Introduction“X‐ray beamline looks complicated ?”Cheiron school 2012 , 25th Sep. 2012, SPring‐8
X ray beamline design Ⅱ
X‐ray

Storagering

Optics Engineeringf x‐ray beamline
for
b
li d
designi

inside shieldingg tunnel ((front end )Haruhiko Ohashi
JASRI / SPring‐8
outside shielding tunnel (optics hutch )What function of each component ?
Light source(IDs/BM)

Key issues for the beamline design

X‐raybeamline

Front end (FE)Radiation
shield hutchLightg source

Key issues

Design components

Applications at the BL ( scientific strategy, concept )• End station( pressure, temperature,• Sample environment
magnetic field…)• Detector, data processing … ( automation )– Photon beam properties at sample
•
•
•
•
•
•

( Power )Human safety
Engineg

InterlockysystemBrake
Ai b
Air‐bags

Machine protection
Radiator
Body• Protection from radiation hazard to healthg to instruments• Protection from radiation damage

Tailoring x‐rays（ Power control ）Mirrors– Utilities––––

User Interface

A vehicle

Steering wheel
Dashboard
Gear leverApplication( drive)

End station

Photon energy,
gy, energy
gy resolution
Flux, flux density
Beam size
Stability( longg , short term )Polarization
Spatial coherence
Priority ?
Time resolution– Human Safety & Machine protection

Monochromator

Transmission
Gear

2

3

Time schedule
Human resources
Available budget, space, technical level
Maintenance & lifetime of BL( hardware, applications )

•
•
•
•
•
•

Light source (ID, BM)
Monochromator, higher order suppression…
Monochromator
suppression
Focusing devices… Optics (ex. mirror)
Polarizer…
Beam position monitor
Window
Window…
RF timing, chopper…

• Radiation shielding hutch …
• Interlock
I t l k systemt• Beam shutter…
•
•
•
•
•
•

Front end

Absorber, FE slit
Cooling method, cooling system
Selection of light sources ( power, angular dist.)
Electronics in hutch ( detector, controller … )Embrittlement (cable, tube )Contamination on optics• Electricity, water, air, network, control• Environments ( temperature, vibration… )Management of the beamline construction

4

Light source(IDs/BM)

Front end (FE)X‐raybeamline

XBPM

Radiation
shield hutch

Heat managementgforhuman safety & machine protection↓
F t endFrontd( FE )

Light source
Human safety
Heat management

InterlockysystemMachine protection

Beam position monitor

Monochromator
Tailoring x‐rays

Optical design

Mirrors( for example, mirrors )User Interface

DesignMetrology

Alignment

Today’s contents

Utilities
Application

Experimental station

6

5

Beamline components for safety

Beamline components for safety

Front end

78

SPring‐8 Tunnel

Schematic Layout inside the SPring‐8 Tunnel

Front end (15～18m)

Tunnel of the storage ring (1/16)

F
Front
end
d (FE)(15～18m)

Why so long FE?

9

Key functions & components of FE(a) Shielding for human safety
Beam shutter (BS), collimator ( radiation shield )(b) Handling high heat load for safety Absorber, masks (to prevent BS from melting)(b’) Handling high heat load for optics
XY slit, filters ( to prevent optics from distorting )(c) Monitoring the x‐ray beam position
XBPM (x‐ray BPM ), SCM (screen monitor )(d) Protection of the ring vacuum
FCS (fast closing shutter ), Vacuum system

Standard
in‐vacuum undulator
Power density :500 kW/mrad2
Total power : 13 kW

10When we operate a main beam shutter (MBS), what happens ?
X‐ray

Absorber ( Abs )Beam shutter ( BS )to protect BS from heat load
A block of
33 kggMoveis moved

to shield you against radiation

Move

Glidcop®
(copper that is dispersion‐strengthened
dispersion strengthened
with ultra‐fine particles of aluminum oxide)

MBS ( = ABS + BS )Shielding wall

is opened,
beam reaches optics hutchthrough shield wall.
11

A block of
30～46 kg
is moved

the thermal conductivity
Heavy metal
not so high(alloy of tungsten)

After Abs is fully closed,
closed BS is closed.
closedAfter BS is fully opened, Abs is opened.
The sequences are essential to keeping safety.

ABS andd BS workk on ways togetherhto protect us from radiation when we enter the hutch.

12

FE: “For users to take lion’s share”

Other key function is to handle high heat load for optics(a) Shielding for human safety(b) Handling high heat load for safety(b’) Handling high heat load for optics( ) Monitoring(c)i i theh x‐ray beambpositionii(d) Protection of the ring vacuum

Beam shutter (BS)(BS), collimator ( radiation shield )Absorber, masks (to prevent BS from melting)
XY slit, filters ( to prevent optics from distorting )XBPM (x‐ray(
BPM ),) SCM (screen(
monitor )FCS (fast closing shutter ), Vacuum system•••

Adding a spatial
Addi
ti l lilimitation
it ti tto photon
h t b
beam,
supplying only a good quality part around the central axis of ID
to transport optical system safely and stably
stably.①Fixed Mask Aperture ②Pre Slit Aperture
322μrad x 322μrad

The size of XY slit is set to 1.05mm□．
XY slit is installed ～30m away from ID.
ID

φ152μrad③XY Slit Aperturep
35μrad x 35μrad⓪②➀Higherorder
These components cut off
the power to prevent
optics from distorting byheat load.
13③

Slit : “Too much is as bad as too little”

1st harmonic
Flux Density

Power Densityy
Helical Mode Operation
at BL15XU 14

Handling Technology of high heat load

1st harmonic fluxf

How to manage
high heat load
by FE XY slit ?

SPring‐8 Standard In‐Vacuum Undulator : 13.7kW, 550kW/mrad2

at SPring‐8i

Spatial distribution of power

29 kg

29 kg
k

Incident angle
0.08 deg(1.5 /100 )to accept the power

15

16

Simulation: “better safe than sorry”

For instance,, the distributions of temperaturepand stress of Be window at FE can be calculated
by FEA (finite element analysis ).

Key issues of FE design
1. There exists a category of the beamline front ends.
They have their proper functions, proper missions based on the principles
of human radiation safety, vacuum protection, heat‐load and radiation
damage protection of themselves.
Th h
They
have tto ddeall with
ith every moded off ringi operation
ti andd every mode
d offbeamline activities.

2. Any troubles in one beamline should not make any
negative effect to the other beamlines.
3. Strongly required to be a reliable and stable system.
We have to adopt key technologies which are reliable, stable and fully
established as far as possible.

HigherHih theth initial
i iti l cost,t theth lowerltheth runningi costt fromfthethlong‐range cost‐conscious point of view.
17

18

Where is XBPM installed ?
XBPM is installed before any spatial limitation. You hardly find it.
It is quietly monitoring beam position at any time.

Monitoring
photon source
stabilityy off p↓
X‐ray beam position monitor( XBPM )Another monitor is installed
after spatial limitation.
It is useful to check the centerof XY slit. Usually it is retracted.

19

20

Revised

Structure of XBPM’s detector head

( PhotoPhoto‐emission
emission type )Fixed‐blade style XBPM‐ Four blades are placed in parallel to the beam axis to reduce heat load.
‐ CVD didiamondd isi usedd becauseb
off excellent
ll t hheatt propertytElectrons from each blade of Ti/Pt/Au on diamond emitted by outer side of photon beam
The horizontal or vertical positions computed by each current

X-ray

for SPring‐8 in‐vacuum undulator,
undulatoretc.
(19 beamlines)

XBPM
XBPM
Surfacediamondis metalized.
for insertion
deviceof(ID)beamlinefor bending magnet (BM) beamline

XBPM is installed on stable stand and stages
22

21High stability of XBPMLong term stability of XBPM at BL47XU

As the stability is compared with other monitors outside wall,
the stability of XBPM for 3 hours and 23 hours are measured.

After 3 hours

After 23 hours

V: 1.7 μm H: 3.5 μm (RMS)

V: 4.7 μm H: 3.2 μm (RMS)

Gaps is set at reference points (Minimum gaps).

All Gaps are set at reference points (Minimum gaps).

Stability of the XBPM is a few microns for a day

under the same conditions ( ID‐gap, filling patter & ring current).

23

24

XBPM of ID‐Gap dependence

Orbit correction using XBPM

Measured at BL47XU
with fixed‐blade style

Ph t
Photo‐emissioni i typetReference point (Minimum gap )The beam
recoveredusing XBPM.
The beam lostat optics hutch.
hutchElectron beam monitored
same orbit before.

G dependence:Gapdd

A ffixed p
point observation off XBPM is
helpful for a regular axis from ID.

～ 100μm for Gap : 9.6 ~ 25 mm , ～300μm for Gap : 9.6 ~ 50 mm
Th positionThe
iti off th
the beamb
att optics
ti hutchh t h isi fi
fixed
d ffor changing
hi ID gap.
25

26

Key issues of XBPM design

What does the XBPM tell us ?
ID‐Gap minimum

What does the XBPM tell us ?
ffor highg powerpundulator radiation in SPring‐8g

ID‐Gap fully opened

1. Dependence of ID gap, ring current, filling pattern
XBPM (photo‐emission(photo emission type ) depends on these parameters.
parameters
2. High stability
XBPM has stabilityy of microns for a day.
y
3. Resolution of x‐ray beam position‐ The
Th resolution
l ti off microniorder
d can beb monitored.
it dBeam divergences are ~ 20 / 5 μrad ( hor. / ver. ), which correspond to
beam sizes of ~ 400 / 100 μm ( hor. / ver. ) at XBPM position (20 m from ID).

Origin of ID‐gap dependence of XBPM:

4. Withstand high heat Load
‐ Blade of diamondMax. power density is ~ 500 kW/mrad2. Metal will melt immediately.

‐XBPM of photo‐emission type has energy dependence.
Radiation from ID changes drastically,
drastically but not from BMs (backgrounds)‐ Backgrounds are asymmetric and usually offset.
1st harmonic:
6 ~ 18 keV,
Background: < several keV near beam axis of ID

5. Fast Response‐ Response time of < 1 msec needs for high frequency diagnostic.
‐ Simultaneous diagnostic over beamlines is important.

XBPM ddepends
d on ID‐gap,
IDfilli pattern
fillingtt& ringi current.
t
The results of XBPM can be compared with the same condition.

27

Ref. of XBPM : for example, H. Aoyagi et al., “High‐speed and simultaneous photon beamdiagnostic system using optical cables at SPring‐8”, AIP Conf.Proc.705‐593 (2004).

28

Intensityy (a.u.)

300

The functions of x‐ray mirrors

200

25nm
100

0
0.0

0.2

0.4

TTailoringil i x‐rayst application
to
li ti
↓
X ray mirrors
X‐raydesign errors,
errors metrology
design,& alignment

0.6

0.8

Position (μm)
No errors• Deflecting• Low ppass filter• Focusingg• Collimatingg• Separation from γ‐ray• Branch / switch beamline• Higher order suppression• Micro‐ / nano‐ probeIi• Imaging• Energy
gy resolution
w. multilayer or crystal mono.

30

29

Intensityy (a.u.)

300

Design parameters of x‐ray mirror

200

25nm

Requirement

100

0
0.0

0.2

0.4

the beam properties both of incident and reflected x‐rays

TTailoringil i x‐rayst application
to
li ti
↓
X ray mirrors
X‐raydesign errors,
errors metrology
design,& alignment

0.6( size, angular divergence / convergence, direction, energy region, power… )0.8

Position (μm)
No errors

We have to know well what kinds beam irradiate on the mirror.

31

Design parameters• Coating material : Rh, Pt, Ni … ( w/o binder , Cr ), thickness: multilayers ( ML )), laterally graded ML• Incident angle: grazing angle ( mrad )How to select• Surface shape: flat,flat sphere,
sphere cylinder,
cylinder elliptic …
: adaptive (mechanically bent, bimorph )• Substrate shape : rectangular,
rectangular trapezoidal…
trapezoidal• Substrate size
: length, thickness, width: indirect or direct,
direct water or LN2…
• w/o cooling• Substrate material : Si, SiO2, SiC, Glidcop…
In addition
addition,some errors such as figure error, roughness…

32

How to select coating material and incident angle ?

The complex atomic scattering factor for the forward scattering

Reflectivity for grazing incident mirrors

k1 =

2π

λ

cos θ , k 2 =k1 − k 2
k1 + k 2
2π

f = f1 + if 2

2

The complex index of refractionn = 1 − δ − iβ

Nr0λ2
δ=
f1 (λ )
2π
N 0λ2
Nr
β=
f 2 (λ )2πn − cos θ2

λ2

The complex index of refraction

r0 =
33

Coating material ( 2 )“t t l reflection”“totalfl ti ”
n1 n2 = cos((θ1 ) cos((θ 2 )

θ1

θ1

θ2

e2
= 2.82 × 10−15 m
4πmc 2

0.488

0.744

Quartz

0.555

2.33

Pt

3.26

20.7

Au

2.96

19.5

μλ
4π

μ: linear absorption coefficient34

The cut off energy of total reflection Ec

Ec ≈ 20 ρ θi
E c ( eV ) , ρ ( g / cm3 ), θ c ( mrad )

θ2

1.0
0.8
0.6

L-edge0.4

K-edge0.2

Rhθi (mrad)
(
d)
3
4
5
6
7
8
9
10

0.0

θ1 = θ 2 < θ c

5

1.0

10

15

20

Energy (keV)25θ c ≅ 2δ = 1.6 ×10−2 λ ρ = 20 ρ E

Reflectticity

Pt ( 21.4 g / cm3 )2

L edgeL-edge0.6

M-edge0.4
0.2
0.0( rad ), ρ ( g / cm3 ) , λ ( nm ) , E ( eV )Absorption
0

5

10

15

30

Pt
θi (mrad)
3
4
5
6
7
8
9
10

0.8

cos(θ c ) = n = 1 − δ , cos(θ c ) → 1 − θ c 2

θc
For example,
Rh ( ρ = 12.4 g /cm3 ) λ=0.1nm, θc =5.68 mrad

Si

N: Number of atoms per volume

Rh ( 1212.4
4 g / cm3 )θ1 = θ cβ(×10 ‐7)β=0θ1 > θ cδ (×10 ‐5)

Coating material ( 3 ) : “cut off, absorption”

Snell’s law

θ1

E ∝ e − i (ϖt −kr )Refleccticity

R (λ , θ , n ) =Coating material (1)“ h complex“thel indexd off refraction”
f
”

20

25

30

Energygy (keV)35

Cut off energy, absorption → incident angle→ Opening of the mirror, length, width of mirror, power density 36

Surface shape (1)Atomic scattering factors, Reflectivity

Purpose of the mirror

for example,• deflectingg• low pass filter• focusing• collimate
lli t

You can easily find optical property in “X‐Ray
X‐Ray Data Booklet
Booklet”
by Center for X‐ray Optics and Advanced Light Source,
Lawrence Berkeley National Lab
Lab.
In the site the reflectivity of x‐ray mirrors can be calculated.

htt // db lbl
http://xdb.lbl.gov//

Easy to make or cost

• flat• spherical• cylindrical• toroidal
t id l• elliptical• parabolic…
adaptive• meridional• sagittal
g

◎
◎
○
○
△
△
△

Take care ofaberration

Many thanks to the authors !
37

38

Surface shape (2) radius and depth2Rm =(1 p + 1 q )sin (θ i )2 sin (θ i )= Rm sin 2 (θ i )Rs =(1 p + 1 q )For parallel beam

By Fermat’s’ principlelq → ∞ ,1 / q = 0

Depth at the center D = R − R − ⎛⎜ L ⎞⎟ ≈ L
2

2⎝ 2R ⎠

2

8R

For example,
examplepp=15～50m,, q=5
q ～20m θi=1～10mrad
Rm=0.1～10 km, Rs= 30～100 mm
R=1 km, L=1m → D = 125 μm

Basic geometry

ESRF

S

R

F
p

D

L

39

by courtesy of Ch. MoraweqSurface shape (3) elliptical

Mirror optics

ESRF

x2 y2
+
=1
a 2 b2z

For example,
15

D
Depth(μmm)

s( x0, y0 )

p+q
2
1
b=
2 pq (1 − cos( 2θ )2
p2 − q2x0 =2 p 2 + 2 pq cos(( 2θ ) + q 2
a=p = 975 m , q = 50 mm , θ = 3 mrad

102

y 0 = −b 1 −
5
0

q

p

u=
0

10

20

30

P iti (
Position(mm)
)

40

50

x0
a2

b
× x0
a
2
a 2 − x02

⎛ s × cos( u ) + x 0 ⎞z ( s ) = − cos( u ) × b 1 − ⎜⎟ + s × cos( u ) sin( − u )a⎠⎝Precise fabrication is difficult.

( Ref * )* M.R Howells et al., “Theory and practice of elliptically bent X‐ray mirrors”, Optical Eng. 39,
422748 (2000).

by courtesy of Ch. Morawe

Ellipticalpmirror mechanicallyy bent
using trapezoidal substrate
Trapezoidal mirror (L170mm)

Trapezoidal mirror (L540mm)

DynamicallyDi ll bbentt KB mirror
iat ESRFLLongbbentt ffocusing
i mirrori
at SPring‐8

ESRF

43

by courtesy of Ch. Morawe

Mirror optics

Multilayer optics

ESRF

X‐ray multilayer reflectivity

ESRF
Numerical calculations
Main features• Bragg peaks and fringes due to interference• Positions depend on E and Λ• Intensities depend on Δρ, N, σ…
Corrected Bragg equationm ⋅ λ = 2 ⋅ Λ ⋅ n2 − n1 cos 2 θ
22

For θ >> θC →m ⋅ λ ≈ 2 ⋅ Λ ⋅ sin θ

q

q

A
B

L
L*sinqby courtesy of Ch. Morawe

ESRF

by courtesy of Ch. Morawe

X‐ray multilayer characterization

Transmission electron microscopy (TEM)• Fabrication errors• Roughness evolution• Crystallinity• Interface diffusion[W/B4C]50

X‐ray reflectivity

ESRF
Reflectivity and phase
Ni/Si

Complementary to x‐ray measurements !

R. Scholz, MPI Halle, Germany

by courtesy of Ch. Morawe

by courtesy of Ch. Morawe[Ni/B4C]20/Si

ESRF

Energy resolution of multilayers

X‐ray multilayer design

ESRF
Period number N:

Peak versus integrated reflectivity:• Rpeak increases with N up to extinction• ΔE/E decreases ~ 1/N in kinematical range• Rint is maximum before extinction
High and low resolution MLs
Optimize N according to needs !

by courtesy of Ch. Morawe

by courtesy of Ch. Morawe
300

Intensityy (a.u.)

Design parameters of x‐ray mirror
Requirement

the beam properties both of incident and reflected x‐rays( size, angular divergence / convergence, direction, energy region, power… )Design parameters• Coating material : Rh, Pt, Ni … ( w/o binder , Cr ), thickness: multilayers ( ML )), laterally graded ML• Incident angle: grazing angle ( mrad )• Surface shape: flat,flat sphere,
sphere cylinder,
cylinder elliptic …
: adaptive (mechanically bent, bimorph )• Substrate shape : rectangular,
rectangular trapezoidal…
trapezoidal• Substrate size
: length, thickness, width: indirect or direct,
direct water or LN2…
• w/o cooling• Substrate material : Si, SiO2, SiC, Glidcop…
In addition
addition,some errors such as figure error, roughness…

51

200

25nm
100

0
0.0

0.2

0.4

TTailoringil i x‐rayst application
to
li ti
↓
X ray mirrors
X‐raydesign errors,
errors metrology
design,& alignment

0.6

0.8

Position (μm)
No errors

52

Contamination and removal“An actual mirror has some errors.”
The tolerance should be specified to order the mirror

before• Reflectivity• Beam size
• Distortion• Deformation …

• RoughnessRh• Density of coating material• Radius error• Figure error

The cost ( price and lead time) depends entirely on tolerance.
We must consider or discuss how to measure it.

• Deformation by self‐weight, coating and support …
• Figure error of adaptive mechanism• Misalignment of mirror• Stability of mirror
mirror’ss position ( angle )• Environment• Deposition of contamination by use• Stages• Decomposition of substrate by use• Cooling system …

After cleaning

UV / ozone cleaning
It takes from 10 min to a few hours.

53

Errors ( 2 )“th self‐weight“thelf i ht deformation”
d f
ti ”

Errors ( 1 )“D i ρ and“Densityd surfacefroughnesshσ”
E c ≈ 20 ρ θ i

R = R0e

Material
SiO2
Density
2.2 g / cm3
Poisson's ratio 0.22
Young’s modulus E = 70 Gpa

L=

2

1.0

Rh
θi: 4 mrad
Density ρ
100 %
90 %
80 %

0.6
0.4

Rh
θi: 4mradrms roughness σ
0 nm
1 nm
2 nm

0.8

Refleccticity

0.8

0.6
0.4

Bottom view

0.2

0.2

0.0

0.0
0

5

10

15

20

Energy (keV)

25

30

0

5

10

15

20

25

Supportedp
byy 3 points
Thickness t = 50mm

L4
D∝
E × t3

By FEA (finite element analysis )30

Energy (keV)

Coating on sample wafer at the same time is helpful to evaluate the density and roughness.
55

6
4
2
0
‐2
‐4
‐6
6
‐8
‐10

Deeformatio
on ofthee height (nm )1.0

Refleccticity⎛ 4πσ sin (θ i ) ⎞
−⎜
⎟
λ
⎝
⎠

54

Position ( m )The self‐weight deformationon the surface of mirror ( SiO2 )16.7 nm PV
This value is larger than figure error byRayleigh’s rule.
( →See next page )Improvement for nanonano‐focusing
focusinga) Substrate → Si ( E ～ 190 GPa )b) Optimization of supporting points and methodc) Figuring in consideration of the deformation
56

Errors (3b)Errors (3a)“figure error estimated by Rayleigh’s rule ”

2

0.06nm (20keV) 3mrad
0 08
0.08nm(15keV)(15k V) 3mrad
3d
1 nm ( 1keV) 10mrad

8θ

p=975m, q=50mm,
θ=3mrad, L=50mm

10
5

2nm
3
3nm
12nm

0

0

10

20

30

Inttensity (a.u.))

57

0.2

0.4

0.6

0.2

0.8

0.6

0.8

0.2

0.4

0.6

0.8

0.2

Positionos t o (μm))
9nmPV (2.5nmRMS)

40

0.4

0.6

0.8

1.0

Position (μm)
30nmPV (8.5nmRMS)

10

20

30

Position (mm)Position(mm)4050Errors of long range order

300

Height erroor (nm)

0.5
0.0
-0.5
-1.0
-1.5
0

10

20

30

40

50

1.0
0.5
0.0
-0.5
-1.0
-1.5
300

Position (mm)

250

1.5

0

25nm
100

0.2

0.4

0.6

0.8

Position (μm))
3nmPV (1.1nmRMS)

0.2

0.4

0.6

0.8

Position (μm))
9nmPV (3.2nmRMS)

Errors of long range order loses shape.

0.2

0.4

0.6

0.8

1.0

Position (μm))
30nmPV (11nmRMS)

59

20

30

40

150
100
50
0.2

0.4

0.6

0.8

1.0

Position (mm)

150
100
50
0.2

0.4

0.6

0.0
-0.5
-1.0
-1.5
300

200

0
0.0

0.5

50

250

200

0.8

Position (nm)Position (nm)

誤差なし
3nmPV (0.85nmRMS)
9nmPV (2.5nmRMS)
30nmPV (8.5nmRMS)

誤差なし
3nmPV (0.9nmRMS)
9nmPV (2.8nmRMS)
30nmPV (9.4nmRMS)

Intensity reduced

200

10

1.0

15

Designed shape10

d DL = 25 nm

1.0

0

10

20

30

40

50

Position (mm)250

Deepth(μm)

0

50

1.0

300

Long range

1.5

Height errorr (nm)Figuree error-1

Middle range

Short range
1.5

Intensitty (a.u.)

30

0Intensity profiles of focusing beam by wavefront simulation
Inttensity (a.u.))

0.4

Errors of short range order decreases intensity. → Roughness

0
0.0

0.8

Errors of short range order

Position (μm))
3nmPV (0.85nmRMS)

Intensiity (a.u.)

20

1

Position(mm)
(
)

0.6

50

25nm

Height errorr (nm)5

Designed surface

0.4

40

100

Inte
nsity
Intensiity (a.u.)

p=975m, q=50mm,
θ=3mrad, L=50mm

Figgure erroorHeight error
H
(nm)
(nm)

Height(μmHm)

15

Position (μm))
No errors30“ estimation by wavefront simulation ”“ estimation by wavefront simulation ”

0.2

20

Position (mm)Position(mm)200Errors (3c)

0
0.0

10

300

0
0.0

10

0

Intensity profiles of focusing beam by wavefront simulation

Position (μm))
No errors

0

0
-1

50

Designed surface

θ

0

40

1

Position(mm)
(
)

h

10

Figgure erroorHeight error
H
(nm)
(nm)

hλ / 4 = λ

15Height(μmHm)

φ = 2hk sin(θ ) → π“ estimation by wavefront simulation ”

5
0

0

10

20

30

40

50

Position(mm)

200
150
100
50
0
0.0

0.2

0.4

0.6

0.8

P iti (nm)Position( )1.0

Performed 25nm

誤差なし
3nmPV (1.1nmRMS)
9nmPV (3.2nmRMS)
30nmPV (11nmRMS)

Shape loses

If the figure error < 3nmPV for all spatial range,th estimatedtheti t d focusingfi sizei performsf
25 nm.
The value corresponds to the result of Rayleigh’s rule.

25nm

The focusing beam of 25 nm was realizedusing high precision mirror with figure error of 3 nm PV*H. Mimura, H. Yumoto, K. Yamauchi et.al, Appl. Phys. Lett. 90, 051903 (2007).60

How to evaluate the errors ?

200

25nm

Designed surface

100

15
0
0.0

0.2

0.4

TTailoringil i x‐rayst application
to
li ti
↓
X ray mirrors
X‐raydesign errors,
errors metrology
design,& alignment

0.6

0.8

Deptth(μm)

Intensityy (a.u.)

300

Position (μm)
No errors

10
5
0

0

10

20

30

40

50

Position(mm)Errors ( long range )Figure errror(nm)

Figure errror(nm)

Errors ( short range )
1
0
-1
0

10

20

30

40

50

1
0
-1
0

10

20

30

40

50

Position (mm)Position (mm)62

61

Metrology instruments for x‐ray optics

Scanning white light interferometer

Field of view, lateral resolution
Long
g/
Sh /
Short
Long /
middlemiddlemiddle
dd e
～1m,
1
Short
～10 mm, ～ 0.1 m,
1 mm Slope
10 μm,μm～101 μm
0 1 mm0.1
FigureRoughness, figure
0.1 nmInterference fringe → HeightLong Trace Profiler( LTP )
Scanning probe
microscopez (0.1nm)

Scanning white lightinterferometer

Fi
Fizeaui t finterferometertz ((0.1nm)) z ((0.1nm))
Vertical resolution (rms)Fringes on CCD

Whitelilight
ht source( Lamp or LED )Beamsplitterli
Mirau orMichelson
objectivelensscanned

R f
Reference
Beam splitter

slope(0.1urad)

Under the test
63

Zygo Corp. NewVeiw®,
Bruker AXS (Veeco) Contour GT® .......

HeightFOV (=lens)～10 mmLateral resolution 1 μm～
Vertical resolution 0.1 nm
Figu
ure error(nm)

RoughnessC
Commercially
i ll available
il bl

1
0

Short / middle range order

1
-1
0

10

20

30

Position (mm)

40

50

64

Fizeau interferometer
Interference pattern → Height
Monochromatic
point lightp
g source

Commercially available

Zygo Corp. VeriFire®,
4DS technologies,
FujiFILM ……

Long trace profiler ( LTP )Direction of laser reflected on the surface → Slope

Slope

d
Z '=
=
2F

Beam
splitterFigure erroor(nm)Collimator
Reference

Cavityy

LaserLight source( Laser )0-1Long / middle range order
10

20

30

40

or line sensor

REF for monitoring stability of system

Easy to measure slope of sub‐μrad on large mirror by NO reference
Many kinds
ki d off LTPs are developingd l i among SR
S facilities.
f ili i50

Position (mm)Not easy to measure large mirror65

For example, S. Qian, G. Sostero and P. Z. Takacs, Opt. Eng. 39, 304‐310 (2000).

LTP
off ESRF, APS, SPring‐8

Figure error and slope error
Errors ( middle range )fθ lens Positionxd on CCD

Z : slopeZ’
Z : height
UnderMirror
the test

0

Detector

F

1

Under the test

Errors ( long range )66

Detector
Optics
Laser

0.2

Slop
pe error(uurad)

0.5µrad

0.0

0.1

Figure error
(nm
m)

0.5

Slo
ope error((urad)FOV ((=stage)g )～2 m
Lateral resolution mm～
Vertical resolution 0.1 μrad

Scanning penta prism

Fizeau fringes on CCD
FOV (=reference) ～0.1 m
Lateral resolution ～0.1 mm
Vertical resolution 0.1 nm

10.2µrad

0.0

-0.1
01

Mirror-0.2-0.5

Figuree error
(nm
m)

d μm
F 1m
Z’ < sub-μrad

Homemade

1

3nm

0
-1
0

10

20

30

40

50

Position (mm)Part of optics

3nm

0

Laser

-1
0

10

20

30

40

Mirror50

Position (mm)Detector

Mi
Mirror

Detector
OpticsΔθrms×L

Errors ( short range )
Δθ

5

L

Penta prism

0-5

Laterall resolution
l
×

-10

Figuree error
(n
nm)

Slo
ope error(urad)

10

1

3nm

0
-1
0

10

20

30

Position (mm)

40

50

LTP :
Laterall resolutionl i
mm～Vertical resolution 0.1 μrad

Mirror67

68

Detector

LTP
off ESRF, APS, SPring‐8

Optics (moving)Roundd robinbi measurement off
1m long toroidal mirror
1m‐long

Laser

Part of optics (moving)

MirrorLaser

Detector

Opticsp((fixed))

Laser
Penta prismp

Mirror
Detector

Figure error profile

Slope error profile

L. Assoufid, A. Rommeveaux, H. Ohashi, K. Yamauchi, H. Mimura, J. Qian, O. Hignette, T. Ishikawa,

Mirror69

Nanometer Optical Component Measuring
Machine (NOM) @HZB
A t lli t → Slope
AutocollimatorSl

C. Morawe, A. T. Macrander and S. Goto, SPIE Proc. 5921-21, 2005, pp.129-140.

70

Stitching interferometer for large mirror
HomemadeHomemade

Scanning

MSI

RADSI

( micro‐stitching interferometer )( relative angle determinable stitching interferometer )Microscopic
interferometer headLight source( LED or laser )Test mirror

FizeauElevation
Pitch
Pitch

Roll

Horizontal scan

0.5m
Test mirror
C ll b ti with
Collaboration
ith Osaka
O k Univ.,
U i JTEC andd SPring‐8
SP i 8
H. Ohashi et al., Proc. Of SPIE 6704, 670405‐1 (2007).

Heightg error off wide range
g order ffor a longg and asphericalp
mirrorwith 1μm of lateral and 0.1 nm of vertical resolution.

Under the test
F Siewert et al.:F.
al : „The
The Nanometer Optic Component Measuring Machine: a new Sub-nm
Sub nm Topography“ SRI 2003, AIP Conf. Proc.

71

Necessity is the mother of invention.

72

Introduction of KB mirrors

200

25nm

Elliptical mirrors

100

0
0.0

0.2

0.4

In 1948, P. Kirkpatrick and A. V.
Baez proposed the focusing opticalsystem.

TTailoringil i x‐rayst application
to
li ti
↓
X ray mirrors
X‐raydesign errors,
errors metrology
design,& alignment

0.6

0.8

Position (μm)
No errors

P. Kirkpatrick and A. V. Baez, “Formation of Optical Imagesby X‐Rays”, J. Opt. Soc. Am. 38, 766 (1948).

Kirkpatrick‐Baez (K‐B) mirrors

Advantages

Disadvantages

73

Overview of
x‐ray focusing devices
Diffraction

focus size,
focal length[energy]energyrange

aberration-coma-chromatic-figure error

Fresnel Zone Plate

12 nm,
f = 0.16 mm[0.7 keV],
30 nm,
f = 8 cm
[8 keV]

-coma
small
soft x-ray -chromatic
hard x-ray existfi
error-figuresmall

Sputter sliced FZP

0.3 µm,f = 22 cm[12 4 keV],
[12.4
keV]
0.5 µm,f = 90 cm[100 keV]

-coma
small
-chromatic
chromaticexist-figure error
large→small

2.4 µm,f = 70 cm[13.3 keV]
Bragg FZP

Multilayer Laue Lens

8 100
8-100
keV

-coma
small
mainly -chromatic
hard x-ray exist-figure error
small

16 nm(1D),-coma
f = 2.6 mm
large
mainly -chromatic[19.5 keV],
25nm×40nm, hard x-ray exist-figuref=2 6mm 4 7mm
f=2.6mm,4.7mm
figure error[19.5 keV]
small

Suitable forxx‐rayraynano‐probe

zLarge acceptable aperture and High efficiency
zNo chromatic aberration
zLong working distancezDifficulty in mirror alignments
zDifficulty in mirror fabrications
zLarge system

74

How small is x‐ray focused ?
Refraction

Pressed Lens

focus size,
focal length[energy]
1.5 µm,f = 80 cm[18.4 keV],
1.6 µm,f = 1.3 m[15 keV]
47nm×55nm,
f = 1cm, 2cm[21 keV]energyrangebtiaberration-coma-chromatic-figure error

mainlyhard x-ray

-coma
coma
small
-chromatic
exist-figure error
largemainlyhard x-ray

-coma
small
-chromatic
exist-figure error
small

Etching Lens

Reflection

Ki k t i k B
Kirkpatrick-Baez
MirrorMi

soft x-ray
hard x-ray

-coma
large
-chromatic
not exist-figure error
small
ll

0.7 µm,f = 35 cm[9 kkeV]]<10 keV

-coma
small
-chromatic
not exist-figure error
large

95 nm,[10 keV]soft x-ray
hard x-ray

-coma
large
-chromatic
not exist-figure error
large

36nm×48nm,
36×48
f=15cm,25cm[15 keV],
7 nm(1D),
f=7.5cm[20 keV]k V]

Wolter Mirror

X-ray Waveguide

For example, by elliptical mirror
15

S0

p θ

q

dG =

q
× S0
p

10
5
0

l
Geometrical size

Depth(μmm)

Intensityy (a.u.)

300

0

10

20

30

40

50

Position(mm)Diffraction limited size(FWHM)
(
)

0.88q
d DL = λ ×l sin(θ )p = 975 m , q = 50 mm , θ = 3mrad
d , l = 50 mm , λ = 0.083
0 083 nm , S 0 = 100 μ m
Mag. = 1 / 19500 !

d G = 5 nm < d DL = 25 nm

The opening of the mirror restricts the focused size even if magnification is large. 76

Difficulty in mirror alignments

Nano‐focusingg byy KB mirror
History since the century

Focal length f

φ
ψ

200

180nm

Focal length fθSpot ssize (nm)

X
X-ray

ψ

150

90nm

100

40nm
30nm 25nm
15nm

50

0
2001

2002

2003

2004
Year

2005

2006

2007

1st Mirror
Front View

Multilayer mirror

7nm

Positioning two mirrors is difficult
because there are at least 7 degree of freedom.

2009

World Record of Spot Size
Focused by KB optics

2nd Mirror
Side View

World Record of spot size is 7 nm (by Osaka Univ., in 2009 *).
It is difficult to use KB mirrors.

Routinely obtained spot size
si e is up to 30 nm.
Ref * : H. Mimura et al., “Breaking the 10 nm barrier in hard‐X‐ray focusing”, Nature Physics 6, 122 (2010).
77

78

KB optics installed in BL29XU‐L

Tolerance limits of mirror alignmentsφψ

2nd Mirror(Vertical focusing) (Horizontal focusing)
100mm

UndulatorθψF l point
Focali
1st Mirror

100mm

DCM

2nd Mirror
Side View

Front View
250

150mm

Side View

250

Ho rizo nta l focusing
Vertical fo cu sin g

200

Glancing angle (mrad)
Mirror length (mm)Mirror aperture (μm)
Focal length (mm)Demagnification
Numerical aperture

1st Mirror
3.80
100
382
252
189
0.75x10-3

2nd Mirror
3.60
100
365
150
318
1.20x10-3

Coefficient a of elliptic function (mm)23.876 x 103

23.825 x 103

Be am s ize ( nm)

98m

102mm

150
Diffractio n l imit invertical fo cu sin g
100

50

13.147

9.609

Diffraction limited focal size
(nm FWHM)
(nm,

48

29

Ref :H. Mimura, H. Yumoto, K. Yamauchi et.al, Appl. Phys. Lett. 90, 051903 (2007).

150
Diffraction limit invertical focusing
100

0

1

2

Glan cin g a ngle er rors (μrad)θ

79

Diffraction limit ingvertical focusing
100

Diffraction limit inhorizontal focusing

Diffraction limit inhorizontal focusing

0
-1
1

150

50

0
50

-2

Horizontal focusing
Vertical focusing

200

Diffracti on limit inh orizontal fo cu sin g-3
3

Coefficient b of elliptic function (mm)250

Horizontal focusing
Vertical focusing

200

Beam ssize (nm)45m

Severe positioning of
two mirrors is required.
The manipulator should bedesigned for these freedom of axis
with the resolution & the range.

X-ray

Beam ssize (nm)

1st Mirror

Incident slit

3

0
-200
200

0
-100
100

0

100

Perpendicularity errors (μrad)

200

50
-50

-30
30

-10
10

10

30

50

In-plane rotation errors (mrad)φFreedom of axis,
axis Resolution,
Resolution rangeψ

Ref: S. Matsuyama, H. Mimura, H. Yumoto et al., “Development of mirror manipulator for hard‐x‐ray nanofocusing
at sub‐50‐nm level”, Rev. Sci. Instrum. 77, 093107 (2006).

80Image on X‐ray CCD camera

1m from focal point( CCD )

Image of reflected x‐ray
UUpper
8.28mm8
28(1.150 m×3.6 mrad × 2)

x‐z planez

1508μm(380×(1/0.252))
2400μm(360×(1/0.150))

Reflected light(twice)Reflection in a verticaldirection

9.52mm952(1.252m×3.8 mrad×2)

x

Focal plane

Focal point
1.92mm(0.252 m
m×3.8
3.8 mradmrad×2)
2)
Max 360μm

L × 2θ = x

θ=

x
2L
81

Alignment of in‐plane rotation(H i t l focusing(Horizontalfi mirror)i)

Reflection in ahorizontal direction

Direct x‐ray(Mirror aperture)
1.08mm(0.150 m×3.6 mrad×2)
82

Alignment of incident angle

y‐z planez

Horizontal focusing
mirrorSide View

Max
380
380μm

Ring

y

・ Foucault test
Rough assessment of focusing beam profile.
This method is used for seeking focal point.

φH
2θ

X
X‐ray
θ

・Wire
Wire (Knife‐edge)(Knife edge) scan method
Final assessment of focusing beam profile.

Rail
Vertical focusing
mirror(X‐ray)Precise adjustment of the glancing angle andfocal distance is performed until the best focusing
is achieved, while monitoring the intensity profile.

θ: 3.8mrad→ 2θ: 7.6mrad
Reflected angle of vertical‐focusing mirror needs to be considered,in the alignment of in‐plane rotation of horizontal‐focusing mirror
mirror.
83

84

Foucault test

Alignment of incident angle

P j ti iimage
Image on CCD Projection

Downstream
X‐ray

X‐ray
CCD
cameraX‐ray Mirror

Focal plane
Knife edge

X‐ray

X‐ray
CCD
camera

Upstream
Whole bright‐area
gradually becomes dark.
dark

X
X‐ray
Mi
Mirror

Knife edge shadow
85

86

Foucault test 1

Foucault test 2

Wire is at downstream of focal point.
Image on CCD become dark from lower side.

Wire is at upstream of focal point.
Image on CCD become dark from upper side.

X‐ray CCD
X
cameraX‐ray CCD
X
cameraEd shadow
Edge
h d

X‐ray

X‐ray

Wire

Wire

87

88

Foucault test 3

Relationshipbbetweenincident
d
angle
l and
d ffocall position

Wire is at the focal point.
Whole bright‐area gradually becomes dark.

X‐ray CCD
X
camera

X‐ray
X ray
X‐ray

Wire

Incident angle→Large ⇒ Focal point → downstream
Incident angle→Small ⇒ Focal point → upstream
89

Wire (Knife‐edge) scan method for measuring beam profiles

90

Relationship between Beam size and Source size

The sharp knife edge is scanned across the beam axis,
axis and the total intensity of the transmitting beamis recorded along the edge position.

Beam size changes depending on source size (or virtual source size).
1st Mirror

Incident slit

Intensity
Detector
(PIN)

X‐ray

2nd Mirror(V i l focusing)(Verticalfi ) (Horizontal(H il focusing)
f
i )
100mm

Undulator

Focal point

100mm

DCM
C
45m
98m

Wire

Beam size = Source size / M
ANDBeam size ≥ Diffraction limit

102mm

150mm

Side View(M: demagnification)
10000
Vertical focusing
Horizontal focusing

Wire scan profile

1.0
08
0.8

1000

Differential
Diff
ti l
profile0.6
0.4

Beam size is selectablefor each application.

0.2
0.0

-0
0.22
-200 -150 -100

-50
0
50
Position (nm)

100

150

200

91

FWHM (nm)The line‐spread function of the focused
beam was derived from the numericaldifferential of the measured knife‐edge
scan profiles.

Intenssity (arb. un
nit)

1.2

100

10
1

10
100
TC1source
slit size
(μm)
Light
size
(μm)

1000

92

Relationship between Beam size and Source size

Scanning X‐ray Fluorescence Microscope: SXFM

1.4

1.0
0.8

Cl

Scanning samples
Focused X‐ray

0.6
0.4

Intensitty (Counts))

Intensity (aarb. units)

3000

10μm (Experimental)
50μm (Experimental)
100
100μm
(E
(Experimental)il)
10μm (Calculated)
50μm (Calculated)
100μm (Calculated)

1.2

Ag

On a細胞中央
Cell
細胞なし
O t off C
Out
Cells
ll

FeKα

2500

Si

2000

S
i

1500

S

1000

Ca

500

FeKβ
Cu

Elastic
Zn

0
0

0.2
0.0
-1000

Horizontal focusing-500

0Position (nm)

1.4
500

Intenssity (arb. unitss)

1.0
0
0.8

X‐ray spectrometer
Measurement principle

0.4

-500

0
Position (nm)

500

93

1000

Zn

Key issues for the beamline design
Key issues

Design components

Which application is the most important at the BL?

• End station( pressure, temperature,• Sample environment
magnetic field…)• Detector, data processing … ( automation )To select the functions of x‐ray mirror
Deflecting, low pass filtering, focusing and collimating → Shape of the mirror

C you specifyCan
if whoh uses theh property at theh BL ?

To specify the incident and reflected beam properties

•
•
•
•
•
•

Energy range , flux
→ absorption,
absorption cut off energy → coating material → incident angle
The beam size and the power of incident beam
→ opening of the mirror, incident angle→ absorbed power density on the mirror → w/o cooling,cooling substrate
Angular divergence / convergence, the reflected beam size
→ incident angle, position of the mirror ( source, image to mirror )Di ti off th
Direction
the b
beam
→ effect of polarization, self‐weight deformation

–
–
–
–
–

To specify
parameters
p fy the tolerance off designedgp
Roughness, density of coating material, radius error, figure error
The cost ( price and lead time) depends entirely on the tolerance.

5.

S

Scanning pitch: 1000nm Scan
area: 60×50μm

Ref: M. Shimura et al., “Element array by scanning X‐ray fluorescence microscopy after cis‐diamminedichloro‐platinum(II)94treatment”, Cancer research 65, 4998 (2005).

Key issues of x‐ray mirror design

4.

10

0.6

0.0
-1000

2.

8

10μm (Experimental)
50μm (Experimental)
100μm (Experimental)
10μm (Calculated)
50μm (Calculated)
100μm (Calculated)

0.2

1.

4
6
Energy (keV)

X-ray Fluorescence spectrum

X‐rayXray fluorescence

1000

1.2

Vertical focusing

2

To consider the alignment

Photon energy, energy resolution
Flux, flux density
The higher, the better ?
The smaller, the better ?
Beam size
More is NOT always better !
Polarization
Spatial coherence Simplify the property.
hTime resolution Get your priorities right.

Time schedule
Human resources
Available budget, space, technical level
M i t
Maintenanceffor kkeeping
i performancefLifetime of the BL ( hardware and application )What to include or not ?
What to develop or not ?

The freedom, resolution and range of the manipulator
95

•
•
•
•
•
•

Light source (ID, BM)
Monochromator, higher order suppression…
Monochromator
suppression
Focusing devices…
Polarizer…
Stability enoughWindow
Window…
t measuretoRF timing, chopper…

• Radiation shielding hutch …
• Interlock
I t l k systemt• Beam shutter…
•
•
•
•
•
•

Safety first !

Absorber, FE slit
Cooling method, cooling system
Selection of light sources ( power, angular dist.)
Electronics in hutch ( detector, controller … )Embrittlement (cable, tube )Contamination on optics• Electricity, water, air, network, control• Environments ( temperature, vibration… )Simple and clear design to accelerate your research

96Ongoing x‐ray beamline

A kAcknowledgmentl dt

X‐ray beamline looks complicated, but the function of each component is simple.
To specify the beam properties is to design the beamline.
New x‐ray beamline for next generation light source such as XFEL is newly constructed.
The components for heat management, x‐ray beam monitors and x‐ray optics
including metrology are newly developed to perform the beam properties.

Challenges at XFEL beamline :coherence preservation
wavefront disturbance or control
at wavelength techniqueultra‐shortlh & hihighh iintense pulselhigh stability
shot‐by‐shot diagnosis of x‐raysg control off x‐rayy pulse
ptimingsynchronization with other source …

97

Thank you for your kind attention.
attention

EEnjoyj Ch
Cheironischoolh l
Enjoy SPring‐8
andEnjoy Japan!
99

S. Takahashi ( front end ), H. Aoyagi (XBPM),
T. Matsushita ( interlock ),H Takano
H.
Takano, Y
Y. Kohmura
Kohmura, T
T. Koyama
Koyama, ( focusing devices )T. Uruga, Y. Senba ( mirrors ),S. Matsuyama, H. Yumoto, H. Mimura, K. Yamauchi( ultimate focusing
g mirror,, alignmentg),C. Morawe ( multilayer ) ESRF
S Goto and T.
S.
T Ishikawa

98