Monochromatic computed tomography using laboratory-scale setup

Abstract

In this article, we demonstrate the viability of highly monochromatic full-field X-ray absorption near edge structure based tomography using a laboratory-scale Johann-type X-ray absorption spectrometer utilising a conventional X-ray tube source. In this proof-of-concept, by using a phantom embedded with elemental Se, Na$$_2$$ 2 SeO$$_3$$ 3 , and Na$$_2$$ 2 SeO$$_4$$ 4 , we show that the three-dimensional distributions of Se in different oxidation states can be mapped and distinguished from the phantom matrix and each other with absorption edge contrast tomography. The presented method allows for volumetric analyses of chemical speciation in mm-scale samples using low-brilliance X-ray sources, and represents a new analytic tool for materials engineering and research in many fields including biology and chemistry.

Inner product regularized multi-energy X-ray tomography for material decomposition

“…We now generalize the eigenvalue bounds for the preconditioned matrix found in [6] to the case of k materials. We recall that the matrix of the Newton system that arises at each interior point iteration can be written as (10), and Θ is a diagonal matrix with strictly positive entries. We suppose that k materials are present.…”

“…Monochromatic data was produced with a new method, where a polychromatic X-ray beam is directed through a spherically bent crystal analyser [10]. It monochromatizes and refocuses the beam at the Rowland circle, which acts as a secondary source.…”

“…All of this can be done easily in a traditional X-ray laboratory (as opposed to a synchrotron facility). See [10].…”

Multi-Energy and Fast-Convergence Iterative Reconstruction Algorithm for Organic Material Identification Using X-ray Computed Tomography

“…As the problem of fast and confident explosive detection represents one of the most fundamental aspects of passenger security, until present, a multitude of non-invasive techniques were proposed that were mainly based on the differential attenuation or diffraction of nuclear radiation. It is the case of X-ray single [ 1 , 2 ], dual [ 3 , 4 ], phase contrast [ 5 ], multiple-energy [ 6 , 7 ], diffraction [ 8 ], or even neutron computed tomography (CT) [ 9 ]. In addition to these techniques, Raman [ 10 ] or nuclear quadrupole resonance [ 11 ] spectroscopy as well as infrared photothermal imaging [ 12 ] gave remarkable results in this field, just to mention some alternative methods not involving the use of X-rays.…”

Laboratory-based X-ray spectrometer for actinide science

“…For example, the HelXAS spectrometer was developed in 2017, and allows studying the 3d metals from Cr to Zn (Lahtinen et al, 2022) and 4f -elements, such as Ce and Nd, and allows the local environment of actinides to be investigated, such as U or heavy metals such as Mo and Zr (Honkanen et al, 2019). In addition to X-ray absorption spectroscopy, the X-ray spectroscopy center has recently implemented near-edge structure-based monochromatic computed tomography using a laboratory X-ray spectrometer (Honkanen & Huotari, 2023). Zimmermann et al (2020) summarized and commented on the most notable developments in experimental laboratory setups -von Hamos and Johann/Johansson type setups.…”