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

Development of a radiation tolerant laser-induced breakdown spectroscopy system using a single crystal micro-chip laser for remote elemental analysis

Tamura, Koji; Nakanishi, Ryuzo; Oba, Hironori; Karino, Takahiro; Shibata, Takuya; Taira, Takunori*; Wakaida, Ikuo

Journal of Nuclear Science and Technology, 61(8), p.1109 - 1116, 2024/08

https://doi.org/10.1080/00223131.2023.2298485

Two-dimensional elemental mapping of simulated fuel debris using laser-induced breakdown spectroscopy

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

Journal of Nuclear Science and Technology, 61(5), p.658 - 670, 2024/05

https://doi.org/10.1080/00223131.2023.2255186

no abstracts in English

Simultaneous analysis of gadolinium and surface imaging using a fiber-coupled acoustic wave-assisted microchip LIBS system

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

Journal of Analytical Atomic Spectrometry, 39(2), p.423 - 432, 2024/02

https://doi.org/10.1039/D3JA00347G

Summary report in FY2022 of subsidy program for "the Project of Decommissioning and Contaminated Water Management (Development of Analysis and Estimation Technology for Characterization of Fuel Debris (Development of Technologies for Enhanced Analysis Accuracy, Thermal behavior Estimation, and Simplified Analysis of Fuel Debris)" started in FY2011

Koyama, Shinichi; Ikeuchi, Hirotomo; Mitsugi, Takeshi; Maeda, Koji; Sasaki, Shinji; Onishi, Takashi; Tsai, T.-H.; Takano, Masahide; Fukaya, Hiroyuki; Nakamura, Satoshi; et al.

Hairo, Osensui, Shorisui Taisaku Jigyo Jimukyoku Homu Peji (Internet), 216 Pages, 2023/11

https://en.dccc-program.jp/wp-content/uploads/20231117_JAEA.pdf

In FY 2021 and 2022, JAEA perfomed the subsidy program for "the Project of Decommissioning and Contaminated Water Management (Development of Analysis and Estimation Technology for Characterization of Fuel Debris (Development of Technologies for Enhanced Analysis Accuracy, Thermal Bahavior Estimation, and Simplified Analysis of Fuel Debris)" started in FY 2021. This presentation material summarized the results of the project, which will be available shortly on the website of Management Office for the Project of Decommissioning, Contaminated Water and Treated Water Management.

Isotope shift and hyperfine structure measurements on triple resonance excitation to the autoionizing Rydberg state of atomic strontium

Iwata, Yoshihiro; Miyabe, Masabumi; Akaoka, Katsuaki; Wakaida, Ikuo

Journal of Quantitative Spectroscopy & Radiative Transfer, 275, p.107882_1 - 107882_9, 2021/11

https://doi.org/10.1016/j.jqsrt.2021.107882

Following the accident at TEPCO's Fukushima Daiichi Nuclear Power Station, an isotope-selective analysis method using laser resonance ionization has been developed for strontium-90. In this study, the isotope shifts and hyperfine structure constants of stable isotopes were measured for two schemes expected to have high isotopic selectivity, and the isotope shifts of strontium-90 were evaluated using the King plot analysis. The measured strontium-90 optical isotopic selectivities ranged from to , which are sufficient for analysis of real samples.

Odd-parity autoionizing levels of uranium observed by two-color two-step photoionization optogalvanic spectroscopy

Miyabe, Masabumi; Satou, Yukihiko; Wakaida, Ikuo; Terabayashi, Ryohei*; Sonnenschein, V.*; Tomita, Hideki*; Zhao, Y.*; Sakamoto, Tetsuo*

Journal of Physics B; Atomic, Molecular and Optical Physics, 54(14), p.145003_1 - 145003_8, 2021/07

https://doi.org/10.1088/1361-6455/abf89f

Two-color two-step photoionization optogalvanic spectroscopy was performed using high-repetition-rate titanium sapphire lasers and a uranium hollow cathode lamp to find the two-step resonance ionization schemes of uranium. Many ionization transitions were observed by exciting uranium atoms in a ground state into five, even parity, excited levels with the first-step laser and by scanning the second-step laser wavelengths. By blocking the first-step laser, single-color, two-photon ionization transitions were also identified. From these results, we have found more than 50 odd-parity autoionizing levels of uranium in the energy, ranging from the ionization potential (49958.4 cm) to 51150 cm. The determined energy levels are within 1 cm of previously reported values.

Highly sensitive detection of sodium in aqueous solutions using laser-induced breakdown spectroscopy with liquid sheet jets

Nakanishi, Ryuzo; Oba, Hironori; Saeki, Morihisa; Wakaida, Ikuo; Tanabe, Rie*; Ito, Yoshiro*

Optics Express (Internet), 29(4), p.5205 - 5212, 2021/02

https://doi.org/10.1364/OE.415308

Laser-induced breakdown spectroscopy (LIBS) combined with liquid jets was applied to the detection of trace sodium (Na) in aqueous solutions. The sensitivities of two types of liquid jets were compared: a liquid cylindrical jet with a diameter of 500 m and a liquid sheet jet with a thickness of 20 m. Compared with the cylindrical jet, the liquid sheet jet effectively reduced the splash from the laser-irradiated surface and produced long-lived luminous plasma. The limit of detection (LOD) of Na was determined to be 0.57 g/L for the sheet jet and 10.5 g/L for the cylindrical jet. The LOD obtained for the sheet jet was comparable to those obtained for commercially available inductively coupled plasma emission spectrometers.

Development of one-dimensional optical fiber type radiation distribution sensing method based on wavelength spectrum unfolding

Terasaka, Yuta; Watanabe, Kenichi*; Uritani, Akira*; Yamazaki, Atsushi*; Sato, Yuki; Torii, Tatsuo; Wakaida, Ikuo

Proceedings of International Youth Nuclear Congress 2020 (IYNC 2020) (Internet), 4 Pages, 2020/05

Development of laser ablation absorption spectroscopy for nuclear fuel materials; Plume expansion behavior for refractory metals observed by laser-induced fluorescence imaging spectroscopy

Miyabe, Masabumi; Oba, Masaki; Akaoka, Katsuaki; Kato, Masaaki*; Hasegawa, Shuichi*; Wakaida, Ikuo

Applied Physics A, 126(3), p.213_1 - 213_10, 2020/03

AA2019-0700.pdf:2.82MB

https://doi.org/10.1007/s00339-020-3368-0

The dynamic behavior of an ablation plume in low pressure rare gas ambient was investigated with laser-induced fluorescence imaging spectroscopy for three refractory metals, i.e. titanium, zirconium and hafnium. A comparison of the plume expansion behaviors for the species of these elements revealed an atomic weight effect on the plume structure formation. A hemispherical thin layer and cavity structure reported previously for gadolinium were observed also for these elements. It was found that the plume size increases as well as the layer thickness decreases with increasing atomic weight. For ground state atoms of Ti, substantial amount of atoms were observed even at the center of the plume. Also, the persistence of the Ti atomic plume was as long as 300 s, which was significantly longer than the other species studied. Furthermore, the mass-dependent elemental separation was observed in the ablation plume produced from a multielement sample. These results suggest that the observed plume structure arises from the ion-electron recombination process and the recoil of the ablated species during the multiple collisions with gas atoms.