1. LUSI Status and Early Science
J. Hastings

3. LUSI CD-4 Dates Ready for CD-4a July 2010 XPP
Diffractometer system, detector system, shared laser
Ready for CD-4b July 2011 CXI
1 micron focus, supported samples, detector system
Ready for CD-4c April 2012
XPP, CXI and XCS complete
Definition:
LUSI early science – XPP capabilities at CD-4a

4. XPP Instrument Location
Near Experimental Hall
X-ray Transport Tunnel
AMO
(LCLS)
XPP
Endstation
XCS
CXI
Far Experimental Hall

5. XPP X-ray Instrumentation Diagram

6. XPP Optics Table (Hutch 2)

7. XPP Diffractometer System
Detector Mover
Orient and Position Samples

8. XPP Detector System Dynamic range 10,000 1024 x 1024 90 micron pixels
Developed by BNL

9. NEH Hutch 3

10. XPP Hutch 3 Components

11. The Pump-probe Technique
The x-ray pump-probe instrument will take advantage of the ultrashort pulse duration of the LCLS to take snapshots of a photo-induced phenomena.
In general, the experiments performed as this endstation will use an ultrafast laser pulse to initiate a transient response in a system. The system will be probed using various x-ray scattering techniques. The time evolution of the response will be mapped by variably delaying the arrival time of the x-ray pulse with respect to the pump laser pulse.
The success of this end station will depend upon the ability to accommodate a wide variety of laser excitation techniques, samples, sample environments and x-ray scattering methods.
C. W. Siders

12. X-ray Pump-Probe Science
Phase Transitions
Order / Disorder
Metal/Insulator
Phonon Dynamics
Charge Transfer Reactions
Photosynthesis
Photovoltaics
Vision
Photoactive Proteins
photo-
excitation
Stampfli and Bennemann Phys. Rev. B 49, 7299 (1994)
The x-ray pump probe instrument will be used to study phenomena that occur on the atomic length and time scales. This includes solid state phenomena such as order/Disorder and metal/Insulator transitions, and the dynamics of phonons; charge transfer reactions that are at the heart of photosynthesis, photovoltaics and vision; and the and photoactve proteins.
photo-
excitation

13. Experimental Techniques
Time-Resolved X-ray Diffraction (TRXD)
Single crystals
Time-Resolve Diffuse Scattering (TRDS)
Single crystals, powders & liquids
Time-Resolved Protein Crystallography (TRPX)

14. Higher Q reflections exhibit faster dynamics (linear in Q)
Observations:
Higher Q reflections exhibit faster dynamics
(linear in Q)
Diffracted intensity decay is Gaussian-like.
Lindenberg et al. Science 308, 392 (2005)

15. The Inertial Transition State
Conclusion: At short times (t<500 fs) following excitation, the atoms move ballistically from their equilibrium positions at room temperature velocities. Overall long-range order is not lost!
2.3 Å /ps
Lindenberg et al. Science 308, 392 (2005)

16. Transition from inertial to diffusive dynamics
and the onset of liquid-like dynamics
inertial regime
D111 = 7 x 10-6 cm2/sec
D220 = 4 x 10-6 cm2/sec
diffusive regime
Extracted diffusion coefficients in good agreement with known values
Indicates influence of surrounding cage of atoms on dynamics
Evidence for anisotropy in the initially-formed non-equilibrium liquid
Gaffney et al., PRL,95, (2005)

17. Femtosecond measurements of the structure of a liquid
Lindenberg et al.,
Phys. Rev. Lett. 100, (2008)

18. Small Q Regime: Observation of divergence at low Q?
• divergence near q=0 implies
g(r) becomes long-ranged
• x-ray analogue of critical opalescence
Indication of critical dynamics, large amplitude fluctuations, clusters and voids developing on longer length-scales
0-30 ps
rarifaction
compression
It takes time for fluctuations on longer length-scales to form.
Lorazo et al. PRB (06)

19. Femtosecond x-ray measurements of coherent vibrations in Bi

20. Nature, 422,p. 287 (2003)
467 fs
Nature 422, 287 (2003)

21. x f n(t),x(t) Ultrafast measurement of atomic displacements N=12463 a
From the data, we can measure the details of the ionic displacements, including the frequency of the coherent A1g phonon, and the equilibrium position of the ions.
D. M. Fritz et al.,
Science 315, 633 (2007)

22. Schotte et al., Science 300, 1944 (03)

23. F. Schotte et.al. Science,300,1944 (2003)

24. LUSI baseline fits the funding profile and delivers XPP, CXI and XCS
Summary
LUSI baseline fits the funding profile and delivers XPP, CXI and XCS
XPP early science starts July 2010 capable of:
Time-Resolved X-ray Diffraction (TRXD)
Single crystals
Time-Resolve Diffuse Scattering (TRDS)
Single crystals, powders & liquids
Time-Resolved Protein Crystallography (TRPX)