1. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument X-ray Pump-Probe Instrument D. M. Fritz Pump-probe Experiments System Description X-ray optics Laser System Detector Sample environments Laser/X-ray Timing Technical Choice Pump-probe Experiments System Description X-ray optics Laser System Detector Sample environments Laser/X-ray Timing Technical Choice

2. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Science Team Specifications and instrument concept developed with the science team. The XRPP team Kelly Gaffney (leader), SSRL/SLAC Jorgen Larsson, Lund Institute of Technology, Sweden David Reis, University of Michigan Thomas Tschentscher, DESY, Germany Specifications and instrument concept developed with the science team. The XRPP team Kelly Gaffney (leader), SSRL/SLAC Jorgen Larsson, Lund Institute of Technology, Sweden David Reis, University of Michigan Thomas Tschentscher, DESY, Germany

3. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument X-ray Pump-Probe Science Phase Transitions Order / Disorder Metal/Insulator Phonon Dynamics Charge Transfer Reactions Photosynthesis Photovoltaics Vision Photoactive Proteins 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. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Time Resolved Scattering

5. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument X-ray Pump-Probe Instrument Offset Monochromator Laser System (Fundamental) X-ray Diffractometer Wavelength Conversion Small Angle Scattering

6. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument X-ray Optics Double Crystal Offset Monochromator Narrows x-ray spectrum for resonant scattering experiments Multiplexes LCLS beam (mono. beam, diagnostic beam) Double Crystal Offset Monochromator Narrows x-ray spectrum for resonant scattering experiments Multiplexes LCLS beam (mono. beam, diagnostic beam) 6 – 24 keVEnergy Range 4 arcsecχ Accuracy 0.02 arcsec  Accuracy 9 0 - 50 0 Scattering Angle 600 mmHorizontal Offset ValueParameter Scattering Angles (2 theta) 1.5 Å0.5 Å Silicon 111 27.6°9.1° Silicon 220 45.8°14.9° Diamond 111 42.5°13.9° Diamond 220 -22.8°

7. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument X-ray Optics Double Crystal Offset Monochromator for 2 µm Si (111) @ 1.5 Å 85% transmission,2.5% - Mono beam, 1.3% - Diagnostics beam Double Crystal Offset Monochromator for 2 µm Si (111) @ 1.5 Å 85% transmission,2.5% - Mono beam, 1.3% - Diagnostics beam

8. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument X-ray Optics Double Crystal Offset Monochromator (cont.) motion 0.02 arcsecond resolution and repeatability (100 nrad) Double Crystal Offset Monochromator (cont.) motion 0.02 arcsecond resolution and repeatability (100 nrad) Flexure Stages Piezoelectric Stages

9. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument X-ray Optics 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 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 Lens Mono 190 m 4 m

10. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Laser System Overview

11. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Ultrafast Laser System Ti:Sapphire Oscillator & Power Amplifiers Compressor, OPA, Harmonic Generation, Delay Stage

12. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Ultrafast Laser System 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 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

13. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Ultrafast Laser System Power Amplifiers Regenerative amplifier ~ 2.5 mJ (< 1% rms stability), 120 Hz, <35 fs Multipass amplifier ~ 20 mJ (<1.5% rms stability), 120 Hz, <35 fs Second Compressor External Pockels Cell Arbitrary laser pulse train structure Power Amplifiers Regenerative amplifier ~ 2.5 mJ (< 1% rms stability), 120 Hz, <35 fs Multipass amplifier ~ 20 mJ (<1.5% rms stability), 120 Hz, <35 fs Second Compressor External Pockels Cell Arbitrary laser pulse train structure

14. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Ultrafast Laser System Temporal Pulse Shaper Create complex excitation pulse envelopes Multi-pulses Compression optimization Temporal Pulse Shaper Create complex excitation pulse envelopes Multi-pulses Compression optimization

15. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument XPP Detector - BNL Pixel array detector 1000 x 1000 pixels 80 micron pixel size High Detector Quantum Efficiency (DQE) 10 4 dynamic range at 8 keV 120 Hz Readout Rate Pixel array detector 1000 x 1000 pixels 80 micron pixel size High Detector Quantum Efficiency (DQE) 10 4 dynamic range at 8 keV 120 Hz Readout Rate

16. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument XPP Diffractometer System Rotary Stages vs. Robot Arm

17. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument XPP Diffractometer System X-ray Diffractometer Operate in both direct and monochromatic beam Sample orientation & translation Detector motion about a spherical surface centered at sample (variable radius from 0.1 m to 1.5 m) Accommodate various sample environments X-ray Diffractometer Operate in both direct and monochromatic beam Sample orientation & translation Detector motion about a spherical surface centered at sample (variable radius from 0.1 m to 1.5 m) Accommodate various sample environments

18. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument 10 µrad angular resolution with XAMPS detector Detector translation Operate in both direct and monochromatic beam 10 µrad angular resolution with XAMPS detector Detector translation Operate in both direct and monochromatic beam Small Angle Scattering Capability

19. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Sample Environments Cryostat System Vacuum shroud Optical and x-ray windows (collinear & non-collinear geometry) Decoupled sample motion Cryostat System Vacuum shroud Optical and x-ray windows (collinear & non-collinear geometry) Decoupled sample motion Det. Array Collinear Geometry Det. Array Non-collinear Geometry

20. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Expected Fluctuations of the LCLS Intensity fluctuations exceeding 30% Expected spatial jitter ~25% of beam diameter Wavelength fluctuations expected to be ~ 0.2% of center wavelength (≈ LCLS intrinsic bandwidth) Pulse duration expected to vary ~15% X-ray Pulse/LCLS RF timing will fluctuate by ~ 1 ps - Diagnostics are required to measure these parameters since they cannot be controlled - This information must be available to accelerator operations and experiments Intensity fluctuations exceeding 30% Expected spatial jitter ~25% of beam diameter Wavelength fluctuations expected to be ~ 0.2% of center wavelength (≈ LCLS intrinsic bandwidth) Pulse duration expected to vary ~15% X-ray Pulse/LCLS RF timing will fluctuate by ~ 1 ps - Diagnostics are required to measure these parameters since they cannot be controlled - This information must be available to accelerator operations and experiments

21. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Coax RF distribution Network e-beam phase to RF phase End Station Laser phase to RF phase Limited to ~ 1 ps ! Sources of Short Term Jitter Accelerating Elements Experimental Pump Laser Electron Gun Master Clock Coax RF Distribution Network Temporal Jitter

22. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Electro-optic Sampling Electro-optic Sampling Laser Pump-probe Laser LTUNEH Temporal resolution is now limited by: 1)Our ability to phase lock the lasers to the RF 2)Intra-bunch SASE jitter Gun Laser Sector 20 Stabilized Fiber Optic RF Distribution (10 fs) LBNL

23. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument SPPS Laser/X-ray Timing 100 consecutive shots Single shot, Lorentzian fit

24. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Data Sorting at SPPS 10 Hz Point Detector

25. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument XPP Data Sorting at LCLS 120 Hz 1 Megapixel Area Detector 2-dimensional binning or data filtering? Real Time Processing Unit Intensity Time of Arrival Wavelength LCLS Beam Parameters X-ray Detector 180 MB/s ~ 1 MB/s t 1 t 2 t 3 t 4 …………………………………………………….………………t N

26. D. M. Fritz dmfritz@slac.stanford.edu LCLS FAC Meeting April 16, 2007 XPP Instrument Key Technological Choices 1.Diamond vs. Silicon Monochromator Crystal - Absorption, Damage vs. Quality 2.Flexure vs. Piezo Monochromator Rotation Stage - Stability vs. Range 3.Robot Arm vs. Rotary Stage Detector Mover - Reciprocal Space Access vs. Control, Safety 4.Hexapod vs. Stages Sample Manipulator - Range of Motion vs. Stability, Control 5.Ti:Sapphire Oscillator vs. Fiber Oscillator - Bandwidth vs. Synchronization 1.Diamond vs. Silicon Monochromator Crystal - Absorption, Damage vs. Quality 2.Flexure vs. Piezo Monochromator Rotation Stage - Stability vs. Range 3.Robot Arm vs. Rotary Stage Detector Mover - Reciprocal Space Access vs. Control, Safety 4.Hexapod vs. Stages Sample Manipulator - Range of Motion vs. Stability, Control 5.Ti:Sapphire Oscillator vs. Fiber Oscillator - Bandwidth vs. Synchronization