X-ray Pump-Probe (WBS 1.2) David Fritz

1. X-ray Pump-Probe (WBS 1.2)David Fritz • System Specifications • System Description • Instrument Layout • X-ray Optics &Diagnostics • Sample Environments • Detectors • Laser System • Costs and Schedule • Summary

2. Science Team • Specifications and instrument concept developed with the science team. The XPP team leaders • Kelly Gaffney, Photon Science, SLAC (leader) • Jorgen Larsson, Lund Institute of Technology, Sweden • David Reis, University of Michigan • Thomas Tschentscher, DESY, Germany

3. 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) photo- excitation

4. Laser/FEL Timing Master Clock RF Distribution Network Accelerating Elements Experimental Pump Laser Electron Gun • Sources of Short Term Jitter • E-beam phase to RF phase jitter • Electron beam energy jitter + dispersive electron optics • End station laser phase to RF Phase • ~ 1 ps limit

5. Traditional Pump-probe Delay will be achieved by optical delay and/or RF phase shift Resolution limited by LCLS/laser jitter ~ 1 ps limit

6. Single Shot Pump-Probe diffracted intensity time (fs) Limited to X-ray diffraction Need ‘large’ effects Imaging resolution affects temporal resolution

7. Non-sequential Sampling Single shot, Lorentzian fit 100 consecutive shots Diagnostic required to measure LCLS/laser timing EOS demonstrated at SPPS

8. Non-sequential Sampling

9. XPP SCOPE - WBS 1.2

10. Photon Shutter FEE Monochromator Photon Shutter Diagnostics Attenuators Primary Slits Focusing Lenses Diagnostics NEH Hutch 3 Laser Port Diffractometer Diagnostics Diagnostics Photon Shutter System Specifications Secondary Slits Wide Angle Stage Small Angle Stage

11. XPP Endstation XPP Instrument Location CXI XCS AMO (LCLS)

12. Laser System (Fundamental) Small Angle Scattering X-ray Diffractometer Wavelength Conversion Offset Monochromator

13. XPP System Description • 1.2.1 Physics support and engineering integration • 1.2.2 X-ray optics • 1.2.3 Laser system • 1.2.4 Detector • 1.2.5 Sample environments • 1.2.6 Laboratory facilities • 1.2.7 Vacuum system • 1.2.8 Installation

14. 1.2.2 X-ray Optics • 1.2.2.1 Double crystal offset monochromator • Narrows x-ray spectrum for resonant scattering experiments • Multiplexes LCLS beam (mono. beam, diagnostic beam)

15. Lens Mono 190 m 4 m 1.2.2 X-ray Optics • 1.2.2.2 Beryllium lens focusing optic • Variable spot size from 2-10 µm and 40-60 µm @ 8.3 keV • Variable spot size from 2-10 µm @ 24.9 keV • > 40% throughput • Positioning resolution and repeatability to 1 µm

16. 1.2.2 X-ray Optics • 1.2.2.3 Slit systems • Variable horizontal and vertical gap from 5 μm – 5 mm • Can withstand full LCLS flux – unfocused • Minimize background scatter from blades B. Lengeler et al., J. Synchrotron Rad., 6, 1153-1167 (1999).

17. 1.2.2 X-ray Optics • 1.2.2.4 Attenuators • Variable, up to 10 6 reduction • High damage threshold (Be or B4C)

18. 1.2.2 Level 4 Direct Costs

19. 1.2.3 Laser System

20. 1.2.3 Laser System Ti:Sapphire Oscillator & Power Amplifiers Compressor, OPA, Harmonic Generation, Delay Stage

21. 1.2.3 Laser System • 1.2.3.1 Ti:Sapphire Oscillator • 119 MHz rep. rate, <30 fs ~ 2.5 nJ/pulse • Frequency stabilized to LCLS RF < 300 fs rms phase jitter • Demonstrated at SPPS Cavity Length Stabilization Mirror

22. 1.2.3 Laser System • 1.2.3.2 Power Amplifiers • Regenerative amplifier • ~ 2.5 mJ (< 1% rms stability), 120 Hz, < 50 fs • Multipass amplifier • ~ 20 mJ (< 1.5% rms stability), 120 Hz, < 50 fs • Second Compressor • External Pockels Cell • Arbitrary laser pulse train structure

23. 1.2.3 Laser System • 1.2.3.3 Temporal Pulse Shaper • Create complex excitation pulse envelopes • Multi-pulses • Compression optimization

24. 1.2.3 Laser System • 1.2.3.6 Laser Diagnostics • Temporal and spectral characterization • Grenouille – Real time pulse duration, spectrum • 3rd Order Correlator – Contrast ratio • Energy characterization • Per pulse Joule meter, 120 Hz, 1% accuracy • Spatial characterization • Profile monitor at a “virtual” sample, 5 μm resolution

25. 1.2.3 Level 4 Direct Costs

26. 1.2.4 Detectors • 1.2.4.1 2D detector (BNL) • 1024 x 1024 pixels • 90 micron pixel size • High Detector Quantum Efficiency (DQE) • 10 4 dynamic range at 8 keV • 120 Hz Readout Rate

27. 1.2.4 Detectors • 1.2.4.2 Dispersive X-ray Emission Spectrometer • 50-100 eV dynamic range • ~ 1 eV energy resolution • Single Shot Capability U. Bergmann and R. Frahm, TDR XFEL workshop series “Methods and Instrumentation for the XFEL”, 52, (2001).

28. 1.2.4 Level 4 Direct Costs

29. 1.2.5 Sample Environments • 1.2.5.1 X-ray Diffractometer • Operate in both direct and monochromatic beam • Sample orientation & translation • Accommodate various sample environments

30. 1.2.5 Sample Environments • 1.2.5.1 X-ray Diffractometer • Operate in both direct and monochromatic beam • Detector motion about a spherical surface centered at sample (variable radius from 0.1 m to 1.5 m)

31. 1.2.5 Sample Environments • 1.2.5.1 X-ray Diffractometer • SAXS - 10 µrad angular resolution with XAMPS detector • Detector translation • Operate in both direct and monochromatic beam

32. Det. Array Collinear Geometry Det. Array Non-collinear Geometry 1.2.5 Sample Environments • 1.2.5.2 Cold Finger Cryostat System • 10 – 350 K Temperature Range • 0.1 K Temperature Stability • >7 W cooling capacity at 20 K • Vacuum shroud • Optical and x-ray windows (collinear & non-collinear geometry) • Decoupled sample motion

33. 1.2.5 Sample Environments • 1.2.5.2 Cryostream System • 20-300 K Temperature Range • < 1 K Temperature Stability

34. 1.2.5 Level 4 Direct Costs

35. 1.2.6, 1.2.7 & 1.2.8 • 1.2.6 Laboratory facilities • 1.2.7 Vacuum system • Hardware-flanges, pumps, bellows,… • Vacuum supports • 1.2.8 Installation

36. X-ray Diagnostics • Transmissive Intensity Monitor • > 95 % Transmission • Relative accuracy < 0.1% • Flourescent Screeens • Diodes

37. Laser/FEL Timing • Electro-optic Sampling • Enhanced Temporal Resolution (~ 100 fs) • Limited by our ability to phase lock the lasers to the RF backbone • Limited by Intra-bunch SASE jitter Stabilized Fiber Optic RF Distribution (10 fs) LBNL Electro-optic Sampling Laser Pump-probe Laser Gun Laser Sector 20 LTU NEH

38. Diagnostic Beam 1.3% Mono. Beam 2.5% 8keV 600mm Transmitted Beam 85% Laser/FEL Timing • Diagnostic Beam for Direct Timing Measurement • Permits destructive x-ray timing measurement in hutch • Same exctitation laser can be used

39. Key Technological Choices • Diamond vs. Silicon Monochromator Crystal - Absorption, Damage vs. Quality • Flexure vs. Piezo Monochromator Rotation Stage - Stability vs. Range • Robot Arm vs. Rotary Stage Detector Mover - Reciprocal Space Access vs. Control, Safety • Hexapod vs. Stages Sample Manipulator - Range of Motion vs. Stability, Control • Ti:Sapphire Oscillator vs. Fiber Oscillator - Bandwidth vs. Synchronization

40. XPP Schedule in Primavera 3.1

41. XPP Milestones CD-1 Aug 01, 07 Conceptual Design Complete Sep 21, 07 CD-2a Dec 03, 07 CD-3a Jul 21, 08 Phase I Final Design Complete Oct 15, 08 Receive Diffractometer Feb 19, 09 Receive Focusing Lenses Feb 27, 09 Receive Laser Optics and Diagnostics Mar 18, 09 Phase I Installation Complete Oct 01, 09 Install BNL XPP Detector Nov 03, 09 CD-4a Feb 08, 10

42. XPP Cost Estimate

43. WBS 1.2 - XPP • Cost estimate at level 3 by fiscal year –

44. 1.2 Level 3 Costs (M$)

45. Summary • Instrument concept is advanced • 100% of Letters of Intent are represented in instrument concept • Standing monthly meeting with XPP team • Instrument concept is based on proven developments made at SPPS and SR sources • Initial specifications well developed • Ready to proceed with baseline cost and schedule development