jean susini - epn campus · 2013. 8. 12. · jean susini. european synchrotron radiation facility...
TRANSCRIPT
Jean SusiniEuropean Synchrotron Radiation FacilityBP 220, 38043 Grenoble Cedex, France
Part IIPart IIntroduction
to synchrotron radiation
Instruments&
Methods
Mostly Illustrated by examples from the ESRF
after W.C. RöntgenÜber eine neue art von Strahlen.
Phys.-Med. Ges., Würzburg, 137, (1895)English translation in Nature 53, (1996)
“... The refractive index.... cannot be more than 1.05 at most.... X-rays cannot be concentrated by lenses….”
“... Photographic plates and film are ”susceptible to x-rays”, providing a valuable means of recording the effects...”
“... Detection of interference phenomena has been tried without success, perhaps only because of their feeble intensity...”
New X-ray sources 3rd generation synchrotron sources
brilliance, coherence, polarisation
New X-ray detectors X-ray imaging X-ray spectrometry X-ray spectroscopy
New X-ray optics high energy resolution monochromator (10-7<∆E/E<10-4) new X-ray lenses (sub-µm…sub-50nm)
PART IIntroduction to synchrotron radiation
1. Origin and physics
2. Synchrotron radiation facilities
3. Historical evolution
4. Three forms of synchrotron radiation
from the Crab Nebula to Kandinsky
3 colour composite of the Crab NebulaNovember 1999
• The Crab Nebula is the remnant of the explosion of a massive star
• 7000 light-years
Credit: ESA, NASA, J. Hester & A. Loll, Arizona State University
Synchrotron radiation is one of the most important emission process in astrophysics
• X-ray synchrotron emission
• Visible emission
• Radio emission
Hester et al., 2002, Arizona State University
luminous regionswhen λ
• Synchrotron radiation is electromagnetic energy emitted by charged particles(e.g., electrons and ions) that are moving at speeds close to that of light when their paths are altered, as by a magnetic field.
• It is so called because particles moving at such speeds in particle accelerator that is known as a synchrotron produce electromagnetic radiation of this sort.
orbit
Centripetalacceleration
Classical case
v << corbit
Relativist case
v ~ c
Isotropic emission Emission concentrated within a narrow forward cone
2mcEe=γ
ψ=1/γ
Ee = 6 GeV (ESRF) mc2 = 511keV
ψ= 10-4 rad = a few 10-3 deg
Particlephysics
First particleaccelerators
Particleswith more and more
energy
bigger and bigger machines
1930
SR was considered a nuisance by particle
physicists
Particlephysics
First particleaccelerators
Particleswith more and more
energy
bigger and bigger machines
1930
First observationof synchrotronradiation
1947
First observation of synchrotron radiation at General Electric (USA).
SR used as a parasitic mode
Particlephysics
First particleaccelerators
Particleswith more and more
energy
bigger and bigger machines
1930
Synchrotron radiation
First observationof synchrotronradiation
Construction of the first“dedicated”machines
1947
1980
http://www.lightsources.org
DIAMOND (UK)SOLEIL (F)
ESRF (F)
ALBA (SP)
PETRA-III (D)
http://www.lightsources.org
APS (Argonne)
http://www.lightsources.org
SPRING8 - Japan
Year1900 1920 1940 1960 1980 2000 2020 2040
105
1010
1015
1020
1025
1030
1035
X-ray tubes
4th generation FELs
3rd generation
2nd generation
1st generationSynchrotron sources
planned
current
parasitic
dedicatedlow emittance
undulator
wiggler
photons/s/mm2/mrad2/0.1%BWBrilliance or Brightness (flux density in phase space) is an invariant quantity in statistical mechanics, so that no optical technique can improve it.
[Photons/sec]
[mm]2 [mrad]2 [0.1% bandwidth]
BendingMagnet
InsertionDevices
• Wiggler• Undulator
mBeEc 2
3 2γ=
)()(665.0)( 2 Τ= BGeVEkeVE ec
)(19572 GeVEmcE
ee ==γ
Ec
In a wiggler or an undulator, electrons travel through a periodic magneticstructure.
The magnetic field B varies sinusoidallyand is in the vertical direction:
=
u
zBzBλπ2cos)( 0
In a wiggler or an undulator, electrons travel through a periodic magneticstructure.
The magnetic field B varies sinusoidallyand is in the vertical direction:
=
u
zBzBλπ2cos)( 0
• Electron motion is also sinusoidal and lies in the horizontal plane. An important parameter characterizing the electron motion is characterized by the deflection parameter K
• The maximum angular deflection of the orbit is Κ/γ
• K >> 1 Wiggler regimeradiation from different parts of the electron trajectory adds incoherently
→ interference effects are less important
• K < 1 Undulator regime radiation from different periods interferes coherently
→ strong interference phenomena
K=0.934 λu [cm] B0 [T]
)2
1(2
2
21Ku +=
γλλ
)2
1)((
)(949.0)( 2
2
Kcm
GeVEkeVEu
e
+=
λ
On-axis
N1
=∆λλ
Fundamental + harmonics
To tweak (or to scan) energy:• E = Fct [K]
• K = Fct [B(z)]
• B(z) = Fct [gap]
To tweak (or to scan) energy:• E = Fct [K]
• K = Fct [B(z)]
• B(z) = Fct [gap]
In vacuum undulator
Revolver undulator
From “Introduction to Synchrotron Radiation”, D. Attwood, Univ. California, Berkeley
],[ 2 IEFctBBM ≈
BMwiggler BNB ×≈ 2
BMundulator BNB ×≈ 2
On-axis
Horizontal linear polarisation
Control of polarisation
Horizontal linear polarisation
ESRF : 844m circumference storage ring
1 relativistic electron ~ 2.85 µsec/lap
Number of bunches 992 870 24x8+1 16 4
Maximum current [mA] 200 200 200 90 40
Rms bunch length [ps] 20 20 25 48 55
Uniform 7/8+1 24*8+1 16 Bunch 4 BunchFilling patterns
High speed shopper (ID09)
The ESRF case
Brightness• 10+22 ph/sec/mrad2/mm2 (10+11 higher than conventional sources)
Small source and highly collimated beam• ~ 10µm and 10µrad
Broad emission spectrum: wavelength tunability• 0.1eV < E < 100keV or 1.2µm < λ < 0.01Å
Polarized radiation• 100% linear or circular or elliptical
Pulsed radiation• 50 10-12 seconds pulses every 10-9 seconds
Power • several kW total power, several 100 W/mm2 power density.
High degree of coherence
http://www.synchrotron-soleil.fr/
Optics hutch
Experimental hutch
Control cabin
Strahlenlinien (beamline)
1866-1944
PART II
Instruments & MethodsFrom Toyota to Jurassic Park
1. Beamline instrumentation
2. X-ray Fluorescence
3. X-ray spectroscopy
4. X-ray imaging
X-ray Diffraction and Protein crystallography : lectures 19-21
Optics cabin
Experiments cabin
Control room
Optics cabin
Experiments cabin
Control room
• Power (heat load) management• Photon beam steering and collimation / focusing• Select / scan photon energy
White beams:• Total emitted power : > 1 kW• Beam size (at 20 m): ~ a few mm2
Monochromatic X-ray beams:• Typical energy bandwidth (∆E/E): ~ 10-4 (a few eV @ 20keV) – 10-8
• Photon flux (∆E/E = 10-4): ~ 1013 - 1014 ph/sec• Focused beam size: ~ µm – 0.05µm
Optics cabin
Experiments cabin
Control room
• Precision mechanics (µm, µrad) almost everywhere • Remote control is mandatory• Large number of actuators (motors, piezoelectric devices)• Highly specialized sample environments• Customized detection scheme
Optics cabin
Experiments cabin
Control room
• Distributed system• Several global and local networks• Centralized data center (CPU & Storage)• Control strategy are SR facility specific!!
Management of the large variety of instruments
Structureof Materials
Electronic Structure& Magnetism
Dynamics & Extreme Conditions
Structural Biology
X-rayImaging
Structure of Soft Matter
32 public beamlines+
8 CRGs*
* Collaborating Research Group
Photo-emissionFluorescence
Elastic scattering Inelastic scattering
TransmissionAbsorptionIncident
photonSample
X-RayFluorescence
X-ray spectroscopy
X-rayDiffraction & scattering
InfraredFTIR-spectroscopy
• Composition• Quantification• Trace element mapping
• Short range structure• Electronic structure • Oxidation/speciation mapping• Molecular groups & structure
• High S/N for spectroscopy• Functional group mapping
• Long range structure• Crystal orientation mapping• Stress/strain/texture mapping
Phase contrast X-ray imaging
• 2D/3D Morphology• High resolution• Density mapping
SpecificSample environments
Chemistry12%
Electronic & Magnetic Properties
12%
Crystals &Ordered Structures
10%
Disordered Systems4%
Applied Materials, Engineering
10%Environment & Culture
7%
Macromolecular Crystallography
15%
Medicine4%
Methods & Instrumentation
2%
Soft Condensed Matter10%
Surfaces & Interfaces10%
Other: Training, feasibility tests,
proprietary research4%
Shifts delivered for Experiments, 2010
The ESRF case
Bragg’s law: 2 d sinθ = nλ
λ : wavelengthθ : incident angled : distance between 2 atomic plansn : diffraction order
First X-ray diagramme by Laue in 1912.
Crystal
X-ray beam
40
Diffraction pattern
Electron density map
3D structure
Proteincrystallisation
Blue-tonguevirus
Yeast prion Ribosome
Nucleosome
See lectures this afternoon
KB mirrors
Samplestage
Video microscopeEDSXRF
2D detectorXRD
2D detectorimaging
Element specific
Co-localization
Quantification
X-rayKen
ergy
continuum
ML
Photo-electroncontinuum
ML
K
KαKβ
Eexc
Energy dispersivedetector
energy
Inte
nsity
Wide energy spectrum (1-100keV)+
High resolution monochromator (∆Ε/Ε ~10-4 – 10-5….. 10-8 )
=X-ray spectroscopy
linear absorption coefficient (cm-1)
µt = ln [ I0 / I ]
t
I = I0 exp[-µt]Beer-Lambert law
Synchrotron energy tunability µ (E)
polychromatic X-rays
monochromaticX-rays
synchrotron source monochromator incident flux
monitor
sample
I0
Transmission EXAFS General method for concentrated samples
Fluorescence EXAFSHigh sensitivity to dilute species
Reflection EXAFSSurface sensitivity enhanced
Surface EXAFSDetection of Auger electrons or total electron yieldOptimal surface sensitivity BUT vacuum required
I0 I1 = I0 e -µt
I0IF ~ I0µεF
I0IR ~ I0µ f(θ)
I0Ie- ~ I0µεY
XANES EXAFS
E (eV)
abso
rptio
n co
effic
ient
µ
EELS = ELECTRON ENERGY LOSS SPECTROSCOPY
provides very similar information to XANES
• EXAFS = EXTENDED X-RAY ABSORPTION FINE STRUCTURE
• XANES = X-RAY ABSORPTION NEAR-EDGE STRUCTURE
• NEXAFS = NEAR-EDGE X-RAY ABSORPTION FINE STRUCTURE
• XAS = X-RAY ABSORPTION SPECTROSCOPY
The photoelectron behaves also as a wave
A
BAmount of water in A depends on:
presence of B (of incoming wave)
size of B (little/much if B is small/big)
whether incoming and outgoing wave crests coincide
probability of electron presence (i.e. of photon absorption) depends on:
presence of neighbour atoms
type of neighbour atoms (C or Pb)
whether RAB is a multiple of wavelength
By measuring the amount of water in A, we learn:
1. How far are the closest islands2. How many and how big they are
By measuring the probability of X-ray absorption, we learn:
1. Nearest neighbour distances2. Number and type of neighbours
A
B
λ = R/3
The probability of absorption oscillates due to constructive and destructive interference
λ = R/3.5
λ = R/4
photoelectron energy increases
wavelength λ decreases
• We’re interested in the energy dependent oscillations in μ (E), as these will tell us something about the neighboring atoms, so we define the EXAFS as:
We subtract off the smooth “ bare atom” background μ0(E), and divide by the“edge step” Δ μ0(E0), to give the oscillations normalized to 1 absorption event.
( ) ( ) ( )( )00
0
EEEE
µµµ
χ∆
−=
0.80
1.00
1.20
1.40
1.60
1.80
2.00
2.20
2.40
12000 12400 12800 13200
Abs
orpt
ion
E (eV)
µ (E
)
∆µ0
E (eV)
µ0(E)
R1
R2, R3
R(Å)
Am
plitu
de o
f FT
-0.10
-0.05
0.00
0.05
0.10
0 5 10 15 20k (A-1)
χ (k
)χ(
k)
k(A-1)
• The frequencies contained in theEXAFS signal depend on thedistance between the absorbingatom and the neighboring atoms(i.e. the length of the scatteringpath).
• A Fourier Transform of theEXAFS signal provides aphotoelectron scattering profileas a function of the radialdistance from the absorber.
NOxCO
HC
CO2
H2O
N2
Oxidation
Reduction
CeO2 ZrO2Type A Type B Type C
performanceLow High
One of the major limitations of todays car catalytic converter is the sintering of these nanoparticlesdue to operation at very high T. When this happens, the catalytic efficiency/atom is drastically reduced because of the reduction of the S/V ratio.
X-Rays
Today
• 200GPa ( 2Mbar)
• T=3600K
Diamond Anvil Cell (DAC)
Quantitative Fe redox for modelling processes at the interior of planets
O. Narygina et al., PEPI (2011)
Absorption
Refractive effects
Interference effects
Collimated beam
Far or/and small source
Quasi monochromatic beam
Absorption contrast
~ 1 / E3
Phase contrast
~ 1 / E
Refractive index n for X-ray wavelengths: n ~ 0.999999
n = 1 - δ + i β
phaseamplitude
Pha
se v
s am
plitu
de
0.1
1
10
100
1000
0.1 1 10 100
Hard X-rays
Soft X-rays
Energy (keV)
(δ/β) = f(E) for Al
0.1
1
10
100
1000
0.1 1 10 100
Energy (keV)
Hard X-rays
Soft X-rays
Pha
se v
s am
plitu
de
(δ/β) = f(E) for Al
no contrast
contrast
• Contrast enhancement at interfaces Sharper images
• Less absorption Less radiation damage
• Small X-ray source
• Low divergence
• Long distance sample-source
• Monochromatic beam
d2ϕ
d2x= 0
λ= 0.7 Å
E=18keV
deformed image of whole objectaccess to phase
if recorded at different distances
D = 310 cm
Incident plane wave
d
Absorption Nearfield
D < d2/ λ
Fresnelregion
D ~ d2/ λ
Fraunhoferregion
D >> d2/ λ
Holo-tomography
each edge imaged independentlyno access to phase
only interface
D = 15 cm
50 µm
Edge enhancement
D
1 - phase retrieval with 4 distances
D = 0.21 m D = 0.51 m D = 0.90 mD = 0.03 m50 µm
D
2 – Tomographic reconstruction: 700 projections at each distance D
• Polystyrene foam• E=18keV
P.Cloetens et al., Appl. Phys. Lett. 75 (1999)
Reconstructedphase map
Tomographicslice
3D holo-tomographic reconstruction
40 µm
Quantitative density map
Improved resolution (<1µm)
P.Cloetens et al., Appl. Phys. Lett. 75 (1999)
Tem
pera
ture
composition
solid
L+S
Partial re-melting
liquid
Solidification
Absorption
β-map
50 µm
edge enhancement
Direct Imaging Phase
δ-map
Al
Al/Si
L. Salvo et al., NIM B 200 (2003)
Volume Rendering (solid transparent)
trapped liquid
Phase map
∆δ ≈ 3.5 10-8
⇓
∆ρ ≈ 0.05 g/cm3
50 µm
L. Salvo et al., NIM B 200 (2003)
Single-hole nozzle Dual-hole nozzle
high-speed fuel injection into a combustion chamber
Breakup and atomization mechanismof the fuel jet
nozzleinternal design, initial flow conditions
More efficient and cleaner combustion
Y. Wang et al., Nature Physics 4, (2008)
Single-hole nozzle Dual-hole nozzle
high-speed fuel injection into a combustion chamber
Y. Wang et al., Nature Physics 4, (2008)
Single-hole nozzle Dual-hole nozzle
high-speed fuel injection into a combustion chamber
Y. Wang et al., Nature Physics 4, (2008)
Y. Wang et al., Nature Physics 4, (2008)
32-ID at APS - ANL
• 472 ns exposure time
• 3.68 μs shot-to-shot delay
• 13.3 keV, 1014 ph s−1 mm−2/0.1% bw
Y. Wang et al., Nature Physics 4, (2008)
10µm10µm
After 40 hours at 675oCBefore heat treatment
• Developed for future generation high field magnets for particle accelerators (LHC-2, ILC).• The aim is to obtain superconducting cables with the highest critical current.• The superconducting properties are strongly dependent upon the microstructure and
microchemistry of the Nb3Sn superconducting phase.• Void formation in Nb3Sn strands causes localized stress concentrations and degrades the
physical superconductor properties.• High energy fast nano-tomography allows to study the void growth in-situ during the reaction
heat treatment.
Vertical slice from 3-D tomographic reconstruction of powder-in-tube type Nb3Sn superconductor fabricated by Shape Metal Innovation (Bruker EAS). Data acquisition time 500s
E = 46 keVM. Di Michiel, M. Scheel, A. Snigirev, I. Snigireva
Courtesy P. Tafforeau et al. ESRF-ID19
Cretaceous enigmatic tiny eggs from Thailand
absorption
Phase
P. Tafforeau et al. ESRF-ID19
THANK YOUFOR YOUR ATTENTION