2008 T.matsushita 1

7/27/2019 2008 T.matsushita 1

1/70

X-ray monochromators

T. Matsushita

Photon FactoryHigh Energy Accelerator Research Organization

7/27/2019 2008 T.matsushita 1

2/70

outline

1. Controlling X-ray beam properties and the roll ofcrystal monochromators

2. Bragg diffraction by crystals3. Dynamical diffraction

4. Double crystal monochromator

5. Heat load and cooling6. Higher harmonics rejection

7. High resolution monochromators8. Phase retarder and polarization conversion

9. Curved crystals

10. Other issues and future problems

7/27/2019 2008 T.matsushita 1

3/70

Synchrotron Radiation - Basic Properties

High flux and brightness Pulsed time structureBroad spectral range

Polarized (linear,

elliptical, circular)

Small source size

Partial coherence

High stability

HIGH VACUUMENVIRONMENT

Flux = # of photons in given /

sec, mrad Brightness (Brilliance)

= # of photons in given /

sec, mrad , mrad , mm2

(a measure of concentration of the radiation)

Winick: Presentation at JASS02 Seminarhttp://conference.kek.jp/JASS02/PDF_PPT/3_2_winick.ppt

7/27/2019 2008 T.matsushita 1

4/70

Designing your experiment

- X-ray optical consideration -EXAFS(Extended X-ray Absorption Fine Structure)

Protein crystallography

180 degree oscillation : 0.7 ~ 3 (E : 18 keV ~4 keV)/ (E/E) : 10-3 ~10-4

Angular divergence : 2 ~ 0.2 mrad

Beam spot size : 5 ~ 200 m

0.375

0.75

1.125

1.5

8500 9000 9500 1 104

CU2A03

UT

t

E/eV

0.3

0.7

1.1

1.5

1.9

8940 8960 8980 9000 9020 9040 9060

CU7B03

UT

E/eV

E: ~4 keV - ~20 keV (~10 keV - ~50 keV)

E/E: ~10-4

Beam size: 1 mm x 10 mm 1 m2

7/27/2019 2008 T.matsushita 1

5/70

Designing your experiment

- X-ray optical consideration -Small angle scattering Powder diffraction

E: 6keV- 20 keV

E/E: 10-3

Angular convergence:0.1- 0.2 mrad (V)1- 2 mrad (H)

Focal spot size:0.3 mm (V) - 1.0 mm (H)

E: 10 keV 35 keV

E/E: ~10-4

Angular divergence:

0.5 1 mrad

Beam size:

V: 0.1 ~ 0.5 mm

H: 1 ~ 3 mm

PF 15A (bending magnet) Spring-8 BL02B (bending magnet)

7/27/2019 2008 T.matsushita 1

6/70

polarization

Energy, energy resolution Spatial spread Time structure

Angular divergence intensity

Controlling the X-ray beam properties by X-ray crystal monochromators

7/27/2019 2008 T.matsushita 1

7/70

Concrete shield

Light source

Storage ring

Experimental hall

Front-end

Optics hutch

Optics and transport channel

Experimentalhutch

Double-crystal

monochromator

Example of beamline structure

@SPring-8

UndulatorBending magnet &

front-end

7/27/2019 2008 T.matsushita 1

8/70

Crystal monochromators

)(

4.12)()sin()(2

keVEnnd ==

d

dsin dsin

cot=

=

E

E

d: Latiice (d)-spacing,

: glancing angle,: X-ray wavelength10 keV : 1.24 ,1 : 12.4 keV

Energy (wavelength) resolution

Higher harmonicsE1 = 10 keV (n = 1)

E2 = 20 keV (n = 2)

E3 = 30 keV (n = 3)

Braggs law of difraction

E1,E2,E3,

7/27/2019 2008 T.matsushita 1

9/70

Lattice planes of silicon

Top view

Side view

[100]

[011]

[010]

[001]

(400)

(511)

(111) : 3.1356

(311) : 1.6375

(400) : 1.3578

(511) : 1.0452

a

a

d-spacing

(111)(311)

a0 = 5.43095

7/27/2019 2008 T.matsushita 1

10/70

Energy range of SPring-8

standard monochromator

ReflectionSi 111 : d = 3.1356

Si 311 : d = 1.6375

Si 511 : d = 1.0452

..

Bragg angle327

Energy range4.4110 keV

e.g. For SPring-8 standard monochromator

0

20

4060

80

100

120

0 5 10 15 20 25 30Bragg angle (deg)

Photonene

rgy(keV)

Si 111 refl.

Si 311 refl.

Si 511 refl.

Photon energy (wavelength) can be selectedby crystal, net planes, and Bragg angle.

E = 12.4/(2d sin)

nd =)sin(2

7/27/2019 2008 T.matsushita 1

11/70

Preparation of crystal monochromator

Courtesy of Sharan Instruments Co. Ltd.

No or less imperfections

dislocations

stacking faultspoint defects (non-uniformlydistributed, striations, aggregations)

7/27/2019 2008 T.matsushita 1

12/70

7/27/2019 2008 T.matsushita 1

13/70

X-Ray Dynamical Diffraction

P. Ewald (1912, 1917):dipoles in the crystal which are excited by the incident X-ray wave and radiate X-rays. C. Darwin (1914): multiple reflection by lattice planes. M. von Laue (1931) :

continuous medium consisting of periodic dielectric constant.

Experimental proof: in 1960s and 1970s, big perfect crystals (silicon, germanium,etc) became available

Since late 1970s, perfect crystals have been used as monochromators onsynchrotron beamlines.

Textbooks and reviewsB. W. Batterman and H. Cole, Rev. Mod. Phys. 36, 681 - 717 (1964)

Dynamical Diffraction of X Rays by Perfect Crystals

A. Authier, Dynamical Theory of X-Ray Diffraction, International Union of Crystallography

Monographs on Crystallography No. 11. Oxford: Oxford University Press, 2001

R. W. James: The Dynamical Theory of X-Ray Diffraction, in Solid State Physics (Seitz andTurnbull) vol.15 (1963), Academic Press

M. von Laue: Roentgenstrahlen Interferenzen , 1941

7/27/2019 2008 T.matsushita 1

14/70

Laue case and Bragg case

K0Kh

n

K0Kh

n

Laue case Bragg case

7/27/2019 2008 T.matsushita 1

15/70

Reflectivityreflectivity for Bragg case, no absorption, and thick crystal:

Mhrhr eF

Vmc

e =2

22

( ) )1(12

2

2

00 = WWWR

0

0.2

0.4

0.6

0.8

1

1.2

-5 -4 -3 -2 -1 0 1 2 3 4 5

W

Reflectivity

{ }hr

rBKW

1

2sin 0+=

For symmetric Bragg case, sigma polarization:

h

BK

hrF=

2sin

2

Darwin widthW= 2

Shift of Bragg angle due to refraction:

BK

rrefraction

2sin0=

rr FVmc

e02

22

0

=

7/27/2019 2008 T.matsushita 1

16/70

Silicon single crystal, E = 10 keV

hkl Braqg angle(degree)

(arc sec)

(rad)

111 11.403 5.476 26.55

220 18.836 3.984 19.32

311 22.246 2.273 11.02

400 27.167 2.495 12.10

422 34.001 1.886 9.142

333 36.379 1.228 5.952

440 40.22 1.543 7.479

0h on the web!!!

http://sergey.gmca.aps.anl.gov/x0h.html

7/27/2019 2008 T.matsushita 1

17/70

)41( 22 += LLR

222222 )(4)1( gWgWgWL +++

For thin absorbing crystal of the Laue-case (transmission geometry), thereflectivity is given by

For thick absorbing crystal in the Bragg-case (reflection geometry), thereflectivity is given by

hr

ig

0

=

rh

hi

=

+++

+

=

2

222

1

sinh)1(sin)21(

)/exp(

W

AWA

W

tR T

/tkA hr=

7/27/2019 2008 T.matsushita 1

18/70

Intrinsic rocking curve for silicon

Features:Diffraction width (Darwin width) of 0.1100 radPeak reflectivity of ~1 for low absorption case

0

0.2

0.4

0.6

0.8

1

-100 -50 0 50 100(rad)

Reflec

tivity

111 refl.10 keV

333 refl.30 keV

Based on the dynamical theory for perfect crystalfor thick crystal and absorption considered:

BK

rrefraction

2sin

0=

BK

hr

2sin

2=

M

hrhr eFVmc

e

= 2

22

rr F

Vmc

e02

22

0

=

7/27/2019 2008 T.matsushita 1

19/70

Angular divergence of sources and

diffraction width

SPring-8 bending

magnet

Divergence of undulator radiation is the same order as

diffraction width of low order reflection.

rad601

r

Undulator (N= 140)

rad51

r N

10-1

100

101

102

103

0 20 40 60 80 100

Photon energy (keV)

F

WHM(rad)

Bending magnet

Undulator 1st

Si 511 refl.

Si 111 refl.

Si 311 refl.

7/27/2019 2008 T.matsushita 1

20/70

Energy resolution E/E=10-510-322

Bcot +=E

E: intrinsic angular width of diffraction

: angular divergence of X-ray beam

(1) -10

1

(2)

2d sin(0) = 0

2d sin(-1) = -1

2d sin(1) = 1

source-to-slit distance = 30 m

slit width = 1 mm

= 3.3 x 10-5

Si 111, 10 keV: = 11.4

E/E = cot = 1.6 x 10-4

For Si 111, = 2.66 x 10-5 rad at 10 keV

E/E = cot = 2.66 x 10-5 x cot(11.4) = 1.32 x 10-4

7/27/2019 2008 T.matsushita 1

21/70

Energy resolution

E/E=10-510-3

22Bcot +=

E

E : divergence of source

: diffraction width

10-5

10-4

10-3

10-2

0 20 40 60 80 100Photon energy (keV)

E/E

Bending magnet + Si 111 refl.


Undulator 1st + Si 111 refl.


Using slit, collimator mirror,.. we can reduce eff

,

7/27/2019 2008 T.matsushita 1

22/70

7/27/2019 2008 T.matsushita 1

23/70

Goniometer and angle accuracy

Courtesy of Kohzu Seiki Co. Ltd.0.2 arc s / step (1 rad / step)

Energy scan (Si 111 d = 3.119478)

E0: 10.000 keV = 11.46246

E1: 10.001 keV = 11.46130

= 0.001162= 4.18 arc s = 20.3 rad

7/27/2019 2008 T.matsushita 1

24/70

Double crystal monochromator

Constant beam direction

beam height changesslightly when E ischanged.

Two crystals should beparallel to each otherwithin sub-arc-seconds.

Tail intensity falls off

rapidly.

g

h

)cos(2 gh =

Alignment of a double crystal monochromator

7/27/2019 2008 T.matsushita 1

25/70

Alignment of a double crystal monochromator

(1) Parallelity in the scattering plane: sub-rad

(2) Parallelity normal to the scattering plane: ~10-3 - 10-4 rad

(3) Parallelity to the rotating axis :

tan2

2=

sin2=

: 10-3

10-4

7/27/2019 2008 T.matsushita 1

26/70

Courtesy of Kohzu Seiki Co. Ltd.

7/27/2019 2008 T.matsushita 1

27/70

Stability and disturbances

Energy :0.1 eV for XAFS,

sub-meV for high resolution inelastic scattering Intensity : less than 1 %. Beam position: typically several tens ~ 1 m

Source instability

Source size change, source position change, charge distribution change

Room temperature variation

Heat load by the radiation itself

Vibrationfloor, cooling water, vacuum pump

Variation at the sample

7/27/2019 2008 T.matsushita 1

28/70

(1) 1+ translation + 2 link (2) + two translation link

B

hy

sin2AB ==

B

hz

cos2OB ==

16/)4/)(4/( 42222 hhzhy =

-stage

Translation stage

1st crystal

2nd crystal

-stage

y

h

B

hy

2tan=

Fixed-exit DCM

Offseth

y B

O

AB

z

1st crystal

2nd crystal

B

B

Exit beam

A number of different schemes have beendeveloped to realize a fixed-exit beam.

7/27/2019 2008 T.matsushita 1

29/70

UVSOR BL 1A, BL 7A

Hiraya et al., RSI 66 (1995)

Kirkland, NIM-A291 (1990)

h= 50 mm, B= 585

Difficult ies for crystal cooling and multi-stage adjustment Low rigidity

Boomerang link type

B= 18.571.5

7/27/2019 2008 T.matsushita 1

30/70

7/27/2019 2008 T.matsushita 1

31/70

7/27/2019 2008 T.matsushita 1

32/70

Crystal cooling

Qin

T1

T0

Radiation & convection

Heat conduction in crystal

Heat transfer

to coolant/holderCoolant/holder

Crystal

Why crystal coolingQin (Heat load by SR) = Qout (Cooling + Radiation,..)

with temperature rise T T = d (d-spacing change) : thermal expansion coefficientor (bump of lattice due to heat load)

Miss-matching between 1st and 2nd crystals occurs: Thermal drift, Loss of intensity, Broadening of beam, loss of brightness Melting or limit of thermal strain Broken !

7/27/2019 2008 T.matsushita 1

33/70

Solution for crystal cooling

We must consider:

Thermal expansion of crystal: ,Thermal conductivity in crystal: ,Heat transfer to coolant and crystal holder.

Solutions:(S-1) / Larger(S-2) Large contact area between crystal and coolant/holder

larger(S-3) Irradiation area Larger, and power density smaller

7/27/2019 2008 T.matsushita 1

34/70

Silicon Silicon Diamond Copper

300 K 80 K 300 K 300 K

(W/m/K) 150 1000 2000 401

(1/K) 2.5x10-6 -5x10-7 1x10-6 16.5x10-6

/ x106 60 2000 2000 24

Figure of merit

Figure of merit of cooling:Figure of merit of cooling:

Good for silicon (80 k) and diamond (300 K)Good for silicon (80 k) and diamond (300 K)

7/27/2019 2008 T.matsushita 1

35/70

7/27/2019 2008 T.matsushita 1

36/70

Direct cooling with fin crystal

Fins with

Inserted metal

Applied to bending magnet beamline

P f f fi l (1)

7/27/2019 2008 T.matsushita 1

37/70

Performance of fin crystal (1)

0

0.2

0.4

0.6

0.8

1

1.2

-40 -30 -20 -10 0 10 20 30 40

Horizontal position (mm)

Intensity(arb.units)

Uniformity0.3%

Si 111 refl.

Si 333 refl.

h= 25 keV

Si 111 refl.

Ring current= 1 mA

Mechanical deformation removed

7/27/2019 2008 T.matsushita 1

38/70

Di t li ith fi t l

7/27/2019 2008 T.matsushita 1

39/70

Reduce radiation damage of rubber O-ring

SR

Direct cooling with fin crystal

P f f fi t l (2)

7/27/2019 2008 T.matsushita 1

40/70


B= 5, E= 43.4 keV

B= 10, E= 21.8 keV

Slit: 3 mmV40 mmH

B= 20, E= 11.1 keV

Current status

Practical use both (311) and (111) crystals24 sec. twist due to fabrication process must be reduced.

No heat strain for (111) crystal at 12 keV photon

Radiation damage of O-ring is improved by side-inletDurability test is under way.

X-ray image for Si 311 refl.

P f f fi t l (3)

7/27/2019 2008 T.matsushita 1

41/70


Si 111 refl.

Ring current= 100 mA

0

10

20

30

40

50

60

70

0 10 20 30 40Slit width (mm)

RockingcurvewidthFWH

M(rad)

E= 7 keV

E= 12.4 keV

E= 18.9 keV

7/27/2019 2008 T.matsushita 1

42/70

7/27/2019 2008 T.matsushita 1

43/70

7/27/2019 2008 T.matsushita 1

44/70

7/27/2019 2008 T.matsushita 1

45/70

7/27/2019 2008 T.matsushita 1

46/70

Cryogenic cooling

7/27/2019 2008 T.matsushita 1

47/70

Cryogenic cooling

LN2 circulator with He refrigerator

Indirect side cooling

Applied to undulator beamline

7/27/2019 2008 T.matsushita 1

48/70

7/27/2019 2008 T.matsushita 1

49/70

7/27/2019 2008 T.matsushita 1

50/70

IIa diamond crystal

7/27/2019 2008 T.matsushita 1

51/70

IIa diamond crystal

(111) (100)

Crystal handling is crucial: Mounting without strain Alignment

Nearly perfect crystal using High Pressure High Temperature (HPHT)synthesis is available in growth direction.

To maximize the photon flux, 111 refl. in Bragg case is used.

Effective size of Diamond (111) is, however, small !

Seed

Seed

5 mm5 mm

Crystal mounting

7/27/2019 2008 T.matsushita 1

52/70

Crystal mounting

Mechanical mounting withSS plates and screws

Release the screws

Temperature increase to ~ 130 CKeep 30 min

Decrease to room temperature

Thermal mounting method

Topograph and rocking curve

7/27/2019 2008 T.matsushita 1

53/70

Topograph and rocking curve

-10 0 100

0.5

1

Rotation angle (arcsec)

Intensity

(a.u.

)

MeasuredCalculated

7/27/2019 2008 T.matsushita 1

54/70

7/27/2019 2008 T.matsushita 1

55/70

Higher harmonics rejection

total reflection mirror

7/27/2019 2008 T.matsushita 1

56/70

Substrate materialSi for white radiation

SiO2 for monochromatic beam Coating materialPt, Rh, Ni,...Depending on energy, reflectivity, absorption edges,..

Glancing angle210 mrad (For SPring-8 X-ray beamline)Depending on energy, reflectivity, absorption edges,..

Mirror length400 mm1 m (For SPring-8 X-ray beamline)Depending on the beam size and glancing anglee.g. 100 rad50 m/5 mrad= 1 m

- total reflection mirror -

7/27/2019 2008 T.matsushita 1

57/70

7/27/2019 2008 T.matsushita 1

58/70

High resolution monochromator

7/27/2019 2008 T.matsushita 1

59/70

double crystal arrangements and the DuMond diagram

7/27/2019 2008 T.matsushita 1

60/70

Extremely HighExtremely High--Resolution XResolution X--RayRay

MonochromatorsMonochromators

7/27/2019 2008 T.matsushita 1

61/70

120eV @ 14.4 keVYabashi et al., PRL (2001)

[email protected] et al., JSR (2001)

Channel-Cut

Asymmetric Channel-Cut

Original Nested-Channel-Cut, [email protected] keVIshikawa et al., RSI (1992)

Alfred Q. R. Baron,a* Yoshikazu Tanaka,b DaisukeIshikawa,b Daigo Miwa,b Makina Yabashia and TetsuyaIshikawaa,b J. Synchrotron Rad. (2001). 8, 1127-1130

MonochromatorsMonochromators

7/27/2019 2008 T.matsushita 1

62/70

Power Load Effects on BackscatteringPower Load Effects on Backscattering

MonochromatorMonochromator

7/27/2019 2008 T.matsushita 1

63/70

Flat CrystalAnalyzer

VerticalTranslation

~130 mWIncident BeamFrom Si (111) mono

Detector

Backscattering MonoAt the (11 11 11)

0

0.2

0.4

0.6

0.8

1

-4 -2 0 2 4

GrazingIncidence

NormalIncidence

Energy Offset (meV)

phase retarder, polarization conversiontransmission through a thin crystal

7/27/2019 2008 T.matsushita 1

64/70

- transmission through a thin crystal -

M. Suzuki and T. Hirono,Hoshako Nov. 2006, Vo.19 No6, pp.444-453

Concept of dispersion surfaces should be utilized to understand.

Sagittal focusing

7/27/2019 2008 T.matsushita 1

65/70

Applied for bending magnet beamline

Bending mechanism

for SPring-8 sagittal focusing

1st crystal

2nd crystal

Focal point

Si 311 refl.

40 keV

SourceCrystal=36.5 m

Crystalfocalpoint= 16.5 m

50 mm

Principle of sagittal

focusing

e.g. Sagittal

focusing images

sin2qp

pqr+

=

r: radius of 2nd crystal

: Bragg anglep: source ~ crystal distance

q: crystal ~ focal point distance

7/27/2019 2008 T.matsushita 1

66/70

7/27/2019 2008 T.matsushita 1

67/70

Other issuesPh l i

7/27/2019 2008 T.matsushita 1

68/70

Phase space analysisposition-angle (position-momentum) space

Extended Phase spaceposition-angle-wavelength spaceposition-angle-energy space

Ray tracing Feedback control of the DCM Compton scattering (heating of the 2nd crystal) Stress due to crystal mounting Surface finish and residual stress layer

Wide band-pass monochromators Quick-scan monochromators

Dispersion surface

Future subjects

7/27/2019 2008 T.matsushita 1

69/70

j

Smaller slope error, smaller roughness, smaller residualstress

optics for handling more coherent X-rays More higher resolution Wide bandpass crystal monochromator

optics for handling more bright( intense) beam optics for handling extremely short pulses

Acknowledgements

7/27/2019 2008 T.matsushita 1

70/70

Dr. S. Goto, Spring-8Dr. T. Ishikawa, RIKEN/Spring-8

Dr. K. Hirano, Photon FactoryProf. H. Winick, SSRLMr. H. Kohzu, Kohzu Seiki Co. LtdMr. Koizumi , Sharan Instruments Co. ltdDr. T. Mochizuki, Spring-8Dr. M. Takata, RIKEN/Spring-8Prof. Y. Amemiya, Univ. of Tokyo

Dr. M. Suzuki, Spring-8Dr. T. Hirono, Spring-8

Documents

2008 T.matsushita 1