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What is 3D X-ray Computed Tomography?So what is 3D X-ray Computed Tomography (CT) and how does it work? Well, it works along the same lines as when a doctor takes an X-ray of a broken bone. However, rather than taking just one 2D X-ray picture, known as a radiograph, hundreds or even thousands of radiographs are taken of the object as it is rotated through 360°. The series of 2D radiographs are then reconstructed into a 3D image using sophisticated software packages coupled with powerful computers. The real advantage of CT lies in the fact that a virtual replica is created where one can slice through the layers of the object to reveal its internal structure, akin to peeling an onion. Further, in some cases one can then follow its structure as it changes over time.
Originally CT was developed in the 1970’s for medical imaging and today it is routinely used in both state and private medical centres for diagnosis purposes, such as for the detection of tumours, etc. Recently, CT has seen an increased use in preventative medicine by the use of body scans as part of a general health check. Although CT has been around for the last 40 years, it is only in the last 10 years that the technology has seen dramatic changes. These changes have been brought about through the combination of massively increased computing power that can handle the huge volumes of data which are produced and the driving force from technological innovation in a number of related fields. These changes have resulted in the capability to perform rapid CT scanning of objects from live biological specimens to the non-destructive testing of aircraft parts, for example. 
CT has a number of advantages over traditional materials analysis techniques such as Scanning Electron Microscopy (SEM) or 3D laser scanning. These include:
The Henry Moseley X-ray Imaging Facility (HMXIF)The Henry Moseley X-ray Imaging Facility (HMXIF) is a unique facility that provides both academic and industrial researchers with access to a unique suite of world-class equipment for the non-destructive 3D imaging of samples up to a metre in size and at spatial resolutions from one millimetre to 50nm in size. This is accompanied by a suite of powerful workstations for the reconstruction, visualisation and quantitative analysis of the acquired data. The facility provides openly available access under both academic and commercial arrangements to 7 differently configured laboratory CT systems, which together offer the widest possible range of spatial resolution capabilities. This capability is further augmented by access to synchrotron X-ray imaging facilities such as those at the UK's national synchrotron source, Diamond, which is sited at the Harwell Science and Innovation Campus in Oxfordshire. The HMXIF complements and extends the capabilities which already exist within the Stress and Damage Characterisation Unit in the School of Materials at the University of Manchester for the non-destructive investigation of materials across a very wide range of disciplines.
Today a number of large technologically driven organisations make use of CT scanning, however few fully utilise the full range of analysis capabilities that is presently possible in terms of length scales and spatial resolution. Within the HMXIF the rapid CT scanning of static specimens and the full 3D reconstruction of data has become a standard procedure and we continue to develop this area of expertise even further through the development of new software, for example. One of our strengths lies in the use of in-situ environments to study samples under a wide range of conditions from stress corrosion, through elevated temperatures to fatigue loading.
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