Heterogeneity effects in micro-beam XRF scanning spectroscopy of binary powdered mixtures and lake sediments

Katsuta, Nagayoshi*; Umemura, Ayako*; Naito, Sayuri*; Masuki, Yuma*; Itayama, Yui*; Niwa, Masakazu; Shirono, Shinichi*; Yoshida, Hidekazu*; Kawakami, Shinichi*

Spectrochimica Acta, Part B, 210, p.106817_1 - 106817_11, 2023/12

https://doi.org/10.1016/j.sab.2023.106817

X-ray fluorescence (XRF) scanning of lacustrine sediments has been used to extend the approach to a wider range of elemental records in both ages and timescales of variations in past environments and climates. However, one of severe problems with effects of the XRF intensity by grain size and mineralogical composition known as "heterogeneity effects" have been pointed out. This study investigated the heterogeneity effect of Fe intensities on X-ray beam using several binary powder mixtures and lacustrine sediment cores.

Spectrochemistry of technetium by liquid electrode plasma optical emission spectrometry and its applicability of quantification for highly active liquid waste

Yamamoto, Masahiko; Do, V. K.; Taguchi, Shigeo; Kuno, Takehiko; Takamura, Yuzuru*

Spectrochimica Acta, Part B, 155, p.134 - 140, 2019/05

https://doi.org/10.1016/j.sab.2019.03.014

The emission spectra of technetium (Tc) by liquid electrode plasma optical emission spectrometry have been investigated in this study. From the spectra, 52 emission peaks of Tc were observed in the 250-500 nm wavelength range. All peaks were assigned to the neutral state or singly ionized state. The relative intensities of these peaks were similar to those excited by an electric spark. The strongest intensity peaks were found at 254.3 nm, 261.0 nm, and 264.7 nm. Spectral interferences of coexisting elements in highly active liquid waste of reprocessing stream on those three strongest peaks were investigated using simulated sample. No spectral interferences were observed around the 264.7 nm Tc peak. Therefore, analytical performance using 264.7 nm peak was evaluated. The detection limit, estimated on standard and blank samples in 0.4 M nitric acid, was 1.9 mg/L. The relative standard deviation of Tc standard sample (12.0 mg/L) was 3.8% (N = 5, 1).

Ablation plume structure and dynamics in ambient gas observed by laser-induced fluorescence imaging spectroscopy

Miyabe, Masabumi; Oba, Masaki; Iimura, Hideki; Akaoka, Katsuaki; Khumaeni, A.*; Kato, Masaaki; Wakaida, Ikuo

Spectrochimica Acta, Part B, 110, p.101 - 117, 2015/08

AA2015-0183.pdf:3.11MB

https://doi.org/10.1016/j.sab.2015.06.004

The dynamic behavior of an ablation plume in ambient gas has been investigated by laser-induced fluorescence imaging spectroscopy. The second harmonic beam from an Nd:YAG laser (0.5-6J/cm) was focused on a sintered oxide pellet or a metal chip of gadolinium. The produced plume was subsequently intersected with a sheet-shaped UV beam from a dye laser so that time-resolved fluorescence images were acquired with an intensified CCD camera at various delay times. The obtained cross-sectional images of the plume indicate that the ablated ground state atoms and ions of gadolinium accumulate in a hemispherical contact layer between the plume and the ambient gas, and a cavity containing a smaller density of ablated species is formed near the center of the plume. At earlier expansion stage, another luminous component also expands in the cavity so that it coalesces into the hemispherical layer. The splitting and coalescence for atomic plume occur later than those for ionic plume. Furthermore, the hemispherical layer of neutral atoms appears later than that of ions; however, the locations of the layers are nearly identical. This coincidence of the appearance locations of the layers strongly suggests that the neutral atoms in the hemispherical layer are produced as a consequence of three-body recombination of ions through collisions with gas atoms. The obtained knowledge regarding plume expansion dynamics and detailed plume structure is useful for optimizing the experimental conditions for ablation-based spectroscopic analysis.

Development of soft X-ray multilayer laminar-type plane gratings and varied-line-spacing spherical grating for flat-field spectrograph in the 1-8 keV region

Koike, Masato; Ishino, Masahiko; Imazono, Takashi; Sano, Kazuo*; Sasai, Hiroyuki*; Hatayama, Masatoshi*; Takenaka, Hisataka*; Heimann, P. A.*; Gullikson, E. M.*

Spectrochimica Acta, Part B, 64(8), p.756 - 760, 2009/08

https://doi.org/10.1016/j.sab.2009.05.013

W/C and Co/SiO multilayer laminar-type holographic plane gratings (groove density 1/1200 lines /mm) in the 1-8 keV region are developed. For the Co/SiO grating the diffraction efficiencies of 0.41 and 0.47 at 4 and 6 keV, respectively, and for the W/C grating 0.38 at 8 keV are observed. Taking advantage of the outstanding high diffraction efficiencies into practical soft X-ray spectrographs a Mo/SiO multilayer varied-line-spacing (VLS) laminar-type spherical grating (1/2400 lines /mm) is also developed for use with a flat field spectrograph in the region of 1.7 keV. For the Mo/SiO multilayer grating the diffraction efficiencies of 0.05-0.20 at 0.9-1.8 keV are observed. The FWHM's of the measured line profiles of Hf-M (1644.6 eV), Si-K (1740.0 eV),and W-M (1775.4 eV) are 13.7 eV, 8.0 eV, and 8.7 eV, respectively. It shows the validity of multilayer lamina-type gratings in the region.

Application of Inductively coupled plasma Mass Spectrometry to the determination of uranium isotope ratios in individual particles for nuclear safeguards

Zhang, X. Z.*; Esaka, Fumitaka; Esaka, Konomi; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu; Watanabe, Kazuo

Spectrochimica Acta, Part B, 62(10), p.1130 - 1134, 2007/10

https://doi.org/10.1016/j.sab.2007.06.013

The capability of inductively coupled plasma mass spectrometry (ICP-MS) for the determination of uranium isotope ratios in individual particles was determined. For this purpose, we developed an experimental procedure including single particle transfer with a manipulator, chemical dissolution and isotope ratio analysis. As the result, the U/U isotope ratio for the particle with the diameter between 0.5 and 3.9 m was successfully determined with the deviation from the certified ratio within 1.8%. The developed procedure was successfully applied to the analysis of a simulated environmental sample prepared from a mixture of indoor dust (NIST SRM 2583) and uranium particles (NBL CRM U050, U350 and U950a). From the results, the proposed procedure was found to be an alternative analytical tool for nuclear safeguards.

The Use of Si carriers for aerosol particle collection and subsequent elemental analysis by total-reflection X-ray fluorescence spectrometry

Esaka, Fumitaka; Watanabe, Kazuo; Onodera, Takashi; Taguchi, Takuji; Magara, Masaaki; Usuda, Shigekazu

Spectrochimica Acta, Part B, 58(12), p.2145 - 2155, 2003/12

https://doi.org/10.1016/S0584-8547(03)00189-7

In order to improve the sensitivity of elemental analysis for aerosol particles by total-reflection X-ray fluorescence spectrometry (TXRF), silicon wafer carriers with diameters of 25 mm were selected and prepared for direct impact collection and subsequent analysis. The detection limits of elements on the carrier were determined and found to be superior to those on glassy carbon and quartz glass carriers used in previous studies. By using the silicon wafer carriers, aerosol particles with the sizes of 2.0 m, 0.3-2.0 m and 0.05-0.3 m were collected at Ibaraki in Japan from January to August 2002 and analyzed by TXRF. Selenium Consequently, the elements with the concentration of ng/m &8211; pg/m in the particles were successfully detected. The results revealed that K, V, Zn, Br and Pb were concentrated in fine particles, which is presumed to arise from anthropogenic sources. In contrast, Ca, Ti and Fe were contained in coarse particles, which is presumed to arise from soil.

Construction and performance of a newly developed X-ray excited optical luminescence spectrometer

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Spectrochimica Acta, Part B, 36(7), p.687 - 695, 1981/00

https://doi.org/10.1016/0584-8547(81)80120-6

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