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Initial analyses showed that asteroid Ryugu's composition is close to CI (Ivuna-like) carbonaceous chondrites (CCs) - the chemically most primitive meteorites, characterized by near-solar abundances for most elements. However, some isotopic signatures (for example, Ti, Cr) overlap with other CC groups, so the details of the link between Ryugu and the CI chondrites are not yet fully clear. Here we show that Ryugu and CI chondrites have the same zinc and copper isotopic composition. As the various chondrite groups have very distinct Zn and Cu isotopic signatures, our results point at a common genetic heritage between Ryugu and CI chondrites, ruling out any affinity with other CC groups. Since Ryugu's pristine samples match the solar elemental composition for many elements, their Zn and Cu isotopic compositions likely represent the best estimates of the solar composition. Earth's mass-independent Zn isotopic composition is intermediate between Ryugu/CC and non-carbonaceous chondrites (NCs), suggesting a contribution of Ryugu-like material to Earth's budgets of Zn and other moderately volatile elements.

Correction to: Nature Astronomy https://doi.org/10.1038/s41550-022-01846-1. Published online 12 December 2022.

Micro X-ray fluorescence (XRF) enables the non-destructive analysis of particle contamination. In this study, we compared the detection sensitivities and the LLD (lower limit of detection) values of micro-metallic particle contaminations on the plastic detected by micro-XRF and confocal micro-XRF. First, to verify the effectiveness of the confocal micro-XRF, we compared the intensities of different shaping copper samples (plate, thin film and particle). The results demonstrated that confocal micro-XRF is more effective than micro-XRF for the detection of micro particles. Second, to compare the SN ratios of different X-ray energies, several micro-metallic particles (Si, Fe, and Cu) set on an acrylic plate were measured by micro-XRF and confocal micro-XRF. It was found that the SN ratios of the confocal micro-XRF when measuring the Si, Fe, and Cu particles were improved to be approximately 14.6, 21.9, and 43.5-times those of the micro-XRF, respectively. It was determined that confocal micro-XRF is more effective for micro-metallic particles in the higher energy region.

Carbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples of the C-type asteroid (162173) Ryugu were retrieved by the Hayabusa2 spacecraft. We measured the mineralogy and bulk chemical and isotopic compositions of Ryugu samples. The samples are mainly composed of materials similar to those of carbonaceous chondrite meteorites, particularly the CI (Ivuna-type) group. The samples consist predominantly of minerals formed in aqueous fluid on a parent planetesimal. The primary minerals were altered by fluids at a temperature of 37° ± 10°C, about 5.2 − 0.7 + 0.8 million (statistical) or 5.2 − 2.1 + 1.6 million (systematic) years after the formation of the first solids in the Solar System. After aqueous alteration, the Ryugu samples were likely never heated above ~100°C. The samples have a chemical composition that more closely resembles that of the Sun’s photosphere than other natural samples do.

Confocal X-ray fluorescence (XRF) spectrometry can be used to perform three-dimensional elemental analysis, which is impossible using general micro XRF spectrometry without any collimating optics in the detection channel. In this study, we designed, for the first time, a new confocal line XRF (C-L-XRF) system that can obtain elemental information of a larger area and higher intensity in XRF analysis than conventional confocal point XRF (C-P-XRF) analysis....

We developed a hybrid X-ray focusing optics, which consisted of a polycapillary X-ray lens (PCXL) and a tungsten conical pinhole (WCP) for micro X-ray fluorescence (μ-XRF) analysis. A single PCXL produced an X-ray micro beam with a spot size of 12 μm. We developed a WCP by using a laser-ablation technique with an input diameter of 39 μm, an output diameter of 2.5 μm, and a thickness of 0.5 mm in a conical shape. This hybrid X-ray optics gave a small spot size of 2.8 μm with a small divergent angle of 12 mrad.

The elemental composition and microscopic-level shape of inclusions inside industrial materials are considered important factors in fracture analytical studies. In this work, a three-dimensional (3D) microscopic elemental analysis system based on a serial sectioning technique was developed to observe the internal structure of such materials. This 3D elemental mapping system included an X-ray fluorescence analyzer and a high-precision milling machine. Control signals for the X-ray observation process were automatically sent from a data I/O system synchronized with the precision positioning on the milling machine. Composite specimens were used to confirm the resolution and the accuracy of 3D models generated from this system. Each of the two specimens was composed of three metal wires of 0.5 mm diameter braided into a single twisted wire that was placed inside a metal pipe; the pipe was then filled with either epoxy resin or Sn. The milling machine was used to create a mirror-finish cross-sectional surface on these specimens, and elemental analyses were performed. The twisted wire structure was clearly observed in the resulting 3D models. This system enables automated investigation of the 3D internal structure of materials as well as the identification of their elemental components.

We developed a transportable micro-XRF (µ-XRF) spectrometer using a polycapillary X-ray focusing half lens, which was placed between the sample and the detector. The total weight of the developed spectrometer was about 2 kg; its dimensions were 18(W) × 26(D) × 40(H) cm. The spatial resolution of the spectrometer with the half lens of a working (focal) distance of 30 mm was 171 µm at Fe Kα, which was evaluated by a wire scanning method. In this setup, it is easy to replace the polycapillary X-ray half lens with one having a different analytical performance, because a precise position-adjustment of the X-ray lens is not required. The spacial resolution with the half lens of a working distance of 16 mm was 106 µm at Fe Kα. Depending on analyzing area on the sample and required spatial resolution, we can easily change the X-ray lens, as in a conventional optical microscope. The calibration curves of V, Cr, Mn, and Ni measured for standard steel materials showed good linear relationships (correlation coefficients >0.993). Clear elemental mapping could be obtained by scanning the sample (Cu mesh). An elemental analysis of a micro-region in an electronic device was also performed by the transportable µ-XRF spectrometer. Sn and Pb were detected at the metallic part (Sn–Pb solder) of the device. Br and Ba were observed at some resin parts of the electronic device. Copyright © 2009 John Wiley & Sons, Ltd.

We have developed a new micro x-ray fluorescence spectrometry (µ-XRF) instrument using polycapillary x-ray lens (PCXL) combined with glass conical pinhole (GCP). The x-rays focused by the PCXL were focused again by the GCP. The size of the obtained x-ray microbeam was estimated by a wire scanning method. In our instrument, the size of the x-ray microbeam end was 25 µm for Cr Kα at 0.5 mm from the GCP. The divergence angle of x-ray microbeam was 15 mrad. In order to evaluate the performance of our instrument, the gain (x-ray flux density) was estimated. The gain in our instrument was corrected by comparison of the intensity per unit area for a Cu pinhole aperture. The gain thus obtained was approximately 1400. This highly intense micro x-ray beam will be useful for micro-XRF analysis. Copyright © 2009 John Wiley & Sons, Ltd.

High-intensity monocapillary X-ray guide tube is studied and compared with a commercially available polycapillary tube. The newly designed monocapillary tube is capable of achieving spatial resolution of 10 μm in beam diameter. In comparison with the polycapillary tube, beam diameter of the present monocapillary tube is not enlarged and allows the sample to be measured at a working distance that is 10 times less. Thus, the monocapillary tube is the more versatile X-ray focusing optics as it provides improvements in spatial analysis of samples.

Several novel imaging modes of the recently developed helium ion microscope (HIM) 1) were explored that may make the HIM a tool of particular value to Cu / low-k (dielectric constant) interconnect structures. Mechanism of the “through dielectric” (2) imaging of the Cu interconnects underneath the low-k SiOC film was proposed, and materials contrast in the low-k regions between Cu lines was imaged which might reflect damaged low-k areas. Furthermore possibility of detection of luminescence induced by the focused helium ion beam using the HIM for materials property characterizations was studied for the first time.

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

The scanning X-ray microscope is an analysis device that irradiates a fine X-ray beam on the sample, measures fluorescent X-rays and transmitted X-rays that occur from the sample while scanning, and obtains fluorescent and transmitted X-ray images. It includes the following features atmospheric analysis (no vacuum required), no requirement for sample pre-treatment and non-destructive analysis (all in contrast with SEM-EDX that must be performed in a vacuum, and often requires a conductive coating). In addition, because of the transmission of X-rays through the sample, analysis can be made inside without exposing the area of interest. The spatial resolution of the scanning Xray microscope depends on the diameter of the X-ray beam. We use a scanning X-ray microscope with mono-capillary X-ray guide tube which has the narrowest X-Ray beam available. The diameter of this X-ray beam is 10 micrometers.