X-ray Pump-Probe Instrument David Fritz XPP Instrument Scientist April 21, 2009

Time Resolved Scattering 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. Siders

X-ray Pump-Probe Science Phase Transitions - Order / Disorder - Metal/Insulator Charge Transfer Reactions - Photosynthesis - Photovoltaics - Vision Vibrational Dynamics Energy Dissipation and Flow photo- excitation Stampfli and Bennemann Phys. Rev. B 49, 7299 (1994) photo- excitation Page 3

XPP Instrument Goals\Requirements Facilitate time-resolved X-ray scattering/spectroscopy using LCLS coherent hard x-rays (4-25 keV) 80 fs rms temporal resolution Global Requirements (SP-391-000-33) Capable of running in a shared beam mode using a future beam splitting monochromator Instrument must be accessible while beam is delivered to FEH Tailor and characterize X-ray and optical beam parameters Spatial profile Intensity Repetition rate Spectral bandwidth Wavelength (optical laser) Temporal profile (optical laser) <1x10-7 Torr beamline vacuum

XPP Instrument Overview Control Room XPP Endstation

XPP Instrument Overview Photon Shutter Requirement Device Tailor X-ray spatial profile ( > 50 microns) X-ray Slits Tailor X-ray spatial profile ( < 50 microns ) X-ray Focusing Lenses Tailor X-ray intensity and spectrum Attenuators Tailor X-ray repetition rate Pulse Picker Tailor X-ray spectrum Harmonic Rejection Mirrors Characterize X-ray pulse intensity Intensity Monitor Characterize X-ray spatial profile Profile Monitor Sample orientation Sample goniometer Position X-ray area detector Detector Mover Measure X-ray scattering pattern Detector Photoexcitation of samples Laser System Characterize spatial profile, temporal profile, spectrum, intensity at a virtual sample Laser Diagnostics Intensity Monitor Slits Profile Monitor Intensity Monitor Slits Focusing Lenses Attenuators Pulse Picker Mirrors Slits Intensity Monitor Profile Monitor Sample Goniometer Detector Mover Profile Monitor Intensity Monitor Photon Shutter

XPP Instrument Overview Detector Mover Ultrafast Laser Detector Diagnostics Sample Goniometer X-ray Optics & Diagnostics Page 7

Laser System XPP Laser System Will utilize and expand upon AMO laser system AMO Laser Requirements > 3 mJ per pulse energy at sample (800 nm) < 50 fs pulse duration 120 Hz < 100 fs phase jitter to LCLS RF Multipass amplifier >20 mJ per pulse energy (800 nm) Frequency conversion capability OPA Harmonic generation Temporal pulse shaping capability Diagnostics suite System designed such that a non-laser trained user can perform an XPP experiment Sufficient automation to control laser parameters Sufficient engineering controls to provide safe working environment

(available in 2012 or before) Scope Early Science Scope (available Mid-2010) CD 4 (available in 2012 or before) Sample Goniometer (Kappa & Tilt Platform) X-ray Focusing Lenses Detector Mover Harmonic Rejection Mirrors X-ray Detector System Laser Power Amplifier Laser System Optics and Diagnostics Optical Parametric Amplifier X-ray Slits X-ray Attenuator/Pulse Picker X-ray Diagnostics X-ray Optics and Diagnostics Supports Vacuum System Controls & Data Systems Hutch Facilities