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Experimental Facilities
John HillDirector, NSLS-II Experimental Facilities Division
NSLS-II User WorkshopJuly 17, 2007
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Novel features of Design
The DBA-30 design has a number of novel features that offer a unique range of opportunities for our large, diverse community of users:
Low emittance Ultra-high flux and brightness soft x-ray and High current, hard x-ray undulator sourceslong straights
Damping wigglers Very intense broad band sources of hard x-rays
Soft Bends Bright sources of soft x-rays Large gaps to provide excellent far-IR source.
3 Pole Wigglers High-flux, bright sources of hard x-rays
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Radiation Sources: Brightness
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Radiation Sources: Flux
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Three-pole Wigglers
Added to provide hard x-ray dipoles without big impact on the emittance.
Each BM port can either be a soft bend or a 3PW source~15 3PWs would increase the emittance ~ 10%
2 mrad source
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Radiation Sources: Infra-Red
Standard gap BMs provide excellent mid and near IR sources Large gap (90 mm) BMs provide excellent far-IR sources
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Electron Beam Size
Type of source Low- straight section (6.6m)
Hi- straight section (8.6m)
0.4T Bend magnet 1T three-pole wiggler
σx [μm] 28 99. 44.2 (35.4 - 122) 136
σx' [μrad] 19 5.5 63.1 (28.9-101) 14.0
σy [μm] 2.6 5.5 15.7 15.7
σy' [μrad] 3.2 1.8 0.63 0.62
Truly tiny electron beams…
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Source Size vs. Photon Energy
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Source Divergence vs. Photon Energy
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Heat Load Calculations
Maximum thermal slope error in beam footprint = ±4 µrad
(cf Darwin width of 31 rad)
-8
-6
-4
-2
0
2
4
6
8
-20 -15 -10 -5 0 5 10 15 20
Crystal surface dimension in y-direction (mm)
Slo
pe e
rror
(mic
ro ra
dian
s)
Undulator
Calculations for worst case U14 superconducting undulator: 2σ beam, Total power = 92 W (filtered)
Wiggler
-25-20-15-10
-505
10152025
-20 -15 -10 -5 0 5 10 15 20
Crystal surface dimension in y-direction (mm)
Slo
pe
err
or
(mic
ro r
ad
ian
s)
Maximum thermal slope error in beam footprint = ± 23 µrad
Calculations for L=7m damping wiggler: 0.25 mrad, Total power = 1.8 kW (unfiltered)
Power from the insertion devices is large, but it can be handled
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Experimental Floor
• 1 pentant (= 6 sectors) served by 1 LOB: 72 offices6 labs (480 sf)
• Vibration studies (FEA) carried out to minimize sources and propagation of vibrations from ground up.• Long beamlines would have hutches outside the experimental hall.
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Vibration Suppression at NSLS-II
Extensive FEA modeling of vibrations in facility underway (N. Simos)Goal is to:
• Understand site• Mitigate external and internal sources• Isolate sensitive beamlines
Possible solutions: slab thickening, isolation joints, trenches…
Studies indicate that cultural noise will be trapped by the floor
Service Bldg
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NSLS-II Beamlines
• 15 low- straights for user undulators• Could potentially drive up to 30 beamlines by canting two undulators
• 4 high- straights for user undulators• Could potentially drive up to 8 beamlines by canting two undulators
• 8 high- straights for user damping wigglers• Could potentially drive up to 16 beamlines by canting two DWs
• 27 BM ports for UV and soft X-rays• Up to 15 of these can have 3-pole wigglers to provide hard x-rays.
• 4 large gap BM ports for far-IRAt least 58 beamlines
More w/ multiple IDs per straightMultiple hutches per beamline are also possible
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Project Beamlines
Project goal: To provide a minimum suite of insertion device beamlines to meet physical science needs that both exploit the unique capabilities of the NSLS-II source and provide work horse instruments for large user capacity.
• The beamlines are:• Inelastic x-ray scattering (0.1 meV)• Nanoprobe (1 nm)• Soft x-ray coherent scattering and imaging• Hard x-ray coherent scattering and SAXS• Powder diffraction (damping wiggler source)• EXAFS (damping wiggler source)
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Nanoprobe
10 nm
1 nm
Mission• Nanoscience: hard-matter • Imaging, diffraction
Capabilities1nm, short working distance10nm, larger working distancePossible remote hutch
SourceU19 in lo- straight*
*A candidate for extended straight.
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Inelastic X-ray Scattering
Mission•Low energy modes in soft matter•Phonons in small samples (Hi-P, single crystal..)
Capabilities0.1 meV, fixed energy1.0 meV, fixed energy
SourceU19 in lo- straight*
*A candidate for extended straight.
0.1 meV
1.0 meV
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Hard X-ray Coherent Scattering
Mission• Slow dynamics in soft matter• Nanoscale imaging of hard matter• time-resolved SAXS (biological processes)
CapabilitiesXPCS/SAXSCoherent Diffraction
SourceU19 in hi- straight*
*gap > 7mm
Secondary optics
Coherent Diffraction/SAXS
XPCS
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Soft X-ray Coherent Scattering
Mission• Imaging of bio samples• Hard matter, magnetic systems
CapabilitiesCoherent imaging + microspectroscopyCoherent scatteringFast switching of polarization
Source2 x EPU 45 in lo- straight (canted at 0.25 mrad)
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Powder Diffraction
Mission• Materials Science• time-resolved catalysis
Capabilities5-50 keVAnalyser-mode and strip-detector modeSample environments (high-P, low-T, high-T..)
Source3m damping wiggler in hi- straight
BM hutch
Powder-I
Powder-II
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XAFS
MissionEnvironmental science, catalysisMaterials science
CapabilitiesMicroprobeIn-situ catalysis, controlled atmosphere
Source3m damping wiggler in hi- straight
BM hutch
EXAFS-I
EXAFS-II
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Path Towards 1 nmKinoforms
=82 nm
Refractive optic with minimal absorptionE-beam at Lucent
Etching at BNL (CFN)
• Achieved 82 nm
• Theoretical calculations show 1nm is possible
• Technical challenge in fabricating multiple lenses with sufficiently smooth walls.
Multi-layer Laue Lenses
-150 -100 -50 0 50 100 150
0.0
0.2
0.4
0.6
0.8
1.0
Sample A Sample B Sample C Gaussian fit
Inte
nsity
(no
rmal
ized
)
X (nm)
=19 nm
Thin film multilayers, sectioned for use as ZPs
• Pioneered at ANL
• Achieved 19 nm
• Theoretical calculations show that 1nm is possible.
• Technical challenge in fabricating thick MLs with atomically smooth layers.
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Path Towards 0.1 meV
Asymmetric Optics acting as Dispersive Elements
Y. Shvyd’ko et al PRL (2006)
• Energy resolution controlled with asymmetry parameter• Achieve high energy resolutions at moderate photon
energies (9 keV)
Technical Challenges:•Fabrication and mounting of large Si crystals•Temperature stability
E=9.1 keV
E=2 meV
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Summary
• Conceptual design of accelerator has matured into an exciting design, promising superlative experimental capabilities.
• World-leading performance extends from the far-IR to the very hard x-ray. A range of sources will be available to match the various scientific needs.
• These include unprecedented energy and spatial resolution for hard x-ray beamlines and world-leading resolution and flux for soft x-ray beamlines.
• Project insertion device beamlines have been identified. User community to define the scientific mission of these beamlines.
• Looking forward to your input and feedback during the workshop.