Recent developments in neutron imaging Nikolay Kardjilov, Ingo - PowerPoint PPT Presentation

CRISP-WIN Workshop, Grenoble 2014 Recent developments in neutron imaging Nikolay Kardjilov, Ingo Manke, André Hilger, John Banhart The Workshop on Imaging with Neutrons has received funding from the European Commission in the frame of the Cluster of Research Infrastructures for Synergies in Physics (CRISP) under the 7th Framework Programme Grant Agreement 283745

X-ray imaging Introduction BESSY II 20 km BER II CRIS-WIN 2014, March 17, Grenoble 2

Introduction X-ray imaging Method development Applications Institute of Applied Materials high resolution Energy sources Neutron Imaging Micro CT Synchrotron conventional n detector x energy-selective imaging Energy storage white-beam imaging Materials research 10 mm magnetic imaging absorption contrast CONRAD at HZB in operation since 2005 10 mm CRIS-WIN 2014, March 17, Grenoble

CONRAD-2 X-ray imaging Labs Cold neutrons Micro-CT Lab Wavelength range: 1.5 Å – 10 Å 3D Data Analytics Lab Large beam CONRAD-2 12000 Beam size: 20 cm x 20 cm 10000 8000 Counts 6000 4000 2000 0 0 2 4 6 8 10 12  [Å] Instrumentation Grating Neutron Velocity Double-crystal interferometry polarizers selector monochromator High flux Flux (guide end): 2.7x10 9 n/cm 2 s CRIS-WIN 2014, March 17, Grenoble 4

X-ray imaging Introduction Contrast Resolution • Neutron interaction with matter - attenuation contrast - diffraction contrast - phase/dark-field contrast - magnetic contrast • Instrument design • Detector development CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Attenuation Contrast 1 cm CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Attenuation Contrast Fuel cells How to optimize water management in a PEM fuel cell? • Neutron Imaging @ V7(CONRAD-2) synchrotron • In-operando visualization of water tomography distribution Quantification of water amount 10 mm Diffusion dynamics revealed with 1 mm D-H contrast ➔ Diffusion dynamics revealed with D-H contrast Understanding of ageing mechanisms M. Klages Journal of Power Sources 239 (2013) 596 CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Attenuation Contrast Combustion chamber Time scale 1 – old sediments 2 2 3 – fresh sediments 1+2 2 2+3 1 volume histogram RAB 09 5000 medium low high absorption absorption abs. (metal) 4000 2 3 1 3000 counts 2000 1+2 1000 2+3 0 1 2 attenuation coefficient CRIS-WIN 2014, March 17, Grenoble 8

X-ray imaging CRIS-WIN 2014, March 17, Grenoble 9

X-ray imaging Diffraction Contrast λ = 4.0 Å 1 cm CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Diffraction Contrast Bragg edges Bragg‘s law polychromatic polycrystalline 2d hkl sin θ =  neutron beam material  d hkl DCM CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Diffraction Contrast Bragg edges Bragg‘s law polychromatic polycrystalline 2d hkl sin90 ° =  neutron beam material  d hkl DCM Cross-sections of iron per atom 2d hkl =  (110) CRIS-WIN 2014, March 17, Grenoble

X-ray imaging 3D Phase mapping in metals Energy-selective neutron tomography of TRIP-steel R. Woracek et al., Advanced Materials , in print (2014) CRIS-WIN 2014, March 17, Grenoble 13

X-ray imaging Diffraction Contrast Residual stresses (Dayakar Penumadu, Robin Woracek, University of Tennessee , Knoxville, USA) Setup for energy selective imaging Multi-Axial Loading System Double crystal monochromator: PCG crystals (mosaicity of 0.8 ° ) Range: 2.0 – 6.5 Å Resolution (  /  ): ~ 3% Neutron flux: ~ 4x10 5 n/cm 2 s (at  =3.0 Å) Beam size: 5 x 20 cm 2 CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Diffraction Contrast Residual stresses (Dayakar Penumadu, Robin Woracek, University of Tennessee , Knoxville, USA) Insert : [110] Bragg Edge for point S1. The position of the Bragg Edge was obtained by fitting using Gauss’s non -linear least-squares method. CRIS-WIN 2014, March 17, Grenoble 15

X-ray imaging Diffraction Contrast Residual stresses (Dayakar Penumadu, Robin Woracek, University of Tennessee , Knoxville, USA) Imaging measurements R. Woracek et al., Journal of Applied Physics (2011) CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Phase/Dark-field Contrast 2 mm CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Phase/Dark-field Contrast Analyser Phase Source Detector grating grating grating Sample Neutrons G 0 G 1 G 2 x G The spatially resolved analysis of the interference pattern (phase, amplitude and offset) reveal information about phase effects, small angle scattering and attenuation introduced by the sample. C. Grünzweig et al, PRL (2008) CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Phase/Dark-field Contrast Grating interferometry for materials science Phase Analyser grating grating Detector Neutrons Al-Si-binary metallic alloys with varying hydrogen content Attenuation Phase/refraction (U)SANS/dark-field medium high low 2 cm Structures M. Strobl et al, PRL (2008) (0.1 – 10µm) CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Phase/Dark-field Contrast Phase Analyser Source Detector Multiple refractions at the domain walls results in local grating grating grating degradation of the beam coherence (decrease of the amplitude in the interference pattern). Sample Neutrons G 0 G 1 G 2 x G Magnetic domains in a 3D domain distribution bulky FeSi single crystal Magnetic domain structure can be visualized in 3D by applying tomographic reconstruction from 2D angular projections I. Manke et al, Nature Communications (2010) CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Magnetic Contrast 1 cm CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Magnetic Contrast Principle Experimental parameters       L • Solid state polarazing benders t Hds L v path • Beam size (WxH): 20 x 4 cm 2 1 cm • Exposure times: ~10 min / image N. Kardjilov, et al, Nature Physics (2008) CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Magnetic Contrast Flux pinning in superconductors Pb cylinder (polycrystalline) T 7.2 K 7.196 K (T c ) 7.0 K 7.0 K 6.9 K 6.8 K 1 cm trapped flux Flux pinning at cooling down below Tc while applying a homogenous magnetic field of 10 mT perpendicular to the beam. The images were recorded after switching off the magnetic field. CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Magnetic Contrast Flux pinning in superconductors Pb cylinder (polycrystalline) T 7.2 K 7.196 K (T c ) 7.0 K 7.0 K 6.9 K 6.8 K 1 cm trapped flux Flux pinning at cooling down below Tc while applying a homogenous magnetic field of 10 mT perpendicular to the beam. The images were recorded after switching off the magnetic field. CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Magnetic Contrast Steps towards quantification Spin flipper Spin flipper 2D- Detector Neutrons y S 1 Polarizer Analyzer S 2 S 3 S 4 z x Flippers Coil 9.5 loops I = 1.5 A 101 Projections 9+1 Tomographies 1 cm CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Magnetic Contrast X Y Z Analysis of Spin component: Simulation Experiment Simulation Experiment Simulation Experiment Rotation angle of the sample: 0 ° 72 ° 144 ° Initial spin direction: X 216 ° y y z z x x 288 ° 360 ° M. Strobl et al, Phys. B (2009); M. Strobl, NIMA 604 (2009) CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Spatial Resolution CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Spatial Resolution Introduction Standard setup (2006) Scintillator: 200 µm 6LiF Detector system Lens system: 50 mm Pixel size: 100 µm Exposure time: 20 s µm 500 400 300 200 100 CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Spatial Resolution Camera: Andor DW436 Lens system: Magnification Pixelsize = 3.375 µm Szintillator: 5 µm Gadox Resolution: 7.9 µm (63.2 lp/mm) 2 mm S. H. Williams et al, Journal of Instrumentation (2012) CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Spatial Resolution Hydrogen storage (MHGC Ti-Mn) Neutron tomography (L. Röntzsch, IFAM, Dresden, Germany) 50 µm 1 mm Resolution: 15 µm (pixel size: 6.5 µm), FOV: 13 x 13 mm 2 , Exp. Time: 20 s CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Spatial Resolution Hydrogen loading of duplex stainless steel (A. Griesche, BAM , Berlin, Germany) H 2 (~ 100 ppm) 5 mm Electrochemically loading A. Griesche et al, Acta Materialica (2014), submitted CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Conclusions  Over the last 5 years, significant developmental work has been performed to expand the radiographic and tomographic capabilities of the neutron imaging facilities worldwide.  New techniques have been implemented, including imaging with polarized neutrons, Bragg-edge mapping, high-resolution neutron imaging and grating interferometry.  These methods have been provided to the user community as tools to help addressing scientific problems over a broad range of topics such as superconductivity, materials research, life sciences, cultural heritage, paleontology and various others. CRIS-WIN 2014, March 17, Grenoble

X-ray imaging Outlook Overlapping between imaging and scattering Gratings High Neutron Res Imaging USANS VSANS SANS 1 nm 10 nm 100 nm 1 µm 10 µm 100 µm 1 mm CRIS-WIN 2014, March 17, Grenoble 33

X-ray imaging CRIS-WIN 2014, March 17, Grenoble 34