Transcript XPP Instrument

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
June 17, 2008
XPP Instrument
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David Fritz
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Outline
Brief Instrument Overview
Sample Goniometer System
Detector Mover System
Optics Table Design
Conclusion
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David Fritz
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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
June 17, 2008
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David Fritz
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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
June 17, 2008
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David Fritz
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Instrument Block Diagram
June 17, 2008
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David Fritz
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XPP Instrument Location
Near Experimental Hall
X-ray Transport Tunnel
AMO
(LCLS)
XPP
Endstation
XCS
CXI
Far Experimental Hall
June 17, 2008
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David Fritz
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Instrument Layout – Plan View
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David Fritz
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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 < 30μm
Open access to allow close proximity laser optics
No interference with direct beamline while in
monochromatic mode
June 17, 2008
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David Fritz
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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
June 17, 2008
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David Fritz
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Sample Goniometer – Tilt Platform (2)
June 17, 2008
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David Fritz
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Sample Goniometer – Kappa Configuration
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David Fritz
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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
June 17, 2008
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David Fritz
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Detector Mover – Coordinate System
June 17, 2008
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David Fritz
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Detector Mover – Coverage Requirements
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David Fritz
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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
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David Fritz
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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
June 17, 2008
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David Fritz
[email protected]
Detector Mover – SOW 1
Test 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 2
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
June 17, 2008
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David Fritz
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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
June 17, 2008
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David Fritz
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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
June 17, 2008
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David Fritz
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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
June 17, 2008
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David Fritz
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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
June 17, 2008
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David Fritz
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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?
June 17, 2008
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David Fritz
[email protected]