Hard X-Ray PCS and Coherent Diffraction at the APS:

Alec Sandy

X-Ray Science Division Argonne National Laboratory

Recent Results &

Future Directions

2

Outline

  Hard x-ray coherent scattering in the USA (APS)

  Beamline 8-ID at the APS –  Small angle XPCS –  Large angle XPCS

  Future Prospects

  Conclusions

Coherent Scattering at the APS Today

  Requirement for 3rd (or 4th) generation source means that all such efforts in the USA are currently hosted at the APS

  2 major types of programs 1  Coherent x-ray diffraction (imaging) (CXD and CXDI)

•  Lensless imaging of thick or buried structures with resolution limited by scattered intensity at large angles

•  CXD and CXDI work is distributed across several beamlines—not by design

2  X-ray photon correlation spectroscopy (XPCS) •  Probe of nanoscale fluctuations in condensed matter •  Mostly dedicated effort at a single beamline at the APS

3

Coherent Scattering at the APS Today   CXD and CXDI occurs at several beamlines:

–  Strain and defects in nanocrystals, nanowires 34-ID-C (50% access) I. Robinson, S. Leake (U. College London) hard x-ray, Bragg R. Harder (ANL) O. Shpyrko, A. Tripathi (UCSD)

–  Subcellular organelles, mineral nanostructure 2-ID-B (25% access) B. Abbey, K. Nugent, G. Williams (U. Melbourne) 1-4 keV, small-angle J. Clark, A. Peele, M. Pfeifer (La Trobe U.) H. Jiang, J. Miao, F. Tamanoi (UCLA) C. Song (RIKEN/SPring-8), S. Risbud (UC Davis) L. Graham, M. Glimcher (Children's Hospital Boston)

–  Nanostructure of complex materials 26-ID-C (just begun) Isaacs, Nugent, Robinson, and Shpyrko teams hard x-ray, Bragg

–  Dealloyed nanofoams, dislocations and strain 8-ID-E/I (0–15% access) K. Chen, D. Dunand (Northwestern U.) hard x-ray, small-angle E. Isaacs (ANL)

M.A. Pfeifer, G.J. Williams, I.A. Vartanyants, R. Harder, I.K. Robinson, Nature 442, 63 (2006)

GaAs nanowire R. Harder

(ANL)

Coherent Scattering at APS Today

  XPCS –  Glasses, jamming, aging, polymers, filled polymers, surfaces 8-ID-I (50%)

B. Leheny (JHU) small-angle L. Lurio (NIU) S. Mochrie (Yale) S. Sinha (UCSD) M. Sutton (McGill) …

–  CDW’s, martensitic transformations, surface diffraction 8-ID-E (20%) J. Logan and E. Isaacs (U. Chicago and ANL) large-angle K. Ludwig (BU) and M. Sutton (McGill) M. Pierce and H. You (ANL) O. Shpyrko (UCSD) J. Su (ANL)

  Near-field speckle (NFS) and ultra-small-angle XPCS (USA XPCS) 8-ID-I (5%) –  Technique development, novel form factors, glassy dynamics

S. Mochrie (Yale) ultra-small-angle

6

Small Angle XPCS at 8-ID: Dynamics in Glasses

  Motivation –  Understanding the glass transition

remains a “grand challenge” in condensed matter physics •  Are there distinct glassy

phases? •  What is the nature of dynamics

in the glassy state?

  Even idealized systems are predicted to display complex phase and dynamic behavior:

F. Sciortino, Nature Materials 1, 145 (2002)

  Repulsive glass may be melted by switching on a weak attractive interaction   Melted glass may be re-vitrified upon further increase in the attraction   Density fluctuations decay logarithmically versus time, in the liquid where

attractive and repulsive arrest mechanisms compete

7

Small Angle XPCS at 8-ID: Dynamics in Glasses

  Glassy dyamics determined via XPCS

Melted phase—liquid-like correlation decays

Repulsive glass

Revitrification—Attractive glass

Melted phase—logarithmic correlation decays

Xinhui Lu, S.G.J. Mochrie, S. Narayanan, A.R. Sandy, M. Sprung, PRL 100, 045701 (2008)

Small Angle XPCS at 8-ID: Viscous Surface Dynamics

  Motivation –  Investigate how or if properties of polymer films vary

under confinement (thin films) or at a free surface •  Free surface dynamics •  Free surface dynamics as h Rg •  Free surface dynamics T glass transition

temperature

  Ongoing multiyear project •  Zhang Jiang and Sunny Sinha (UCSD)

(Ph.D. Thesis 2007) •  Hyunjung Kim, Sogang University •  Mrinmay Mukhopadhyay and Larry Lurio (NIU) •  Suresh Narayanan (ANL)

8

Small Angle XPCS at 8-ID: Viscous Surface Dynamics

  Overdamped capillary waves investigated on relatively thick entangled PS films on Si at elevated temperatures

9

PS Film

H. Kim et al., PRL 90, 68302 (2003)

Small Angle XPCS at 8-ID: Viscous Surface Dynamics

  Previous investigations extended to –  Films at temperatures approaching the glass transition

10

Z. Jiang, M.K. Mukhopadhyay, S. Song, S. Narayanan, L.B. Lurio, H. Kim, S.K. Sinha, to be published

Large Angle XPCS at 8-ID-E

  Set-up(s) not nearly so polished as small-angle XPCS

11

Large Angle XPCS at 8-ID: Cr SDW/CDW’s

  Fluctuating charge domains, corresponding to fluctuating spin density domains, in Cr studied as a function of temperature

  Transition from higher temperature thermally-activated fluctuations to lower-temperature quantum fluctuations

12

λ 2

1

1

1

2 23

3

O.G. Shpyrko, E.D. Isaacs, J.M. Logan, Yejun Feng, G. Aeppli, R. Jaramillo, H.C. Kim, T.F. Rosenbaum, P. Zschack, M. Sprung, S. Narayanan, A.R. Sandy, Nature 447, 68-71 (2007)

Large Angle XPCS at 8-ID: Martensitic Transformations

  Heterogeneous dynamics in the martensic transformation of Co [C. Sanborn, K. Ludwig (BU) and M. Sutton (McGill)]

13

C.-S. Yoo et al. J. Phys. Cond. Matt. 10 L311 (1998).

P (GPa)

T (K

)

ε (hcp) - Co

γ (fcc)

Blaschko et al., PRL 60, 2800 (1988).

Cobalt: fcc → hcp martensitic phase transition Change in stacking sequence: …ABCABC… → …ABABAB… via avalanches

Pixel P

ixel

(013) speckle pattern

Large Angle XPCS at 8-ID: Martensitic Transformations

  Quench from 610 450 °C and observe structural avalanches

14

t1 (min)

t 2 (m

in)

Two-Time Correlation Function <I(t1)I(t2)> from the Co martensitic transformation shows avalanches

of structural change.

Fluerasu et al., PRL 94, 055501 (2005)

15

XPCS at 8-ID: Summary

  Work presented points to expanded future needs: –  Time scales probed continuously from

≈ 10 ms >1,000 s •  Considerably more coherent flux required –  Dynamics with multiple decays,

intermittent dynamics

•  Fast small-pixel area detectors [P. Falus and S.G.J. Mochrie (Yale)] –  Faster and more reliable required

•  On-the-fly compression –  Increased robustness and real-time data

reduction required •  Robust diffractometer with multiple sample

environments LBNL-ANL Fast CCD Project

Courtesy B. Leheny, JHU

Future Prospects

  Currently the only hard x-ray coherent-scattering beamlines in the USA are at the APS

  In the near future, there will be several new and improved facilities •  LCLS •  NSLS-II •  Upgraded APS?

  How should coherent scattering work done at these new facilities distinguish and complement each other?

16

Future Prospects

17

  LCLS peak brilliance is another 10 orders of magnitude higher!

  Time-averaged brilliance

Future Prospects

  LCLS –  Average brilliance 10× greater than that expected from NSLS-II and

1,000× more than the APS today! –  Peak brilliance 10 decades beyond these numbers –  Time scales

•  > 10 ms –  LCLS rep rate

•  < 1 µs –  Delay line XPCS

  Coherence-based experiments that take advantage of LCLS peak brilliance and provide access to completely unique time scales are most exciting –  Delay-line XPCS

18

Future Prospects

  NSLS-II –  Extraordinary brightness (2 X 1021 ph/s/mm2/mrad2 at ~ 8 keV)

promised (for a 3rd generation source) via •  High current (500 mA) •  Extremely small emittance (< 1 nm-rad) •  Long ID’s

•  Coherent hard x-ray (CHX) beamline – –  Approved as 1 of 6 facility beamlines –  Pros

•  Brilliance •  Large budget for optimized detector

•  ms µs dynamics •  Dedicated to small-angle XPCS (and µ-beam SAXS)

–  Cons •  Lower energy ring •  Dedicated to small-angle XPCS (and µ-beam SAXS)

19

Future Prospects

  NSLS-II –  CHX Beamline

20

Future Prospects

  APS –  Many tremendous (coherent scattering) capabilities have been

developed at the APS but these facilities remain significantly under-optimized •  Mostly ½-filled “short” straight sections with generic ID’s •  Ring current significantly below storage ring design values •  Partially dedicated sectors especially for CXD(I) •  Lack of optimized detectors

–  APS Renewal process has kicked off •  (3rd time in 4 years!) •  Workshops Monday and Tuesday next week •  APS Renewal white paper early 2009 •  Full APS Renewal proposal later in 2009 •  ???

21

Future Prospects

  Proposed APS coherent scattering upgrades –  CXD and CXDI

•  Beamline 34-ID-C (proposed) upgrades –  Separation of 34-ID-C (coherent diffraction) from 34-ID-E

(microdiffraction) via canted ID’s and offset monochromator –  Markedly improved sample and optics support and positioning

capabilities –  Wide dynamic range detectors like Pilatus –  Incorporation of hard x-ray CXDI capabilities

•  AXI Beamline Letter of Intent –  Currently unfunded

22

ID-D ID-C

ID-A

200m 70m

II bldg.

200 m beamline for wide-field phase imaging, future CDI hutch

Argonne Imaging Institute Long ID-C hutch for CDI

Future Prospects

23

  Proposed APS coherent scattering upgrades –  XPCS

•  Beamline 8-ID (proposed) upgrades –  Long straight section (8 m) with canted shorter-period ID’s to

separate XPCS program from GISAXS –  Brilliance-preserving vertical focusing –  Higher x-ray-energy XPCS

2X Undulator

8-ID-A FOE

8-ID-D

8-ID-E

8-ID-I

Mono (or pink) beam

0 m

30 m 51 m

65 m

GISAXS, GIWAXS

Small Q and large Q XPCS

Mono beam

8-ID-F

Key White beam Pink beam Mono beam Aperture Mirror Monochromator

8-ID “Tomorrow” via Upgrade

Conclusions

  Coherent beams from LCLS will provide access to totally unprecedented time and length scales

  NSLS-II and APS (I hope!) will provide access to –  LCLS inaccessible time scales (ms µs) –  Hard x-rays (APS) –  Extended beam time and more experiments

24

Acknowledgements

  Beamline 8-ID partner users –  Prof. Larry Lurio, Northern Illinois University –  Prof. Simon Mochrie, Yale University –  Prof. Mark Sutton, McGill University

  Graduate Students –  Peter Falus, Yale University

25