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Indus Synchrotrons Utilization Division RRCAT Indore Advances in Science Engineering and Technology Colloquium TIFR August 20 2010 lodharrcatgovin Focused XRay Beams Generation and Applications ID: 418358

optics ray synchrotron high ray optics high synchrotron indus radiation source beamline magnetic phase structure focus imaging materials multilayer

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Slide1

G S Lodha

Indus Synchrotrons Utilization Division

RRCAT, Indore

Advances in Science, Engineering and Technology Colloquium TIFR, August 20, 2010

lodha@rrcat.gov.in

Focused X-Ray

Beams :

Generation

and ApplicationsSlide2

X-ray Interaction with Matter

source:

Spring-8 web siteSlide3

Focused X-ray Beams

W.C. Roentgen

: Refractive index of all materials ≈ unity

Difficult to make an x-ray lens.

With the recent availability of extremely bright x-ray sources (synchrotron storage rings, x-ray free electron lasers, …), R&D efforts towards focusing x-rays to smaller and smaller size have become intense.

At present it is possible to generate focused x-ray beam of <30 nm, using the

reflection, diffraction and refraction phenomena in the x-ray region. Slide4

Optics for X-ray (~10

keV

) Complex refractive index: n=1-δ+iβ

Refraction is small: Re(n)=1-δ with δ

=10-6 ….10

-5

Focal length: f=R/2 (n-1) = R/2

δ

Absorption is high: absorption lengths 1

μm … 10μm

Figure of merit: β

/

δ

= 10-5 (Li,Be) …10-3 (C,Al,Si) …10-1 (Au,Pt,W)Dilemma smaller f smaller R more flux larger aperture larger RSlide5

Why focus x-ray to sub micron size?

X-ray microscopy:

Most materials are heterogeneous at length scale of micron to nm (transmission microscopy, scanning microscopy…). Increased flux: Higher sensitivity due to reduced background. Small samples

or samples in different environment (pressure, temperature, magnetic field …)Slide6

General Terminology in

X-Ray Optics

Magnification Numerical Aperture

Resolution Depth of focus Astigmatism

Chromatic Aberration Slide7

Ideal focusing lens: Converts plane wave to a spherical wave, with the conservation of the coherence

In-coherent source

Geometric Optics Refraction 1/F = (n-1) (1/D

o + 1/Di)Coherent source

Wave Optics Refraction

Phase shift along the optical path

For generating x-ray micro/

nano

focused beam M~10

-2

to 10

-4 in synchrotron beamline

.

Magnification: M=D

i

/DoSlide8

Numerical Aperture

Measure of light collection power

NA= n Sin θmaxNA ~ 0.5 (D/f)

NA is very closely related to performance of the optics (e.g. depth of focus, diffraction limited resolution, flux etc.). Low NA is one of the

major constraint for x-ray optics.Slide9

For high photon flux at the focus:

High brightness and large numerical aperture

Focusing increases the angular spread. Brightness: B= P/ (Δ

As . ΔΩs) P : radiated power; Δ

As :source area ; ΔΩ

s : source divergence

The photon flux at the focus is ~ B

.

2

. NA

2. η

is spot size and

η

is the efficiency of the optics. Thus the high photon flux at the focus requires high source brightness and large numerical aperture optics.Slide10

Rayleigh’s Criterion: Resolution Limit

Point sources are spatially coherent

Mutally incoherent

Intensities

add

Rayleigh criterion (26.5% dip)Conclusion : With spatially coherent illumination, objects are “just resolavable

” when

source

: D. Attwood Slide11

Resolution improves with smaller

λSlide12

Depth of focus

Where

 is a spot size

source

:

Xradia

Slide13

Astigmatism

Source

Focus

or

Synchrotron radiation sources

or

Horizontal and

vertical focusing

are separated at

grazing incidence

.

f

m

=

(R Sin

θ)

/2

f

s

= R/(2Sin

θ

)

Reflection Crossed mirror pair (Kirkpatrick-Baez system)Slide14

Chromatic aberration

Reflective Optics:

Can focus pink beams using grazing incidence optics. Grazing angles can be higher by using x-ray multilayer reflector, but at the cost of limited energy Diffractive

Optics : f ~ E , small NARefractive Optics

: f ~ E2 Slide15

X-ray

Micro

focussing optics Reflective optics Diffractive optics

Refractive opticsSlide16

X-ray Reflectivity: Single and Multilayer

Single

Layer

Total external reflection when θ<θc

(a few mrad)

c

= √2

 =

λ√

Z

Multilayer

Large

θ

leads to larger acceptance or shorter mirror length.

Spectral bandwidth ~ a few %Slide17

Advantages

Layer thicknesses can be tailored

Can be deposited on figured surfaces

X-ray Multilayer OpticsSlide18

Reflective optics

Schwarzschild objective Wolter microscope Capillary optics

Kirkpatrick-Baez mirrorsSlide19

Schwarzschild objective

Near normal incidence with multilayer coating (126 eV)

N.A. > 0.1

Imaging microscope

source

: F.

Cerrina

(UW-Madison), J. Underwood (LBNL

)Slide20

Wolter

microscope

Use 2 coaxial conical mirrors with hyperbolic and elliptical profile

Imaging microscope

Difficult to polish for the right figures

and roughnessSlide21

Multi- bounce condensing capillary

Easy to make with small opening (submicron)

Short working distance (100 μm) Low transmission

Capillary optics

One-bounce capillary

Large working distance (cm)

Compact: may fit into space too

small for K-B

Nearly 100% transmission

N.A. ~ 2-4 mrad (¡Ü 2θc) Difficult to make submicron spot

source

: D.

Bilderback

(Cornell)Slide22

Kirkpatrick-Baez mirrors

A horizontal and a vertical mirror arranged to have a common focus

Achromatic: can focus pink beam (but not with multilayer coating)

Can be used to produce ~ round focal spot

Very popular for focusing in the 1-10

μm

APS

85x90 nm

2

ESRF 45 nm, Spring8 25x30 nm2

(diffraction limit ~ 17 nm)Slide23

Diffractive optics

Fresnel zone plates (FZP) Multilayer Laue Lens (MLL)Slide24

Fresnel zone plates

(Phase ZP and Amplitude ZP)

Phase For a phase shift of

Efficiency of an amplitude ZP with opaque zones ~ 10

%

Efficiency of a

phase ZP with π-phase shift ~ 40%Slide25

Fabrication Fresnel zone plates

E Anderson, A

Liddle

, W Chao, D Olynick and B Harteneck

(LBNL)Slide26

Hard X-ray ZP: recently available

W. Yun (Xradia

)Δr = 24 nm, 300 nm thick, Aspect Ratio = 12.5 (Xradia)

Aspect ratio > 100 is probably difficult to achieve with lithographic zone plates!Slide27

Multilayer Laue Lens (MLL)

For high aspect ratio

Aspect ratio > 1000 (Δ

r = 5-10 nm, 10 μm thick) demonstrated

Source : A

.

Macrander

(APS)Slide28

Refractive optics

Compound refractive lens (CRL)f = R/2N

R radius (~200 m)

N number of lenses (10 …300)

 real part of refractive index (10

-5

to 10

-6

)

2R0  800 m -1000 m

d 10

m

-50

mParabolic profile : No spherical aberrationSmall aperture Small focusing strengthStrong absorption E>20keVSource : Achen Univ., APL 74, 3924 (1999)Slide29

What is Synchrotron Radiation?

Synchrotron radiation is emitted from an electron traveling at almost the speed of light (0.99999999C) and its path is bent by

a magnetic field. It was first observed in a synchrotron in 1947. Thus the name "

synchrotron radiation".Slide30

Generation of Synchrotron Radiation

Synchrotron radiation is emitted at a bending magnet or at an insertion device. Corresponding to the weak and strong magnetic field, there are two types of insertion devices: an

undulator and a wiggler.Slide31

General Properties of

Synchrotron Radiation

Ultra-bright Highly directional

Spectrally continuous (Bending Magnet /Wiggler) or quasi-monochromatic (Undulator)

Linearly or circularly polarized

Pulsed with controlled intervals

Temporally and spatially stableSlide32

Synchrotron Radiation SpectrumSlide33

Brightness of synchrotron sourcesSlide34

X-ray Sources: Peak BrillianceSlide35

America: 18

Asia: 25

Europe: 22Oceania: 1IV generation light sources under construction/ planning stage.

Synchrotron

Radiation(SR) Sources…Slide36

A Typical Synchrotron FacilitySlide37

(1) Electrons are generated here

(2) Initially accelerated in the LINAC

(3) Then they pass into the booster ring accelerated to   c

(4) And are finally transferred into the storage ring

Creating

SR light

A typical Synchrotron source

With

BM and IDSlide38

Building a Synchrotron Source…

Synchrotron

Magnets

RF systemsLCW

Beam physics

Power supplies

Survey and alignment

Health physics

Beam diagnostics

Cryogenics

etc.

UHV

Controls

Chemical Cleaning

Fabrication and metrology shopSlide39

Utilization of the properties of the SR beam: A few examples

Microbeam

: Diffractometry, microscopy

Pulsed Structure : Time-resolved experiments Energy Tunability:

Crystal structure analysis, anomalous dispersion

High collimation:

Various types of imaging techniques with high spatial resolution

Linear / circular

polarizion

:

Magnetic properties of materials.

High energy X-ray: High-Q experiments, Compton scattering, Excitation of high-Z atoms

High spatial coherence: X-ray phase optics and X-ray

interferometry

Slide40

Application of SRSlide41

Life Science

Atomic structure analysis of protein macromolecules Elucidation of biological functionsSlide42

Materials Science

Precise electron distribution in inorganic crystals Structural phase transition

Atomic and electronic structure of advanced materials superconductors, highly correlated electron systems and magnetic substances

Local atomic structure of amorphous solids, liquids and meltsSlide43

Chemical Science

Dynamic behaviors of catalytic reactions X-ray photochemical process at surface

Atomic and molecular spectroscopy Analysis of ultra-trace elements and their chemical states

Archeological studiesSlide44

Earth and Planetary Science

In situ X-ray observation of phase transformation of earth materials at high pressure and high temperature Mechanism of earthquakes

Structure of meteorites and interplanetary dustsSlide45

Environmental Science

Analysis of toxic heavy atoms contained in bio-materials Development of novel catalysts for purifying pollutants in exhaust gases

Development of high quality batteries and hydrogen storage alloysSlide46

Industrial Application

Characterization of microelectronic devices and nanometer-scale quantum devices Analysis of chemical composition and chemical state of trace elements

X-ray imaging of materials

Residual stress analysis of industrial products

Pharmaceutical drug designSlide47

Medical Application

Application of high spatial resolution imaging techniques to medical diagnosis of cancersSlide48

SR Based Research Methods

X-ray Diffraction and Scattering Spectroscopy and

Spectrochemical Analysis X-ray Imaging

Radiation EffectsSlide49

Indus building complexSlide50

Synchrotron Complex at RRCAT housing Indus-1 and Indus-2Slide51

TL-3

TL-1

TL-2

Indus-2, 2.5 GeV SRTrials to store the beam began in December 2005 Indus-1

(450 MeV, 100 mA)(Working since 1999)

Booster Synchrotron

(700 MeV)

(Started in 1995)

Microtron

(20 MeV)(Started in 1992)

Schematic View of Indus ComplexSlide52

Indus-1 Storage RingSlide53

X-ray absorption and Infra red spectroscopy

beamlines

under installation

Five beamlines have been operational. Several publications (~50) have resulted from utilization of these beamlines.

Schematic representation of experimental hallSlide54

Beamline

Range (nm)

Beamline

Optics

λ/

Δλ

Experimental station

Pre and Post mirror

Monochromator

Reflectivity (RRCAT)

4-100

Au coated

Toroidal

1.4 m TGM with three gratings

~400

Reflectometer

and time of flight mass spectrometer

 

Angle Integrated PES (UGC-DAE-CSR)

6-160

Pt coated

Toroidal

2.6 m TGM with three gratings

~600

Hemi-spherical analyzer (HSA)

Angle Resolved PES (BARC)

4-100

Pt coated

Toroidal

1.4 m TGM with three gratings

~400

Angle resolved HSA electron analyzer

Photo Physics (BARC)

50-250

Au coated Toroidal

1 m Seya-

Nomioka

~1000

Absorption cell , sample manipulator

High resolution VUV (BARC)

70-200

Au coated cylindrical

6.65 m off plane Eagle mount spectrometer

~70000

High temperature furnace, absorption cell

Beamlines

operational on Indus-1Slide55

Reflectivity

near absorption edge energies Hydrogen

bond braking near absorption edge energies Interface studies

Photo dissociation spectroscopy

X-ray

multilayer optics and optical response in soft x-ray region

X-ray

Telescope Calibration

Recent studies using Indus -1Slide56

BM

Beamlines

BL#

Groups

ADXRD (

commissioned)

BL-12

RRCAT

EDXRD (

commissioned)

BL-11

BARC

EXAFS

(

commissioned

)

BL- 8

BARC

GIMS (

being installed)

Bl-13

SINP

PES

(being installed)

BL-14

BARC

Under Construction

BM MCD/PES

BL-1

UGC-DAE-CSR

Imaging

BL-4

BARC +

UGC-DAE-CSR

ARPES/PEEM

BL-6

BARC

White-beam lithography

BL-7

RRCAT

Scanning EXAFS

BL-9

BARC

XRF-microprobe

BL-16

RRCAT

SWAXS

BL-18

BARC

Protein Crystallography

BL-21

BARC

X-ray diagnostics

BL-23

RRCAT

Visible diagnostics

BL-24

RRCAT

Soft X-ray

BL-26

RRCAT

Installed

being installed/

under construction

Indus-2

beamlinesSlide57

X-ray Multilayer

Deposition LaboratorySlide58

Reflectivity

Beamline

Indus-1Slide59

Normal incidence soft x-ray reflector: Mo/Si multilayerSlide60

ASTROSAT :One of the most ambitious space astronomy

programme

initiated by Space Science Community in India.Payload of soft x-ray imaging telescope (SXT) sensitive to 0.3 to 8 keV is planned.Performance of SXT grazing incidence foil mirrors evaluated using Indus-1 soft x-ray reflectivity beamline

Archana et al Experimental Astronomy (2010) 28:11-23

X-ray calibration: Soft X-ray TelescopeSlide61

Soft & Deep X-ray Lithography (SDXRL)

beamline

-BL7Slide62

MEMS (Micro-Gears, …)

High aspect ratio micro-structures

Ø

  

Fabrication of Hard x-rays optics

Ø

  

Small periodicity gratings

Ø

Micro Electro Mechanical Systems (MEMS)

Ø   Photonic band gap crystals (for visible radiation)Ø   Quantum wires and quantum dots devices (high density pattering over large areas)

Ø   Fabrication of high density hetrostructures for nano devices  

SDXRL

beamline

- ApplicationsZone PlateSlide63

Primary slits

X-ray mirrors with manipulators

Installed beamline inside hutch

X-ray Scanner

SDXRL

beamline

– Present StatusSlide64

BL16

Beamline Front End

Beamline opticsPre-DCM section

DCM

Front end

exit

Beam transport pipes and vacuum components

KB mirrorSlide65

X-ray Microprobe

beamline

Beamline opticsPost-DCM section

Optics table

Beam transport pipes and vacuum components

DCM

Slide66

Road Ahead….

A modest start has been done at RRCAT with the availability of synchrotron radiation sources Indus-1 and Indus-2. These sources are being operated on a round the clock basis, week after week.

Few x-ray beamlines have become operational, with many more in implementation stage.These are national science facilities. Users from various fields are welcome to plan research using these facilities, which will significantly help us to improve the performance further. It will be our endeavor to support all users of this national facility.Slide67

67

Thank you

All are welcome to Indus SR FacilitySlide68

Acknowledgements:Slide69

X-ray Diffraction and Scattering

Research Methods

Typical Examples of Research SubjectsMacromolecular

crystallography ( I-2)

Atomic structure and function of proteins. X-ray diffraction under extreme conditions

(I-2)

Structural phase transition at high pressure / high or low temperature

X-ray powder diffraction

(I-2)

Precise electron distribution in inorganic crystals

Surface diffraction

(I-2)

Atomic structure of surfaces and interfaces. Phase transition, melting, roughening, morphology and catalytic reactions on surfaces

Small angle scattering

(I-2)

Shape of protein molecules and biopolymers. Dynamics of muscle fibersX-ray magnetic scattering Magnetic structure. Bulk and surface magnetic propertiesX-ray OpticsX-ray interferometry

. Coherent X-ray optics. X-ray quantum opticsSlide70

Spectroscopy and

Spectrochemical

AnalysisResearch MethodsTypical

Examples of Research SubjectsPhotoelectron spectroscopy (I-1)

Electronic structure of advanced materials such as superconductors, magnetic substances, and highly correlated electron systems.

Atomic and molecular spectroscopy

(I-1)

Photoionization

spectra,

photoabsorption

spectra and photoelectron spectra of neutral ,

atoms and simple molecules. Spectra of

multicharged

ions.

X-ray fluorescence spectroscopy (I-2)Ultra-trace element analysis. Chemical states of trace elements. Archeological and geological studies. X-ray absorption fine structure (I-2)Atomic structure and electronic state around a specific atom in amorphous materials, thin films, catalysts, metal proteins and liquids.X-ray magnetic circular

dichroism

(I-2)

Magnetic properties of solids, thin films and surfaces. Orbital and spin magnetic moments.

Infrared spectroscopy

(I-2)

Infrared

microspectroscopy

. Infrared reflection and absorption spectroscopy.

X-ray inelastic scattering

Electronic excitation. Electron correlations in the ground state. Phonon excitation. Slide71

X-ray Imaging

Research Methods

Typical Examples of Research Subjects

Refraction-contrast imaging (I-2)lmaging

of low absorbing specimens.

X-ray fluorescence microscopy

(I-2)

Imaging of trace elemental distribution with a scanning X-ray microprobe.

X-ray microscopy

(I-2)

Imaging of materials by magnifying with

microfocusing

elements.

X-ray topography

(I-2)

Static and dynamic processes of crystal growth, phase transition and plastic deformation in crystals. Crystal lattice imperfections.Photoelectron emission microscopy (I-2)Element-specific surface morphology. Chemical reaction at surface. Magnetic domains.Slide72

Radiation Effects

Research Methods

Typical Examples of Research Subjects

Material processing (I-2)Soft X-ray CVD.

Microfabrication.

Radiation biology

(I-2)

Radiation damage of biological substances. Slide73

Mo/Si soft x-ray Polarizer multilayerSlide74
Slide75
Slide76