DxX 1x5 P3 - psi.ch · J. Stahn: focusing reflectometer, IKON2, 2.2012 2.0 generic instrument...
Transcript of DxX 1x5 P3 - psi.ch · J. Stahn: focusing reflectometer, IKON2, 2.2012 2.0 generic instrument...
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Selene
Paul Scherrer Institut
Kbenhavns Universitet
Syddansk Universitet
Jochen StahnTobias Panzner, Uwe Filges
Marite Cardenas
Beate Klosgen
progress report of the
Swiss-Danish instrument initiative
for the ESS
WP2
focusing reflectometer
IKON 2
09.10. 02. 2012, Malm, Sweden
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 1.0
aims
development and proof of concepts for two reflectometers for the ESS,
optimized for:
small samples (< 1mm2)
horizontal scattering geometry
polarization & analysis
voluminous sample environment
moderate to low resolution
. . .
liquid surfaces
vertical scattering geometry
time-resolved studies (t < 1 s)
wide qz-range with one (few) angular setting(s)
high to low resolution
. . .
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 2.0
generic instrument layout
cut in the scattering plane
stretched by 10 normal to incident beam
initial slit = projected sample size
sample
detector
1st elliptic reflector
no direct line of sight
2nd elliptic reflector
knife blade
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 2.1
generic instrument
why focusing?
beam
pro
file
penumbra
umbra
beam
pro
file
umbra
slits
reflective/
refractiveoptics
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 2.2
generic instrument
why an elliptic reflector?
an elliptic reflector allows for
a parabolic reflector turns beam size into divergence and vice versa
point-to-point focusing
small source point
convenient beam manipulation (chopper, filtering)
early beam definition
low background
low radiation
disentangling of spot size and divergence
/ encoding
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 2.3
generic instrument
why only one branch of an ellipse?
no structured I(, z)
in most cases one branch can cover
I(, z) map
"./mapes.dat"u 2:1:3
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2-3
-2
-1
0
1
2
3
/deg
z/m
m
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 2.4
generic layout
why two subsequent elliptic guides?
convenient beam manipulation
guide dimensions not too large
correction for coma aberration!
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 3.0
operation modes:
for TOF (non-TOF operation is also possible!)
definition of spot-size
polarization / -filtering
monochromatization
chop beam
definition of divergence
definition of
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 3.1
operation modes:
almost conventional
beam is still convergent
off-specular measurements are feasible
2 4 6 8 10 12 14 16 1
2
3
4
5
6
2
0 0.02 0.04 0.06 0.08
0
0.02
0.04
0.06
0.08
kzf/A
1
kz i /A1
qz
x
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 3.2
operation modes:
wide q-range
vary with fixed sample position
shift diaphragm (chopper) between pulses
suited for liquid surfaces
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 3.3
operation modes:
small spot size
uses focusing due to coma aberration
scanning mode possible
use coma aberration to reduce beam size
height/
mm
/ deg
I(y , z) and I(z , z) at the sample
for a 1 1mm2 entrance slit
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-0.5
0
0.5
1
0 0.5 1 1.5 2 2.5 3
z/mm
y / mm z / deg
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 3.4
operation modes:
angle/energy encoding
uses a ml-monochromator at the intermediate image
spectral analysis of the beam: / encoding
large on small
wide qz-range
I(, ) after ml monochromator/deg
/ A
3.5 4 4.5 5 5.5 6 6.5 7 7.5 8
-1
-0.5
0
0.5
1
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 3.5
operation modes:
high-intensity specular reflectivity
energy- and angle-dispersive gain > 10
for fast scanning (T ,H,E . . . )
or if off-specular scattering is no problem
2 4 6 8 10 12 14 16 1
2
3
4
5
6
2
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-3
-2
-1
0
0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16
log10[R(qz) ]
qz / A1
qz
x
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 3.6
operation modes:
high-intensity specular reflectivity vs. almost conventional
qz
x
qz
x
2 4 6 8 10 12 14 16 1
2
3
4
5
6
2
2 4 6 8 10 12 14 16 1
2
3
4
5
6
2
specularoff-specular
incoherent
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 3.7
operation modes:
high-intensity specular reflectivity vs. almost conventional
[ La2/3Sr1/3MnO3 /SrTiO3 ]4 /NGO 4 5mm2
no focusing in sample plane
TOF mode, [2 . . .18 A]
measurement time:
conventional 6.5 h
Selene 45min
gain-factor 8.3
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-2
-1
0
0.02 0.04 0.06 0.08 0.1 0.12 0.14
qz/A1
log10[R
(qz)]
by courtesy of C. Aruta and F. Miletto
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 4.0
prototype on BOA
Boa is a test beam line at SINQ, PSI
guide-end (40 150mm2, y = 1.4, z = 2.0
)
chopper ( = 150mm)
slit elliptic guides
sample position
area detector
x/y translation, 2/ rotation stages
total length 8.6m
[1.5, 12] A
polarized beam
setup operational 8. 2012
-1.5 -1 -0.5 0 0.5 1 1.5-1.5
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-0.5
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0.5
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1.5
z/deg
x/deg
0 0.5 1 1.5 2 2.5 3-1
-0.5
0
0.5
1
z/deg
z/mm
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 4.1
concept for the ESS
schematic lay-out of the reflectometer for tiny samples
x/m0 2 67 20 50
concrete
source
coarse slit
initial slit
intermediate image
sample
detectory/mm
087
261
872
2180
2180
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 4.2
concept for the ESS
source
coarse slit
initial slit
intermediate image
sample
detector
total length
repetition rate multiplication chopper / 1%
ml-monochromator qz/qz 5% . . .20%
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 5.0
schedule
McStas simulations
prototype on BOA
January February Mars April May June July August September
concept studies
generic instrument (T. Panzner)
adaption to BOA
incl. off-specular scattering (K. Lefmann)
incl. gravity (E. Rantsiou)
ESS instrument for small samples (N.N.)
ESS instrument for liquid surfaces (U. B. Hansen)
construction (D. Graf, M. Schild)
manufacturing (PSI)
offer for guides (SwissNeutronics)
set up on BOA
experiments
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J. Stahn: focusing reflectometer, IKON2, 2. 2012 6.0
Selene is a guide concept
which . . .
prevents direct line of sight
reduces radiation in the guide
allows for convenient beam manipulation
reduces illumination of the sample environment
allows for a convergent beam set-up
flux gain > 10