Specifications
CXI Scientific Capabilities
| Scientific Applications |
|
|---|---|
| Techniques and Scattering Geometry |
|
Source Parameters
| Photon Energy | 5-10 keV for the 1st harmonic* |
|---|---|
| Up to 25 keV for 2nd and 3rd harmonic | |
| Source Size | 60 x 60 µm2 (H x V) FWHM @ 8.3 keV |
| 78 x 78 µm2 (H x V) FWHM @ 2 keV | |
| Source Divergence | 2 x 2 µrad2 (H x V) FWHM @ 8.3 keV |
| ~7 x 7 µrad2 (H x V) FWHM @ 2 keV | |
| Repetition Rate | 120 , 60, 30, 10 Hz, Single shot mode |
| Pulse Duration | 40-300 fs (high charge mode) |
| <10 fs (low charge mode) | |
| Pulse Energy | 1-3 mJ (high charge mode) |
| ~ 0.2 mJ (low charge mode) | |
| Photons per Pulse | ~1 x 1012 (high charge mode @ 8.3 keV) |
| ~1 x 1011 (low charge mode @ 8.3 keV) |
* Energies below 5 keV are in principle usable but the beam size at the end station is large leading to poor focusing performance and reduced flux. Also, the detector efficiency drops rapidly below 5 keV.
Photon Beam Properties
| Focusing Capability | KB1 mirrors (1.3 µm focus) |
|---|---|
| KB01 mirrors (~100 nm focus) | |
| Beryllium Lenses in XRT (10 µm focus) | |
| Beryllium Lenses in Hutch 5 (~1 µm focus) | |
| Beam Size at Sample (8 keV)
(Calculated for perfect optics) |
1.3 x 1.3 µm2 FWHM with 1 micron KB pair (KB1) |
| 90 x 150 nm2 FWHM (V x H) with 100 nm KB pair (KB01) | |
| 10 x 10 µm2 FWHM with XRT Be Lenses | |
| ~1 x 1 µm2 FWHM with Hutch 5 Be Lenses | |
| 750 x 750 µm2 FWHM unfocused beam | |
| Beam Divergence
(Calculated for perfect optics) |
0.12 x 0.12 mrad2 FWHM with 1 micron KB pair (KB1) |
| 2 x 1 mrad2 FWHM (V x H) with 100 nm KB pair (KB01) | |
| 170x 170 µrad2 FWHM with XRT Be Lenses | |
| ~0.3 x 0.3 mrad2 FWHM with Hutch 5 Be Lenses | |
| 2 x 2 µrad2 FWHM unfocused beam | |
| Beam Size at Sample (4 keV) | 4 x 4 µm2 FWHM with 1st KB pair (KB1) |
| 300 x 450 nm2 FWHM (V x H) with 2nd KB pair (KB01) | |
| Unusable with XRT Be Lenses | |
| Unusable with Hutch 5 Be Lenses | |
| 3000 x 3000 µm2 FWHM unfocused beam | |
| Energy Range | 2-10 keV (1st harmonic) |
| 10-25 keV (2nd and 3rd harmonic) | |
| Energy Resolution ΔE/E | ~0.2% (bandwidth of the LCLS beam) No monochromator currently |
Sample Environment and Detector
| Sample Environment |
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|---|---|
| Particle Injector |
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| Detectors |
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Short Pulse UV Laser
In order to improve the overall time resolution of ultrafast X-ray scattering measurements performed at the CXI instrument, the UV capabilities of the CXI laser are being upgraded to produce shorter pulses. This is being done in 2 stages: first the 3rd and 4th harmonics (267 nm and 200 nm, respectively) of the Ti:sapphire laser are being improved by increasing the spectral bandwidth and minimizing the dispersion of the travelling pulses. In a second phase of upgrade, an OPA and a variety of sum frequency generation schemes will be used to generate tunable pulses in the 185-265 nm range.
Phase 1: Improving the time resolution of the 3rd and 4th harmonics
| Current Pulse Width (FWHM) |
Expected Performance (FWHM) |
|
| 267 nm (3ω) | ~80 fs | ~30 fs |
| 200 nm (4ω) | ~120 fs | ~35 fs |
Phase 2: Generating tunable deep UV pulses
| Current Capability | Target Capability | |
| 185-265 nm | - | 30-40 fs |
Completion of phase 1 is expected by the start of user operations in run 18 (March 2020), and completion of phase 2 is expected during the summer/fall of 2020. All expected performance values are based off a best effort basis.
CXI Links
CXI Technical Specifications
CXI Contact Info
Meng Liang
Scientist
(650) 926-2827
mliang@slac.stanford.edu
Andy Aquila
Scientist
(650) 926-2682
aquila@slac.stanford.edu
Alex Batyuk
Scientist
(650) 926-4957
batyuk@slac.stanford.edu
Matt Hayes
CXI/MFX Area Manager
(650) 926-3060
hayes@slac.stanford.edu
Mark Hunter
Scientist
(650) 926-6294
mhunter2@slac.stanford.edu
Ray Sierra
Scientist
(650) 926-3148
rsierra@slac.stanford.edu
Sebastien Boutet
Department Head
(650) 926-8676
sboutet@slac.stanford.edu
CXI Control Room
CXI Hutch
(650) 926-6291
CXI Location
Far Experimental Hall (FEH), Hutch 5
Complete Instrument Map
