X-ray Coherence2003

Satelli

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August 22-23 te Meeting of SRI'03

Berkeley California

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International Workshop on

X-ray Science with Coherent Radiation

-- Satellite Meeting of SRI 2003

August 22-23, 2003

Building 50 Auditorium Lawrence Berkeley National Laboratory

1 Cyclotron Road, Berkeley, CA 94720, USA

Workshop Chairs Qun Shen (CHESS, Cornell)

John Spence (Arizona State/LBNL) John Arthur (SSRL, Stanford)

International Committee Donald Bilderback (Cornell)

Steve Dierker (BNL) Sol Gruner (Cornell)

Tetsuya Ishikawa (SPring-8) Janos Kirz (SUNY, Stony Brook)

Bruno Lengeler (Aachen) Andreas Magerl (Erlangen)

Gerhard Materlik (Diamond) Ian McNulty (APS)

Keith Nugent (Melbourne) Howard Padmore (ALS)

Jean Susini (ESRF) Mark Sutton (McGill)

Edgar Weckert (Hasylab)

Local Coordinators Virginia Bizzell (CHESS, Cornell) Cathy Cooper (LBNL) Laura Brown (CHESS, Cornell)

Financial Support by US National Science Foundation through CHESS, Cornell University and by US Department of Energy through Lawrence Berkeley National Lab Argonne National Lab

Workshop Proceedings: http://erl.chess.cornell.edu/ Cover: View from Cyclotron Road. Photograph provided by Lawrence Berkeley National Lab.

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Table of Contents

Workshop Program .................................................................................................................. 4

Friday, August 22 ............................................................................................................... 4 Saturday, August 23 .......................................................................................................... 5

Invited Talk Abstracts ............................................................................................................. 6

Energy recovery linac source properties ........................................................................... 7 Linac based x-ray sources: temporal & spatial coherence ............................................... 7 Tutorial: Coherence in x-ray physics ................................................................................ 8 X-ray intensity correlation spectroscopy ........................................................................... 8 Dynamic SAXS with coherent x-rays ................................................................................ 8 Soft x-ray coherent magnetic scattering experiments ....................................................... 9 Inversion of coherent diffraction images of nanocrystals .................................................. 10 Ptychography and diffractive imaging with x-rays & electrons .......................................... 10 Coherence preserving reflecting and crystal optics .......................................................... 11 Shaping x-rays by diffractive coded nano-optics .............................................................. 12 X-ray coherence measurements ....................................................................................... 12 Nanometer imaging with high brightness source .............................................................. 13 Coherence and x-ray microscopy ..................................................................................... 15 Recovering phase and correlations from x-ray fields ........................................................ 16 3D phase tomography ...................................................................................................... 16 X-ray vortices in coherent wavefield ................................................................................. 17 Diffractive optics and shearing interferometry .................................................................. 18 Fourier transform holography ........................................................................................... 19 Two-photon interferometry ................................................................................................ 19 Diffraction Imaging of the general particle ........................................................................ 20 Diffraction imaging with coherent x-rays ........................................................................... 20 3D X-ray microscopy by phasing diffraction patterns ........................................................ 20 Hydrodynamic models of x-ray irradiated bio-molecules ................................................... 21 Poster Abstracts ...................................................................................................................... 22

Focusing x-ray beams to nanometer dimensions ........................................................... 23 Magnetic speckles from nanostructures .......................................................................... 23 Single-element elliptical hard x-ray micro-optics .......................................................... 24 A fast CCD camera for x-ray photon correlation spectroscopy and time-resolved x-ray scattering and imaging ................................................................ 24 Some consequences of focusing in coherent diffraction ............................................... 25 Lessons from an experiment of high resolution fourier transform holography with coherent soft x-rays ....................................................................... 25 Time-resolved phase contrast radiography and DEI with partial coherent hard x-ray at BSRF ....................................................................... 26 Invalidity of low-pass filtering in atom-resolving x-ray holography ................................... 26

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Table of Contents Measurements of spatial coherence of x-ray laser from recombining Al plasma ..................................................................................... 27 Avoidance and removal of phase vortices in reconstruction of noisy coherent x-ray diffraction patterns .............................................................. 27 Pushing the limits of coherent x-ray diffraction: Imaging single sub-micrometer silver nanocubes .................................................................. 28 Coherent soft x-ray branchline at the Advanced Light Source ........................................ 29 Near-diffraction limited coherent X-ray focusing using planar refractive lenses made in epoxy resist SU8 ................................................................ 29 Quantum-deceleration self-modulation of high energy electron beam and the problem of optimization of coherent photon collider ................................... 30 Coherent hard x-ray scattering experiments at large diffraction angles ............................ 31 Multilayer x-ray optics: Progress in coherence preservation ......................................... 32 Attendees List ........................................................................................................................... 33

Area Map ........................................................................................................................ Last Page

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Program: Friday, 22 August, 2003

7:30 - 8:30 Continental breakfast, registration, poster set-up. 8:30 Qun Shen (Cornell) Welcome

Session 1: New Sources and Tutorial Janos Kirz (SUNY-SB) - Chair

8:35 Sol Gruner (Cornell) Energy recovery linac source properties 8:55 Jerry Hastings (Stanford) Linac based X-ray sources: temporal & spatial coherence

9:15 Bruno Lengeler (Aachen) Tutorial: Coherence in X-ray physics 10:05 Coffee Break and Poster Viewing (25 min.) Session 2: Coherent Diffuse Scattering Sunil Sinha (UCSD) - Discussion Leader

10:30 Mark Sutton (McGill) X-ray intensity correlation spectroscopy 11:00 Gerhard Grübel (ESRF) Dynamic SAXS with coherent x-rays 11:30 Jeroen Goedkoop

(Amsterdam) Soft x-ray coherent magnetic scattering experiments

12:00 Discussion on coherent diffuse scattering 12:15 Lunch: no-host (LBNL cafeteria), and Poster Viewing

Session 3: Coherent Diffraction on Nanocrystals Steve Wilkins (CSIRO) - Discussion Leader

14:00 Ian Robinson (UIUC) Inversion of coherent diffraction images of nanocrystals 14:30 John Spence (ASU) Ptychography and diffractive imaging with x-rays & electrons

15:00 Discussion on coherent diffraction on nanocrystals 15:15 Coffee Break and Poster Viewing (25 min.)

Session 4: X-ray Optics for Coherence Don Bilderback (Cornell) - Discussion Leader

15:40 Tetsuya Ishikawa (SPring8) Coherence preserving reflecting and crystal optics 16:10 Enzo Di Fabrizio (Eletra) Shaping x-rays by diffractive coded nano-optics 16:40 David Paterson (APS) X-ray coherence measurements 17:00 Wenbing Yun (Xradia) Nanometer imaging with high brightness source

17:20 Discussion on x-ray optics for coherence 17:35 Adjourn for the day

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Program: Saturday, 23 August, 2003

7:30 - 8:20 Continental breakfast.

Session 5: Phase Contrast Microscopy Ian McNulty (APS) - Discussion Leader

8:20 Chris Jacobsen (SUNY-SB) Coherence and x-ray microscopy 8:50 Keith Nugent (Melbourne) Recovering phase and correlations from x-ray fields 9:20 Peter Cloetens (ESRF) 3D phase tomography 9:50 Andrew Peele (Melbourne) X-ray vortices in coherent wavefield

10:10 Discussion on phase contrast microscopy

10:25 Coffee Break and Poster Viewing (20 min.)

Session 6: Holography and Interferometry Ken Finkelstein (Cornell) - Discussion Leader

10:45 Christian David (PSI) Diffractive optics and shearing interferometry 11:15 Anatoly Snigirev (ESRF) Fourier transform holography 11:45 Makina Yabashi (SPring8) Two-photon interferometry

12:15 Discussion on holography and interferometry 12:30 Lunch: brown-bag (Bldg.50 Auditorium), and Poster Viewing

Session 7: Coherent Diffraction Imaging John Spence (ASU) - Discussion Leader

14:00 David Sayre (SUNY-SB) Diffraction Imaging of the general particle 14:30 John Miao (Stanford) Diffraction imaging with coherent x-rays 15:00 Coffee Break and Poster Viewing (20 min.) 15:20 Malcolm Howells (LBNL) 3D X-ray microscopy by phasing diffraction patterns 15:50 Stefan Hau-Riege (LLNL) Hydrodynamic models of x-ray irradiated bio-molecules

16:10 Discussion on coherent diffraction imaging 16:25 John Arthur (Stanford) Workshop summary 16:40 End of Workshop

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Invited Talks

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Invited Abstracts: Friday Morning

Energy Recovery Linac (ERL) Source Properties

Sol M. Gruner Physics Dept. & Cornell High Energy Synchrotron Source (CHESS)

Cornell University, 162 Clark Hall, Ithaca, NY 14853-2501 Energy Recovery Linacs are being explored as next generation synchrotron light sources. The fundamental x-ray beam properties from storage ring sources, such as the source size, brilliance, and pulse duration are limited by the dynamic equilibrium characteristic of the magnetic lattice that is the storage ring. Importantly, the characteristic equilibration time is long, involving thousands of orbits around the ring. Advances in laser-driven photoelectron sources allow the generation of electron bunches with superior properties for synchrotron radiation. ERLs preserve these properties by acceleration with a superconducting linac, followed by transport through a return loop hosting insertion devices, similar to that of a 3rd generation storage ring. The loop returns bunches to the linac 180° out of accelerating phase for deceleration through the linac and disposal. Thus, the electron beam energy is recycled back into the linac RF field for acceleration of new bunches and the equilibrium degradation of bunches never occurs. The superior properties of ERLs beams include extraordinary brilliance and small source size, with concomitant high tranverse coherence, x-ray pulse durations down to ~100 femtoseconds, and flexibility of operation. The source properties will be discussed in terms of coherent applications. Linear Accelerator Based X-Ray Sources: Temporal and Spatial Coherence

J. B. Hastings

SSRL Stanford Linear Accelerator Center

Accelerator based synchrotron radiation (SR) sources are now commonplace in the world with the USA (APS), Japan (Spring-8) and Europe (ESRF) each operating storage ring sources in the hard x-ray energy range that provide unique radiation for studies in the chemical, biological and materials sciences. These sources are critical to the understanding of complex static structures and through inelastic x-ray scattering the dynamics. They have also been applied to time resolved diffraction on the scale of the photon pulse length ~100 psec. Photon beams with all the properties of SR but with pulse lengths of ~100 fsec are now available from linear accelerator based sources, for example the Sub-Picosecond Pulse Source (SPPS) at the Stanford Linear Accelerator Center (SLAC). X-ray free electron lasers providing unprecedented pulse intensities, full transverse coherence, and pulse lengths of ~ 100 fsec. are operating in the 100nm wavelength range and are in various stages of planning to reach the 0.1 nm range. The FEL process and the unique properties of these sources will be discussed.

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Invited Abstracts: Friday Morning

Tutorial: Coherence in X-ray Physics

B. Lengeler Aachen University

The concept of coherence is used in quantum mechanics, optics, x-ray and neuron scattering, mesoscopic electron transport. It will first be discussed what interferes in a physical event and what destroys interference. Then we treat chaotic light sources and one-mode lasers and the description of that light in terms of coherence functions of first and second order. The influence of the sample on coherence will be treated in a third part. The uncertainty in the momentum transfer defines a generalized coherence volume. When its size is larger than the illuminated volume speckle can be observed. Differences in x-ray, neutron and electron transport will be addressed. A few examples will illustrate the concepts.

X-ray Intensity Fluctuation Spectroscopy

Mark Sutton McGill University

Intensity fluctuation spectroscopy (IFS) is an ideal way to study the kinetics of fluctuations in a system provided that the scattering intensity is sufficient for the time scales of the system under study. For the last three to four decades, it has been extensively used with light scattering to study a large variety of systems. With the extension of the technique into the x-ray region, one has the advantage of accessing opaque materials, probing much shorter length scales and being less affected by multiple scattering. The prime disadvantage of x-rays over visible light is the much lower intensity levels of x-ray sources. This talk will summarize some of the recent results using the technique and then discuss current limitations with respect to new sources, new optics and new detector developments.

Dynamic Small Angle Scattering with Coherent X-Rays

G. Grübel European Synchrotron Radiation Facility, BP 220, 38043 Grenoble, France

Complex relaxations in disordered systems have been studied successfully by scattering of both visible light and neutrons. Neutron based techniques can probe the dynamic properties of matter at high frequencies from ω typically equal to 1014 Hz down to about 107 Hz and achieve atomic resolution. Photon Correlation Spectroscopy (PCS) with visible light can cover low frequency dynamics (ω<106 Hz), but probes only the long wavelength Q< 4*10-3 Å-1 region in materials not absorbing visible light. Coherent x-ray beams from third generation synchrotron radiation sources provide the possibility for correlation spectroscopy experiments with coherent x-rays (XPCS) capable of probing the low frequency dynamics (106 Hz to 10-3 Hz) in a Q range from 1.10-3 Å-1 up to several Å-1. XPCS can thus provide

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10 µm beamG d M 5 resonance

40 nm G dFe180 nm period

(M FM )

-1 0 1

Invited Abstracts: Friday Morning atomic resolution, but has proven to be particularly powerful in the small angle scattering regime and for the study of complex fluids. XPCS can operate in optically opague materials and is not subject to multiple-scattering effects. We will review the status of XPCS in the SAXS regime by discussing the properties of static x-ray speckle as well as its applications for the study of dynamical phenomena in soft condensed matter systems (suspensions of colloidal particles, polymer micelles, surface dynamics on complex liquids).

Soft X-Ray Coherent Magnetic Scattering Experiments

J.B. Goedkoop, M.A. de Vries, J.F. Peters, J.Miguel Van der Waals –Zeeman Institute

University of Amsterdam Valckenierstraat 65, NL1018 XE Amsterdam

goedkoop@science.uva.nl

N.B. Brookes, S.S. Dhesi ESRF, B.P. 220, F-38034 Grenoble Cedex

The increased coherence of third generation synchrotron sources allows us to port laser techniques such as holography and dynamical light scattering from the visible to the x-ray spectral range. In addition to the obvious improvement in resolution, the x-ray range may allow for new variants that are not possible in the visible, as exemplified by techniques that use the strong magnetic contrast at soft x-ray resonances. In this talk I will report on soft x-ray coherent magnetic scattering experiments performed on stripe magnetic domain systems as occurring in amorphous GdFe thin films with perpendicular anisotropy. This system was chosen in order to have maximum magnetic contrast, negligible charge scattering and minor multiple scattering. These experiments were performed at the ESRF on a spectroscopy beam line using a phosphor screen + visible CCD detector. A careful Kramers Kronig analysis of the magnetic cross section was made at both the Gd M5 and the Fe L3 resonances, which matches experimentally observed scattering cross sections remarkably well and is in agreement with atomic calculations. Despite non-ideal conditions we were able to obtain very high resolution speckle patterns both of ordered and disordered stripe systems from which the local magnetic correlation function can be obtained straightforwardly. Attempts at speckle inversion of these data have been foiled by lack of q-range.

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Invited Abstracts: Friday Afternoon We will discuss the field and energy dependence of the speckle patterns. We show that the scattered intensity in our experiment do not show energy-dependent anomalous interference between the magnetic and charge scattering contributions. Finally, first attempts at critical scattering at the Gd M5 edge of epitaxial Gd (0001) layers on W are reported. Despite mK temperature resolution and stability no such scattering could be observed, explainable by sample imperfections, lack of sufficient flux and detector insensitivity.

Inversion of Coherent Diffraction Images of Nanocrystals

Ian Robinson

University of Illinois, Urbana, IL.

In this talk, I will present the progress we have made towards reconstruction of real space images by inversion of coherent X-ray diffraction from small crystals. We have found that iterative Fourier transform methods based on the Fienup/Gerchberg/Saxton method can be successful under some circumstances. These methods work because the diffraction pattern can be oversampled with respect to the spatial Nyquist frequency. A strong real-space constraint in the form of a "support" region surrounding the object appears to be sufficient, but some anti-stagnation strategy is also necessary. The resulting images of gold nanocrystals are interesting in that internal striations are present [1]. The striations probably arise because of stresses present during the growth of the crystals. I will discuss the merits of possible enhancements to the technique enabled by the introduction of focusing optics in front of the sample. [1] "Three-dimensional Imaging of Microstructure in Gold Nanocrystals", G. J. Williams, M. A. Pfeifer, I. A.

Vartanyants and I. K. Robinson, Physical Review Letters 90, 175501-1 (2003).

Ptychography and Coherent Diffractive Imaging - X-rays and Electrons

John Spence Arizona State Univerisyt, Physics, and LBNL

Spence@asu.edu Several ideas, developed over half a century, have now converged to provide a working solution to the non-crystallographic phase problem. These include Sayre's 1952 observation that Bragg diffraction undersamples diffracted intensity relative to Shannon's theorem, that iterative ("HiO") algorithms with feedback rarely stagnate (Gerchberg-Saxton-Feinup), producing an astonishingly successful optimization method, and that these iterations are Bregman Projections in Hilbert space. Modern algorithms based on these ideas have recently produced the first spectacular atomic-resolution image of a double-walled nanotube

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Invited Abstracts: Friday Afternoon from experimental electron diffraction patterns (Zuo et al, Science, 300, 1419 (2003) ), and lensless X-ray images at 20nm resolution (Miao et al Nature, 400, p. 342 (199), He et al Phys Rev B. 67, p. 174114 (2003) ). In this talk two new ideas will be presented. First, recent experimental application of the "Shrinkwrap" HiO algorithm (Marchesini et al, (2003) in press) will be given. This algorithm inverts X-ray speckle patterns to images without knowledge of the object boundary. Experimental results are given with 20nm resolution. Secondly, the use of compact support along the beam direction in the transmission geometry for a thin diffracting slab will be described as a phasing method. Simulations for cryo-TEM tomography of protein monolayers shows that this use of the HiO algorithm greatly reduces the number of TEM images needed to provide known phases for the three-dimensional diffraction data (Spence et al, J.Struct Biol, in press, also Weierstall et al, Ultramic 90, 171 (2001). Finally, a conceptual connection between the HiO "oversampling" method (which requires diffracted intensity measurements at half the "Bragg" angle) and Ptychography (which uses interference between adjacent coherent diffraction orders) will be suggested.

Coherence Preserving Reflecting and Crystal Optics

Tetsuya Ishikawa SPring-8/RIKEN

Kouto 1-1-1, Mikazuki-cho, Sayo-gun, Hyogo 679-5148; e-mail: ishikawa@spring8.or.jp

Perfect preservation of x-ray coherence requires x-ray mirrors with atomic scale smoothness. The SPring-8 is collaborating with the Osaka group for producing better x-ray mirror. Image profiles of the reflected x-ray beam with coherent illumination are well reproduced by combining a calculation based on numerical Fresnel-Kirchhof integration with surface figure data measured with micro-stitching interferometry. Since figuring methods developed by the Osaka group are numerically controllable, we can correct the surface figure to a limit posed by the metrology. An elliptical mirror gave a nearly diffraction-limited focus line of 200 nm width. Kirkpatric-Baes combination of two elliptical mirrors gave a point focus of 200×200 nm2. After making some figure correction, the focal spot size was reduced to 90×180 nm2. Up to now, we do not make any coating on mirror surface. If we can coat heavy metals to increase the numerical aperture without degrading the surface figure, the calculated focal size in ideal case will be down to 30×60 nm2.

We have given an integral-form solution of time-dependent Takagi-Taupin equation for perfect crystal, and discussed propagation of coherence through dynamical x-ray diffraction. This has led to a simple method of measuring the modulus of mutual coherence function. One important conclusion is that we cannot always longitudinal and transverse coherence components. We will report the present status of synthetic diamond crystals in Japan and discuss some issues on diamond crystals in view of coherence preservation.

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Invited Abstracts: Friday Afternoon

Shaping X-Rays by Diffractive Coded Nano-Optics

E. Di Fabrizio TASC-NNL-INFM (National Institute for the Physics of Matter) Elettra Synchrotron Light Source

- Lilit Beam-line S.S.14 Km 163.5, Area Science Park, 34012 Basovizza - Trieste (Italy)

The current intense interest in extreme ultraviolet and x-ray microscopy is mainly due to the availability of a nearly ideal optical source for nano-optics based on diffraction, that is, a source with low divergence whose wavelength can be tuned over a range of several keV and whose spectrum can be monochromatised with a band pass ∆λ/λ of less than 10-4. Synchrotrons of the latest generation and free electron lasers (in the near future) are devices that produce x-rays with these characteristics. When a source of electromagnetic radiation is bright enough, that is, point-like and monochromatic, a new world opens for the designer of optical instruments and for a wider community of experimenters and theorists. This happened with the invention of the optical microscope and is still happening with x-ray microscopes of the latest generation. Although available x-ray sources have coherence characteristics very close to those of lasers at visible wavelengths, up to now the design of new optical devices has not proceeded much beyond simple focusing optical elements. In fact the zone plate, that can be now considered a well established focusing element for x-rays, was invented more than hundred years ago but due to technological difficulties, they have been implemented only in the last two decades.

In this article we show that it is possible to design, fabricate and easily use new optical elements that, beyond focusing, can perform new optical functions. In particular, the intensity (and polarization for extreme ultraviolet wavelength ) of light in the space beyond the optical elements can be redistributed with almost complete freedom. In other words, already available extreme ultraviolet and x-ray sources are suitable as ideal sources for diffractive optical elements designed to perform new optical functions that can conveniently be summarized under the expression .of. “beam shaping”. To our knowledge this is the first example of design, fabrication and application of novel x-ray optical elements that can perform multi-focusing in a single or multiple focal plane, beam shaping of a generic monochromatic beam into a well defined geometrical and “artistic” shape. These new optical functions, can be used for many applications ranging from microscopy, such as differential interference contrast microscopy, bio-imaging, maskless lithography and chemical vapour deposition induced by extreme ultraviolet and x-ray radiation.

X-ray spatial coherence measurements

David Paterson, Advanced Photon Source

Conventional spatial coherence measurement techniques rely upon a sequential series of measurements to completely map the coherence function of a source. Typically, the separation of slits – for example in a Young’s slits experiment – pinholes or mirrors must be varied. This is time consuming, limiting the parameter space that can be explored in an experiment and makes measurements of pulsed sources very difficult.

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Invited Abstracts: Friday Afternoon A technique that uses a diffracting mask to achieve the measurement of the entire coherence function with a single recording of a diffraction pattern will be described. The technique is directly applicable to measurement of sources with pulsed or DC nature. The mask is a class of coded apertures called a uniformly redundant array (URA). The technique can be performed with the URA as an absorption diffraction mask or a phase-shifting mask to measure harder x-ray sources. The analysis method and spatial coherence function measurements of 1.1–1.8 keV and 7.9 keV undulator radiation at the Advanced Photon Source will be described.

Uniformly redundant array design

Nanometer Imaging with a High Brightness Source

Wenbing Yun Xradia, Inc., 4075A Sprig Drive, Concord, CA 94520

The future high brightness synchrotron sources will permit development of x-ray

imaging techniques with sub-10 nm resolution and unprecedented capabilities, including 3D tomography for imaging biological specimens and studying crack initiation and propagation in materials science, spectromicroscopy for chemical state mapping of soil and environmental samples, and microdiffraction for mapping of crystallography phases and textures. As in the optical spectrum, the development of suitable lenses with the required optical property is of critical importance to realize these capabilities.

Zone plate lens has demonstrated 20-nm resolution, which is the highest spatial resolution achieved over the whole electromagnetic spectrum. The inherent high fabrication accuracy by advanced lithography technology means that it has a high degree of the source coherence preservation, as manifested by its diffraction limited focusing demonstrated by many researchers at high spatial resolution. Fabricating high-resolution zone plates for multikeV x-rays is very challenging because it requires producing precise nanometer scale structures with a high aspect ration (defined as thickness/feature-size). The challenge increases with x-ray energy because the aspect ratio required for maintaining a reasonable focusing efficiency increases with x-ray energy. Currently, Xradia is producing some of the

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Invited Abstracts: Friday Afternoon best performing x-ray zone plates for multikeV x-rays. With a focusing efficiency exceeding 10% for 3-10 keV x-rays, Xradia’s zone plate has an outermost zone width of 50-nm. This zone plate has a spatial resolution of 60-nm using its first order diffraction and 20-nm with a reduced efficiency using its third order diffraction. In principle, there is no fundamental limit to the resolution of a zone plate and the practical limitation is the fabrication of precise and accurate nanostructures with extreme high aspect ratio. While the challenge is substantial to develop zone plates with improving spatial resolution, the available resources are limited for research labs as well as companies like Xradia.

We will discuss some exciting possibilities of some synchrotron-based x-ray imaging techniques, including high spatial resolution sub-10 nm resolution and spectromicroscopy capable of chemical state mapping and elemental specific imaging at high spatial resolution. We will also present the development of zone plate lenses for coherent hard x-ray applications. Dr. Wenbing Yun Xradia, Inc., 4075A Sprig Drive, Concord, CA 94520, Phone 925-288-1818, Fax 925-288-0310. E-mail wyun@xradia.com.

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Invited Abstracts: Saturday Morning

Coherence and x-ray microscopy

Chris Jacobsen Department of Physics & Astronomy, Stony Brook University

Microscopy with coherent x-ray beams can take many forms. The coherent beam can be focused to a diffraction-limited spot which is then scanned

through a specimen. If a large area detector is used, the resulting imaging process is incoherent, whereas if a spatially segmented detector is used one can carry out partially coherent imaging. With Brookhaven Lab and MPI Garching, our group has developed a segmented detector (1) that can be used for delivering both amplitude and phase contrast images from a single scan of the specimen (2). Absorption contrast is particularly favorable for soft x-ray spectromicroscopy studies of chemical heterogeneities in biological and environmental science specimens (in particular when clustering or pattern matching approaches are used for data analysis (3)), but efforts to extend chemical analysis to phase contrast imaging will also be discussed.

The coherent beam can also directly illuminate the specimen, with the exit wave carrying information about the specimen. X-ray holography provides one means for recording and reconstructing this exit wave (4, 5), and this can be extended to three dimensions using diffraction tomography (6-8), as will be discussed by Cloetens. The characteristics of holography will be compared with other approaches such as far-field diffraction reconstruction and transport of intensity equation reconstruction.

With any of these methods, the information that can be obtained about the specimen is ultimately limited by radiation damage. The effects of radiation damage can be minimized by maintaining the specimen at cryogenic temperatures. This approach works very well for preserving specimen mass and structure at larger spatial scales (9); however, it appears to provide less protection to near-edge absorption resonances used for chemical state imaging (10). 1. M. Feser et al., in X-ray micro- and nano-focusing: applications and techniques II I. McNulty, Ed. (SPIE,

Bellingham, WA, 2001), vol. 4499, pp. 117-125. 2. M. Feser, C. Jacobsen, P. Rehak, G. De Geronimo, Journal de Physique IV 104, 529-534 (2003). 3. C. Jacobsen et al., Journal de Physique IV 104, 623-626 (2003). 4. M. Howells et al., Science 238, 514--517 (1987). 5. I. McNulty et al., Science 256, 1009--1012 (1992). 6. A. J. Devaney, IEEE Transactions on Image Processing 1, 221--228 (1992). 7. W. Leitenberger, T. Weitkamp, M. Drakopoulos, I. Snigireva, A. Snigirev, Optics Communications 180,

233-238 (2000). 8. T. Beetz, C. Jacobsen, A. Stein, Journal de Physique IV 104, 31-34 (2003). 9. J. Maser et al., Journal Of Microscopy 197, 68-79 (2000). 10. T. Beetz, C. Jacobsen, Journal of Synchrotron Radiation 10, 280-283 (2003).

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Invited Abstracts: Saturday Morning

Recovering Phase and Correlations from X-ray Fields

Keith A Nugent1, Andrew G Peele1, Chanh Tran1, Ann Roberts1, Henry N Chapman2, Adrian P Mancuso1 and David Paterson3

1School of Physics, The University of Melbourne, Vic., 3010, Australia 2Lawrence Livermore National University, PO Box 808, Livermore, CA., 94550, USA

3Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Ave, Argonne, Ill, 60439, USA

The development of x-ray free-election lasers promises the acquisition of diffraction

data from very small crystals, or even single molecules. Recent work has demonstrated the reconstruction of such non-crystallographic specimens from diffraction data, although the uniqueness of the reconstruction cannot be guaranteed. Successful unique real-space phase recovery methods, such as the transport of intensity approach, have been demonstrated and successfully applied but have hitherto been thought to fail in the far-field limit.

In this talk we consider the real-space ideas in the context of the diffraction of fields containing phase curvature, which we term astigmatic fields. We show that astigmatic diffraction patterns allow unique recovery of structural information from diffracted intensities in reciprocal space. We demonstrate an algorithm that allows the phase to be recovered uniquely and reliably.

We then go on to consider the next level of complexity, which is the recovery of the correlations in the wavefield. We outline a technique by which complete coherence information may be recovered from a beam and we present some experimental results recently obtained at the Advanced Photon Source.

3D Phase Contrast Tomography

P. Cloetensa, J.P. Guigaya, O.Hignettea, W. Ludwigb, R. Moksoa, M. Schlenkerc and S. Zablera (Email: cloetens@esrf.fr)

aEuropean Synchrotron Radiation Facility, BP 220, F-38043 Grenoble bGEMPPM, INSA de Lyon, F-69621 Villeurbanne, France.

cLaboratoire Louis Néel du CNRS, F-38042 Grenoble, France

Phase imaging can be instrumentally very simple at third generation synchrotrons due to the spatial coherence of the X-ray beam, provided by the small cross-section of the source and, on the imaging beamline ID19, to the large source-to-specimen distance of 145 m. Phase images can be understood as resulting from Fresnel diffraction, i.e. simple propagation. They can be used in two distinct modes. When the specimen-to-detector distance D is 'small', the phase discontinuities are revealed through fine fringes. These can be used as the input for approximate three-dimensional reconstruction. On the other hand, the Fresnel fringe systems that turn the images into an in-line hologram can be used to retrieve the phase distribution, through a holographic reconstruction process, based on the use of a series of images, taken at different distances from the sample. The phase maps are used as the input for tomographic reconstruction, yielding quantitatively the 3D distribution of the electron density (holotomo-

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Invited Abstracts: Saturday Morning graphy). In order to overcome in an efficient way the resolution limit of hard X-ray detectors (of the order of one micron) image magnification can be obtained in a projection microscope by focusing the beam upstream of the sample. Using a Kirkpatrick-Baez mirror system, beams with diameter below 90 nm have been obtained at 20 keV. A very high flux (up to 1012 ph/s) is obtained by using the first multilayer coated mirror to select a given undulator harmonic. The magnification allows to improve very significantly the spatial and time resolution of phase contrast imaging. Putting the object in the focus and through a scanning procedure micro-fluorescence maps of selected portions of the specimen are obtained. This gives, at a very fine scale, element specific information complementary to the micro-structural information obtained by phase imaging. Future needs in the field of coherent 3D imaging with respect to source properties, X-ray optics and detector technology will be considered.

X-ray Vortices in Coherent X-ray Wavefields

Andrew G Peele School of Physics, The University of Melbourne, Vic., 3010, Australia

Undergraduate optics courses treat waves as if they are completely coherent and have

a well-defined and continuous phase. It is now well accepted that most waves are not coherent and so it is necessary to take partial coherence effects into account. It is less well-established that phase distributions are rarely continuous. Indeed, the visible coherent optics community is only now coming to terms with the phenomena associated with phase discontinuities through the new field of “singular optics”. It is to be anticipated that x-ray “singular optics” is also an area of potential importance to the coherent x-ray optics community.

Singularities in the phase of a wavefield arise whenever the field amplitude is zero. In particular, these discontinuities in the phase can always be analysed in terms of a combination of edge discontinuities and vortex discontinuities (where the phase spirals around a point singularity with an integer multiple of 2π increase in the phase for each turn). In the optics community, singular optics has found application in the development of optical vortex solitons and in optical trapping (the optical spanner). It is also interesting to note that a wave structure containing a phase vortex carries orbital angular momentum in addition to the spin angular momentum associated with polarization.

The role of singular optics in coherent x-ray optics is not yet clear. At the University of Melbourne, we are interested in these structures in the context of phase recovery, where discontinuities play a critical role. It can be shown that propagation-based phase recovery is only able to yield a unique solution when it is known that phase singularities are absent. We speculate that singularities also play a significant, but not yet understood, role in methods to recover correlations in the wavefield. Techniques that use only measurements of intensity will fail when there is a rotational symmetry in the phase. The key issue being that the intensity distribution of a vortex wave structure is independent of the direction of rotation of the vortex. In this context, we have recently begun an exploration of vortex phenomena at x-ray wavelengths. While vortices are expected to be ubiquitous at all wavelengths, we have recently demonstrated the surprising fact that it is particularly easy to create these objects in a controlled way at x-ray wavelengths. I will describe these experimental results and discuss the concepts and role of phase discontinuities in phase recovery methods, as well as in measurements of the phase space properties of a wave.

18

Invited Abstracts: Saturday Morning

Diffractive Optics and Shearing Interferometry

C. David a, T. Weitkamp a, B. Nöhammer a, H.H. Solak a, A. Diaz a, M. Stampanoni b, E. Ziegler c, J.F. v.d. Veen a Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen-PSI, Switzerland

b Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen-PSI, Switzerland c European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France

The dramatical increase of coherence that will be available from the planned fourth

generation x-ray sources gives rise to the question as to what extend optical elements in the beam can preserve this high level of coherence. The deformations of the x-ray wave fronts should be much below one wavelength. In the case of diffractive x-ray optics operated in transmission, this directly translates into a placement accuracy of the diffractive structures of much better than one structure width. State-of-the-art lithography tools are capable of placement accuracies in the range of nanometers, meaning that the above condition can be met in most practical cases. In consequence, diffractive optics have a significant advantage over refractive or reflective x-ray optics in terms of aberrations that may deteriorate the degree of coherence of an x-ray beam. This is of special importance in context with future hard x-ray sources with transverse coherence lengths in the millimeter scale. To make effective use of such a beam, optical elements should be of similar size and simultaneously control the wave fronts with sufficient precision.

At the Laboratory for Micro and Nanotechnology we have been developing a large number of diffractive x-ray optics for a wide range of photon energies and applications. The areas of these elements cover, in some cases, many square millimeters. In addition to Fresnel lenses for micro-focusing applications, we have recently developed diffractive hard x-ray optical elements made by wet chemical etching of single crystal silicon. These elements serve as beam splitters and analysers in interferometer set-ups. The applications of such interferometers include phase contrast imaging, wave front sensing and metrology of x-ray mirrors. Although the above-mentioned devices are at the moment optimised for use with radiation from third generation sources, the majority of the developed technological processes could be applied to produce optical elements tailored to the requirements of fourth generation sources. Furthermore, the presented interferometry techniques could be used in interesting novel applications taking advantage of the dramatically increased coherence lengths and flux levels.

Left: Silicon diffraction grating for interferometry applications. Right: Hard x-ray interferogram of polymer spheres.

19

Invited Abstracts: Saturday Morning

Fourier Transform Holography

Anatoly Snigerev

European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France

(Abstract missing)

Two-photon interferometry

Makina Yabashi SPring-8/JASRI

Characterization of x-ray coherence is very important for performing a number of

applications based on coherence, as well as for diagnosing high-quality synchrotron sources. Two-photon interferometry originally introduced by Hanbury-Brown and Twiss [1] has a potential to determine spatial and temporal coherence (first-order coherence) and the photon statistics (higher-order coherence) with a very fast resolution. For present synchrotron sources, twophoton interference can be measured as an enhancement of coincidence probability of photoelectric pulses from a single bunch. A high-resolution monochromator must be used in order to get a reasonable enhancement of the coincidence probability [2]. We have developed a system for two-photon interferometry at SPring-8. As a key optics a high-resolution monochromator (HRM) based on 4-bounced asymmetric diffractions has been developed. The device enables to produce monochromatic x-rays with an extremely small bandwidth E = 120 µeV at E = 14.41 keV [3]. First we have measured a spatial coherence profile, particularly along the vertical direction, at the 27-m undulator beamline (19LXU) of SPring-8. Enhancement of coincidence probability was measured as a function of vertical slit width. The large enhancement (~ 30% max.) allowed us to determine spatial coherence profile with high accuracy [4]. Recently we have performed a similar experiment at the beamline 29XU of SPring-8, equipped with a 4.5-m undulator called a SPring-8 standard undulator. From the coherence length and the betatron function, we have determined a vertical source size and emittance, which are in good agreement with estimation by the accelerator group. We have also proved that the method can be applied to diagnose coherence propagation by optical elements. For temporal domain, we have succeeded in determination of pulse width (32 ps in FWHM) from measurement of the coincidence probability as a function of energy bandwidth [5]. The method will provide an essential information for ultrafast synchrotron sources which are currently developed.

[1] R. Hanbury-Brown and R. Q. Twiss, Nature (London), 177, 27 (1956). [2] E. Ikonen, Phys. Rev. Lett., 68, 2759 (1992); Y. Kunimune et al., J. Syn. Rad., 4, 199 (1997). [3] M. Yabashi, K. Tamasaku, S. Kikuta, and T. Ishikawa, Rev. Sci. Instrum., 72, 4080 (2001). [4] M. Yabashi, K. Tamasaku, and T. Ishikawa, Phys. Rev. Lett., 87, 140801 (2001). [5] M. Yabashi, K. Tamasaku, and T. Ishikawa, Phys. Rev. Lett., 88, 244801 (2002).

20

Invited Abstracts: Saturday Afternoon

Diffraction Imaging of the General Particle

D. Sayre, J. Kirz, C. Jacobsen, D. Shapiro, and E. Lima

Dept. of Physics and Astronomy SUNY at Stony Brook, NY 11794

For many years crystallographers have been performing high-resolution lensless

imaging of the unit cells of crystals by x-ray diffraction. With the arrival of more powerful x-ray sources it now appears probable that the technique can be successfully extended to general small structures. Assuming that this is so, a result will be a large increase in the consumption of photons, as well as in the range of structures which can be imaged. The subject, including imaging resolution issues, will be briefly reviewed.

Diffraction Imaging with Coherent X-rays

John Miao (SSRL) When a coherent diffraction pattern of a finite sample is sampled at a spacing finer

than the Nyquist frequency (i.e. the inverse of the sample size), the phase information is embedded inside the diffraction pattern itself and can be directly retrieved by using an iterative process. In combination of this oversampling phasing method with coherent X-rays, a new imaging methodology (i.e. coherent imaging) has recently been developed to determine the electron density of nano-crystals, non-crystalline materials and biological samples. In this talk, I will discuss the principle of the oversampling method and present some recent experimental results.

3D X-ray microscopy by phasing diffraction patterns: prospects and limitations

M. R. Howells1, H. Chapman2, R. M. Glaeser1, S. Hau-Riege2, H. He1, J. Kirz1,3,

S. Marchesini1, H. A. Padmore1, J. C. H. Spence4,1, U. Weierstall4. 1Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.

2Lawrence Livermore National Laboratory, Livermore, CA 94550, USA. 3State University of New York, Stony Brook, NY 11794, USA.

4Arizona State University, Tempe, AZ 85287, USA. Corresponding author: mrhowells@lbl.gov

This presentation addresses the questions of what performance can we expect from a

3D diffraction microscope and what will set the limits. In particular we make a quantitative calculation of the dose required for imaging at any given resolution and statistical accuracy with a model sample consisting of protein against a background of water. We derive the dose

21

Invited Abstracts: Saturday Afternoon needed for 3D imaging by use of the dose-fractionation theorem of Hergel and Hoppe and determine that for 3D imaging, the dose scales inversely as the fourth power of the resolution. Thus far the calculation has made no reference to the amount of dose that the sample can tolerate. The critical dose for destruction of features of a given size in a protein sample has been fairly widely investigated by various interested communities (spot-fading experiments etc) and we have assembled a body of information from the literature of both x-ray and electron imaging. When the dose required for imaging a feature according to the Rose criterion and the critical dose for destruction of features is displayed on a common plot of the dose against feature-size, one can see that imaging life science samples with a resolution of about 10 nm should be possible. For the more radiation-resistant samples investigated in material science research, significantly better resolution of about 2-4 nm is expected. Another requirement for these experiments to be useful is that the exposure time should be not more than a few hours for a complete tilt series. We address this question in a similar way to the dose and find that (a) the required coherent flux also scales with the inverse fourth power of the resolution and (b) the exposure times are reasonable even for present-day synchrotron sources provided that optimally chosen undulators and optical systems achieving their design performance are used.

Acknowledgements This work was supported by the Director, Office of Energy Research, Office of Basics Energy Sciences, Material Sciences Division of the U. S. Department of Energy, under Contract No. DE-AC03-76SF00098.

Hydrodynamic Model of X-Ray Irradiated Biological Molecules

Stefan P. Hau-Riege, Richard A. London, and Abraham Szöke

Lawrence Livermore National Laboratory, Livermore, CA 94550, USA

X-ray free electron laser (XFEL) synchrotron radiation sources can produce extremely short and intense X-ray pulses that potentially allow the three-dimensional structure determination through single-molecule diffraction imaging. One of the critical issues is the deterioration of a molecule induced by X-ray irradiation.

Recently, molecular-dynamics calculations of the damage dynamics of biological molecules have been presented by Neutze et al. (Nature 406, 752 (2000)). In contrast, we have developed a simpler hydrodynamic model, but added several physical effects that strongly affect the dynamics. Most important is the effect of trapped electrons that have been stripped from the atoms but that are trapped by the electrostatic field of the molecule.

In this paper, we will present a simple dynamics model that includes an approximate description of the dominant physical effects. We used this model to survey a wide range of parameters to obtain the image resolution as a function of molecule size, particle composition, and beam parameters. Classification of individual diffraction images according to the molecule orientation constrains the beam parameters further (G. Huldt et al., to be submitted). We determined the optimum resolution as a function of beam and molecule parameters considering both radiation damage and image classification.

This work was performed under the auspices of the U. S. DOE by LLNL under Contract No. W-7405-ENG-48.

22

Poster Abstracts

23

Poster Abstracts

Focusing X-ray Beams to Nanometer Dimensions

C. Bergemann1,*, H. Keymeulen2, and J.F. van der Veen2

1Laboratorium für Festkörperphysik, ETH-Hönggerberg, CH-8093 Zürich, Switzerland 2Paul Scherrer Institut, CH-5232 Villigen, and ETH-Zürich, Switzerland

We address the question: what is the smallest spot size to which an X-ray beam can be

focused? We show that confinement of the beam within a narrowly tapered waveguide leads to a theoretical minimum beam size on the order of 10 nm (FWHM), the exact value depending only on the electron density of the confining material. This limit appears to apply to all X-ray focusing devices. Mode mixing and interference can help to achieve this spot size without the need for ultra-small apertures. *Present address: Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 OHE, UK.

Magnetic Speckles from Nanostructures

K. Chesnel, M. Belakhosky, G. van der Laan, G. Beutier, A. Marty, F. Livet ALS, LBNL

1 Cyclotron road, MS 7R0100, Berkeley, CA 94709 Ph: 510-495-2830; Fax: 510-486-4229; Kchesnel@lbl.gov

The recent development of Resonant Magnetic Scattering (XRMS) in the soft X-ray

range provides increasing opportunities to study magnetic order and reversal processes in nanostructures. Indeed, besides the chemical selectivity and the polarization sensitivity, this technique gives the possibility to penetrate thin layer in depth and study the magnetic ordering at the nanoscopic scale. Moreover, the use of coherent light and 2D detection provides remarkable speckle patterns that are related to the local magnetic topology. Magnetic speckles have been recorded in a reflection geometry on two types of systems with perpendicular magnetic anisotropy: thin epitaxied FePd films with striped magnetic domains [1] and etched lines grating covered by Co/Pt multilayer [2]. The resulted images from FePd layers exhibit magnetic speckles with a strong intensity contrast, evidencing the high coherence of the incident light [3]. This coherence degree, close to 90%, results from the excellent beam quality and the use of a pinhole placed very close to the sample, thus opening possibilities to perform real space reconstruction. In case of CoPt lines, the scattering pattern presents a serial of sharp peaks related to the grating periodicity. In some specific demagnetized state, remarkable magnetic satellites appear in between the structural peaks, evidencing a tendency to antiferromagnetic order [2]. This scattering pattern is significantly modified when a magnetic field is applied on the system, perpendicularly to its surface. By following the signal variations through the whole magnetization loop, starting from the demagnetized point, one can observe antiferromagnetic satellites disappearing at the saturated state, then a wider magnetic signal appearing at the coercive point. This magnetic signal evolution gives information about the ordering and switching processes. In conclusion, these coherent XRMS results performed with in situ magnetic field show rich possibilities to study local magnetic behavior in nanostructures and open the door to dynamic studies.

24

Poster Abstracts [1] H.A. Durr and al., Science 284, 2166 (1999) [2] K.Chesnel and al., Phys. Rev. B 66, 024435 (2002) [3] K.Chesnel end al., Phys. Rev. B 66, 172404 (2002)

Single-Element Elliptical Hard X-Ray Micro-Optics

K. Evans-Lutterodt Brookhaven National Laboratory

Using micro-fabrication techniques, we have manufactured two optics; a single

element kinoform lens in single-crystal silicon with an elliptical profile for 12.4 keV (1Å) x-rays, and a Fresnel prism. By choosing to fabricate an optic optimized at a fixed wavelength, absorption in the optic can be significantly reduced by removing 2π phase-shifting regions, while maintaining phase coherence across the optic. This permits short focal length devices to be fabricated with small radii of curvatures, allowing one to obtain a high demagnification of a finite synchrotron electron source size. We present our first results from experiments at the National Synchrotron Light Source X13B beamline. Research carried out at the National Synchrotron Light Source under DOE Contract No. DE-AC02-98CH10886.

A fast CCD camera for x-ray photon correlation spectroscopy and time-resolved x-ray scattering and imaging

Peter Falus, Matthew A. Borthwick

Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 Simon G. J. Mochrie

Departments of Physics and Applied Physics, Yale University, New Haven, CT 06520

It was widely recognized at the beamline proposal stage that one of the most exciting scientific opportunities o®ered by coherent X-ray sources is the possibility of carrying out x-ray photon correlation spectroscopy (XPCS) experiments. As increasingly challenging experiments are attempted and the demand for synchrotron beam time grows, in order to collect the most meaningful data most e±ciently, it is also essential to optimize the beam line optics, and the x-ray detection scheme. However, in contrast to the intensive e®ort to increase source brilliance and improve beam line optics, with a few notable exceptions, the development of x-ray detectors has often seemed a relatively neglected area. The purpose of this poster is to describe a new, inexpensive, fast, charge-coupled device (CCD)-based, x-ray area detector – the SMD1M60 – which we have implemented in the context of a research e®ort at beam line 8-ID at the Advanced Photon Source to carry out x-ray photon correlation spectroscopy (XPCS) experiments. The key feature of the SMD1M60 detector for XPCS experiments is that it permits us to continuously acquire images at full-frame data rates of up to 60 Hz and one-sixteenth-frame data rates of up to 500 Hz. While very fast the detector is photon counting, suppressing any detector noise. Thus, it is straightforward to acquire data with a time resolution of as little as 2 ms, and data from a considerably larger solid angle can

25

Poster Abstracts be collected if a time resolution of 17 ms is acceptable. The much greater data rate possible with the SMD1M60 permits a 100 fold increase in the XPCS Signal to Noise Ratio in cases where sub-second time steps are called for. In addition, the SMD1M60 is based on an inexpensive, commercially-available CCD camera. It is also lightweight and conveniently transportable to the synchrotron. Beyond XPCS, because of the superior data rates possible, we expect that this detector may find application in time-resolved x-ray scattering experiments of all sorts, especially where the scattering is weak and diffuse. In addition, we have found it capable of collecting superior small angle x-ray scattering (SAXS) data.

Some Consequences of Focusing in Coherent Diffraction

K. D. Finkelstein CHESS Wilson Lab, Cornell University, Ithaca, New York 14853

A quantitative understanding of incident beam angle and energy spread, and similar

information about the detector are needed to understand the resolution in an x-ray scattering experiment. Are the consequences of these considerations different when the incident beam is a coherent wave front? We report on simulations made to explore the influence on the diffraction pattern of very simple systems, when the incident beam is focused on the specimen. The results offer some guidance on when concentrating optics may be useful, and how sensitive the scattering pattern is to phase variation in the incident beam.

Lessons from an Experiment of High Resolution Fourier Transform Holography with Coherent Soft X-rays

H. He, S. Marchesini, M. Howells, U. Weierstall, G. Hembree, and J. C. H. Spence

Lawrence Berkeley Nation Lab. and Arizona State University

A well separated reference wave and an unknown object together with the coherence of the beam source are the basic needs to do a Fourier transform holography (FTH) experiment. Holograms from a 2D random array of 50 nm gold balls that fulfill such conditions has been recorded accidently in beamline 9.0.1 in Adavanced Light Source using coherent soft X-rays at 2.1 nm wavelength. Reconstruction using direct numerical Fourier transform is readily obtainable and features better than 50 nm is resolvable. Attempt of higher resolution reconstruction with deconvolution will be reported. Various experimental approaches that satisfy FTH conditions will be discussed. Comparison of FTH to other reconstruction methods will be made.

26

Poster Abstracts

Time-Resolved Phase Contrast Radiography and DEI with Partial Coherent Hard X-Ray at BSRF

G. Li, Z Y Wu

Beijing Synchrotron Radiation Facility, IHEP, Beijing 10039, China

Continuously nice phase contrast images of different specimens, characterized by a negligible absorption contrast, have been obtained at Beijing Synchrotron Radiation Facility (BSRF), using the wiggler source of one of the last first-generation synchrotron ring still in operation. These phase contrast images shows details of the specimens and some interesting change related to the inner physiological and chemistry process of the specimens, when the object-film distance is between 5 and 100 cm, which can not be observed in any conventional radiographic images, that appear such as the defocused images of those recorded using the phase contrast method. These experiments at BSRF demonstrates that phase contrast radiographic methods, although limited by the partial coherence of the source, can achieve significant improvements in image quality and that this technique may have a wide range of applications in life science, biology, biomedicine and of course materials science.

Invalidity of low-pass filtering in atom-resolving x-ray holography

D. V. Novikov 1, S. S. Fanchenko2, A. Schley1, M.Tolkiehn1, G. Materlik3 1Hamburger Synchrotronstrahlungslabor HASYLAB am Deutschen Elektronen-Synchrotron

DESY, D-22607 Hamburg, Germany 2Institute of Information Technologies, RRC Kurchatov Institute, Kurchatov square 1,

Moscow 123182, Russia 3Diamond Light Source Limited, Rutherford Appleton Laboratory, Chilton, Didcot,

Oxfordshire OX11 0QX, United Kingdom

Atom-resolving x-ray holography is a recently developed method for direct imaging of local three-dimensional structures at the atomic level. We investigate analytically and numerically additional effects arising from the long-range order in an object. It is shown that they are not correctly taken into account by existing image reconstruction procedures used commonly in the analysis of experimental data. We prove that low-pass filtering may lead to strong artefacts and cannot be used for extracting information about the short-range order in crystalline samples. Possible ways for solving the problem are discussed.

27

Poster Abstracts

Measurements of Spatial Coherence of X-ray Laser from Recombining Al Plasma

Yuuji Okamoto, Naohiro Yamaguchi, Hideki Yamaguchi, and Tamio Hara

Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511, Japan

Tabletop x-ray lasers which operate at wavelengths shorter than 20 nm are promising tools for many important applications such as x-ray photoelectron spectroscopy, x-ray microscopy, x-ray holography and x-ray lithography. The x-ray lasers are characterized by its high brightness, high coherence and monochromatic radiation. Especially, the degree of coherence of radiation plays a critical role in many of novel applications.

We measured the spatial coherence of the soft x-ray laser from the recombining Al plasma under various x-ray amplification configurations for the first time. A theoretical calculation model which was based on two-beam interference with partially coherent and quasimonochromatic light was developed to analyze the observed fringe patterns. The x-ray source was assumed to have a Gaussian intensity distribution, and a deviation of x-ray source from the optical axis of the Young’s interference experiment was introduced. Then we can reproduce a fringe pattern, numerically which fits to an observed fringe pattern, though it has an asymmetric pattern. In the experiments, the fringe pattern representing the interference from the pair of Young’s slits has been observed for the Al XI 3d-4f line (15.47 nm), while there has not been observed the fringe visibility for the other non-lasing lines. It is clarified that spatial coherence of the Al XI 3d-4f line is developed in accordance with its amplification.

Avoidance and Removal of Phase Vortices in Reconstruction of Noisy Coherent X-ray Diffraction Patterns

Mark Pfeifer, University of Illinois at Urbana-Champaign

Phasing the oversampled X-ray diffraction from a coherently illuminated crystal

provides sufficient information to reconstruct the density function of the diffracting crystal. This phasing, which is accomplished through use of an error reduction or hybrid input-output algorithm, can result in non-physical phase vortices in the reciprocal space reconstruction if the noise level of the data is too high. These vortices can cause significant error in the reconstructed image and are very difficult to remove since they are global defects in the phase- two vortices of opposite chirality must annihilate each other to be removed. While acquiring data with low levels of noise is preferable, it is sometimes not possible in experiments with time dependence or very small particles. Patching the amplitude and phase around vortices with random values can sometimes remove them from two-dimensional patterns, but this procedure is not feasible in three dimensions. Attempts are being made to avoid vortices or drive them by selection of starting conditions or modification of the input data.

28

Poster Abstracts

Pushing the Limits of Coherent X-Ray Diffraction: Imaging Single Sub-

Micrometer Silver Nanocubes

F. Pfeiffera, Yugang Sunb, Younan Xiab, and I.K. Robinsonc aSwiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.

bDepartment of Chemistry, University of Washington, Seattle, WA 98195-1700, USA. cDepartment of Physics, University of Illinois, Urbana, Illinois, 61801, USA.

X-ray crystallography has been proven to be an extremely efficient investigation

method to solve the structure of matter at the atomic scale. Although several methods have been employed to circumvent the intrinsic phase problem, other limitations do exist for classical x-ray crystallographic methods. In particular, disordered materials, single nanostructures, or noncrystalline and/or nonrepetitive biological structures (e.g. some important viruses or proteins) cannot be accessed by this approach.

As first considered by Sayre et al. [1], a combination of coherent x-ray diffraction with a so-called oversampling phasing method can overcome these limitations. In a first demonstration experiment, Miao et al. used that method to invert the soft x-ray forward-scattering pattern measured from a fabricated object [2]. More recently, the reconstruction of 2D and 3D crystalline and non-crystalline (!) structures has been reported [3, 4]. Particularly the latest results from Williams et al. [5], where the complete 3D phase and shape information of a micrometer-sized gold crystal could be retrieved, impressively demonstrate the high potential of this nondestructive method. With the work presented in this poster we particularly focus on the feasibility of pushing the limits of imaging small crystals by using coherent x-ray diffraction into the nanometer range.

As demonstration samples we have used chemically synthesized, single crystalline silver nanocubes with an average typical size of 175 nm [6]. The coherent x-ray diffraction experiments have been carried out at the ID34/UNICAT beamline at the Advanced Photon Source (Argonne) using monochromatic x-rays with an energy of 8.5 keV.

In order to have both sufficient flux and the opportunity to select single nanocrystals a Kirk Patrick-Baez (KB) mirror system has been used to focus the x-ray beam to typically 1.0 x 1.5 2mµ at the position of the sample. The diffraction data was recorded using a CCD placed at a position corresponding to the 111 Bragg reflection of the silver crystal lattice.

The following major conclusions could be drawn from the experimental results: Firstly and most importantly, the high-resolution reciprocal diffraction patterns clearly demonstrate the feasibility of carrying out such measurements on single nanocrystals with a size in the nanometer range. Depending on the orientation of the individual nanocrystals the measured diffraction patterns showed a nice three- and fourfold symmetry and up to typically 5-10 high contrast interference fringes in directions corresponding to the facets of the cubic structure. Furthermore we have not found any negative effects on the trasverse coherence by using the experimentally crucially important KB focusing optics. Finally, the obtained results agree well with model calculations based on a simple Fourier transform of two-dimensionally projected single silver nanocube.

Encouraged by this successful first demonstration experiment of coherent x-ray diffraction on sub-micrometer single crystalline nano-objects we are currently working on the direct reconstruction of a full 3D diffraction data by using the oversampling phasing method.

29

Poster Abstracts [1] D. SAYRE, Imaging Processes and Coherence in Physics, Springer Lecture Notes in Physics Vol. 112,

229 (1980). [2] J. MIAO, P. CHARALAMBOUS, J. KIRZ, and D. SAYRE, Extending the Methodology of X-ray

Crystallography to allow Imaging of Micrometer-sized Non-crystalline Specimens, Nature 4000, 342 (1999).

[3] J. MIAO, T. ISHIKAWA, B. JOHNSON, E.H. ANDERSON, B. LAI, and K.O. HODGSON, High Resolution 3D X-ray Diffraction Microscopy, Phys. Rev. Lett. 89 (2002).

[4] I.K. ROBINSON, I.A. VARTANYANTS, G.J. WILLIAMS, M.A. PFEIFER, and J.A. PITNEY, Reconstruction of the Shapes of Gold Nanocrystals using Coherent X-ray Diffraction, Phys. Rec. Lett. 87, 19 (2001).

[5] G.J. WILLIAMS, M.A. PFEIFER, I.A. VARTANYANTS, and I.K. ROBINSON, Three-dimensional Imaging of Microstructure in Gold Nanocrystals, Phys. Rev. Lett. 90, 17 (2003).

[6] YUGANG SUN and YOUNAN XIA, Shape-Controlled Synthesis of Gold and Silver Nanoparticles, Science 298, 2176 (2002).

Coherent Soft X-ray Branchline at the Advanced Light Source

Kristine Rosfjord1,2, Charles Kemp1, Paul Denham1, Eric Gullikson1, Phillip Batson1,

Senajith Rekawa1, David Attwood1,2 1Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA 94720

2Electrical Engineering & Computer Science Department, UC Berkeley, Berkeley, CA 94720

A new coherent soft X-ray branchline at the advanced light source has begun operation. Using the third harmonic from an 8cm period undulator, this branch delivers coherent soft x-rays ranging from 200eV to 1000eV. There are two sub-branches, one with 8x demagnification and optimized for 800eV and the other with 14x demagnification and optimized for 500eV. The monochromator consists of a variable-line-spacing grating and an exit slit, enabling a bandwidth of 0.1%. Soft X-rays have been propagated through the exit slit of the monochromator, matching spectral features of nitrogen (410eV) and titanium (454eV). We are currently working to characterize the spatial coherence properties of this radiation. We have shown single pinhole Airy patterns, and by the time of the workshop we expect to have performed two-pinhole interference measurements of the transverse coherence length.

Near-diffraction limited coherent X-ray focusing using planar refractive lenses made in epoxy resist SU8.

I. Snigireva*, A. Snigirev*, V. Nazmov**, E. Reznikova**, M. Drakopoulos*, J.Mohr**,

V.Saile**, V. Kohn*** * ESRF, BP-220, 38043 Grenoble Cedex, France

** Institut für Mikrostrukturtechnik, FZK, 76021 Karlsruhe, Germany *** Russian Research Centre “Kurachatov Institute“, 123182 Moscow, Russia.

We present results on optical properties of high resolution planar refractive lenses

studied with hard X-ray coherent radiation. Large aperture (up to 1mm) and high aspect ratio planar parabolic lenses were manufactured in epoxy type SU8 resist using deep synchrotron lithography. Resolution of about 250 nm was measured for the Su8 lens consisting of 62

30

Poster Abstracts individual lenses at 14 keV in a distance of 58 m from the source. In-line holography of B-fibber was realized in imaging and projection mode with a magnification of 3 and 20 respectively. Submicron features of the fiber were clearly resolved. Coherent properties of the set-up allow to resolve near-focus fine structure in scanning and imaging mode with lens defocusing. This fine structure is determined by the tiny aberrations caused by lens imperfections close to the parabola apex.

Quantum-Deceleration Self-Modulation of High Energy Electron Beam and the Problem of Optimization of Coherent Photon Collider

Vladimir I. Vysotskii, Mickle V. Vysotskii

Kiev Shevchenko University, Radiophysical Faculty, 01033, Kiev, Ukraine

The problems of creation of a sources of coherent hard radiation and high energy photon colliders optimization were studied. It is well known that low efficiency of gamma-gamma colliders is the result of very low cross-section of laser quanta scattering on relativistic electrons. The method of controlled non-threshold quantum-deceleration self-modulation of high energy electron beam in space (space period of self-modulation equals Λ) and time (frequency of modulation equals Ω = 2πv/Λ) with effectiveness about 1 for photon-electron scattering is discussed. The result of colliding resonant interaction of this modulated electron beam and optical laser beam with intensity J0, wave-length λ and frequency ω0 is generation of intensive gamma-beam with frequency of gamma-radiation ω=4γ2ω0 and intensity J=KJ0.

The method of self-modulation of electron beam is the following. The total wave function of each electron of the nonmodulated beam after passing of this beam through thin periodical diaphragm with thickness L0 and period D0+D1 (see fig.) has the form of coherent superposition

Ψ( r⊥ , z>L0,t)=Ψ0(r⊥ , z, t) + Ψ1(r⊥ , z,t) = Ψ0(r⊥ ) exp[-i2π(E0t-p0z)/h]+Ψ1(r⊥ )exp[-i2π(E1t-p1z)/h].

Here Ψ0(r⊥ ,z,t) is the wave function of an electron which has passed through one of microholes (with size D0) in diaphragm; Ψ1(r⊥ ,z,t) is the wave function of an electron which has passed through one of the absorptive parts (size D1) of this diaphragm and has reduced energy E1=E0-∆E(L0). Here ∆E(L0)=E0L0/Lc

rad; Lcrad<< Lrad is a coherent

radiation length of diaphragm crystal; E1=E0-∆E(L0) and p1=p0-∆p(L0) are longitudinal energy and impulse of each electron in the state Ψ1; E0=γmc2, p0=γmv; ∆p(L0) = p0 - [E0-∆E(L0)]2 - m2c41/2/c ≈ γ∆E(L0)/c(γ2-1)1/2.

The phenomenon of non-threshold quantum-deceleration self-modulation of electron beam takes place in the region of mutual coherence Li≤z≤ Lcoh of electron eigenfunctions Ψ0,1((r⊥ , z,t).

Here Li ≈ (D0+D1)/∆θd = 2πγmv(D0+D1)2/h; Lcoh ≈ Λγ2Q = λγQ.

L0 Electron beam Gamma-beam (E0 , p0) (λ 0/4γ2)

D1

D 0 Laser beam Thin periodical Li Λ Lcoh (λ 0)

diaphragm

E1 , p1

E0 , p0

31

Poster Abstracts For this region the electron concentration and current density of electron beam have the

forms of relativistic electron quasicrystal and n(z,t)=|Ψ0(r⊥ ,z,t)+Ψ1(r⊥ ,z,t)|2; jz(r⊥ ,z,t)=(ieh/4πm)ΨdΨ*/dz-Ψ*dΨ/dz=j01+gexp[i(Ωt-kz)]+g*exp[-i(Ωt-kz)]. Here j0= (ehp0/2πm)[|Ψ0|2+|Ψ1|2]; g =Ψ1Ψ0*/(|Ψ0|2+|Ψ1|2), Ω = 2π∆E(L0)/h,

k=2πΛ-1=2π∆p(L0)/h, Q=E0/[<(δE0)2>+<(δE1)2>]1/2 is the quality of the electron beam, δEi is a fluctuation of energy Ei. For the optimal case of symmetric diaphragm (D1=D0, <|Ψ0(r⊥ )|2>r⊥ =<|Ψ1(r⊥ )|2>r⊥ ) we have

the phenomenon of total electron beam self-modulation and formation of “running electron periodical lattice” n(z,t) = n01+cos (Ωt - kz); jz(z,t) = j01+cos (Ωt - kz); n0 ≡ |Ψ(z=0)|2. For realization of a requirement of a Bragg interaction (Bragg diffraction) of laser beam with wave lengh λ0=4γ2Λ=4γ2h/∆p(L0) and this electron beam with period of modulation Λ the condition of Bragg diffraction L0=4γhLñ

rad/λ0mc in back direction θ=π is necessary. For the case of periodical diaphragm made of zeolite-like crystal (Lc

rad<<1 cm, D0≈D1≈20 A) and at laser wave-length λ0=1µm we need L0≈10-5 Lc

rad γ cm. The total cross-section σ of diffraction of laser beam on this modulated beam and the total coefficient K of reflection (coefficient of diffraction) of laser beam with cross-section S equal K=σ/S, σmax=∫(dσ/do)do=2(e2λ/γmc2)2n0

2S(Lcoh-Li)2≈2S(e2λ2n0Q/mc2)2. For the laser beam with total cross-section S=10-4 cm2 and wave-lengh λ0=1µm and for the

case of relativistic electron beam with electron density n0=1014 cm-3 and quality Q=104 we have Lcoh ≈ γ cm, Li≈10-3 γ cm, σmax≈10-5 S and Kmax=10-5 that by many order of magnitude more that in the case of usual non Bragg-like gamma-gamma colliders.

Coherent hard x-ray scattering experiments at large diffraction angles

F. Yakhoua, F. Livetb, M. de Boissieub, F. Bleyb

aESRF, BP 220 F-38043 Grenoble, FRANCE bLTPCM-ENSEEG,BP 75 F-38402 St Martin d’Hères, FRANCE

In the promising framework of coherent x-ray scattering, the use of hard x-rays of

energy in the few keV range has not been developed as far as its soft x-rays counterpart, in particular at large diffraction angles. The increased difficulty compared to soft x-rays and small angle scattering arises mainly from a smaller coherence volume at higher energies and a rapid smearing of the contrast at large diffraction angle because of an optical path length difference that increases beyond the longitudinal coherence length.

A special setup was developed on the ID20 Magnetic Scattering beamline at ESRF to perform coherent scattering experiments at large diffraction angles up to 75° in 2θ. Special care was taken to lessen the number of windows in the x-ray path. A secondary source was defined by means of a set of slits placed 3 meters away from the collimating pinhole. The size of the source was adjusted so that the transverse coherence length would match the size of the pinhole. A monochromatic undulator beam from a double Si111 monochromator was used and a total coherent flux of 3109 ph/s at 190 mA ring current through a 10 µm pinhole was obtained at 8 keV.

32

Poster Abstracts

Promising examples will be given of the study of speckle patterns from antiferromagnetic domains in UAs [1], manganite charge and orbitally ordered domains [2] and phasons in quasicrystals. [1] F.Yakhou, A. Létoublon, F. Livet, M. de Boissieu and F. Bley, Journal of Magnetism and Magnetic Materials 233 (2001) 119-122 [2] C.S. Nelson, J. P. Hill, D. Gibbs, F. Yakhou, F. Livet, Y. Tomioka, T. Kimura and Y. Tokura, Physical Review B 66 (2002) 134412

Multilayer X-Ray Optics: Progress in Coherence Preservation

E. Ziegler, T. Bigault, P. Cloetens, C. Morawe European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France

C. David Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen-PSI,

Switzerland

The recent development of experiments taking advantage of the partial coherence of the x-ray beams produced by high-brilliance low-emittance x-ray sources has naturally stimulated the development of new optics. For techniques based on phase contrast imaging, severe requirements on the wavefront distortion are indeed necessary for being able to retrieve information on the sample under study. In the case of tomography, it was shown1 that, a multilayer with an energy resolution one to two order of magnitude that of a perfect crystal would make an ideal optics, providing it could conserve the homogeneity and the coherence of the beam.

In this presentation we report on our effort to improve the quality of multilayer mirrors in terms of coherence preservation. The quality of the mirror substrate turned out to be the key factor since multilayer coatings would generally mimic the substrate surface. In principle, the mirror surface slope errors should be smaller than α/2, α representing the angular source size However, the progress in mirror technology is constantly challenged by the advent of better sources. For a substrate with a given shape error the phase distortion of the wavefront increases with the beam incidence angle. This was demonstrated by imaging a series of multilayer coatings (W/B4C, Ru/B4C) with different d-spacing made on substrates of same quality. Recent results on a 300-mm long silicon mirror coated with a 4nm (Ru/B4C)80 multilayer are also presented. The slope error was measured to be around 0.2 µrad. The quality of the bare substrate and of the multilayer-coated substrate was assessed by a number of means, including the Talbot imaging and hard x-ray shearing interferometry2 techniques. 1. See P. Cloetens, Session 5 of this workshop. 2. See C. David, Session 6 of this workshop.

33

Attendees List

34

As of 8/11/03 - Total of 117 Adams, Bernhard APS / ANL Argonne, IL 60439 Email: adams@aps.anl.gov Amemiya, Yoshiyuki Univ of Tokyo Advanced Materials Science 5-1-5 Kashiwanoha Kashiwa, Chiba, Japan 277-8561 Email: amemiya@r.u-tokyo.ac.jp Phone: 81 4 7136 3750 Fax: 81 4 7136 3750 Arthur, John SSRL/SLAC 2575 Sand Hill Rd. Menlo Park, CA 94025 Phone: 650 926 3169 Fax: 650 926 4100 email: jarthur@SLAC.stanford.edu Bazarov, Ivan Cornell University Wilson Lab Ithaca, NY 14853 Email: bazarov@cornell.edu Phone: 607 254 8933 Becker, Michael Brookhaven National Lab Biology Bldg. 463, PO Box 5000 Upton, NY 11973 Email: mbecker@bnl.gov Phone: 631 344 4739 FAX: 631 344 3407 Beetz , Tobias Stony Brook University Physics & Astronomy Dept. of Physics Stony Brook, NY 11794-3800 Email: tobias.beetz@stonybrook.edu Phone: 631-632-8056 Fax: 253-541-9489 Beckmann, Felix GUSS Institute for Materials Research C/O DESY Notkestr. 85

Hamburg, Germany 22607 Email: felix.beckmann@gyss.de Phone: ++49 40 8998 4535 Fax: ++49 40 8998 2787 Bilderback, Donald Cornell University CHESS 281 Wilson Lab Ithaca, NY 14853 Email: dhb2@cornell.edu Phone: 607 255 0916 Fax: 607 255 9001 Bizzell, Virginia CHESS Wilson Lab Email: vfb2@cornell.edu Borthwick, Matthew MIT 77 Mass Ave, Rm 13-2925 Cambridge, MA 02139 Email: matt@lindy.mit.edu Ph: 617 253 8928 Chesnel, Karine LBNL ALS 1 Cyclotron Road, MS 7R0100 Berkeley, CA 94709 Email: kchesnel@lbl.gov Phone: 510 495 2830 Fax: 510 486 2830 Cinque, Gianfelice INFN-Laboratori di Frascati Lab DAFNE-Light Via E. Fermi 40 Frascati (Roma) ITALY Email: cinque@inf.infn.it Phone: 39 06 9403 2282/2218 Fax: 39 06 9403 2597 Cloetens, Peter ESRF BP220 Grenoble, FRANCE 38063 Email: cloetens@esrf.fr Phone: 33 4 76 88 25 50 Fax: 33 4 76 88 22 52

35

Dadamukhamedov, Turgun Tashkent State Automobile & Road Institute Physics Tashkent Sebzar House 30, Apt. 36 Tashkent 700019 Uzbekistan Phone: 998712 405775 Dale, Darren Department of Applied Engineering Physics Cornell University Ithaca, NY 14853 Email: dd55@cornell.edu David, Christian Paul Scherrer Institute Lab for Micro & Nanotechnolgy Villigen Switzerland CH-5232 Email: Christian.david@psi.ch Phone: 91-56 310 3753 Fax: 91 56 310 2646 Dierker, Steven Brookhaven National Lab NSLS PO Box 5000 Bldg., 725B Upton, NY 11973 Email: dierker@bnl.gov Phone: 631 344 4966 Fax: 631 344 5842 Di Fabrizio, Enzo National Institute for the Physics of Matter TASC Laboratory S.S. 14 km 163,5 – Basovi22A Trieste, Italy 34012 Email: difabrizio@tasc.infm.it Phone: 39 040 375 8417 FAX: 39 040 226767 Donath, Tilman GUSS Institute for Materials Research C/O DESY Notkestr. 85 Hamburg, Germany 22607 Email: tilman.donath@gyss.de Phone: ++49 40 8998 4528 Fax: ++49 40 8998 2787 Dufresne, Eric University of Michigan Physics Dept. MHATT-CAT.

APS, Sec 7, ANL Bldg 432D 9700 S Cass Ave Argonne, IL 60439 Email: dufresne@umich.edu Phone: 630 252 0274 Fax: 630 252 0279 Evans-Lutterodt, Kenneth Brookhaven National Lab Building 725D, Rm –162 Upton, NY 11973 Email: kenne@bnl.gov Phone: 631 344 2095 Fax: 631 344 3238 Falus, Peter NIT – Physics Yale University – SPL 29 217 Prospect St. New Haven, CT Email: falus@nit.edu Phone 203 432 4086 Fax: 203 432 9710 Fan, Lixin Argonne National Lab APS 9700 S. Cass Ave Argonne, IL 60439 Email: lfan@anl.gov Phone: 630 252 1628 Fax: 630 252 9303 Feng, Renfei Alberta Synchrotron Institute X-ray University of Alberta Research Transition Facility 8308-114 St., Suite 2080 Edmonton, AB, Canada T6G 2E1 Email: renfei.feng@asi-cls.ca Phone: 780 492 5464 Fax: 780 492 6160 Finkelstein, Kenneth Cornell University CHESS, 285 Wilson Lab Ithaca, NY 14853 Email: kdf1@cornell.edu Phone: 607 255 0914 Fax: 607 255 9001 Fontes, Ernest CHESS

36

Cornell University Ithaca, NY 14853 Email: ef11@cornell.edu Goedkoop, Jeroen University of Amsterdam Van der Waals Zeeman Institute Vsalckenierstraat 65 Amsterdam, The Netherlands HL1018 XI Email: Goedkoop@science.uva.nl Phone: 31 20 525 6362 Fax: 31 20 525 5102 Gruebel, Gerhard ESRF Experiments Division Avenue Jules Horowitz, BP220 Grenoble, France 38043 Email: gruebel@esrf.fr Phone: 04 76 88 23 57 Fax: 04 76 88 2160 Gruner, Sol Cornell University Physics – 162 Clark Hall Ithaca, NY 14853 Email: smg26@cornell.edu Phone: 607 255 3441 Fax: 607 255 8751 Hastings, Jerome SSRL/SLAC Email: jby@slac.stanford.edu Phone: 650 926 3107 Fax: 650 926 4100 Hau-Riege, Stefan LLNL Physics and Applied Technical PO Box 808, L-395 Livermore, CA 94539 Email: Hauriege1@LLNL.Gov Phone: 925 422 5892 Fax: 925 422 8761 He, Haifeng LBNL Advanced Light Source 1 Cyclotron Road, MS 7-222 Berkeley, CA 94720 Email: hfhe@lbl.gov Phone: 510 495 2270 FAX: 510 486 7588

Hermes, Christoph EMBL Notkestr. 85 Hamburg, Germany D-22067 Email: hermes@embl-hamburg.de Phone: +49 40 8990 2117 Fax: +49 40 8990 2149 Hirano, Keiichi KEK Photon Factory 1-1, Oho Tsukuba, Ibaraki 305-0801 JAPAN Email: keiichi.hirano@kek.jp Phone: +81 29 864 5649 Fax: +81 29 864 2801 Hirano, Musatsugu Osaka Univ Grad School of Medicine Interdisciplinary Image Analysis D11.2.2 Yamadaoka Suita, Osaka, Japan 565 0871 Email: hirano@imagemed.osaka-u.ac.jp Phone: 81 6 6879 3564 Fax: 81 6 6879 3569 Hornberger, Benjamin Stony Brook University Dept. Physics & Astronomy Stony Brook, NY 11794-3800 Email: benjamin.hornberger@stonybrook.edu Phone: 631-632-8056 Fax: 419-828-8145 Howells, Malcolm LBNL Email: MRHowells@lbl.gov Hu, Zhengwei Marshall Space Flight Center (MSFC) BAE – Biological and Physical Space Research SD-46, NASA Huntsville, AL 35812 Email: Zhengwei.hu@msfc.nasa.gov Phone: 256 544 3805 Fax: 256 544 2102 Huang, Yu-Shan National Synchrotron Radiation Research Ctr 101 Hsin-Ann Road Science Based Industrial Park Hsinchu, Taiwan 300 Email: jade@nsrrc.org.tw

37

Phone: 886 3 5780281 X7320 Fax: 886 3 5783813 Ilinski, Petr P Argonne National Lab APS 9700 S Cass Ave Argonne, IL 60439 Email: ilinski@aps.anl.gov Phone: 630 252 0145 Fax: 630 252 0161 Ishikawa, Tetsuya Spring-8/Riken Coherent X-Ray Optics Laboratory Kouto 1-1-1 Mikazuki, Hyogo, 679 5148 Japan Email: ishikawa@spring8.or.jp Phone: 81 791 58 2805 Fax: 81 791 58 2807 Ito, Kazuki Stanford University SSRL/SLAC, Building 274 MS99 2575 Sand Hill Road Menlo Park, CA 94035 Email: kazuki@slac.stanford.edu Phone: 650 926 4078 Fax: 650 926 2258 Jacobsen, Chris Stony Brook University Dept. of Physics & Astronomy Stony Brook, NY 11794-3800 Email: chrisjacobsen@stonybrook.edu Ph: 631 821 0360 Kaznatcheeva, Konstantine Canadian Light Source 101 Perimeter Road Saskatoon, Canada 57N0X4 Email: Kaznache@cls.usa.sk.ca Phone: 306 657 3546 Fax: 306 657 3535 Kazimirov, Alexander Cornell University CHESS 277 Wilson Lab. Ithaca, NY 14853 Email: ayk7@cornell.edu Phone: 607 255 2538 Fax: 607 255 9001

Kincaid, Brian Advanced Light Source 915 Cole Street #378 San Francisco, CA 94117 Email: BMK Phone: 415 355 0330 Fax: 415 355 1755 Kirz, Janos Stony Brook University Physics & Astronomy Dept. of Physics Stony Brook, NY 11794-3800 Email: kirz@xray1.physics.sunysb.edu Phone: 631-632-8181 Kitamura, Hideo Spring-8/RIKEN Harima Institute Kouto, Mikazuki Sayo, Hyogo, Japan 679-5148 Email: kitamura@spring8.or.jp Phone: 791 58 2809 Fax: 791 58 2810 Kleineberg, Ulf University of Bielebeld Faculty of Physics Universitactsstr.25 Bielefeld, Germany Email: kleineberg@physik.uni-bielefeld.de Phone: 49 521 106 5456 Fax: 49 521 106 6001 Krasnicki, Felix (Szcsesny) Argonne National Lab Experimental Facilities Division 9700 S. Cass Ave., Bldg. 401 Argonne,IL 60439 Email: krasnick@aps.anl.gov Phone: 630 252 9186 Fax: 630 252 9303 Laundy, David Daresbury Lab S.R. Keckwick Lane Warrington, Cheshire, U.K. WA6 7LZ Email: d.laundry@dl.ac.uk Phone: 44 1925 603238 Fax: 44 1925 603124 Lengeler, Bruno RWTH Aachen University

38

Physics Huyskensweg Turm 28 Aachen, NRW, Germany Email: lengeler@physik.rwth-AACHEN.DE Tel: 49 241 80 17075 Fax: 49 242 80 22306 Lerotic, Mirna Stony Brook University Dept. of Physics & Astronomy SUNY Stony Brook Stony Brook, NY 11734-3800 Email: Lerotic@xray1.physics.sunysb.edu Phone: 631 632 8097 Fax: 631 632 8101 Leupold, Olaf ESRF Experiments Division 6 rue Jules Horowitz Grenoble, France F-38043 Email: leupold@esrf.fr Ph: 33476882452 Fax: 33476882624 Li, Gang Institute of High Energy Physics Chinese Academy of Science P.R. China Beijing Synchrotron Radiation Facility No. 19 Yuquan Rd. PO Box 918 2-7 Beijing, P.R. CHINA 100039 Email: lig@lhep.ac.cn Phone: 86 10 882335993 Fax: 88 10 68186229 Liang, Keng National Synchrotron Radiation Research Ctr 101 Hsin-an Road Science Based Industrial Park Hsinchu, Taiwan 300 Email: ksliang@nsrrc.org.tw Phone 886 3 5780281 ext 2203 Fax: 886 3 5783813 Lin, Binhua University of Chicago James Frank Inst & CARS 5640 S. Ellis Ave. Chicago, IL 60637 Email: b-lin@uchicago.edu Ph: 630 252 0463 Fax: 630 252 0460

Lindau, Ingolf Stanford University SSRL/SLAC, MS 69 2575 Sand Hill kRoad Menlo Park, CA 94025 Email: lindau@ssrl.clac.stanford.edu Phone: 650 926 3456 FAX: 650 926 4100 Luning, Jan Stanford University SSRL 2575 Sand Hill Road,. Mailstop 69 Menlo Park, CA 94025 Email: jluning@sganford.edu Phone: 650 926 4539 Fax: 650 926 4100 Luning, Katharina Stanford University SSRL 2575 Sand Hill Road., MS 69 Menlo Park, CA 94025 Email: Kluening@slac.stanford.edu Phone: 650 926 2098 Fax: 650 926 4100 Macrander, Albert Argonne National Lab APS – Experimental Facilities Division 9700 S. Cass Ave, Bldg 401 Argonne, IL 60439 Email: atm@aps.anl.gov Phone: 630 252 5672 Fax: 630 252 9303 Matsushita, Tadashi Institute of Materials Structure Science Photon Factory 1-1 oho Tsukuba, Ibaraki, Japan 305 0801 Email: tadashi.matsushita@kek.jp Phone: 81 29 879 6020 Fax: 81 29 864-3202 Matyi, Richard Nat’l Inst of Standards & Technolgy Physics Lab 100 Bureau Drive, Stop 8422 Gaithersburg, MD 20899 Email: richard.matyi@nist.gov Ph: 301 975 4272 Fax: 301 975 3038

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McNulty, Ian Argonne National Lab APS Building 401, 9700 S. Cass Ave Argonne, IL 60437 Phone: 630 252 2882 Fax: 630 252 9303 Email: mcnulty@aps.anl.gov Menk, Ralf Sincrotrone Trieste S.S. 14 KM 163.5 Trieste, Italia 34012 Fax: 0039 040 9380905 Miao, John SSRL/SLAC 2575 Sand Hill Road, MS 69 Menlo Park, CA 94025 Email: miao@slac.stanford.edu Phone: 650 926 5168 Fax: 650 926 4100 Nefedov, Alexei Ruhr University Biochemistry Institute of Experimental Physics University Str 150 Bochum Germany D-44780 Email: Alexei.nefedov@ruhr.-univ-bochum.de Phone: 49 234 322 3620 Fax: 49 234 321 4173 Nelson, Art Lawrence Livermore Nat Lab 7000 East Avenue – L-350 Livermore, CA 94550 Email: nelson63@llnl.gov Phone: 925 422 6488 Niebuhr, Marc EMBL Hamburg Outstation C/O DESY Notkestrasse 85 Hamburg, Germany 22603 Email: niebuhr@embl-hamburg.de Phone: +49 40 8990 2171 Fax: +49 40 8990 2149 Nishino, Yoshinori Spring –8 Riken 1-1-1 Kouto Mikazuki, Sayo, Hyngo, Japan 679-5148

Email: nishino@spring8.or.jp Phone: 81-791-58-0802, ext 3406 Fax: 81-791-58-2807 Novikov, Dmitri DESY HASYLAB Notkostr.85 Hamburg, Germany D-22607 Email: dmitri.novikov@desy.de Phone: 49 40 8998 3124 Fax: 49 40 8998 2487 Nugent, Keith Univ of Melbourne Melbourne, Australia Email: kan@physics.unimelb.edu.au Oka, Toshihiko Spring-8/JASRI Life & Environmental Science Division 1-1-1 Kouto, Mikazuki Sayo, Hyogo Japan 679-5198 Email: oka@spring8.or.jp Phone: 81 791 58 0833 Fax: 81 791 58 2512 Okamoto, Yuuji Toyota Technological Institute X-ray Laser-Plasma Engineering Lab. Hisakata 2-12-1, Tempaku Email: y-okamoto@toyota-ti.ac.jp Phone: +81 52 809 1837 Fax: +81 52 809 1837 Nagoya, Aichi Japan 468-0034 Padmore, Howard LBNL ALS MS 2-400 LBL Berkeley, CA 94720 Email: HAPadmore@LBL.gov Phone: 510 486 5787 Fax: 510 486 7696 Paterson, David APS ANL Experimental Facilities Division 9700 South Cass Avenue Argonne, IL 60439 Email: paterson@aps.anl.gov Phone: 630 252 8005 Fax: 630 252 0161

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Peele, Andrew University of Melbourne School of Physics Parkville, Victoria Australia 3010 Email: peele@physics.unimelb.edu.au Phone: 613 8344 5458 Fax: 613 9347 4783 Pfeifer, Mark U of Illinois at Urbana-Champaign Physics – MC704 Urbana, IL 61801 Email: mapfeife@uiuc.edu Phone: 217 333 6322 Fax: 217 244 2278 Pfeiffer, Franz Paul Sherrer Institute Swiss Light Source WPGA 12, CH-5232 Villigen PSI Switzerland Email: Franz.Pfeiffer@Psi.ch Phone: 41 56 310 5262 Fax: 41 56 310 3171 Quinn, Frances Daresbury Lab. Synchrotron Radiation Dept. Keckwick Lane Warrington, Cheshire, UK WA4 4AD Email: f.m.quinn@dl.ac.uk Phone: 44 1925 603589 Fax: 44 1925 603124 Revesz, Peter Cornell University CHESS Wilson Lab. Ithaca, NY 14853 Email: pr20@cornell.edu Phone: 607 255 0915 Fax: 607 255 9001 Robinson, Ian University of Illinois 1110 West Green Urbana, IL 61801 Email: ikr@uiuc.edu Rosfjord, Kristine UC Berkeley Electrical Engineering & Computer Science 1 Cyclotron Rd., MS 2-400

Lawrence Berkeley Lab Berkeley, CA 94720 Email: rosfjord@eecs.berkeley.edu Phone: 510 486 4079 Fax: 510 486 4550 Sayre, David State University of New York Physics & Astronomy Stony Brook, NY 11794 Email: sayre@xray1.physics.SUNYSB.edu Phone: 908 595 6854 Schlotter, William Stanford Linear Accelerator Center SLAC 2675 Sand Hill Road MS69 Menlo Park, CA 94025 Email: wschlott@stanford.edu Ph: 650 926 2345 Fax: 650 926 4100 Shapiro, David SUNY at Stony Brook Physics & Astronomy Nichols Road Stony Brook, NY 11794-3800 Email: dshapiro@xray1.physics.sunysb.edu Ph: 631 632 8097 Fax: 631 632 8101 Shen, Qun Cornell University CHESS, Wilson Lab Ithaca, NY 14853 Email: qs11@cornell.edu Phone: 607 255 0923 Fax: 607 255 9001 Shintake, Tsumoru Riken/Spring8 RIKEN Harima Institute 1-1-1 Kouto Hyogo, Japan 679-5143 Email: shintake@spring8.or.jp PH: 81 791 58 2929 Fax: 81 791 58 2810 Sinha, Sunil Univ of Calif San Diego 9500 Gilman Drive LaJolla, CA 92093 Email: ssinha@physics.ucsd.edu PH: 858 822 5637

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Smolsky, Igor Stanford University SLAC 2575 Sand Hill Road Menlo Park, CA 94025 Email: smolsky@ssrl.slac.stanford.edu Phone: 650 926 5103 FAX: 650 926 2258 Snigirev, Anatoly ESRF Experiments 6 Ave Jules Horowitz BP 220 Grenoble, FRANCE 38043 Email: snigirev@esrf.fr Phone: 33 4 76 88 26 27 FAX: 22 4 76 88 25 42 Snigireva, Irina ESRF Experiments 6 Ave Jules Horowitz BP 220 Grenoble, France 38043 Email: irina@esrf.fr Phone: 33 4 76 88 23 60 Fax: 33 4 76 88 25 42 Sorensen, Larry University of Washington Physics Dept. Box 351560 Seattle, WA 98195 Email: Sorensen@phys.washington.edu Ph: 206 543 0360 Fax: 206 525 6924 Spence, John Arizona State University Physics Department Tempe, AZ 85287-1504 Email: Spence@asu.edu Phone: 480 965 6486 Stewart, Andrew Cornell University CHESS Wilson Lab Ithaca, NY 14850, USA Email: aas52@cornell.edu Phone: 607 255 9894 Fax: 607 255 9001

Sutton, Mark McGill University Physics 3600 University St. Montreal, QC, Canada H3A-2T8 Email: mark@physics.mcgill.ca Phone: 514 398 6523 Fax: 514 398 8434 Suzuki, Yoshio Spring-8 Mikazuki, Hyogo, Japan 679 5198 Email: yoshio@spring8.or.jp Phone: 81 791 58 0831 Fax: 81 791 58 0830 Takeuchi, Akihisa JASRI/Spring-8 Life and Environment Division Kouto 1-1-1, Mikaduki Sayo, Hyogo, JAPAN 679-5198 Email: take@spring8.or.jp Phone: 81 791 58 0833 FAX: 81 791 58 0830 Tamasaku, Kenji RIKEN Coherent X-ray Optics Lab. 1-1-1 Kouto, Mikazuki-cho Sayo-gun, Hyogo, Japan 670-5148 Email: tamasaku@postman.riken.qo.jp Phone: 81 791 58 0802, ext 3821 FAX: 81 791 58 2907 Tang, Mau-Tsu National Synchrotron Radiation Research Center Research Division 101 Hsin-an Road Hsinchu, Taiwan 30077 Email: mautsu@spring8.or.jp Phone: 886 03 5780281 Fax: 886 03 5783892 Uaji, Yoshinori University of Tokyo Graduate School of Frontier Sciences 5-1-5 Kashiwanoha Kashinon, Chiba, Japan 277 8561 Email: uaji@k.u-tokyo.sc.jp Phone: 81 4 7136 3751 Fax: 81 4 7136 3751

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Uesugi, Kentaro JASRI/Spring-8 Life and Environment Div Kouto 1-1-1, Mikaduki Sayo, Hyogo, Japan 679 5198 Email: ueken@spring8.or.jp Phone: 81 791 58 0833 FAX: 81 791 58 0830 Van der Veen, Friso Paul Scherrer Institute Synchrotron Radiation WSLA/117 Villigen, Switzerland 5232 Email: friso.vanderveen@psi.ch Phone: 41 56 310 5118 Fax: 41 56 310 3151 Vogt, Thomas Brookhaven National Lab Physics, Bldg. 510A PO Box 5000 Upton, NY 11973-5000 Email: tvogt@bnl.gov Phone: 631 344 3731 Fax: 631 344 2918 Vysotskii, Mickle Kiev Shevchenko University Vladimirskaya St. 64, Radio Physical Dept. Kieve, Ukraine 01033 Email: mihas@vhome.kiev.ua Weckert, Edgar DESY HASYLAB Notkestrasse 85 Hamburg, Germany D-22603 Email: edgar.weckert@desy.de Phone: +49 40 8998 4509 Fax: +49 40 8998 4475 White, Jeffrey Cornell University CHESS – 181 Wilson Lab. Ithaca, NY 14853 Email: jaw7@cornell.edu Phone: 607 255 0913 Fax: 607 255 9001 Wilkins, Steve CSIRO, Mfg. & Infrastructure Technology PB33 Clyaton Sth, Vic 3169 Australia

Email: steve.wilkins@csiro.au Phone: 61 (0)3-9545-2918 Fax: 61 (0)3-9544-1128 Woll, Arthur Cornell University CHESS – 200L Wilson Lab. Ithaca, NY 14853 Email: aw30@cornell.edu Phone: 607 255 3617 Fax: 607 255 9001 Yabashi, Makina Spring-8/JASRI Beamline Division Kouto 1-1-1, Mikazuki-cho Sayo-gun, Hyogo, Japan 679 5198 Email: yabashi@sp8sun.spring8.or.jp Phone: 81 791 58 0831 Fax: 81 791 58 0830 Yakhou-Harris, Flora ESRF BP 220, 38043 Grenoble Cedex 9 France Email: yakhou@esrf.fr Phone: 33 476882491 Fax: 33 476992542 Yamagucki, Naohiro Toyota Technological Institute 2-1 2-1 Hisakata, Tempaku Nagoya, Japan 468 8511 Email: yamagch@toyota-ti.ac.jp Phone: 81 52 809 1836 Fax: 81 52 809 1837 Yamamoto, Masaki Spring-8/RIKEN Coherent X-ray Optics Laboratory 1-1-1 Kouto, Mikazuki Sayo, Hyogo, Japan 679-5148 Email: yamamoto@postman.riken.go.JP Phone: 81 791 58 2806 Fax: 81 791 58 2806 Youn, Hwa Shik Postech Pohang Light Source 31 San, Hyoja-dong Pohang, Korea 79-784 Email: hsyoun@postech.ac.kr PH: 82 54 279 1532 Fax: 82 54 279 1599

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Yun, Wenbing Xradia, Inc. 4075 A Spring Drive Concord, CA 94520 Email: wyun@xradia.com Phone: 925 288 1818 Fax: 925 288 0310 Zhong, Yuncheng Argonne National Lab APS 9700 S Cass Ave., Bldg. 401

Argonne, IL 60439 Email: yzhong@aps.anl.gov Phone: 630 252 9748 Fax: 630 252 9303 Ziegler, Eric ESRF BP 220 Grenoble Cedex 38043 France Email: Ziegler@esrf.fr Phone: 33 47688 2170 FAX: 33 47688 2957