The SXR Instrument

1
The SXR Instrument

• The SXR is a instrument for Soft X-ray Materials
  Research on the LCLS
• SXR is the second soft x-ray instrument at the
  LCLS
• SXR is compatible with multiple techniques for
  studying materials with ultra short soft x-rays
  pulses
• SXR spans both hutches 1 2 with the end station
  in Hutch 2
• SXR compliments the AMO experiment
• Michael Rowen
• Project Engineer

2
Science
Charge, spin and orbital order
Solution based ultrafast chemistry
Pump-probe Ultrafast Surface Chemistry
Magnetic Imaging
3
Scientific Drivers for SXR

• X-Ray Scattering Spectroscopy on Strongly
  Correlated Materials
• Pump-Probe Ultrafast Chemistry
• Magnetic Imaging
• Ultrafast Coherent Imaging

4
Science Driven Requirements

• Soft X-ray Beam Line, 500-2000eV
• Monochromatic, E/DE of 5000
• Focused or unfocused beam at end station
• Switch between monochromatic and white beam
  without moving experimental system
• Open end station for interchangeable user systems
• Capabilities for fast, single shot, transmission
  spectroscopy
• LCLS operations will be at photon energies
  gt825eV in the near term.

5
SXR Beam Line

• Major Components
• Monochromator
• Exit slit
• Focusing Optics
• No fixed end station
• Transmission sample chamber (up stream of mono)
• Spectrometer detector (insertable, at exit slit)

6
SXR Layout
Basic AMO SXR layout in hutches 1 2
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Grating Monochromator

• Varied Line Spacing (VLS) grating monochromator
• 2 optical elements (vertically deflecting)
  spherical mirror, VLS plane grating
• Energy scan by rotation of grating
• Erect focal plane for spectrometer
• mode and fixed slit position.
• B4C coated optics

Courtesy Phil Heimann
8
Monochromator Layout
M1 Mirror Grating
Exit Slit
Monochromator spans the first and second hutches
9
Resolution vs Energy

• 100 l/mm grating

200 l/mm grating
At 800 eV DE 0.19 eV
At 1200 eV DE 0.23 eV
Resolution goal of 0.2 eV at 1000 eV is achieved.
10
Optical tolerances

• The figure tolerances are difficult because we
  need to preserve the brightness of a source 100
  mm in diameter and at a 100 m distance.
• That accuracy has been achieved by two venders
  for the LCLS SOMS and HOMS mirrors.

11
Grating efficiency
Grating frequency (1/mm) Groove depth (nm) Groove width (mm)
100 28 7.2
200 13 2.95

• Grating efficiency calculations with Gsolver by
  Phil Heimann.

12
Fourier optics simulations

• At the exit slit.
• Assuming 2 nm rms figure error.

• From Jacek Krzywinski

13
Fourier optics simulations (cont.)
X profile
Y profile

• At the focus in end station.
• Assuming 2 nm rms figure error.

14
Behind the focus (10 cm)

• When the focus of the KB mirrors are not at the
  sample, there is more structure in the beam.
• The peak intensity is still reduced, here by
  1/100.

15
Pulse duration preservation

• Pulse stretching N m l 40 fs at 826 eV
• (i.e. at high dispersion)
• An adjustable aperture near grating can be used
  to reduce pulse stretching with a decreased
  intensity and energy resolution.
• For dispersive measurements and white beam, LCLS
  pulse duration is unaffected.

16
Focusing Optics

• K-B Optics
• Silicon Substrates
• Profiled mirrors bent to elliptical cylinders
• Focus to lt10x10mm
• B4C coatings
• Un-bend one or both mirrors for line or
  unfocused beam

17
K-B Refocusing Mirrors
Focus End Station lt10x10 mm

• K-B Mirrors

18
Use ALS beamline mechanical designs

• ALS standard monochromator 0.1 mrad motion of
  pre-mirror and grating, Horizontal translation
  of chamber.

• ALS bendable mirror Motorized leaf springs,
  Flange mounted.

• Plan to use existing mechanical designs with
  minimal modifications in the LCLS SXR Instrument.

19
Optical Design Review 7/15/08

• Committee
• Peter Stefan (SLAC) chair, Alistair MacDowell
  (ALS), Rolf Follath (BESSY)
• General comments
• Overall, the review committee felt that the
  optical design presented is good, and will likely
  work. The assembled SXR design team has good
  experience in this area and a good track
  record. Also, the damage issues seemed properly
  considered.
• Specific recommendations
• Because of the as-coated density of B4C, the
  mirror incidence angles were changed 15 -gt 14
  mrad.
• The Fourier optics calculations were repeated
  with the correct orientation between the offset
  mirrors and the monochromator.

20
Optical layout and table
21
Spectrometer Mode

• Transmission Sample Location

Spectrometer Detector at Exit Slit
22
Pump Laser System
Replicate system from AMO
Courtesy Greg Hays
23
SXR / AMO Interfaces

• AMO SXR engineers are working closely to
  resolve all conflicts as the are identified.
• Space is tracked
• Systems checked for compatibility
• Ideas and designs are shared (i.e. mostly stolen
  from AMO and LUSI)
• Operational boundaries have been defined

24
Space between instruments is closely tracked
Minimize diameter SXR beam pipe
Clears AMO instrumentation
25
AMO K-B optics and SXR Mono being designed by the
same engineer
Space for extension AMO into 2nd Hutch
Rack space is apportioned
26
Operations

• Operations on the SXR beam line requires
  installation of the monochromator which is
  scheduled for installation winter shutdown
  09-10.
• Initial operational mode No access to hutches
  with beam, i.e. no access to Hutch 1 when AMO is
  running. (July Dec 09)
• Intermediate operational mode No access to
  hutches with active experiments. Access to
  hutches with beam passing through. (as soon after
  start of SXR operations as possible, Mar 10)
• Final operational mode Access to hutches with
  active soft x-ray experiments, Hutch 1 or Hutch
  2.
• SXR is working with Radiation Physics on defining
  and building in the necessary shielding and
  controls for access soon after SXR operations
  start.
• Operations with samples in the transmission
  chamber (Hutch 1) for spectrograph mode will
  require additional approvals, testing and
  implementation of a shielding plan.

27
Endstations
8 Endstations described in the TDR document
Stöhr
Chapman
Nilsson
Hussein-Shen
28
Institutional Roles
Institution Role Support level (k)
Stanford Initial support for conceptual design (TDR) Purchase long lead optical components Engineering and design 750
LBNL X-ray optical design and on going technical support Engineering and design of X-ray optical systems 380
DESY Provides hardware and support for assembly Technical expertise FEL instrumentation 1500
CFEL Provides hardware and support for assembly 300
LCLS Provides overall management structure, pays for installation and integration, will manage operations 1517
4447k
Total estimated cost
29
SXR Status

• The SXR scientific case has been reviewed by SAC.
• Technical Design Report (TDR) has been written
  and accepted.
• LCLS has reviewed the project for compatibility.
• The X-ray optical design has been reviewed.
• The base MoU is signed.
• Integration of SXR into the LCLS construction
  project has started.
• Proposals for Long lead optical components are
  coming in and the first contracts have been
  placed.

30
Status of MoU

• The MoU between SLAC and DESY has been signed by
  DESY and SLAC.
• The technical addendum defining contributions and
  roles of the members of the consortium is in
  final draft and should be completed by ??.

31
SXR Schedule
SXR is just starting to be integrated into the
LCLS schedule. These completion dates are the
earliest possible dates. Expected final
installations are in Dec 09/Jan 10.
32
SXR Instrument team

• Anders Nilsson (Stanford) Wilfried Wurth
  (Hamburg) consortium leaders
• Phil Heimann Nicholas Kelez (ALS)
  monochromator and KB optics
• Yves Acremann (Stanford) Alexander Foehlisch
  (Hamburg) diagnostics and with Bill White Greg
  Hays (LCLS) laser beam delivery
• Stefan Moeller (LCLS) LCLS contact
• Gunther Haller, Perry Anthony, Dave Nelson
  (SLAC) controls
• Amedeo Perazzo, Chris OGrady Remi Machet data
  acquisition
• Jacek Krzywinski (LCLS) fourier optics
  simulations
• Regina Soufli (LLNL) optical coatings
• Michael Rowen (LCLS/SLAC) overall beam line
  systems, budget, schedule, interfaces
• Only full-time person.