Rich Nonlinear Tomography for advanced materials (LEAD)

Lead Research Organisation: University of Manchester
Department Name: Mathematics

Abstract

Tomographic imaging allows scientists and engineers to see inside material and components, using x-rays, neutrons and electrons to form three dimensional images. These techniques already help develop advanced materials, test manufactured components and develop new electronic devices. Each little cube in the 3D image (voxel) is assigned a grey scale value. In new rich tomography methods more data is collected, for example frequency spectra or diffraction patterns and this leads to the possibility to recover more complicated properties in each voxel. With diffraction methods we can image the strain in a solid material, which helps understand if a component will break, and helps us design better silicon chips as the strain affects the electronics. We can also measure the microstructure, for example where small crystals or fibres are are aligned in a certain direction in a materials. Using spinning neutrons we can image magnetic fields which have direction as well as magnitude. This will help develop better magnetic materials, for example the cores of transformers in electricity supply, or image the currents on a small scale in batteries.

While measurement techniques are under developed for all these methods, the mathematics is lagging behind, and there has been a disconnect between mathematicians who know relevant theory and experimental scientists. Mathematical methods will show which data is needed to unambiguously for the required image. We can also produce efficient algorithms to reconstruct images from data. Currently rich tomography systems produce huge amounts of data, swamping their storage and computational facilities. Collecting the right data and finding better algorithms is now essential for progress.

In this project the mathematical team will work closely with leading experimental groups to develop both the measurement methods and practical reconstruction techniques, and make sure science and engineering users benefit from our work.

Publications

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Ametova E (2021) Crystalline phase discriminating neutron tomography using advanced reconstruction methods in Journal of Physics D: Applied Physics

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Bangsgaard K (2023) Low-rank flat-field correction for artifact reduction in spectral computed tomography in Applied Mathematics in Science and Engineering

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Jørgensen J (2021) Core Imaging Library - Part I: a versatile Python framework for tomographic imaging in Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences

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Papoutsellis E (2021) Core Imaging Library - Part II: multichannel reconstruction for dynamic and spectral tomography. in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences

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Tovey R (2021) Scanning electron diffraction tomography of strain in Inverse Problems

 
Title Can the second moment of the Bragg edge be resolved for neutron strain measurement? 
Description Brag gedge neutron data for the VAMAS plug and ring sample 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes  
Impact Resulted in the publication https://doi.org/10.1063/5.0085896 and inspired further research in to Bragg edge tomography and texture tomography 
URL https://data.isis.stfc.ac.uk/doi/INVESTIGATION/108682283/
 
Title Data for Laminography in the Lab: Imaging planar objects using a conventional x-ray CT scanner 
Description This data accompanies the publication Laminography in the Lab: Imaging planar objects using a conventional x-ray CT scanner by Sarah L Fisher, Danny J Holmes, Jakob S Jørgensen, Parmesh Gajjar, Julia Behnsen, William R B Lionheart and Philip J Withers Measurement Science and Technology, Vol. 30, No. 3, 2019 https://doi.org/10.1088/1361-6501/aafcae The computed laminography (CL) and limited angle CT (LACT) data sets for the lego sample of the paper are provided, including both raw projection data and the final reconstructions, a total of 4 files for each of the CL and LACT cases. The files are (for CL) CLProjectionData.zip: zip file with the raw projection images and meta data as produced by the Nikon instrument. CLShadingCorrection.zip: zip file containing dark and flat field images. CLreconstruction.mat: MATLAB mat-file with final CL reconstruction, size 798x798x200 voxels. CLreconstruction.vol: Same CL reconstruction but in a generic binary file that for example simplify the loading of data into Avizo. The same set of files is available for the CT data. The CT data reconstruction has size 798x798x798. Accompanying MATLAB reconstruction code is available from https://github.com/sarahfisher1/Laminography 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes  
Impact This data set has been used as a test by ourselves and others as a test data set for the principle of laminography and in training for tomographphic reconstruction. It inspired our work on electron tomography of viruses 
URL https://zenodo.org/record/2540509
 
Description Conference talk in Russia 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Quasilinear Equations, Inverse Problems and Their Applications talk entitled
Applications of tomography of higher awareness of physical applications of theoretical work
Year(s) Of Engagement Activity 2022
URL https://qipa2022.mipt.ru/program
 
Description Imaging the Coronavirus: inverse problems in electron tomography 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact I organized an led a virtual workshop on the mathematical and computational challenges of electron microscopy for SARS COV-2
Year(s) Of Engagement Activity 2020
URL https://www.icms.org.uk/seminars/2020/imaging-coronavirus-inverse-problems-electron-tomography
 
Description SAXS tomography workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact I gave a talk at a workshop of Diamond light source users on the mathematics and software of diffraction tomography
Year(s) Of Engagement Activity 2022
URL https://www.diamond.ac.uk/Home/Events/2022/SAXS-Tensor-Tomography-Workshop.html