1. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 1 The X-ray Pump-Probe Instrument Instrument Scientist: David Fritz Second Scientist: Marc Messerschmidt Lead Engineer: J. Brian Langton Designer: Jim Defever Designer: Jim Delor

2. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 2 Outline Brief Instrument Overview Sample Goniometer System Detector Mover System Optics Table Design Conclusion

3. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 3 XPP Experimental Techniques Time-Resolved X-ray Diffraction (TRXD) Time-Resolve Diffuse Scattering (TRDS) Time-Resolved Protein Crystallography (TRPX) X-ray Emission Spectroscopy (XES) Small Angle X-ray Scattering (SAXS) Optical Probing of X-ray Transients * The instrument budget is not sufficient to provide capability to all techniques

4. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 4 XPP Instrumentation Categories X-ray Beam Preparation (spatial profile, intensity, spectrum, repetition rate) Delivery to sample Characterization (spatial profile, intensity, arrival time) Optical Beam Creation Preparation (spatial profile, intensity, spectrum, repetition rate, temporal profile) Delivery to sample Characterization (spatial profile, intensity, spectrum, temporal profile) Sample Environment Orientation & Positioning X-ray Detection

5. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 5 Instrument Block Diagram

6. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 6 XPP Instrument Location XCS AMO (LCLS) CXI XPP Endstation Near Experimental Hall Far Experimental Hall X-ray Transport Tunnel

7. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 7 Instrument Layout – Plan View

8. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 8 Detector Mover – Design Goals Flexibility to accommodate a wide variety of sample environments Capable of orienting small samples (~ 50 μm) over a wide range of reciprocal space Sphere of confusion < 30 μm Open access to allow close proximity laser optics No interference with direct beamline while in monochromatic mode

9. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 9 Sample Goniometer – Tilt Platform 400 mm x 400 mm top surface ± 5°angular range of arc segments Large load capacity (>> 50 kg) 200 mm working distance

10. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 10 Sample Goniometer – Tilt Platform (2)

11. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 11 Sample Goniometer – Kappa Configuration

12. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 12 Detector Mover – Design Goals Operate in both interaction points 10 cm – 100 cm sample to detector distance in forward-scattering upper hemisphere quadrant 10 cm – 50 cm sample to detector distance in back-scattering upper hemisphere quadrant Repeatable position the XPP detector pixels to a fraction of the pixel size Definitively know the position of all detector pixels to a fraction of the pixel size

13. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 13 Detector Mover – Coordinate System

14. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 14 Detector Mover – Coverage Requirements

15. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 15 Detector Mover – Concept 6-axis Industrial Robot Load capacity (> 20 kg) ± 50 µm repeatability Floor or ceiling mountable No counterweights Remotely variable sample to detector distance Remote control of detector clocking angle

16. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 16 Detector Mover – Path Forward Engineering and manufacturing will be broken up into 3 work packages Statement of work 1 Verify that a industrial robot has the capability of meeting motion requirements Statement of work 2 Create a concept for integrating robot into the XPP instrument Statement of work 3 Manufacturer, install, test and integrate system

17. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 17 Detector Mover – SOW 1 Test 1 – Spherical motion and pointing System is capable of moving the detector about a spherical surface of a user defined radii while pointing the detector at the interaction region Test 2 – Repeatability Measure repeatability and hysterisis of system Test 3 – Detector Clocking Angle Measure how well the clocking angle can be controlled Test 4 – Stability Measure long term (~ hours) motion drift for various fixed positions Test 1 Test 2

18. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 18 Detector Mover – SOW 2 Concept for integrating system into XPP Robot arm mounting Reach requirements can be met without intruding into mechanical stay clear zones Safety system

19. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 19 Optics Support Table – Design Goals Repeatable position optics in two operating positions (mono, direct) Initial beam based alignment is expected for each position but the desire is to have a configuration file loaded for each operating mode without the need for alignment Stably support X-ray optics and diagnostics Design logic: Optical axis will be defined by XPP slits X-ray optics and interaction point can drift together on the order of 100 µm with minimal impact However, the diffractometer thermal drift is an unknown It was determined that it was best to design a support table that fixes the position and alignment of the optical elements to the highest extent reasonably achievable This reduces misalignment issues to a one dimensional problem Design goals in priority order: Stability of optics with respect to each other over short and long term periods Absolute position stability Slits are the gold standard and need to be the most stable of all elements

20. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 20 Optics Support Table – Case Studies Analyzed component displacement due to bowing of support structure for a 2° F temp change Analyzed global displacement of entire structure due to 2° F thermal expansion Large granite surface plate with a low profile strongback was best option Themalization time constant of the granite is many days However, the drawback is the rigging effort – must be moved in through the FEH

21. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 21 Optics Support Table – Design Strongback has been split into two sections to minimize bowing and to prevent system overconstraints Strongback is strategically tied down to rails near locations of slits

22. David Fritz XPP Instrumentdmfritz@slac.stanford.edu June 17, 2008 22 Questions for the Committee Is the sample goniometer design optimized form the scientific goals of the instrument? Are the sample mover design requirements reasonable? Does the sample mover path forward seem reasonable? Is the design logic of the optics support table valid? Any other concerns/comments?