Bimodal Imaging Using Neutrons and X-rays
A. Kaestner, M. Morgano, J. Hovind, E. LehmannNeutron Imaging and Activation Group
Laboratory for Neutron Scattering and Imaging
Paul Scherrer Institut, Villigen, Switzerland
Outline
Introduction
Beamlines
Examples
Summary
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 2(23)
Introduction Beamlines Examples Summary
Introduction
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 3(23)
Introduction Beamlines Examples Summary
Typical neutron imaging experiment and challenges
Hydrology
• Segmentation accuracy
• Estimate water content
Cultural heritage
• Segmentation accuracy
• Material classification
Buildung materials
• Estimate water content
• Dimensional changes
Material science
• Penetration power
• Ambiguous readings
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 4(23)
Introduction Beamlines Examples Summary
Why multiple modalities?
Reasons to select or reject a specific imaging method
Advantages
• Good transmission
• Good contrast
• Relevant features visible
• Materials can be identified
Disadvantages
• Low transmission
• Low contrast
• Not all features visible
• Ambiguous response
Purpose of multi-modality
Match the advantages of each method against the disadvantages ofthe other methods to obtain more information than using eachmethod individually.
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 5(23)
Introduction Beamlines Examples Summary
Neutron and X-ray – What is the difference?
Neutrons
����������
������� ������������
• Interacts with nucleus
• No direct relation with Z
• Isotope sensitive
X-rays
������������������
�� �������������
• Interacts with electrons
• Direct relation with Z
• Attenuation ∼ density
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 6(23)
Introduction Beamlines Examples Summary
Comparing Neutrons with X-rays
Neutrons
� � � � � � � � � �� �� �� �� �� �� �� ��
�
�
�
�
�
�
�
����
�
����
����
����
����
����
�
��
�
��
��
��
��
�� � � � � � ��
�� �� � � � �� ��
�� � ! " �� �# �� �$ � �% &# '� '� �� �� �� ��
�� ( &� �� �$ ! �% �) �* �� �* +# �# �� !� + ,�
�� �- !� . �� �� +� �/ �% �� !� �� � �$ �/ �#
�� �- 0� �� �) �� �/ 0� �� 1%� 1%/ 1%2 1%3 1%) 1%� 1%$
���
���
����
���
���
����
����
���
����
����
����
�
���
����
���
�
����
����
��
�
��
��
����
�
��
����
����
�
����
����
�����
�
����
���
���
�
��
����
����
�
����
��
���
�
���
��
����
���
���
�
���� ���� �� ����
����
���
����
���
����
�
�
��
���
���
����
�
���
���
����
���
�
����
���
����
�
�
���
����
����
�
�
����������
�������
�� �� �� �* �4 �4 5% '* !� 06 �$ 5� !4 (� �%
� !) �� 1 �3 �% �4 �4 �7 �- 5� �4 �* �$ ��
���� ��� ��� �� ���
� ���� ���� ���� ����
��
�����
�����
����
����
�
����
�
�����
�
����
�
����
�
����
�
���
�
���
�
'�$%3
��� $*
�
X-rays
� � � � � � � � � �� �� �� �� �� �� �� ��
�
�
�
�
�
�
�
����
�
����
����
����
����
����
�
��
�
��
��
��
��
�� � � � � � ��
�� �� � � � �� ��
�� � ! " �� �# �� �$ � �% &# '� '� �� �� �� ��
�� ( &� �� �$ ! �% �) �* �� �* +# �# �� !� + ,�
�� �- !� . �� �� +� �/ �% �� !� �� � �$ �/ �#
�� �- 0� �� �) �� �/ 0� �� 1%� 1%/ 1%2 1%3 1%) 1%� 1%$
����
����
����
���
����
����
���
����
����
����
����
�
����
����
�����
�
���
���
����
�
����
����
�����
�
����
����
����
�
���
���
����
�
���
����
����
�
���
����
����
�
����
���
���
�
���
���
����
����
�����
�
���� ���� ���� ����
����
����
����
����
����
���
�
����
����
��
����
�
����
����
���
����
�
����
����
����
�����
�
����
���
����
�
�
����������
�������
�� �� �� �* �4 �4 5% '* !� 06 �$ 5� !4 (� �%
� !) �� 1 �3 �% �4 �4 �7 �- 5� �4 �* �$ ��
���� ��� ���� ���� ����
����� ��� ���� ��� �
����
�
����
�
��
�
���
�
�����
�
�����
�
�����
�
����
�
���
�
�����
�
'�$%3
��� $*
�
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 7(23)
Introduction Beamlines Examples Summary
Combinations for different applications
Hydrology
NH
3.48
O
0.18
Si
0.12
Al
0.10
XH
0.18
O
0.15
Si
0.33
Al
0.38
Cultural heritage
NH
3.48
Fe
1.20
Cu
1.00
Pb
0.37
XH
0.18
Fe
1.55
Cu
2.00
Pb
22.80
Buildung materials
NH
3.48
O
0.18
C
0.63
Si
0.12
Fe
1.20
XH
0.18
O
0.18
C
0.30
Si
0.33
Fe
1.55
Material science
NAl
0.10
Fe
1.20
Ti
0.59
Ni
2.10
XAl
0.38
Fe
1.55
Ti
0.74
Ni
1.98
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 8(23)
Introduction Beamlines Examples Summary
Beamlines
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 9(23)
Introduction Beamlines Examples Summary
SINQ – The neutron spallation source at PSI
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 10(23)
Introduction Beamlines Examples Summary
Neutron imaging beamlines at PSI
NEUTRAFeatures
• Termal neutrons.
• In-line X-ray source
• Highly activated samples[Lehmann et al., 2001]
ICON
Features
• Cold neutrons
• Micro tomography (6.5 µm)
• Energy selector
• Grating interferometer[Kaestner et al., 2011]
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 11(23)
Introduction Beamlines Examples Summary
Geometries for combined neutron and X-ray imaging
Inline Oblique Slanted
Neutrons
X-ray
X-ra
y
Neutrons
Neutrons
X-ray
(a) (b) (c)
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 12(23)
Introduction Beamlines Examples Summary
Xtra the NX-setup at NEUTRA
a
Neutrons/X-rays
b
c
db
e
f
Components
a X-ray source
b Neutron flight tube
c Beam limiter
d Midi camera box
e Maxi camera box
f Sample environment
Neutrons
• Thermal neutron spectrum
• Almost parallel beam
• Camera/Scintillator
X-rays
• 350kV, 75W source
• Almost parallel beam
• Camera/Scintillator
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 13(23)
Introduction Beamlines Examples Summary
The NX-setup at ICON
a
c
e
d
f
b
bc
Neutrons
Components
a Neutron imaging system
b Flat panel detector
c X-ray source
d Neutron beam limiter
e Frame for X-ray beamline
f Neutron flight tube
Neutrons
• Cold neutron spectrum
• Almost parallel beam
• Camera/Scintillator
X-rays
• 150kV, 75W source
• Cone beam (42◦)
• Flat panel detector
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 14(23)
Introduction Beamlines Examples Summary
Chosen X-ray components
X-ray source
Hamamatsu L12161-07
Tube voltage 40–150 kV
Tube current 0–500 µA
Power 75W
Spot size 7–50 µm
Cone angle 42◦
Detector
PaxScan 2530HE
Active area 24.9×30.2 cm2
Pixels 1792×2176
Pixel pitch 139 µm
Frame rate 9 fps (full frame)
A/D conv 16 bits
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 15(23)
Introduction Beamlines Examples Summary
Examples
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 16(23)
Introduction Beamlines Examples Summary
Zuger Degen
Experiment using the Xtra option at NEUTRA.
Neutrons
• Wood structure
• Better metal penetration
X-rays
• Amalgam inlays
• Wood shape
[Mannes et al., 2015]
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 17(23)
Introduction Beamlines Examples Summary
Roots in the rhizosphere
Experiment using the cone beam X-ray source in-line at ICON.
Neutrons
• Roots visible
• Textured soil
• Stones transparent
X-rays
• Roots visible as voids
• Soil homogeneous
• Stones visible
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 18(23)
Introduction Beamlines Examples Summary
Segmentation using Bivariate histogram
Background
Roots
Soil
Roots
Soil
Background
Background
Roots and soil
kgro
H1
H2
H0
• Classes better separated
• Linear decision lines
H0 : N (m0,C0)
H1 : N (m1,C1)
H2 : N (m2,C2)
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 19(23)
Introduction Beamlines Examples Summary
Summary
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 20(23)
Introduction Beamlines Examples Summary
Outlook
Instrumentation
• Complete beamline installation at ICON
• Evaluate need for shielding to minimize crosstalk
• Evaluate operation parameters
• Develop calibration methods
Handling multimodal data
• Multimodal reconstruction
• Registration methods
• Multivariate segmentation
• Multivariate estimation
• Visualization
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 21(23)
Introduction Beamlines Examples Summary
Conclusions
• The sum of two is more than each alone.
• Neutrons and X-rays work well together.
• Two beamlines for NX imaging at PSI.
• Research applications in• Energy storage• Porous media• and Cultural heritage https://youtu.be/VESMU7JfVHU
Welcome to submit proposals
Submission portal at http://duo.psi.ch
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 22(23)
Introduction Beamlines Examples Summary
Bibliography I
Kaestner, A., Hartmann, S., Kuehne, G., Frei, G., Gruenzweig, C., Josic,L., Schmid, F., and Lehmann, E. (2011).
The ICON beamline - A facility for cold neutron imaging at SINQ.
Nuclear Instruments and Methods in Physics Research Section A:
Accelerators, Spectrometers, Detectors and Associated Equipment,659(1):387 – 393.
Lehmann, E. H., Vontobel, P., and Wiezel, L. (2001).
Properties of the radiography facility NEUTRA at SINQ and its potentialfor use as european reference facility.
Nondestructive Testing and Evaluation, 16(2-6):191–202.
Mannes, D., Schmid, F., Frey, J., Schmidt-Ott, K., and Lehmann, E.(2015).
Combined neutron and x-ray imaging for non-invasive investigations ofcultural heritage objects.
In Lehmann, E., Kaestner, A., and Mannes, D., editors, Proceedinings of
the 10th World Conference on Neutron Radiography. Paul ScherrerInstitute, Physics Procedia, Elsevier Science Publishers.
A. Kaestner et al., Bimodal Neutron/X-ray Imaging DIR2015, Ghent, June 2015 23(23)