the sxr instrument
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
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 pulsesSXR spans both hutches 1 & 2 with the end station in Hutch 2SXR compliments the AMO experiment
Michael RowenProject Engineer
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Scientific Drivers for SXR
X-Ray Scattering Spectroscopy on Strongly Correlated Materials Pump-Probe Ultrafast ChemistryMagnetic Imaging Ultrafast Coherent Imaging
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Science Driven Requirements Soft X-ray Beam Line, 500*-2000eV:
Monochromatic, E/E of ~5000Focused or unfocused beam at end stationSwitch between monochromatic and “white” beam without moving experimental systemOpen end station for interchangeable user systemsCapabilities for fast, single shot, transmission spectroscopy
* LCLS operations will be at photon energies >825eV in the near term.
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
SXR Beam LineMajor Components:
MonochromatorExit slitFocusing OpticsNo fixed end stationTransmission sample chamber (up stream of mono)Spectrometer detector (insertable, at exit slit)
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
SXR Layout
Basic AMO & SXR layout in hutches 1 & 2
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Grating Monochromator
Varied Line Spacing (VLS) grating monochromator:
2 optical elements (vertically deflecting): spherical mirror, VLS plane gratingEnergy scan by rotation of gratingErect focal plane for spectrometer mode and fixed slit position.B4C coated optics
Courtesy Phil Heimann
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Monochromator Layout
M1 Mirror & Grating Exit SlitMonochromator spans the first and second hutches
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Resolution vs Energy100 l/mm grating
At 800 eV E = 0.19 eV At 1200 eV E = 0.23 eV
Resolution goal of 0.2 eV at 1000 eV is achieved.
1.0
0.8
0.6
0.4
0.2
0.0
Res
olut
ion
(eV
)
140012001000800600Photon energy (eV)
Source M1 Mirror 100 l/mm Grating Total
1.0
0.8
0.6
0.4
0.2
0.0
Res
olut
ion
(eV
)
200018001600140012001000800Photon energy (eV)
Source M1 Mirror 200 l/mm Grating Total
200 l/mm grating
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Optical tolerances
The figure tolerances are difficult because we need to preserve the brightness of a source 100 m in diameter and at a 100 m distance.
That accuracy has been achieved by two venders for the LCLS SOMS and HOMS mirrors.
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Grating efficiency
Grating efficiency calculations with Gsolver by Phil Heimann.
Grating frequen
cy (1/mm)
Groove depth (nm)
Groove width (m)
100 28 7.2200 13 2.95
0.4
0.3
0.2
0.1
0.0
Effic
ienc
y
5 6 7 8 91000
2
Photon energy (eV)
100 l/mm 200 l/mm
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Fourier optics simulations
From Jacek Krzywinski
At the exit slit. Assuming 2 nm
rms figure error.
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Fourier optics simulations (cont.)
At the focus in end station.
Assuming 2 nm rms figure error.
Y profile
X profile
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
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.
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Pulse duration preservation
Pulse stretching: N m = 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.
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Focusing Optics
K-B Optics:Silicon Substrates Profiled mirrors bent to elliptical cylinders Focus to <10x10m B4C coatings Un-bend one or both mirrors for line or unfocused beam
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
K-B Refocusing Mirrors
K-B Mirrors Focus End Station <10x10 m
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
ALS “standard” monochromator: 0.1 rad motion of pre-mirror and grating, Horizontal translation of chamber.
Use ALS beamline mechanical designs
ALS bendable mirror: Motorized leaf springs, Flange mounted.
Plan to use existing mechanical designs with minimal modifications in the LCLS SXR Instrument.
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Optical Design Review 7/15/08Committee
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 recommendationsBecause of the as-coated density of B4C, the mirror incidence angles were changed 15 -> 14 mrad.The Fourier optics calculations were repeated with the correct orientation between the offset mirrors and the monochromator.
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Spectrometer Mode
Transmission Sample Location Spectrometer Detector at Exit Slit
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
PM1
PM2C
3/2-1
PM3
Harmonics C1
C2
C4
C5
PM4VEC
To Experiment
PM5
To Experiment2VEC
/2-3
/2-4
Lase
r
/2-2
SpectrometerCsp
Oscillator Controls
PMOsc
F1
F2 Laser HallHutch 2
AC
L1L2
L3
L4
L5
M3M4
M1M2
Oscope
Pump Laser SystemReplicate system from AMO
Courtesy Greg Hays
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
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
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Space between instruments is closely tracked
Minimize diameter SXR beam pipe
Clears AMO instrumentation
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
AMO K-B optics and SXR Mono being designed by the same engineer
Space for extension AMO into 2nd HutchRack space is apportioned
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
OperationsOperations 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.
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Endstations
Nilsson Hussein-Shen
ChapmanStöhr
8 Endstations described in the TDR document
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
Institutional Roles
Institution Role Support level (k$)
StanfordInitial support for conceptual design (TDR)Purchase long lead optical componentsEngineering and design
750
LBNLX-ray optical design and on going technical supportEngineering and design of X-ray optical systems
380
DESYProvides 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
$4447kTotal estimated cost:
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
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.
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
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 ??.
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
SXR ScheduleSXR 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.
Michael Rowen
LCLS FAC Meeting [email protected]
November 12, 2008
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 O’Grady & 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.