2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Physicists managed to accelerate neutron tomography due to a new neutron source almost sevenfold, which made it possible to reduce the time taken to obtain one frame to 10 milliseconds. To demonstrate the possibilities, the authors recorded the dynamics of the movement of water in the soil with a time resolution of one and a half seconds, but the potential of the method is much wider, scientists write in the Optics Express journal.
Neutron tomography is a type of computed tomography that allows you to obtain three-dimensional images of objects by scanning with a neutron flux. Since different atomic nuclei vary significantly in terms of the cross section of interaction with this type of particle, substances of different composition are displayed as areas of different contrast.
Three-dimensional images are obtained by transillumination of the sample from different sides and subsequent computer processing. The limiting spatial resolution of modern neutron tomography is on the order of 25 microns, which is somewhat worse than that of conventional computed tomography using X-rays. Nevertheless, in some areas, the use of neutrons appears to be preferable.
Mainly, neutron tomography is used in industry to diagnose various devices without the need to disassemble them, as well as in the field of materials science. There are also examples of successful applications in medicine, but the interaction of neutrons with some isotopes leads to the appearance of radioactive nuclei, which holds back the spread of technology. In the field of biology, this method is used to scan fossils that are only slightly different in properties from the surrounding rocks.
Scientists from Germany and France, led by Christian Tötzke of the University of Potsdam, describe the first results of neutron tomography using the recently launched NeXT (Neutron and X-ray Tomography) particle source at the French Laue-Langevin Institute. The authors write that the neutron flux is currently the main limiting factor of this method.
The new source made it possible to obtain images much faster. The researchers managed to reduce the time taken to obtain one frame to 10 milliseconds, and it took only one and a half seconds to form one full-fledged three-dimensional scan based on 155 projections, which is 6, 7 times less than the previous record. The spatial resolution was about 200 microns.
As a demonstration of the technology's capabilities, scientists have recorded the process of movement of water in the soil and its absorption into the roots of the plant. To increase the contrast of the image, the authors poured heavy water into a pot of lupine, that is, containing an increased amount of deuterium, an isotope of hydrogen with a neutron and a proton in the nucleus. The authors presented the results both in the form of separate frames and on video.
The authors plan to increase the capabilities of fast neutron tomography. In particular, they are going to develop faster cameras that monitor the scintillation of neutrons on a special screen behind the scanned object, as well as improve the rotation system of the sample, which is necessary to obtain various projections. In the future, other studies will be possible, for example, the dynamics of the movement of lithium atoms inside lithium-ion batteries.
Earlier it was reported that astrophysicists were able to make tomography a supernova, physicists examined individual atoms using magnetic resonance imaging, and tomography of chips clarified the conditions for proper frying. We also compiled a gallery with the results of scanning vegetables in a tomograph.
