Research with Synchrotron Radiation - DESY · 2-Aug-06 E. Weckert: Research with Synchrotron...

2-Aug-06 E. Weckert: Research with Synchrotron Radiation 1

Research with Synchrotron Radiation

Edgar Weckert

• Introduction: what is synchrotron radiation ?

• Radiation sources at DESY

• Interaction of radiation with matter

• Experiments at Storage Rings

- Diffraction/Scattering

- Spectroscopy

- Imaging

• Experiments at Free Electron Lasers


Spektrum einerWolfram Röntgen-Röhre

wide spectral range

high intensity

pulsed

polarised

time

wiggler / undulators

strongly collimated

Production of synchrotronRadiation:

Opening angle:

Bending magnet: Undulator:

γ= E/mec2


Bending magnets / Wigglers (60’s)

I ∝ nm × ne

Undulators (60’s)

I ∝ nm2 × ne

Free-electron-lasers FEL (70’s)

I ∝ nm2 × ne

2

e-

e-

e-

Production of synchrotron radiation


Wiggler at DORIS III


The SASE-principle for free electron lasers


Characteristics of FEL radiation

• 1012-1013 photons/pulse• 100 fs pulse length• intrinsic energy resolution: 0.1%• from single pulse to ~40000 pulses/s

FEL:


DORIS III38 beamlines

PETRA III13 beamlines

XFEL

VUV-FEL

Photon Facilities at DESY


Photon Facilities at DESY

DORIS III VUV-FEL

PETRA II/III XFEL


Source Properties

FELs

PETRA III

DORIS III

PhotonsProperties:- high brilliance and flux- infrared up to hard X-rays (>100keV)- polarization- time structure

Applications:- spectroscopy- diffraction/scattering- imaging

Fields:- solid state physics- crystallography- structural biology- chemistry/catalysis- geo-/environmental science- materials science, nano science- medical science- atoms, molecules and clusters- magnetism- engineering science


Radiation source properties:• flux: F [ph/(s 0.1%BW)]

• brilliance: B=F/((2π)2σTxσTx’σTyσTy’) [ph/(s mm2mrad20.1%BW)]

• coherent flux: Fc = B(λ/2)2 [ph/(s 0.1% BW)]λ: wavelength; σTx: photon source size; σTx’: photon source divergence

Electron beam properties:

• horizontal emittance: εx = σx·σx’ ~ E2/NB3; NB: No. of B-Magnets

• vertical emittance: εy = σy·σy’ = κ·εx; κ: horiz./vert. couplingσx: electron beam size; σx’: electron beam divergence


Beamlines at DORIS III

38 beamlines, 70 experimental stations

11 Stations operated by external organizations:- EMBL: 7 - MPG: 1 - GKSS: 1- GFZ: 2

16 stations operated with supportfrom external institutions: - BMBF-Verbundforschung- FZ Jülich- University Hamburg- University Kiel- University Aachen- Debye Inst. Utrecht- RISØ- MPI Golm


http://petra3.desy.de

The PETRA-III Project


PETRA III Project

P

Parameters:- rebuild of 1/8 of PETRA- refurbishment of 7/8 of PETRA- energy: 6 GeV- current: 100 mA- emittance: 1 nmrad- undulators: 14- undulator length: 2, 5, 20 m- top up operation mode

Brilliance Comparison


20 m undulator

Labs and offices

ID-sectors

max. BL-length 103 m (from the source)

9 straight sectionsseparation: 5°

Use of canted undulators(5 mrad, 2 m device length):

14 separate undulator BLs

Sector 1

Sector 9A/B

Sector 2 Sector 3A/B


23 m

Canted undulators beam separation 5 mrad


FLASH user facility

100 μm

20 μm/unfocused

10 μm

VLS gratingspectrometer

high resol. PGMmonochromator

opticallaser

100 μmmicrofocus

20 m

~42 m to undulatorGas absorber

intensity monitor(gas ionization)

Start of userOperation: 2005 superconducting linac: 1 GeV

minimal wavelength: 6nmfive experimental platforms with different focal spots/optics


VUV-FEL


VUV-FEL


PG2BL1

BL3

BL2visible laser light

FLASH experimental hall


European XFEL Project

More than 1000 scientists contributed to the Technical Design Report

The XFEL part is based on8 workshops with190 participants

stand alone facility


XFEL: Schematic Layout

injector

Linear accelerator in superconducting TESLA technology

Electron beam switchyardwith undulators

expe

rimen

tal h

all

Linac: 20GeVmin. wavelength: ~1Åphotons per pulse: ~1012

pulse length: ~100fs

2 X-ray SASE FELs, 1 SASE XUV-FELs, and 2 beamlines for short pulse

physics using spontaneous radiation

10 experimental stations


XFEL Accelerator Tunnel


XFEL Site Schenefeld

phase II

phase I


Experiments building, Nov 2004

Experimental Hall of the 0.1 nm European X-ray FEL Project


DESY site: Injector complex, infra-structure





Interaction of electromagnetic radiation with matter







Structural Biology at DORIS IIIBeamlines and experimental stationsfor structural biology are operatedby the EMBL and MPG outstation:

EMBL:• in total 5 stations for proteincrystallography (PX)

• biological EXAFS• biological SAXS• one PX station in collaboration

with German universities• serving the community by anumber of training activities

MPG:• one beamline for protein crystallography

• three groups for structural biology

Protein crystallography

EXAFS

s, nm-1 0 1 2 3 4

lg I, relative

1

2

3 (1)(2)(3)(4)

His110

N

NH

N

NH

NHN

O

O

O

NHN

ZnOH

ZnO NH

NHis56

His54 Asp58

His59

His173Asp134

SAXS


Macromolecules

Polychromatic

Monochromatic


Macromolecules: representations


Important macromolecular structure


Extremely large complexes (virus)

J.M. Grimes, J.N. Burroughs, P. Guet, J.M. Diprose, R. Malby, S. Zientra, P. Mertens, D.I. Stuart, Nature, 395, 470-478 (1998)

example: Blue Tongue Virus


e.g. due to radiation damage


Powder Diffraction


Technische Universität Darmstadt Material- und Geowissenschaften

Schematic setup of the powder diffractometer at B2


Technische Universität Darmstadt Material- und Geowissenschaften

Multidetector concept for high resolution studies

W.-H. Kaps

J. Ihringer

W. Prandl

…

Detektor 4Detektor 3

Detektor 2

Detektor 1

Si(111) Analysator

Blenden

SpiegelMonochromator


Powder Diffraction


Texture Analysis


Materials science

Energy range: 50-100 keV; 5cm in Al

Grain properties to be determined: position, morphology, orientation, deformation (plastic/elastic), composition

Achievable resolution: 1.5 x 5 x 50 μm3


Diffraction with nm spatial resolution

Investigation of the strain of SiO2 on Si

Focussing by wave guides

S. Di Fonzo et al. Nature, 403, 638 (2000)


SurfaceDiffraction


Surface Diffraction


Diffraction from interfaces: Structure close to thesolid-liquid interface

System: Si(001)-Pb(liquid; TM+10K)

Energy: ~80 keV

H. Reichert et al., Nature, 408, 839 (2000)


Diffractionfromliquids


Small Angle Scattering (SAXS)


USAXS (4000Å)


Micro SAXS

Orientation of microfibrils in wood cells.

Spatial resolution: 2 μm


Micro focus applications (SAXS)

I. Dobbie, M. Linari, G. Piazzesi, M. Reconditi, N. Koubassova, M.A. Ferenczi, V. Lombardi, M. Irving, Nature, 396, 383-387 (1998)


Intravenous Coronary Angiography



Microtomography at HASYLAB/DESY

xy

z

X-ray camera

sample manipulator

CCD camera lens fluorescent screen

monochromaticbeam

sample

optical mirrors

beamstop


Porous PLGA scaffold(In cooperation with E. Wintermantel, B. Müller, ETH Zürich, Switzerland)

µCT at BW2 using 9 keVsample diameter: 5 mm

slice (2 x 2 mm²)spatial resolution: 5.4 µm


Titania hollow spheres (TiO2)(In cooperation with E. Wintermantel, B. Müller, ETH Zürich, Switzerland)

µCT at BW2photon energy: 19 keV

sample height: 1.05 mm

spatial resolution: 2.1 µm


Titania hollow spheres (TiO2)(In cooperation with E. Wintermantel, B. Müller, ETH Zürich, Switzerland)

µCT at BW2

using19 keV

spatial resolution: 2.1 µm


Absorption micro tomographyParallel radiation, high resolution 2D-detector

example: wetting of Al-grain boundaries by Ga (ESRF ID19)

3D-grain distributionInvestigation of deformed Al


Phase-contrast Microtomography

xy

z

X-ray camera

sample manipulator

interferometerCCD camera lens fluorescent screenmonochromatic

beam

rotating phase shiftersample in liquid


Rat trigeminal nerve (PµCT at 12 keV)

nerve fibers (diameter 25 µm)

noticeable density change 1 mg/cm³


Mouse kidney: µCT and PµCT at 12 keV

µCT: τ ∝ Z4 E-3 ρ PµCT: Φ ∝ σ E-1


Phase contrast imaging

requirement: lateral partially coherent radiation

Lateral coherence length: ξ ~ λL/sL: distance from the source; s: source size


Phase contrast images


Phase contrast tomography

example: SiC in Al:

Micro tomographicreconstructions for different strains.

Energy: 25 keV

Distance sample-detector: 82 cm

P. Cloetens, R. Barret, J. Baruchel, J. Guigay, M. Schlenker, J. Phys. D, 29,133-145 (1996)


monochromator

I0

I1 I2

sample

reference

Quelle

I (Fluorescence)

experimental set up of X-ray absorption spectroscopy

J. Wienold


-0.6

-0.7

-0.8

-0.9

-1.020 20.25 20.5 20.75

abso

rptio

n [a

.u.]

photon energy, keV

I = I0*exp(-μd) (Lambert's law)

1750

2000

2250

2500

20 20.25 20.5 20.75

Inte

nsity

, au

Photon energy, keV

Features ofX-ray absorption spectroscopy

μ = linear absorption coefficent

μd = ln(I0/I)


0.00.0

-0.25

-0.5

-0.75

20 20.25 20.5 20.75

abso

rptio

n [a

.u.]

photon energy [keV]XANES (X-Ray Absorption Near Edge Structure)NEXAFS (Near Edge X-Ray Absorption Fine Structure)

EXAFS (Extended X-Ray Absorption Fine Structure)

Regions in the XAS spectra

2-Aug-06 E. Weckert: Research with Synchrotron Radiation 77J.Wienold, Geometrische Strukturen, Abt. AC, Fritz-Haber-Institut(MPG), Berlin, Germany

Fermis Golden rule:

IXAS ~ |<Φf|ê•r| Φi>|2δEf-Ei-ħω

Φi = inital state

Φf= final state= Φoutgoing+ Φbackscattered

ê•r = dipol matrix elementê = electriv field polarisationvector of the photon, r = coordinatevector of the electron

h*ν ⇒ Fluorescence⇒ Auger electrons⇒ Absorption⇒ X-ray emission


0.00.0

-0.25

-0.5

-0.75

20 20.05 20.1 20.15

abso

rptio

n [a

.u.]

photon energy [keV]

Pre edge (inneratomare Übergänge)

Kantenlage(Valenz)

XANES is, ‘Fingerprint’ of a single material and can be used via Principal Component Analysis(PCA, Faktor Analyse) for quantitative analysis

XANES


EXAFS

0.00.0

-0.25

-0.5

-0.75

20 20.25 20.5 20.75

abso

rptio

n [a

.u.]

photon energy [keV]

0.0

0.25

0.5

0.75

1.0

0.0

20 20.25 20.5 20.75

norm

. abs

orpt

ion

[a.u

.]

photon energy [keV]

Energie calibration, background substraction,normalization

0.0

0.25

0.5

0.75

1.0

0.0

0 5 10 150-5

norm

. abs

orpt

ion

[a.u

.]

k [Å -1 ]

konversion

( )02 EEmk −=h

0.0

0.25

0.5

0.75

1.0

0.0

0 5 10 150-5

norm

. abs

orpt

ion

[a.u

.]

k [Å -1 ]

μ(k) - μ0(k) μ0(k)χ(k) =

Substraction of μ0


0.0

2.0

0.0

-2.0

5 7.5 10 12.5

χ(k

)*k

3

k [Å -1 ]

χ(k)


HPGe-detectorMono

capillary

XYZSamplestage

Microscope

SR μ-XRF setup at

Strahl L, HASYLAB,

HamburgHPGe-detector

Monocapillary

XYZSamplestage

Microscope



Refractive optics in the X-ray regime

Snigirev et al., Applied Optics 37, 653 (1998)


Micro fluorescence tomography

example: root of mahagoni tree

Lengeler et al. JSR, 6, 1153-1167 (1999)


XPCS (X-ray photon correlation spectroscopy)

requirement: coherent radiation

5-10 μm pinhole to mask the coherent part of the radiation

T. Seydel et al., Phys. Rev. B 63(7), (2001)


Inelastic scattering under high pressure


Geo-Science Experiments

1750t press for in situ studies of large sample volumes.pressure: ~25GPatemperature: >2000KOne further similar facility at SPring8.Study of material under the conditions of the earths lower mantle.

Activities of GFZ at DESY


Inelastic scattering under high pressure

Speed of sound of Fe under pressure (ESRF: 2 ph/min)

G. Fiquet et al., Science (2000)

gasket

sample

diamond

X ray

1 mm

P=28GPa


VUV-FEL (phase 1)

0 2 4 6 8 10 12 1410-12

10-11

1x10-10

1x10-9

1x10-8

1x10-7

1x10-6

1x10-5

1x10-4

E = Eshexp(z/Lg)Wsh ~ 1-2 W

TTF FEL saturation September 10, 2001λ = 98.1 nmLg = 0.68 mEsat = 90 μJ

E [J

]

z [m]

VUV-FEL (phase 1) in saturation at 98nm

Radiation wavelength 80-125 nmRadiation pulse energy at saturation 30-100 μJRadiation pulse duration (FWHM) 30-100 fsRadiation peak power 1 GWSpectrum width (FWHM) 1%Radiation spot size [FWHM] 200 μmRadiation angular divirgence [FWHM] 260 μradRadiation peak brilliance up to 1029

Number of photons per bunch 1012-13

Achieved performance at VUV-FEL (phase 1):

Undulator length [m] V. Ayvazyan et al., PRL 88(2002)104802

transverse coherence


VUV-FEL (phase 1) First Experiments

Xe-cluster experimentEphot= 12.8eVEion = 12.1eV

Wabnitz et al., Nature, 420 (2002) 4820 1 0 0 2 0 0 3 0 0 4 0 0 5 0 0 6 0 0 7 0 0

0 .0

0 .1

0 .2

0 .3

X e +

inte

nsity

[arb

. uni

ts]

t im e o f f l ig h t [n s ]

a to m

0 .0

0 .1

0 .2

0 .3

0 .4

6 +7 +

X e 3 +

8 +

X e + +

N ~ 2 -2 0

0 .0

0 .1

0 .2

0 .3

0 .4

5 +

4 +

N ~ 8 0

0 .0

0 .1

0 .2

0 .3

0 .4

0 .5

4 23876 5 1

N ~ 3 0 0 0 0

Cluster size dependence


Silicon Graphite (HOPG)

Results: Time-Resolved Microscopy

K. Sokolowski-Tinten et al.


multilayer mirror

CCD

15o

-15o

Pulse #1: Diffraction reveals structure before radiation damage occurs

Pulse #2 sees structure destroyed by pulse #1

To beam dump

Incident FEL pulse: 30 fs, 32 nm, 3 x 1013 W cm-2

sample

First demonstration of ultrafastcoherent X-ray diffraction

H. Chapman, J. Hajdu et al.


Schotte et al., Science 300(2003)1944

Example:Time resolved investigation of the photo ionization of CO-myoglobinat ID9 (ESRF):- pump-probe technique- X-ray crystallography

Time resolved investigation

Variable delay betweenlaser pump pulse and X-ray probe pulse.

32 exposures per image

‘pink’ Laue technique,range: 0.72-1.24 Å


XFEL: 1000 times better timeresolution than today

Time resolved crystallography

Schotte et al., Science 300(2003)1944

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