Effect of sample temperature and laser ablation angle on optical emission and acoustic signals from laser-induced Zirconium plasma

Batsaikhan, M.; Oba, Hironori; Karino, Takahiro; Akaoka, Katsuaki; Wakaida, Ikuo

Optics Express (Internet), 32(24), p.42626 - 42638, 2024/11

https://doi.org/10.1364/OE.538774

Incorporation of U, Pb and rare earth elements in calcite through crystallisation from amorphous calcium carbonate; Simple preparation of reference materials for microanalysis

Miyajima, Yusuke*; Saito, Ayaka*; Kagi, Hiroyuki*; Yokoyama, Tatsunori; Takahashi, Yoshio*; Hirata, Takafumi*

Geostandards and Geoanalytical Research, 45(1), p.189 - 205, 2021/03

https://doi.org/10.1111/ggr.12367

Uncertainty for elemental and isotopic analyses of calcite by LA-ICP-MS is largely controlled by the homogeneity of the reference materials (RMs) used for normalization and validation. In order to produce calcite RMs with homogeneous elemental and isotopic compositions, we incorporated elements including U, Pb, and rare earth elements into calcite through heat- and pressure-induced crystallization from amorphous calcium carbonate that was precipitated from element-doped reagent solution. X-ray absorption spectra showed that U was present as U(VI) in the synthesized calcite, probably with a different local structure from that of aqueous uranyl ions. The uptake rate of U by our calcite was higher in comparison to synthetic calcite of previous studies. Variations of element mass fractions in the calcite were better than 12% 2RSD, mostly within 7%. The Pb/Pb ratio in the calcite showed 1% variations, while the U/Pb ratio showed 3-24% variations depending on element mass fractions. Using the synthetic calcite as primary RMs, we could date a natural calcite RM, WC-1, with analytical uncertainty as low as 3%. The method presented can be useful to produce calcite with controlled and homogeneous element mass fractions, and is a promising alternative to natural calcite RMs for U-Pb geochronology.

Laser-induced breakdown spectroscopy and related resonance spectroscopy for nuclear fuel cycle management and for decommissioning of "Fukushima Daiichi Nuclear Power Station"

Wakaida, Ikuo; Oba, Hironori; Miyabe, Masabumi; Akaoka, Katsuaki; Oba, Masaki; Tamura, Koji; Saeki, Morihisa

Kogaku, 48(1), p.13 - 20, 2019/01

By Laser Induced Breakdown Spectroscopy and by related resonance spectroscopy, elemental and isotope analysis of Uranium and Plutonium for nuclear fuel materials and in-situ remote analysis under strong radiation condition for melt downed nuclear fuel debris at damaged core in "Fukushima Daiichi Nuclear Power Station", are introduced and performed as one of the application in atomic energy research field.

Effect of defocusing on laser ablation plume observed by laser-induced fluorescence imaging spectroscopy

Oba, Masaki; Miyabe, Masabumi; Akaoka, Katsuaki; Wakaida, Ikuo

Japanese Journal of Applied Physics, 55(2), p.022401_1 - 022401_4, 2016/02

https://doi.org/10.7567/JJAP.55.022401

We used laser-induced fluorescence imaging with a varying beam focal point to observe ablation plumes from metal and oxide samples of gadolinium. The plumes expand vertically when the focal point is far from the sample surface. In contrast, the plume becomes hemispherical when the focal point is on the sample surface. In addition, the internal plume structure and the composition of the ablated atomic and ionic particles also vary significantly. The fluorescence intensity of a plume from a metal sample is greater than that from an oxide sample, which suggests that the number of monatomic species produced in each plume differs. For both the metal and oxide samples, the most intense fluorescence from atomic (ionic) species is observed with the beam focal point at 3-4 mm (2 mm) from the sample surface.

Hydrodynamics driven by ultrashort laser pulse; Simulations and the optical pump - X-ray probe experiment

Inogamov, N. A.*; Zhakhovsky, V. V.*; Hasegawa, Noboru; Nishikino, Masaharu; Yamagiwa, Mitsuru; Ishino, Masahiko; Agranat, M. B.*; Ashitkov, S. I.*; Faenov, A. Y.*; Khokhlov, V. A.*; et al.

Applied Physics B, 119(3), p.413 - 419, 2015/06

https://doi.org/10.1007/s00340-015-6039-7

Diagnostics of pulsed plasma in laser ablation of boron compounds

Oba, Hironori; Saeki, Morihisa; Yokoyama, Atsushi

Proceedings of Plasma Science Symposium 2005/22nd Symposium on Plasma Processing (PSS-2005/SPP-22), p.331 - 332, 2005/01

A plasma produced by a XeCl laser ablation of boron compound was investigated using ion probes and a quadrupole mass spectrometer. Although the ablated neutral boron atoms had a natural abundance ratio, the isotope ratio of singly ionized boron atoms having a greatly different from the natural abundance ratio was observed. The observed isotope ratio of boron ions was different from the natural abundance.

Preparation of TiO nanoparticles by pulsed laser ablation; Ambient pressure dependence of crystallization

Matsubara, Masakazu*; Yamaki, Tetsuya; Ito, Hisayoshi; Abe, Hiroaki*; Asai, Keisuke*

Japanese Journal of Applied Physics, Part 2, 42(5A), p.L479 - L481, 2003/05

Pulsed laser ablation with a KrF excimer laser was used to prepare fine particles of titanium dioxide (TiO). The ablation in an atmosphere of Ar and O (5:5) at total pressures of 1 Torr led to the formation of TiO nanoparticles composed of anatase and rutile structures without any suboxides. The weight fraction of the rutile/anatase crystalline phases was controlled by the pressure of the Ar/O gas. The TiO nanoparticles had a spherical shape and their size, ranging from 10 and 14 nm, also appeared to be dependent on the ambient pressure.

High-quality epitaxial TiO thin films grown on -AlO substrates by pulsed laser deposition

Shinohara, Ryuji*; Yamaki, Tetsuya; Yamamoto, Shunya; Ito, Hisayoshi; Asai, Keisuke*

Journal of Materials Science Letters, 21(12), p.967 - 969, 2002/06

https://doi.org/10.1023/A:1016090110315

no abstracts in English

Removal of metal-oxide layers formed on stainless and carbon steel surfaces by excimer laser irradiation in various atmospheres

Kameo, Yutaka; Nakashima, Mikio; Hirabayashi, Takakuni*

Nuclear Technology, 137(2), p.139 - 146, 2002/02

https://doi.org/10.13182/NT02-A3263

In order to apply laser ablation technique for decontamination of metal wastes contaminated with radioactive nuclides, the effect of irradiation atmospheres on removal of oxide layers on steel surfaces by laser ablation was studied. Based on the assumption that the absorption of laser light follows the Lambert-Beer law, ablation parameters, such as absorption length and threshold fluence for ablation, of sintered FeO and stainless and carbon steels were measured in He, O, Kr or SF atmosphere. The results indicated that SF was the most effective gas of all irradiation atmospheres studied for the exclusive removal of oxide layers formed on stainless and carbon steel samples in high temperature pressurized water. Secondary ion mass spectroscopic measurement and scanning electron microscopic observation confirmed that no oxide layer existed on the steel samples after the exclusive removal with laser irradiation.

Preparation of TiO-anatase film on Si(001) substrate with TiN and SrTiO as buffer layers

Sugiharuto; Yamamoto, Shunya; Sumita, Taishi; Miyashita, Atsumi

Journal of Physics; Condensed Matter, 13(13), p.2875 - 2881, 2001/04

https://doi.org/10.1088/0953-8984/13/13/302

An epitaxial TiO-anatase thin film was grown on the Si(001) substrate with SrTiO/TiN as the buffer layers by pulsed laser deposition technique under an oxygen gas supply. The characterization of the epitaxial TiO-anatase film was performed using the X-ray diffraction method. The crystallographic relationships between the TiO-anatase film and SrTiO/TiN buffer layers were analyzed by the -2 scan and pole figure measurement. The growth direction of the films was determined as / / / and their in-plane relationship // // // . The crystalline quality of TiO-anatase was examined by the rocking curve analysis. The composition of the thin film packaging was characterized by Rutherford backscattering spectrometry (RBS) using 2.0 MeV He beam.