Add new comment

       If we can harness the power of nuclear fusion, it will solve a lot of the world’s energy problems. The Sun runs on nuclear fusion but in order to create fusion on Earth, it is necessary to create even higher temperatures and pressures than those in the center of the Sun. One of the critical problems that has to be dealt with is engineering components that can hold up to these extreme conditions. 
       Researchers from Swansea University and Culham Centre for Fusion Energy in the U.K., ITER in France, and the Max-Planck Institute of Plasma Physics in Germany have combined images from x-ray and neutron imaging systems to reveal the robustness of parts for use in fusion reactor research. Their work indicates that each type of imaging captures different aspects of a component and that combining the images yields more information that could be gained from just one type of imaging system.
       One of the main approaches to nuclear fusion is called magnetic confinement. In this type of fusion reactor, extremely powerful magnetic fields are used to compress and heat a plasma. Some reactors use external superconducting magnets to create the field while other approaches induce currents into the plasma itself to heat and compress it. Temperatures as high as one hundred and fifty million degrees Celsius are required to initiate fusion. Researchers must be able to analyze the integrity of a component without destroying it in the process.
       The international research team from the different institutions decided to focus their efforts on one particular critical component. This is a pipe carrying coolant that is called a monoblock. A tungsten monoblock was imaged with an X-ray system. It was then imaged by the ISIS Neutron and Muon Source's neutron imaging instrument, IMAT.
        Dr. Triestino Minniti is with the Science and Technology Facilities Council. He said, “Each technique had its own benefits and drawbacks. The advantage of neutron imaging over x-ray imaging is that neutrons are significantly more penetrating through tungsten.”
        “Thus, it is feasible to image samples containing larger volumes of tungsten. Neutron tomography also allows us to investigate the full monoblock non-destructively, removing the need to produce ‘region of interest’ samples."
        Dr. Llion Evans works at the Swansea University College of Engineering. He said, “This work is a proof of concept that both these tomography methods can produce valuable data. In future these complementary techniques can be used either for the research and development cycle of fusion component design or in quality assurance of manufacturing.”
        The next step in the research program will be to convert the 3D images produced with the two imaging systems into engineering simulations which will have micro-scale resolution. This is a technique which is called the image-based finite element method (BFEM). It allows the direct analysis of the performance of each individual component. Minor deviations from design caused by the manufacturing processes can be accounted for by this method.
       The work on dual imaging by this research group will be a welcome addition to the toolkit of organizations working on nuclear fusion research.