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MARX
Miroirs Actifs Rayons X
pour micro et nanofocalisation
X-ray Active Optics for micro and
nanofocalisation
Goal of the MARX Project :
– To develop an X-ray active mirrors for micro or nano
focalisation
1st part of the talk1st part of the talk
– To develop at wavelength an in situ alignment system
2nd part part of the talk2nd part part of the talk
– To validate the potential of X-ray active mirrors (for micro
and nano focalisation)
Still in progressStill in progress
Outline
MARX PROJECT Team and fundingMARX PROJECT Team and funding
• Partners
• SOLEIL - project management and experimentation
• ISP SYSTEM - development of the active mirror
• IMAGINE OPTIC – development of wave front sensor
• Finances
• 50% from the ANR (Agence Nationale pour la
Recherche)
• 50% partners financing
MARX main GOALSMARX main GOALS
– Elliptic shape error less than 0.5 !rad RMS
– Focal distance 300 to 350 mm
– High range of elliptic shapes
– Possibility to correct residual polishing
defaults of the mirror
– Possibility to correct aberrations from the
optical system
Active optics = Magic Mirror25 years old 45 years old
Adaptive mirrors is the solution
Active optics = Magic Mirror
true example
We can win a lot from the Astrophysics research and expertise in
adaptive optics and wavefront analysis
Active optics = Magic Mirror
MARX
1st Part
Active mirror
PRINCIPLE OF ACTIVE MIRRORPRINCIPLE OF ACTIVE MIRROR
– The design of MARX permits to obtain naturally an elliptic shape withonly 1 bender
– The AME actuators apply correction strengths to the initial form inorder to obtain best focalisation and reduce the optical aberrations;
– Mirror characteristics:• Dimensions : 350x50x8mm
• Material : Silicium
– The ISP SYSTEM original concept has been recently patented
AME 2 AME 3 AME 4
320mm
AME 5AME 1 AME 9AME 8AME 7AME 6 AME 10
– 10 actuators generating micro forces along themirror
– 1 bender
!"##$#%
&' &( &) &* &+ &, &- &. &/ &'0
ISP SYSTEM DESIGN
• Active Kirckpatrick-Baez
mirrors system :
2 mirrors activated by
– 2 kinds of actuators :
• 1 bender
• and 10 micro strength
actuators (AME)
MARX Mirror DESCRIPTION
• The mirror is supported :
– At the first extremity by athin plate with strictionswhich allows 1 rotationand 1 translation. The jointis glued to the mirror
– At the other side, by apivot joint. The mirror ishold by a tighteningcontrolled system (jaws).
• The AME are fastened to softpads glued on the back face ofthe mirror. Soft pads are usedto limit the “print effects” on theactive face of the mirror.
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MARX Mirror DESCRIPTION
• A dedicated Control
Rack has been specially
developed and realized
for MARX application.
• The 19’’ Rack includes :
– 10 AME and 1
bender actuators
controllers with
integrated
microcontroller et
power driver
– Interface
communication
from a PC via RS
232
– Power supply
MARX Mirror CONTROL RACK
• Every actuator controller includes an algorithm of calibration with a dedicatedmathematical grading
ISP SYSTEM’s Micro Strength Actuator (AME)
• AME have been especially developed by ISP SYSTEM to be used in activeoptic systems which require very precise shapes (focalisation or wave frontcorrection).
• The concept, based on a calibrated strength generation, has been patented since2002.
• The strength generation is obtained by coupling a screw-nut system energized by abipolar stepping motor, with a floating head including springs.
• The strength range is about +/-30N with a repeatability of 10mN (othersconfigurations are available for customer applications).
D?F)0:8>2@:J$#:?D1K D?F(0:8>2@:J$#:95>2#>L:<#"!2@:54:?MN1OPO1D:(00,E"642#654"$659:2Q;"R"4"$6:$J:!"3#$:!23;56"3:"6@8>4#SG
APPLICATION FOR LASERS Mégajoule
Laser example
• Laser wave front correction
system
• Mirror : BK7
• shape : square mirror
• size :400x400mm
• material : BK7 glass
• Fitted of 39 ISP System’s
AME20 actuators
Mirror : Flat rectangular Silicon mirror (350 mm ! 40 mm ! 8 mm)Slopes errors measured on LTP at 0.5 "rad rms over 340 mm pupil size
Working conditions : P = 35000 mm / Q = 300 à 350 mm / # = 0.35°! Working curvature from 100 to 115 m! Working sag about 100 "m
Target ellipse
MARX Mirror targets
MARX
2nd Part
Active mirror
Metrology
• 1D local slopes measurement.
• Active surface can be face-up, face-down or on the side.
• Maximum length : 1 m.
• Precision : Curvature 0.3%, slope errors 0.2 "rad r.m.s.
• Calibration : on a flat reference surface - precision : 0,1 %.
• Radii of curvature : from 3 m to infinite.
• Gratings groove density measurements.
• Shape reconstruction by Stitching algorithm available.
Long Trace Profiler (LTP) – Laboratoire de Métrologie Optique @ SOLEIL
Polarizationinterferometer
MARX MIRROR OFF-LINE METROLOGY
M. Thomasset, S. Brochet, F. Polack
LTP measurement of the standing alone mirrorMirror dimensions: 350 mm ! 40 mm ! 8 mm
3 traces spaced by 10 mmMeasurement over 340 mm by 1 mm steps
LD: R = 22.2 km $ = 0.5 "rad rmsLC: R = 19.1 km $ = 0.5 "rad rmsLG: R = 19.5 km $ = 0.6 "rad rms
Slopes ("rad)
Heights (nm)
Roughness1.7 Å rms8 nm PV
Twist correction - interferometer- LTP
Alignment of the mirror
LTP measurements
Measurement over
300 mm by 1 mm steps
-374.5 mm
350 mm
Activejaw
-24.5 mm
Flexor
LTP direction of measurementEnding point
-40 mmStarting point
-340 mm
300 mm
11 10 9 8 7 6 5 4 3 2
0
20
40
60
80
100
120
140
0 5000 10000 15000 20000 25000 30000
couple Actionneur 1 (mN)
erre
ur
de
form
e (n
m)
0
0.5
1
1.5
2
2.5
0 5000 10000 15000 20000 25000 30000
couple Actionneur 1 (mN)
erre
ur
de
form
e (!
rad
)Curvature actuator : classical x-ray benderCurvature actuator : classical x-ray bender
Residual shape errors ("rad rms)
Residual shape errors (nm)
PV
rms
The mirror is pre-curved (R = 140 m)Curvature dynamic range : 140 to 72 m
Heigth at the center : 80 to 160 "m
-80000
-60000
-40000
-20000
0
20000
40000
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
hau
teurs
(nm
)
0
1000
5000
10000
15000
20000
25000
29000
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
fonct
ion d
'infl
uen
ce (
nm
/mN
)
5000
10000
14000
Pousser/Tirer autour de 15000
70
80
90
100
110
120
130
140
150
0 5000 10000 15000 20000 25000 30000
couple Actionneur 1 (mN)
R (
m)
Curvature (m) vs. AME1 strength
In principle able to go from Flat to 55 m
Shape correction actuators
! Case of actuator n°6
We realized successive shape measurements for different strength values of AME6.(the nominal shape of the mirror is subtracted from all measurements).! Deformation of the mirror surface is symmetric.
The influence function is the same on the whole range of the actuator.
!Demonstrate the linearity of the system
(true for all actuators)
INFLUENCE FUNCTIONS
-80000
-60000
-40000
-20000
0
20000
40000
60000
80000
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
hau
teurs
(nm
)
0
10000
20000
29000
-10000
-20000
-29000
-0.5
0
0.5
1
1.5
2
2.5
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
fonct
ion d
'infl
uen
ce (
nm
/mN
)
10000
20000
29000
The actuators at the edges of the mirror induce 4 times less deformation of the surface (~0.5nm/mN) than those in the middle (~2 nm/mN).
INFLUENCE FUNCTIONS
-0.5
0
0.5
1
1.5
2
2.5
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
fon
cti
on
d'in
flu
en
ce
(n
m/m
N) Act2
Act3
Act4
Act5
Act6
Act7
Act8
Act9
Act10
Act11
Shape correction actuators
Shape correction actuators EIGEN MODES
SLOPE
HEIGHT
-4
-2
0
2
4
6
8
10
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
erre
urs
de
pen
tes
(!ra
d)
$ = 1.42 "rad rmsh = 24 nm rms
H = 81.6 nm PV
y = 6.861E-06x3 - 2.266E-02x2 + 7.167E+00x + 4.351E+03
0
1000
2000
3000
4000
5000
6000
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
pen
tes
(!ra
d)
Residual to bestelliptical fit
Curvature actuator @ 0
R = 139.519 m
Nominal shape measurement (all actuators @ 0)
Shape correction using the 10 inside actuatorsTarget: Best elliptical fit from nominal shape measurement
! = 0.59 "rad rms
h = 3.921 nm rms
H = 16.317 nm PV
Residual to bestelliptical fit
R = 139.6 m
Residual to target
R = 139.519 m! = 1.65 "rad rms
h = 389.4 nm rms
H = 1291.4 nm PV
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
erre
urs
de
pen
tes
(!ra
d)
-10
-8
-6
-4
-2
0
2
4
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
erre
urs
de
pen
tes
(!ra
d)
! Correction in a single iteration! Small drift in final curvature (can be corrected using AME1)
(strengths between -7N and +6N)
Mirror is hold in correction and curved to 100 m
! = 0.84 "rad rms
h = 9.86 nm rms
H = 39.66 nm PV
y = 6.861E-06x3 - 2.266E-02x2 + 7.167E+00x + 4.351E+03
0
1000
2000
3000
4000
5000
6000
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
pen
tes
(!ra
d)
Residual to bestElliptical fit
-3
-2
-1
0
1
2
3
4
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
erre
urs
de
pen
tes
(!ra
d)
Small degradation of the surface shape errors by curving the mirror
Curvature actuator @ 12N
R = 100 m
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
erre
urs
de
pen
tes
(!ra
d)
-3
-2
-1
0
1
2
3
4
5
6
7
-200 -150 -100 -50 0 50 100 150 200
abscisses (mm)
erre
urs
de
pen
tes
(!ra
d)
! = 0.55 "rad rms
h = 3.06 nm rms
H = 15.9 nm PV
Residual to bestelliptical fit
R = 100.32 m
Residual to target
R = 100 m
! = 1.357 "rad rms
h = 204.4 nm rms
H = 630 nm PV
! Correction in 2 iterations using the same interaction matrix
! Small drift in curvature
Shape correction using the 10 inside actuatorsTarget: Best elliptical fit from previous shape measurement (strengths between -10N and +9N)
- Curvature range from 140 to 72 m (possible to go from flat to 55 m)
- The mirror system is linear.- 1 single interaction matrix can be used.- Slope errors can be corrected to 0.6 "rad rms, in 1 or 2 iterations.- Small drift on curvature respect to the target ellipse.
- Upgrades:Use of AME1 to correct the drift in curvature: 2 steps correction
1- Curvature adjustement (use of AME1)
2- Residual shape errors correction (use of the 10 inside actuators)
- Coupling with a hard X-ray Hartmann wavefront sensor and closed loop experiment on
synchrotron radiation beamlines (end of 2008).
CONCLUSION
3rd Part
Wavefront
sensor
Principle of Shack Hartmann
wavefront sensor
f
%x&&
Microlenses array
Wavefront
sensingCCD
M(x)
tan(")=#x / f
Principle of Hartmann
wavefront sensor
L
Hole array EUV CCD camera
! = "y/L
x
y
z
Ref
eren
ce f
lat
wa
vef
ron
t
Reference spot
centroid position"y!
Ab
erra
ted
wa
vef
ron
t
Aberrated spot
centroid position
Hartmann wavefront sensor
1st TEST
0.6 "m
Perfect diffracted wavefront
Hartmann wave-front measurement at 13.4 nm with # EUV 120
accuracy Optics Letters, Vol. 28 Issue 17 Page 1534 (September 2003)
P. Mercère, P. Zeitoun, Mourad Idir, S. Le Pape, D. Douillet, X. Levecq, G. Dovillaire, S. Bucourt, K.A. Goldberg, P. Naulleau, S. Rekawa
CXRO Beamline 12.0 ALS
0.6"m pinhole
Reproducibility Sensibility – Precision
0.6"m pinhole
1.86 "m in the X direction
#EUV/125 rms , #EUV/16 PV
0.1 nm rms, 0.8 nm PV
#EUV/100 rms , #EUV/19 PV
0.13 nm rms, 0.8 nm PV
• Wavefront precision ~ #/100 rms (0.1 nm rms)
• Tilt Precision ~ 0.02 !rad rms
• Focal distance precision ~ 1. 10-5 m –1 rms
EUV Calibration
ALS beamline 12.0 wavefront measurement without spatial filtering
010
2030
40
0
10
20
30
40-4
-2
0
2
4
illuminated subpupils
illuminated subpupils
wavefront
(x Lambda=13.4nm)
42 "
m
23 "m
Measured spot size
(YAG crystal+"scope objective)
Ray tracing calculated
with Hartmann sensor software
based on phase measurement
KB optimization
SLS LUCIA wavefront system
Generation II
Hartmann Hartmann WavefrontWavefront measurement andmeasurement and correction correction
Calibration of the sensor on a spatially filtered reference beam at 700 eV
1-"m pinhole diffracted waveseen by the sensor
Absolute wavefront measurement after calibration
Closed loop correction at 3.64 keV
-6090 -6080 -6070 -6060
-500
0
500
1000
1500
2000
FWHM = 2.40 "m
Knife Edge Scan of Vertical X-ray beam at LUCIA
Derivative of Knife Edge Data Gauss Fit
Derivative o
f F
luore
scence
Vertical Position (!m)
5025 50305030 5035 50405040 5045 50505050 5055 50605060 5065
-450
00
450
900900
1350
18001800
2250
27002700
Derivative of Knife Edge Data Gauss Fit
Derivative o
f F
luore
scence
Horizontal Position (!m)
Knife Edge Scan of Horizontal X-ray beam at LUCIA
FWHM = 2.55 "m
Before correction After correction
7.7 nm rms
30.9 nm PV
0.8 nm rms
4.6 nm PV
Accuracy of the sensor is limited by shot noise.
But signal to noise ratio can be improved by accumulation of several images :
répétabilité vs moyennage image à 900 eV
0
0.5
1
1.5
2
2.5
3
0 5 10 15 20 25 30 35 40 45 50
nombre d'images cumulées
rép
éta
bilit
é (
nm
)
0
20
40
60
80
100
120
140
160
180
rap
po
rt s
ign
al/b
ruit
rms PV rapport signal sur bruit
Signal to noise ratio
Repeatability nm PV
Repeatability nm rms
répétabilité vs moyennage image à 2100 eV
0
0.5
1
1.5
2
2.5
3
0 5 10 15 20 25 30 35 40 45 50
nombre d'images cumulées
rép
éta
bilit
é (
nm
)
0
20
40
60
80
100
120
rap
po
rt s
ign
al/b
ruit
rms PV rapport signal sur bruit
Signal to noise ratio
Repeatability nm PV
Repeatability nm rms
Use of a high readout rate (30 Hz)
Hamamatsu CCD camera" Possible
IMPROVEMENTS
Accumulation of 500 images : 15 s
Repeatability : 0.038 nm rms
0.28 nm PV
Accumulation of 100 images : 3 s
Repeatability : 0.06 nm rms
0.42 nm PV
Direct detection
Hartmann
GridCCD
Wavefront1000x1000 pixels of 8!m
Grid pitch of 57 !m
Distance grid / CCD of 100mm
Problems :
The shot noise limits the sensor sensitivity
The CCD is slowly « destroyed »
by hard Xrays
The direct detection sensor is
adapted to soft Xrays
Hartmann wavefront sensors for Xray beams
Indirect detection : adapted for hard Xrays
640x480 pixels of 7.4!m
Visible magnification x4.5
Grid pitch of 20 !m
Distance grid / YAG of 14mm
Sensor sensitivity : 0.023 nm rms
Sensor accuracy : 0.25 nm rms
limited by the calibration process
The X-ray Hartmann wave-front sensor
for in situ alignment
Calibration process :
For visible wavefront sensors
Source on translation stages
Single mode fiber : no aberration
Measured tilts and curvature must fit the real movement of the source
Sensor
For XRays wavefront sensors
1/ We use a visible source, the Talbot diffraction effect gives us a calculable
image to adjust the main parameters of the calibration
2/ « at wavelength » on the most possible « aberration free » beam, some
measurements are done to finalize the calibration
Soft Xrays : A small pinhole is set in the beam to diffract a pure diverging
beam.
Hard Xrays : Some small areas of the beam are used for different positions
of the sensor relatively to the beam. These measurements are averaged.
Hartmann wavefront sensors for Xray beams
Hard Xrays : measurement of the influence of a curvable cristal on CRISTAL
beam line at SOLEIL at 10.6 keV
We plotted the curvature measured by the sensor (in dioptries) in function of the
position of the motors. The fit is obtained by using the laser propagation theory.
influence of a curvable cristal on the measured curvature by a WFS
-0.01
0
0.01
0.02
0.03
0.04
0.05
0.06
0 100 200 300 400 500 600 700 800 900
C1-C2 motors postions in steps
measure
d
curv
ature
in
1
/m
measurements
Laser theory
• Xrays beams can be modelized by
the propagation of a gaussian beam
in vaccum.
• Even at this short wavelength, the
effect of diffraction must be taken into
account.
• The Xrays source can be considered
as a « Waist »
19 m 18 m
SourceHard Xrays WFS
Motors to change the cristal curvature
Hartmann wavefront sensors for Xray beams
Conclusion
• Hartman based Wavefront sensor are available
from VUV to hard X-ray (Imagine Optic)
• Small actuator design on specs are available (ISP
System)
• A full adaptive optics solution is available
(Wavefront sensor + mirror on specifications) are
avalabile (Imagine Optic)
More to do
Test on a beamline the full system
SOLEIL and DIAMOND end of November
1. Development of KB mirrors with mirror cooling fixture for more
powerful X-ray beams ( MARX2)
2. Smaller mirror possible
130 x 40mm (torpédo shape)
2 AME40 (+40N) for curvature
8 AME3 (+/-3N) for small correction
10 mm distance
- Minimum radius 23 m
Mini MARX
– SYNCHROTRON SOLEIL• Mourad IDIR
• Pascal MERCERE• Thierry MORENO
• Murielle THOMASSET + Sylvain Brochet
– IMAGINE OPTIC• Xavier LEVECQ
• Samuel BUCOURT
• Guillaume DOVILLAIRE
• Johan FLORIOT
– ISP SYSTEM• Paul SAUVAGEOT
• Lionnel ESCOLANO
• Nicolas NIVELET
• Benjamin SAUX
THANKS TO THE MARX PROJECT TEAM