Dynamics of materials with X-ray Photon Correlation ......Directing Matter and Energy: Five Challenges for Science and Imagination (BESAC) XPCS •“Mesoscale” structure determines

1 BROOKHAVEN SCIENCE ASSOCIATES

Dynamics of materials with X-ray Photon Correlation Spectroscopy - Opportunities and detector requirements

Andrei Fluerasu [email protected]

Washington DC, August 2012

Quasi-static speckles from colloidal suspension near random compact packing volume fraction

Speckles near the (409) Bragg peak of concanavalin A


X-ray Photon Correlation Spectroscopy

Impact: Understanding dynamics may be the critical element in switching from a science ofobservation to a science of control.

“How do we characterize and control matter away—especially very far away—from equilibrium?” Directing Matter and Energy: Five Challenges for Science and Imagination (BESAC)

XPCS• “Mesoscale” structure determines most (if not all)

macroscopic properties of materials. • X-ray Photon Correlation Spectroscopy (XPCS)

measures collective “meso-scale” dynamics

Scientific opportunities● Structure and dynamics of complex materials:

colloids, emulsions, polymers, gels and glasses, membranes, liquid crystals, bio-materials

● “crowded” systems = structure & dynamics affected by entropy, weak forces

● Wide range of time & length scales

Examples of mesoscale structure: (a) porous silicon; (b) sponge phase in a polymer blend (S. Mochrie)(c) bicontinuous microstructure arrested by interfacial colloidal jamming (A. Moharaz et al.); (d) self-assembled amphiphilic nanotubes (Park C et al. PNAS 2006;103:1199-1203)

a) b) c)

d)

Applications: → photonics, lithography, high-tech materials, photovoltaics, paints, food, cosmetics, etc→ fundamental science: glass transition, rheology, jamming, non-equilibrium physics, complexity (“more is different” - P. Anderson)


XPCS: New Opportunities

However: Current detector technology is limited to 1-3 kHz maximum frame rate

New detectors enabling > MHz acquisition are required in order to capitalize on the unprecedented performance of the new, high brightness, light sources

XPCS at NSLS-II:• “Mesoscale” structure determines most (if not all)

macroscopic properties of materials. • X-ray Photon Correlation Spectroscopy (XPCS)

measures collective “meso-scale” dynamics

Focus on:● Soft matter: colloids, emulsions, polymers, gels and

glasses, membranes, liquid crystals, bio-materials● “crowded” systems = structure & dynamics

affected by entropy, weak forces● Wide range of time & length scales

Examples of mesoscale structure: (a) porous silicon; (b) sponge phase in a polymer blend (S. Mochrie)(c) bicontinuous microstructure arrested by interfacial colloidal jamming (A. Moharaz et al.); (d) self-assembled amphiphilic nanotubes (J. Douliez et al.)

a) b)

10μm

c)

d)

Applications: → photonics, lithography, high-tech materials, photovoltaics, paints, food, cosmetics, etc→ fundamental science: glass transition, rheology, jamming, non-equilibrium physics, complexity (“more is different” - P. Anderson)

XPCS at high brightness SR sources: NSLS-II, APS, ERL(?)

• SNR=brightness*τ1/2

• e.g. NSLS-II >10 x brighter than other SRs

• 100 x faster time scales (i.e. reaching 1 μs) and shorter length scales than was ever possible before.


XPCS 101

From R. Leheny

Dynamic structurefactor

Reference: e.g. M. Sutton, CR Physique 9, 657 (2008)


What is an ideal XPCS detector?

•Specifications (from P. Siddons)● 1000 Mpixels● 1 μm pixels● 1 ns frame rate; no dead time● 100% efficiency at all energies● 100 bit dynamic range● free

From O. Shpyrko


Maxipix (ESRF)• Based on chip developed by Medipix collaboration

• 1.4 kHz, 55 μm pix size, single ph sensitivity,100% efficiency (8keV), ~12-bit dynamic range

C. Ponchut et al., J. Instrumentation 6, 01069 (2011)

• Enabled new science (@ ID10, ESRF) e.g. :• cooperative behavior of nanoparticles suspended in a

supercooled liquid C. Caronna et al., Phys. Rev. Lett. 100, 055702 (2008)

• Dynamics and rheology under steady shear flow A. Fluerasu et al., New J. of Phys. 12, 035023 (2010)

Detectors for XPCS - Current State of the Art

Eiger (SLS)• To become available ~2013

• 24 kHz*, 75 μm pix size, single ph sensitivity,100% efficiency (8keV), ~12-bit dynamic rangeB. Schmidt, unpublished* Dectris development – 3kHz (but possible future upgrades)


Next best option for an XPCS detector?

•Photon counting provides best S/N•Specifications

● 1-9 Mpixels● 1 μs frame rate, ~10-20 ns time resolution (time stamping)● 70-80 μm pixels● negligible dead time● 100% efficiency at 8keV● 4 bit dynamic range● “electronic shutter”

•VIPIC project (FNAL/BNL) is close to matching these ideal/realistic specs:

● 10 μs frame rate, ~20 ns time resolution (time stamping)● 80 μm pixels, scalable to >1M pixels

16 Serial Output Lines (LVDS)

Preamp X6

Disc.

ts=250 ns

Program latches

Serial Output Line

Sparsification

Two 5 bit counters

Serializer and LVDS Output

Inject/option Feedback Th

2 3 7 4X64


Applications

•Example of science that is impossible to do without fast 2D detectors● Dynamics in out-of-equilibrium “glass” complex

materials● Non-stationary and non-equilibrium dynamics

(two-time correlations)● Speckle Visibility Spectroscopy (with applications

in mitigating beam damage, low scatterers, etc)


Challenges:• Wide-range of time/length scales, with

samples that are often beam sensitive and/or low scatterers

• Current experiments → photon-limited

• Samples are often non-ergodig

• or non-stationary (e.g. aging) → see next slide

Correlation functions from hard-sphere suspensions near the colloidal glass transition (P. Kwasniewski et al., unpublished)

Dynamics of out-of-equilibrium system: complex fluids, “glassy” and “jammed” materials

Opportunities:• Understanding phenomena such as the

colloidal glass transition

• Understanding the interplay between dynamics and rheology; designing complex fluids with specific viscoelastic properties

Self-assembled monodisperse “supra-molecular” assemblies from polydisperse nanoparticles

T.D.Nguyen, S. Glotzer, et al.

Nature Nanotech 2011


Challenges:• Most complex system exhibit complex time-dependent behavior (i.e. aging)

• Dynamics is often heterogeneous

Two-time correlation functions showing non-equilibrium effects (“aging”) and heterogeneous dynamics (let) in colloidal gels or dynamical “rare events” in a colloidal glass (right) (AF et al.)

Dynamics of out-of-equilibrium system: non-stationary and aging samples

Opportunities:• Measuring time-dependent dynamics using two-time analysis

M. Sutton et al. Optics Express 11, 2268, 2003

• Characterize dynamical heterogeneities or “rare events”A. Duri and L. Cipelletti, Eur. Phys. Lett. 76, 972, 2006 C. Sanborn et al. Phy. Rev. Lett 107, 015702, 2011

• Using two-time analysis and higher order correlations to understand and control phenomena such as self-assembling in complex systems


Beam damage, low scattering Solution: speckles are detected from single images by analyzing the probability of

measuring 1,2,3,4,... scattered photons near Bragg spots of PXs

Intensity distribution (speckles)Left: Reference sample (colloid)Right: scattering near the (409)Bragg spot of concanavalinAincoherent scattering should follow Poisson statistics while speckles from coherent illumination follow neg binomial statistics (J.W. Goodman, 2007)

Speckles from protein crystals: the low scattering limit

Challenges:

Opportunities: Measuring dynamics of proteins using speckle visibility spectroscopy

P.K. Dixon and D. J. Durian, Phys. Rev. Lett. 90, 184302 (2003)


Conclusions

•Exciting (& challenging) opportunities for studying microscale dynamics of materials (examples show here focus on soft- and bio- matterials)

•Unprecedented coherent flux (e.g. NSLS-II) and experimental capabilities become available

•Fast 2D detectors for coherent scattering (speckles) are the single most important required development.

•Availability of such detectors would allow experiments that would capitalize on the unprecedented brightness of the new SRs and which are otherwise impossible

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Dynamics of materials with X-ray Photon Correlation ......Directing Matter and Energy: Five Challenges for Science and Imagination (BESAC) XPCS •“Mesoscale” structure determines