1 BROOKHAVEN SCIENCE ASSOCIATES Cylindrical Collimating Mirror EPU Elliptical cylinder KB refocusing mirrors Exit Slit Experimental Station Plane Mirror

1 BROOKHAVEN SCIENCE ASSOCIATES

Cylindrical Collimating Mirror

EPU

Elliptical cylinderKB refocusing mirrors

Exit Slit

ExperimentalStation

Plane Mirror

EPU

Plane Grating

Beam Chopper

NSLS-II Soft X-ray Undulator Beamlines

Steve Hulberta

Dario Arenaa

Cecilia Sánchez-Hankea

Ruben Reiningerb

aBrookhaven National LaboratorybScientific Answers & Solutions, Madison, WI


NSLS-II source brightness

1015

1016

1017

1018

1019

1020

1021

1022

Bri

gh

tnes

s [p

ho

ton

s/se

c/0.

1%b

w/m

m2 /m

rad

2 ]

10 eV 100 eV 1keV 10keV 100keV

Photon Energy

VUVhcrit

EPU100 VUV undulator100mm, L=4m, Kmax=14.0

EPU45 SXU45mm, L=4.0m, Kmax=4.33

U14 SCU14mm, L=2.0m, Kmax=2.2

W60 SCW,B=3.5T, 60mm,L=1.0m, K=19.6

DW100-1.8T,B=1.8T, 100mm,L=7m, K=16.8

U19 CPMU19mm, L=3.0m, Kmax=2.03

Ring parameters: 3.0 GeV, 0.5A, h=0.55nm, v=0.01nm, energy spread=0.001

Straight section parameters: 5m length: h=2.7m, v=0.945m; 8m length: h=18.2m, v=3.09m; h=v=h=v=h=v=0

Bend magnet parameters: h=0.65m, v=25.1m, h=0.032, v=-0.044, h=0.04m, h=0.056, v=v=0

25m-radius bend,B=0.4T, Ec=2.39keV


1019

2

4

6

810

20

2

4

6

810

21

2

Bri

gh

tnes

s [p

ho

ton

s/se

c/0.

1%b

w/m

m2 /m

rad

2 ]

102

2 3 4 5 6 7 8 9

103

2 3 4 5 6 7 8 9

104

Photon Energy

Soft X-ray Elliptically-polarized Undulator

VUVhcrit

EPU42, linear modeperiod=42mm, L=4.0m, Kmax=4.3

Ring parameters: 3.0 GeV, 0.5A, h=0.55nm, v=0.01nm, energy spread=0.001

Straight section parameters: 5m length: h=2.7m, v=0.945m; 8m length: h=18.2m, v=3.09m; h=v=h=v=h=v=0

Bend magnet parameters: h=0.65m, v=25.1m, h=0.032, v=-0.044, h=0.04m, h=0.056, v=v=0

EPU45, min. linear modeperiod=45mm, L=4.0m, Kmax=4.3

EPU42, circular modeperiod=42mm, L=4.0m, Kx,max=Ky,max=2.9

EPU45, circular modeperiod=45mm, L=4.0m, Kx,max=Ky,max=2.7

Higher harmonic interference: use QEPU

Source polarization: linear (horiz., vert. or any angle in between), circular, or elliptical


Proposed NSLS-II soft x-ray undulator beamlines

High resolutionSoft x-ray resonant magnetic and inelastic scattering (XRMS, RIXS)

High fluxSoft x-ray imaging and coherent scattering

XRMS

RIXS

Imaging

Coherent

Source: Two 2m-long EPUs (EPU42 or EPU45) located in a 5m NSLS-II straight section.

Operating modes: (1) uncanted and phased as a single 4m-long EPU, or (2) canted, by ~0.25 mrad, for fast-switching polarization capability.


High resolution soft x-ray undulator beamline : XRS, XRMS

XRS, XRMS (x-ray resonant [magnetic] scattering) endstationScientific themes / drivers:

1. Ordering Phenomena in Correlated Electron Materials2. Magnetic multilayers, superlattices & spintronic materials / devices3. Nanomagnetism: patterned & self-assembled4. “Soft” materials (e.g. complex polymers; C, N, O K-edges)

Beamline requirements- small spot size

>4 m spot overfills ~100 m crystal at critical angle of ~4° (h=700eV)- high energy resolution (select different multiplet states)- high flux (detect weak, diffuse features in scattered beam)

Comparable endstations (incomplete list) 1. NSLS X1B, X13A, U4B

2. ALS BL 4.0.1 3. APS 4-ID-C 4. ESRF ID-08 (N. Brookes), Rogalev BL, XMaS

5. Diamond: Peter Hatton endstation, BLADE 6. BESSY-II: Helmut Zabel endstation

7. Pohang LS: J-H Park BL 8. Swiss Light Source 9. Spring-8


High resolution soft x-ray undulator beamline : RIXS

RIXS (resonant inelastic x-ray scattering) endstationScientific themes / drivers:

1. Correlated Electron Materials• low energy excitations (excitions, orbitons, HTc “stripe” formation, etc.)• field- and temperature-driven phase transitions• bulk sensitivity

2. Organic molecules (incl. fullerenes, nanotubes)

Beamline requirements- Small spot size (collect large solid angle, possibly no entrance slit)

- Very good energy resolution (precise selection of initial state)- Highest flux possible (very low inelastic cross section)

Comparable endstations (incomplete list)1. NSLS X1B (commercial Scienta analyzer)2. MAX-III (J. Nordgren program)3. ALS beamlines 7.0.1, 8.0.1, MERLIN (lower energy) 4. ESRF: AXES instrument (U. of Milan)5. Swiss Light Source: SAXES6. ELETTRA: ComIXS, BACH beam line


High flux soft x-ray undulator beamline : Coherent Scattering

Techniques: scattering, diffraction, coherent SAXS, diffraction imaging, holography,…

Scientific themes / drivers:• image the mesoscopic non-crystalline world (few x 10nm resolution), e.g. large cells,

magnetic domains, …• measure time-dependent fluctuations in materials (correlated spectroscopy)• 3D imaging of granular materials (with grains around 30 nm)

Eisebit & Luening, Nature 432, 885-888 (2004)

Beamline requirements (with 2013-state-of-the-art optics)

- flux > 1013 photons/s on sample- beam size ~few m on pinhole- resolving power ~104

Comparable endstations (incomplete list)• ALS – Cryo-capable Diffraction and Topography (transmission

and reflectivity)• ALS – Steve Kevan’s Flange-o-Saurus• SSRL – speckle; EPU• BESSY• ESRF - Goedkoop; Van der Laan• NSLS - CCD based (transmission)


High flux soft x-ray undulator beamline : Microscopy

Techniques: STXM, phase contrast scope, full field scope, PEEM, spectro-scopy, …Scientific themes / drivers:

• Imaging nano- and mesoscopic world, simultaneous spectroscopic measurements• Imaging of single nano-elements , nano-contacts, or nano-magnets, to understand

isolated behavior (no collective phenomena)• Structural and electronic information, differences between boundaries/interfaces and

bulk.

Magnification

Acceleration, focusing and magnification

Energy and angle selection

Beamline requirements (with 2013-state-of-the-art optics)- resolving power ~104

- STXM: flux > 1012 photons/s on sample, beam size 10m x 10m on Fresnel zone plate (full transverse coherence), <10nm x <10nm on sample

- PEEM: flux > few x 1013 photons/s on sample, beam size ~few m on sample

Comparable endstations (incomplete list)

• NSLS/CFN, ALS, BESSY, ESRF, SLS, Trieste, Spring8, Pohang Light Source, Diamond, Soleil, HASYLAB, …

PEEM

http://xraysweb.lbl.gov/peem2/PEEM2-02.html


Plane M3

PlaneGratingVLS

ExitSlit

CylindricalM2

Sample

Plane Ellipticals M4, M5

Soft x-ray beamline design:VLS PGM illuminated by collimated light

Side View

Horizontal Focusing by M4 -- 52:1

Rapid Switching: change M2 and M4

μrad (39) 28 μrad, (42) 32

μm (25) 35 μm, (47) 54

m) (2 4mL

200eV,h @ sizes source Effective

y'x'

yx

Possible planarM1

Beamline High resolution

High flux

Source to M1 27m 30m

M1 to M2 1m 1m

M2 to M3 PGM design PGM design

M2 to grating ~2m ~2m

Grating to exit slit 20m 10m

Exit slit to M4 1.85m 1.85m

M4 to M5 0.5m 0.5m

M5 to sample 1.0m 1.0m

Total 53.35m 46.35m


Sample spot size

100nrad RMS planes0.5rad RMS Elliptical, cylinder meridional

-6

-4

-2

0

2

4

6

y (1

0-3m

m)

-4 0 4

x (10-3

mm)

root:'200 eV 1800 5': Sample Both

Good:6541 x: 0.0022797 Avg:1.9683e-05 y: 0.0011478 Avg:8.1257e-06

h=200eV: h=2.3m, v=1.1mh=1000eV: h=2.1m, v=1.1m

-3

-2

-1

0

1

2

3

y (1

0-3ra

d)

-3 -2 -1 0 1 2 3

x (10-3

rad)

root:'200 eV 1800 5': Sample Both Div

Good:6541 x: 0.001092 Avg:3.6449e-05 y: 0.00043957 Avg:4.4434e-06

h=200eV: h’=1.1mrad, v’=0.44mradh=1000eV: h’=0.8mrad, v’=0.3mrad

Req’d figure error

and divergence


Calculated flux & resolving powerHigher resolution beamline1010’s @ 105 rp; 1012’s @ 104 rp

Higher flux beamline1012’s @ 2104 rp; 1013’s @ 5103 rp

Each soft x-ray undulator beamline would be equipped with at least 3 gratings, interchangeable under computer control


3D schematic of soft x-ray undulator layout

Cylindrical Collimating Mirror

EPU

Elliptical cylinderKB refocusing mirrors

Exit Slit

ExperimentalStation

Plane Mirror

EPU

Plane Grating

Beam Chopper


M2

RCP LCP

M1

M3 M5

Side viewSingle beam mode

M5Top viewSingle beam mode

M1

M3

Top viewFast switching mode

M1

M3

Planar gratings

M4

RCP LCP

Planar gratings

M4

M2

Planar gratings RCP

LCP

RCP LCP

M2

M5M4

MechanicalChopper

Canted undulator optical schematic, polarization switching

Exit slit

Exit slit

Exit slit


h=200eV: h=2.2m, v=1.1mh=1000eV: h=2.4m, v=1.1m

h=200eV: h=2.6m, v=1.1mh=1000eV: h=2.0m, v=1.1m

Spot sizes on sample, dual (canted) undulator beams

Near, e.g. LCP, beam Far, e.g. RCP, beam

To ensure complete overlap, defocus and/ortrim with baffles


Comparisons of selected soft x-ray beamlines in the US


NSLS-II soft x-ray undulator beamlines

• High-resolution, high-flux, polarization-switchable, soft x-ray beamline design, well matched to the high-brightness NSLS-II accelerator design

• Example soft x-ray scientific programs well matched to this beamline design: XRMS, RIXS, imaging, coherent scattering

• Actual buildout of soft x-ray beamlines will be based on the NSLS-II scientific program, including input from all stakeholders (NSLS-II staff, EFAC, NSLS-II users, …).

Documents

1 BROOKHAVEN SCIENCE ASSOCIATES Cylindrical Collimating Mirror EPU Elliptical cylinder KB refocusing mirrors Exit Slit Experimental Station Plane Mirror