And now for something completely different..…? · And now for something completely...
Transcript of And now for something completely different..…? · And now for something completely...
And now for something
completely different..…?
neutron imaging
Markus Strobl
Instrumentation Division@ ESS
Vienna
Berlin Helmholtz Zentrum
Lund
Copenhagen
46
Multi-PurposeImaging
Energy
Magnet ism
Engineering Materials
Geoscience
Agricultural Science
Soft Matter and Biology
Cultural Heritage
Industrial Applicat ions
High resolution Multi-Purpose ImagingA unique inst rument that combines imaging with reciprocal space
techniques in a novel way. It representsa versat ile inst rument concept
using high-resolut ion at tenuat ion-based imaging as well as t ime-of-
flight neutron imaging techniques with novel capabilit ies based on
spat ially resolved scat tering effects. Thevariablechoiceof wavelength
resolut ions between 0.3% and 10% over tunable wavelength bands
combined with polarizat ion analysis opensup thepossibility of highly
efficient polarized-neut ron and Bragg-diffract ion imaging as well as
dark-field imaging opt ions. The inst rument isalso capableof spat ially
resolved SANS invest igat ions.
Instrument DescriptionThe unique source characterist ics of ESS allow the inst rument to be opt imized for a large variety of neu-
t ron imaging techniques with high efficiency. The high source brightness, a bi-spect ral ext ract ion and an
opt imized neut ron guide system enable not only high resolut ion and high-speed at tenuat ion cont rast imag-
ing, but also permit the user to take advantage of corresponding energy-select ivemeasurements increasing
e.g. sensit ivity. The length of the inst rument , chosen to 60 m to the detector, provides sufficient wave-
length resolut ion for efficient t ime-of-flight dark-field cont rast imaging. This corresponds to measuring
small-angle scat tering where the spat ial resolut ion is determined by beam modulat ion techniques. Other
imaging modes profit from the potent ial to tune the t ime-of-flight resolut ion from 1% down to 0.3% with
a wavelength frame mult iplicat ion chopper system. It features an opt ically blind, pulse shaping, double
chopper system. In this system the variable distance of the disks, operated such that the closing of the
first disk coincides with the opening of the second disk, defines the wavelength resolut ion at the detector.
Both the separat ion of thewavelength frames (bands) as well as the choice of thewavelength band with or
without pulse suppression require addit ional choppers. The corresponding wavelength resolut ion provides
efficient polarized neut ron imaging or Bragg edge studies. The prompt pulse background is avoided by a
T0 chopper at 9m from the moderator.
Polarized neut ron imaging is based on keeping t rack of the neut ron polarizat ion as it passes through
a magnet ic field, and can be used for quant itat ive invest igat ions of magnet ic fields and st ructures with
spat ial resolut ion. Bragg edgesaresteps in the t ransmit ted total crosssect ion deriving from coherent elast ic
(Bragg) scat tering. Measuring the Bragg edge pat tern in the t ransmit ted spect rum with 1% and 0.3%
wavelength resolut ion can be ut ilised to map crystalline phases or texture and lat t ice st rains, somewhat
akin to convent ional diffract ion.
ESS – future for neutron scattering in Europe
ODIN Optical and Diffraction Imaging with Neutrons
One out of the two first
instruments endorsed by
the ESS SAC for a build
decision!
Is neutron imaging in
fact just another
scattering technique?
When do we talk
about an image?
When about imaging?
H. Sato, T. Kamiyama and Y. Kiyanagi, Nucl. Instr. and Meth. A 605 (2009) 36.
Example: CT imaging of elements and temperature
distributions in a double layered cylinder
0.0
2.6
1.3
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In nuclide density (×1019 cm-3)
0.00
3.70
1.85
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
109Ag nuclide density (×1019 cm-3)
0
180
90
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In temperature (℃)
1 mm
4 mm
0.5 mm9 mm
In2O3 : 7 mg/cm3
Al2O3 : 1 g/cm3{In2O3 : 14 mg/cm3
Ag2O : 36 mg/cm3
Al2O3 : 1 g/cm3{Heater
Al
images
transmission
reflection
“transmission” image
with light
i.e. photogram
images
Contrast
• Radiation used
• Materials examined
• Instrumentation
9
/
4
5
Transmission
• Cross sections:
Microscopic cross section: s
Unit of s : 1 barn = 10-24 cm2
Macroscopic cross section : S (i.e. m linear attenuation coefficient)
S = N . s , N = number of nuclei per cm3 .
Unit of S is [cm-1].
ds
dW= number of interacting particles / unit time × unit cone dW
number of incident particles / unit time x unit area ×unit cone dW = [area]
S dxxeI
)(
0I =
Contrast
page
10/45
Photoelectron
Absorption
Photon Energy E0
Scattering
Nucleus
X-ray interaction with matter
Contrast
page
11/45
Absorption
Scattering
Neutron Energy E0
Nucleus
Transmission
Contrast
neutron interaction with matter
page
12/45
light
elements
metals heavy
elements
Contrast
page
13/45
Contrast Thermal neutrons Cold neutrons
Contrast
X-ray
page
14/45
Absorption
Scattering
Neutron Energy E0
Nucleus
Transmission
scattering cross sections
Contrast
page
15/45
0
10000
20000
30000
40000
50000
0 20 40 60 80 100 120 140 160
distance [mm]
tran
sm
issio
n [re
l. un
its]
2,34%
3,5%
4.74%
3,5% + 3,95% Gd
enrichment
Determination of the U-235 content (enrichment) in nuclear fuel elements
Contrast
page
16/45
Contrast variatio
H2O D2O
5 min 20 min 40 min
Contrast
page
17/45
Contrast
page
18/45
Contrast
Contrast Resolution
• Instrumentation
• Detectors
images
No optics
images
No optics
But spatial resolution!
Clearly a condition for imaging!
Camera obscura
page
22/45
Resolution
Source Collimator Detector Object
collimation ratio typical: several 100 blur
db =
D
L d
L/D
page
23/45
Resolution
L
L
L L2
1L
2L
3L
flux limitations 109 cm-2s-1
blur d
b =L/D
Resolution
page
24/45
L/D=71 L/D=115 L/D=320 L/D>500.
Radiographs of a small motor taken at different beam positions
with different L/D ratios.
Resolution
page
25/45
Radiographs of a 3,5" floppy drive in 0 cm, 10 cm and 20 cm distance
from a film + Gd sandwich taken at a cold neutron guide with L/D=71.
Resolution
images
photogramm
No optics
Detection?
page
Detector
recent developments
PSI: development of advanced scintillators @ 30 µm
HZB: adapting X-ray scintillators (GADOX) @15 µm NIST(UCLA, Nova Scientific Inc.): MCP-detectors @ 13 µm
Resolution
3H e + 1n 3H + 1p + 0 .77 M eV
6Li + 1n 3H + 4H e + 4.79 M eV
10B + 1n 7Li + 4H e + 2.78 M eV (7% )
7Li* + 4H e + 2.30 M eV (93% )
155G d + 1n 156G d + ´s + C E´s (7.9 M eV )
157G d + 1n 158G d + ´s + C E´s (8.5 M eV )
235U , 239Pu 1n fission products + 80 M eV
GADOX
LiF-ZnS/Ag
page
CCD MCP
Imaging Detectors
Resolution
page
29
Routine resolution today 50 μm
Best today <15μm
Aiming at 1μm
Resolution of DIGITAL detectors
Transmission also enables tomography: 3D imaging!
page
30
reconstruction
Radon
Transform
Fourier
Slice
Theorem
page
31/45
So now we have it all…
…do we really?
page
32
Some advantages:
High penetration power
High sensitivity to Hydrogen
Low radiation damage
Neutron Imaging at NIST
Research Focus
Fuel Cells
Li-ion / Alkaline Batteries
Hydrogen Storage
Phase Imaging
Refrigeration
Geology
Bio Imaging
Residual Stress
Uses
Operates 24/7 for 250 days a year
About Sixty users per year
Three Times Over Subscribed
About 50% Proprietary Research
Financially Self Reliant
M. Arif
Neutron Physics Group: Physical Measurement Laboratory, NIST
Neutron imaging
page
33
Some advantages:
High penetration power
High sensitivity to Hydrogen
Low radiation damage
Isotope sensitive
Neutron Imaging at NIST
Research Focus
Fuel Cells
Li-ion / Alkaline Batteries
Hydrogen Storage
Phase Imaging
Refrigeration
Geology
Bio Imaging
Residual Stress
Uses
Operates 24/7 for 250 days a year
About Sixty users per year
Three Times Over Subscribed
About 50% Proprietary Research
Financially Self Reliant
M. Arif
Neutron Physics Group: Physical Measurement Laboratory, NIST
5 min
Neutron imaging
Enrichmet of fuel element
page
34
…also some disadvantages
Low phase space density – slow
Low spatial resolution
Expensive
Neutron imaging
page
35
Some advantages:
High penetration power
High sensitivity to Hydrogen
Low radiation damage
Isotope sensitive
Neutron imaging
page
36
N. Kardjilov, I. Manke, M. Strobl,
A. Hilger et al.
Nat. Phys. 4 (2008)
Some advantages:
High penetration power
High sensitivity to Hydrogen
Low radiation damage
Isotope sensitive
Magnetic moment
Neutron imaging
M. Schulz et al.
page
upper
neutron
guide beam
stop
monochromatic beam
rotation + tilt
stage
PCG
crystals
CCD detector
sample
lower
polarizer analyser
)y,x(cos12
1)dsexp()y,x(I)y,x(I
path
0 s =
N. Kardjilov, I. Manke, M. Strobl, A. Hilger et al. Nature Phys. 4 (2008)
Polarised neutron imaging
dsh
Bm
path
nn
=
38/45
I(x,y) I(x,y)/Ia(x,y)
xx xy xz yx yy yz zx zy zz
3D vector quantification through polarimetric imaging
M. Strobl et al. Phys B (2009)
Polarized neutron imaging
H. Sato, T. Kamiyama and Y. Kiyanagi, Nucl. Instr. and Meth. A 605 (2009) 36.
Example: CT imaging of elements and temperature
distributions in a double layered cylinder
0.0
2.6
1.3
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In nuclide density (×1019 cm-3)
0.00
3.70
1.85
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
109Ag nuclide density (×1019 cm-3)
0
180
90
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In temperature (℃)
1 mm
4 mm
0.5 mm9 mm
In2O3 : 7 mg/cm3
Al2O3 : 1 g/cm3{In2O3 : 14 mg/cm3
Ag2O : 36 mg/cm3
Al2O3 : 1 g/cm3{Heater
Al
images
4
0
/
4
5
What about scattering now?
Thickness of a homogeneous absorber
ln(Nin/Nd)
Practical case
Ideal case (no spectral
shifting)
Artifacts!
4
1
/
4
5
Unit of s : 1 barn = 10-24 cm2
Macroscopic cross section : S (i.e. m linear attenuation coefficient)
S = N . s , N = number of nuclei per cm3 .
Unit of S is [cm-1].
ds
dW= number of interacting particles / unit time × unit cone dW
number of incident particles / unit time x unit area ×unit cone dW = [area]
S dxxeI
)(
0I =
Contrast
Interaction of neutrons with matter:
Scattering & Absorption
Cross sections:
Microscopic cross sections : s = sa ss
4
2
/
3
0
Total neutron cross section
Most significant
4
3
Bainitic sample
Examples
cryst. inhom. / phase distribution /strain / grain structure
PSI/HZB HZB ISIS JPARC
Energy resolved
2 3 4 5 6 70.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Atte
nu
atio
n c
oe
ffic
ient,
S [cm
-1]
Wavelength [Å]
Fe
4
4
3D-XRD, diffraction imaging
H. Sato, T. Kamiyama and Y. Kiyanagi, Nucl. Instr. and Meth. A 605 (2009) 36.
Example: CT imaging of elements and temperature
distributions in a double layered cylinder
0.0
2.6
1.3
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In nuclide density (×1019 cm-3)
0.00
3.70
1.85
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
109Ag nuclide density (×1019 cm-3)
0
180
90
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In temperature (℃)
1 mm
4 mm
0.5 mm9 mm
In2O3 : 7 mg/cm3
Al2O3 : 1 g/cm3{In2O3 : 14 mg/cm3
Ag2O : 36 mg/cm3
Al2O3 : 1 g/cm3{Heater
Al
images
H. Sato, T. Kamiyama and Y. Kiyanagi, Nucl. Instr. and Meth. A 605 (2009) 36.
Example: CT imaging of elements and temperature
distributions in a double layered cylinder
0.0
2.6
1.3
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In nuclide density (×1019 cm-3)
0.00
3.70
1.85
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
109Ag nuclide density (×1019 cm-3)
0
180
90
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In temperature (℃)
1 mm
4 mm
0.5 mm9 mm
In2O3 : 7 mg/cm3
Al2O3 : 1 g/cm3{In2O3 : 14 mg/cm3
Ag2O : 36 mg/cm3
Al2O3 : 1 g/cm3{Heater
Al
images
images
H. Sato, T. Kamiyama and Y. Kiyanagi, Nucl. Instr. and Meth. A 605 (2009) 36.
Example: CT imaging of elements and temperature
distributions in a double layered cylinder
0.0
2.6
1.3
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In nuclide density (×1019 cm-3)
0.00
3.70
1.85
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
109Ag nuclide density (×1019 cm-3)
0
180
90
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In temperature (℃)
1 mm
4 mm
0.5 mm9 mm
In2O3 : 7 mg/cm3
Al2O3 : 1 g/cm3{In2O3 : 14 mg/cm3
Ag2O : 36 mg/cm3
Al2O3 : 1 g/cm3{Heater
Al
images
H. Sato, T. Kamiyama and Y. Kiyanagi, Nucl. Instr. and Meth. A 605 (2009) 36.
Example: CT imaging of elements and temperature
distributions in a double layered cylinder
0.0
2.6
1.3
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In nuclide density (×1019 cm-3)
0.00
3.70
1.85
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
109Ag nuclide density (×1019 cm-3)
0
180
90
- 9
+ 9
0
- 9 + 90
Position x / mmP
osi
tio
n y
/ m
m
115In temperature (℃)
1 mm
4 mm
0.5 mm9 mm
In2O3 : 7 mg/cm3
Al2O3 : 1 g/cm3{In2O3 : 14 mg/cm3
Ag2O : 36 mg/cm3
Al2O3 : 1 g/cm3{Heater
Al
images
page
modulated imaging beam?
Grating Interferometer
source grating absorption grating
phase grating detector
F. Pfeiffer et al. Phys. Rev.Lett. 96, 215505 (2006)
page
Dark field contrast
source grating
grating interferometer
-15 -10 -5 0 5 10 154000
4500
5000
5500
6000
6500 Instr. Curve
Sample
cou
nts
/ m
inarcsec
b
0 20 40 60 80 100
0.0
0.1
0.2
0.3
0.4
mod
ulat
ion
(am
plitu
de/o
ffse
t)
width of scattering curve [arcsec]
==
path
dsyxR
yxNyxtwtP
),(
),(),(),()(
2
2 s
M. Strobl et al. PRL (2008)
-0.25
-0.2
-0.15
-0.1
-0.05
0
0 0.5 1 1.5 2 2.5 3 3.5 4
Series1
Series2
theory
measured
corelation length [microm]
modulated imaging beam?
page
Dark field contrast
2024-T3 Al alloy
fatigue test sample
Al-Si binary metallic alloys
castings with varying levels
of hydrogen concentrations
in the initial melts
A. Hilger et al. JAP (2010)
page
Dark-field NI
magnetic
domain domain
wall
K. M. Podurets et al. Phys. B 1989
M. Strobl et al. APL 2007
Ch. Grünzweig et al. APL 2009
page
Dark field contrast
magnetic
domain domain
wall
PhD thesis
C. Grünzweig
I. Manke et al., Nature comm. 2010
H. Sato, T. Kamiyama and Y. Kiyanagi, Nucl. Instr. and Meth. A 605 (2009) 36.
Example: CT imaging of elements and temperature
distributions in a double layered cylinder
0.0
2.6
1.3
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In nuclide density (×1019 cm-3)
0.00
3.70
1.85
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
109Ag nuclide density (×1019 cm-3)
0
180
90
- 9
+ 9
0
- 9 + 90
Position x / mm
Po
siti
on
y/
mm
115In temperature (℃)
1 mm
4 mm
0.5 mm9 mm
In2O3 : 7 mg/cm3
Al2O3 : 1 g/cm3{In2O3 : 14 mg/cm3
Ag2O : 36 mg/cm3
Al2O3 : 1 g/cm3{Heater
Al
images
Direct spatial
correlation of
individual structures
in object and image
No
Matter
How
Contrast
Is
Achieved
Thank you !
Markus Strobl
Instrumentation Division@ ESS
Courtesy E. Lehmann, PSI
Neutron imaging applications
58/24
R&D
Biology
& Agriculture
Geology
Archeology
Paleontology
Art History
Material science
& Engineering
Industry
etc.
n Imaging Applications
Reviews on neutron imaging
M. Strobl et al.
J. Phys. D (2009) &
N.Kardjilov..M.Strobl et al.
Materials Today (2011)
I. Manke,.., M.Strobl et al., APL(2008)
Introduction Neutron imaging