After the initial beam time adjustments are complete, the experiment is typically performed with the following procedure.
- 1. Install the sample in the sample chamber
- 2. Vacuum the sample chamber
- 3. Determine the interaction point between the high-power nanosecond laser and the sample
- 4. Pointing adjustments of the high-power nanosecond laser
- 5. Adjust the measurement equipment
- 6. Align the sample
- 7. Perform the data acquisition shot
- 8. Open the sample chamber to the atmosphere
Data from the SACLA standard detectors can be accessed using the SALCA HPC.
HPC user guide
Related Results
Press release
Papers published
・M. O. Schoelmerichet al., “Evidence of shock-compressed stishovite above 300 GPa”, Scientific Reports 10, 10197 (2020).
・Y. Inubushiet al., “Development of an Experimental Platform for Combinative Use of an XFEL and a High-Power Nanosecond Laser”, Applied Sciences 10, 2224 (2020).
What to check before applying for an assignment
If you are planning an experiment using the high-power nanosecond laser introduced on this page, and the available laser conditions apply, please contact the XFEL Utilization Division before applying for an assignment.