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Journal Articles

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

 Times Cited Count:0 Percentile:0(Optics)

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 $$mu$$m and a liquid sheet jet with a thickness of 20 $$mu$$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 $$mu$$g/L for the sheet jet and 10.5 $$mu$$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.

Journal Articles

Development of microwave-assisted, laser-induced breakdown spectroscopy without a microwave cavity or waveguide

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

Japanese Journal of Applied Physics, 59(6), p.062001_1 - 062001_6, 2020/06

 Times Cited Count:0 Percentile:0(Physics, Applied)

Using a semiconductor microwave source and a coaxial cable for microwave transmission, a compact microwave-assisted, laser-induced breakdown spectroscopy system without a microwave cavity or waveguide was developed. Several types of electrode heads were tested, so that the emission intensity was 50 times larger than without microwave. The limit of the enhancement effect was also found.

Journal Articles

A New measuring method for elemental ratio and Vickers hardness of metal-oxide-boride materials based on Laser-Induced Breakdown Spectroscopy (LIBS)

Abe, Yuta; Otaka, Masahiko; Okazaki, Kodai*; Kawakami, Tomohiko*; Nakagiri, Toshio

Proceedings of 2019 International Congress on Advances in Nuclear Power Plants (ICAPP 2019) (Internet), 7 Pages, 2019/05

Since the hardness of fuel debris containing boride from B$$_{4}$$C pellet in control rod is estimated to be two times higher as that of oxide, such as UO$$_{2}$$ and ZrO$$_{2}$$, it is necessary to select the efficient and appropriate operation for removal of fuel debris formed in the severe accident of nuclear power plants. We focused on the characteristics of LIBS, an innovative rapid chemical in-situ analysis technology that enables simultaneous detection of B, O, and other metal elements in fuel debris. Simulated solidified melt specimens were obtained in the plasma heating tests (CMMR-0/-2, performed by JAEA) of simulated fuel assembly (ZrO$$_{2}$$ is used to simulated UO$$_{2}$$ pellet, other materials such as stainless steel, B$$_{4}$$C are same as fuel assembly). The LIBS signals of (B/O)/Zr ratio showed good linear relationship with Vickers hardness. This technique can be also applied as in-situ assessment tool for elemental composition and Vickers hardness of metal-oxide-boride materials.

Journal Articles

Development of remote sensing technique using radiation resistant optical fibers under high-radiation environment

Ito, Chikara; Naito, Hiroyuki; Ishikawa, Takashi; Ito, Keisuke; Wakaida, Ikuo

JPS Conference Proceedings (Internet), 24, p.011038_1 - 011038_6, 2019/01

A high-radiation resistant optical fiber has been developed in order to investigate the interiors of the reactor pressure vessels and the primary containment vessels at the Fukushima Daiichi Nuclear Power Station. The tentative dose rate in the reactor pressure vessels is assumed to be up to 1 kGy/h. We developed a radiation resistant optical fiber consisting of a 1000 ppm hydroxyl doped pure silica core and 4 % fluorine doped pure silica cladding. We attempted to apply the optical fiber to remote imaging technique by means of fiberscope. The number of core image fibers was increased from 2000 to 22000 for practical use. The transmissive rate of infrared images was not affected after irradiation of 1 MGy. No change in the spatial resolution of the view scope by means of image fiber was noted between pre- and post-irradiation. We confirmed the applicability of the probing system, which consists of a view scope using radiation-resistant optical fibers.

Journal Articles

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.

Journal Articles

Improvement in quantitative performance of underwater laser-induced breakdown spectroscopy based on the understanding of laser ablation phenomena

Matsumoto, Ayumu

Reza Kako Gakkai-Shi, 23(3), p.222 - 231, 2016/10

no abstracts in English

JAEA Reports

Measurement of uranium spectrum using laser induced breakdown spectroscopy; High resolution spectroscopy (470-670 nm)

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

JAEA-Research 2016-005, 40 Pages, 2016/05

JAEA-Research-2016-005.pdf:1.82MB

Laser Induced Breakdown Spectroscopy (LIBS) method is an attractive technique because real-time, in-situ and remote elemental analysis is possible without any sample preparation. The LIBS technique can be applied for analyzing elemental composition of samples under severe environments such as the estimation of impurities in the next generation nuclear fuel material containing minor actinide (MA) and the detection of fuel debris in the post-accident nuclear core reactor of TEPCO Fukushima Daiichi Nuclear Power Plant. For applying LIBS to the analysis of nuclear fuel materials, it is indispensable to identify the emission spectrum and its intensity on impurities intermingled within complex emission spectra of matrix elements such as uranium (U) and plutonium (Pu). In the present study, an echelle spectrometer with a resolving power of 50,000 was employed to identify spectra of natural uranium of wavelength ranging from 470 to 670 nm. The 173 atomic spectra and 119 ionic spectra can be identified. We have confirmed that the measured wavelength and oscillator strength of spectra are consistent with published values.

JAEA Reports

Measurement of uranium spectrum using laser induced breakdown spectroscopy; High resolution spectroscopy (350-470 nm)

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

JAEA-Research 2015-012, 48 Pages, 2015/10

JAEA-Research-2015-012.pdf:2.22MB

It is important to analyze the next generation nuclear fuel material containing minor actinide (MA) and the fuel debris generated at the accident of Fukushima Daiichi Nuclear Power Station. Therefore, the remote analysis for nuclear fuel materials using Laser Induced Breakdown Spectroscopy (LIBS) is studied. For applying Laser Induced Breakdown Spectroscopy (LIBS) to the analysis of nuclear fuel materials, it is very important to identify the emission spectrum and its intensity on impurities intermingled within complex emission spectra of matrix elements such as uranium (U) and plutonium (Pu). Then, the high resolution spectra of natural uranium of wavelength region of 350-470 nm are measured using LIBS, 247 atomic spectra and 294 single ion spectra were identified. We have confirmed that the measured wavelength and oscillator strength of spectra are consistent with published values.

Oral presentation

Emission characteristics of microwave-assisted laser plasma induced in air, Ar, and He gases

Khumaeni, A.; Miyabe, Masabumi; Akaoka, Katsuaki; Wakaida, Ikuo

no journal, , 

Oral presentation

Development of laser remote spectroscopy for onsite and in-situ analysis of nuclear fuel debris under severe environment

Wakaida, Ikuo; Akaoka, Katsuaki; Miyabe, Masabumi; Oba, Hironori; Saeki, Morihisa; Ito, Chikara; Oba, Masaki; Kato, Masaaki

no journal, , 

In the decommissioning of "Fukushima Daiichi Atomic Power Plant", it will be difficult work by the extremely high radioactivity from fission products and meltdown nuclear fuel debris. Technical innovations and some breakthrough will be indispensable for a safety accomplishment of this work. For the basic R&D on the decommissioning, Japan Atomic Energy Agency has opened the new research center "Collaborative Laboratories for Advanced Decommissioning Science". The development of onsite and in-situ analysis of fuel debris is one of the most important for the planning and working of the decommissioning. Quick, easy, non-contact, no-preparation, direct and remote analysis technique by Laser Induced Breakdown Spectroscopy (LIBS) based on radiation resistant optical fiber will be now under developing. Pulsed Nd:YAG laser will be propagated though an optical fiber and focused on the sample. Plasma emission produced by the laser on the surface of the sample is collected by the same focusing lens, propagated through the same optical fiber and put into the spectrometer. Elemental identification and the composition are evaluated by specific atomic emission line and its intensity. Under strong irradiation condition; dose rate of 10 kGy/h and after total dose of 2 MGy, radiation resistant optical fiber had good transmission, no damage by laser light propagation, and had good performance for plasma emission spectroscopy. In addition, we have successfully observed and identified the specific spectra of Zr and U from the simulated sample of molten debris made by sintered oxide of Zr and U which is the raw materials of the fuel assembly. Quantitative analysis of the composition ratio of Zr/U has been also evaluated from the intensity ratio of specific emission lines.

Oral presentation

Challenging in laser based spectroscopy for nuclear engineering

Wakaida, Ikuo; Oba, Hironori; Akaoka, Katsuaki; Miyabe, Masabumi; Oba, Masaki; Ito, Chikara; Saeki, Morihisa; Kato, Masaaki

no journal, , 

In nuclear engineering, especially for the decommissioning of severe accident atomic power plant, development of quick, easy, non-contact, no-preparation, direct, remote, onsite and in-situ analysis of nuclear fuel materials which has very complex and large amount of optical emission lines will be indispensable. In these R&D, it may be important how we realize high sensitivity and high resolution spectroscopy and perform the identification of the specific element among a large number of emission spectra. Various kind of technique, such as Double-pulse LIBS and Microwave assisted LIBS for multiply the emission intensity, high resolution LIBS by ultra-high resolution spectrometer or Laser Ablation Resonance Absorption Spectroscopy for isotope analysis, Ultra-thin Liquid flow LIBS for liquid phase application and LIBS based on radiation resistant optical fiber for onsite/in-situ monitoring of melt downed nuclear fuel debris, will have been under investigation. Japan Atomic Energy Agency has opened the new research center "Collaborative Laboratories for Advanced Decommissioning Science", and laser based spectroscopy will be restarted as one of the basic projects.

Oral presentation

Development of laser remote analysis for nuclear fuel materials under severe environments

Wakaida, Ikuo; Akaoka, Katsuaki; Miyabe, Masabumi; Oba, Hironori; Saeki, Morihisa; Ito, Chikara; Oba, Masaki; Kato, Masaaki

no journal, , 

For the decommissioning of "Fukushima Daiichi Nuclear Power Plant", development of onsite and in-situ remote diagnostic/analysis techniques under high radioactive environments will be strongly required. For the basic R&D on the decommissioning, Japan Atomic Energy Agency has opened the new research center "Collaborative Laboratories for Advanced Decommissioning Science". The concept of probing by light and diagnostic by light will be one of the powerful choices to accomplish these requirements. So, we are now developing the remote diagnostic technique for onsite, in-situ monitoring of nuclear debris. Optical Fiber based LIBS probe made by radiation resistant optical fiber was constructed, and we have successfully observed some specific spectra from the simulated sample of molten debris made by sintered oxide of Zr and U under the severe environment such as radioactive condition of 10 kGy/h and after total dose of 2 MGy.

Oral presentation

Laser remote analysis for MOX fuel and its application for rapid and in-situ analysis in decommissioning of "Fukushima Daiichi" Nuclear Power Station

Wakaida, Ikuo; Akaoka, Katsuaki; Miyabe, Masabumi; Oba, Hironori; Saeki, Morihisa; Oba, Masaki; Ito, Chikara; Kato, Masaaki

no journal, , 

Laser Induced Breakdown Spectroscopy (LIBS) for elemental analysis and Laser Ablation Resonance Absorption Spectroscopy (LARAS) for isotope analysis have been developed as an analytical technique for Low-decontaminated MOX fuel with fissionable Miner Actinide elements (MA) and as for one of the diagnostic tool of nuclear fuel debris and polluted materials in the decommissioning of the severe accident nuclear power station. Specialized glove box with auto and remote arraignment system for LIBS and LARAS was constructed, and the detection limit of Pu in MOX to be several 1000 ppm and some hyper fine structures of $$^{239}$$Pu were demonstrated. For the diagnostic tool in the decommissioning of damaged core, optical fiber based portable LIBS probe made by radiation resistant optical fiber is under construction, and just now, some specific spectra from the simulated sample of molten debris made by sintered oxide of Zr and U is successfully observed under water condition or strong radiation field.

Oral presentation

Development of onsite/in-situ, rapid and radio-resistance remote analysis by optical fiber based laser induced breakdown spectroscopy

Wakaida, Ikuo; Oba, Hironori; Akaoka, Katsuaki; Miyabe, Masabumi; Saeki, Morihisa; Oba, Masaki; Ito, Chikara; Kato, Masaaki

no journal, , 

Oral presentation

Challenging in LIBS technology for decommissioning of damaged reactor "Fukushima Daiichi Nuclear Power Station"

Wakaida, Ikuo; Oba, Hironori; Oba, Masaki; Matsumoto, Ayumu; Ruas, A.; Toshimitsu, Masaaki; Akaoka, Katsuaki; Miyabe, Masabumi

no journal, , 

For the decommissioning of "Fukushima Daiichi Nuclear Power Station", Optical Fiber based LIBS probe is constructed, and under water condition, we have successfully observed some specific spectra from the simulated sample of molten debris made by sintered oxide of Zr and U. For the use of more longer optical fiber, long-pulse laser with the pulse duration about 100 ns will be introduced to compensate the delivery power loss and/or to enhance the emission signal to be about several times by the time integration of emission signal. As for the signal enhancement technique, microwave assisted LIBS technique coupled with simple antenna for the combination use with fiber LIBS will be under developing, and about ten times enhancement was observed under the atmosphere condition. For the application to the liquid phase sample, especially for the analysis of the polluted cooling water, the thin-sheet liquid jets will be also introduced as the convenience and high sensitive monitoring for dissolved elements of nuclear fuel debris.

Oral presentation

Development of quick and remote analysis for severe accident reactor, 2-1-1; Characteristics of fiber-optic probe LIBS using a long duration ns pulse

Oba, Hironori; Matsumoto, Ayumu; Toshimitsu, Masaaki; Akaoka, Katsuaki; Wakaida, Ikuo

no journal, , 

no abstracts in English

Oral presentation

Expansion dynamics of laser-produced plasma in long-pulse fiber-optic LIBS of metal target in air

Matsumoto, Ayumu; Oba, Hironori; Akaoka, Katsuaki; Wakaida, Ikuo

no journal, , 

Oral presentation

Consideration of material analysis using simulated fuel assembly heating test, 2; Study of the evaluation method by LIBS

Kawakami, Tomohiko*; Abe, Yuta; Spaziani, F.*; Nakano, Natsuko*; Nakagiri, Toshio

no journal, , 

no abstracts in English

Oral presentation

Evaluation method using material analysis of specimen in plasma heating experiment, 2; Application possibility of materials analysis and LIBS using the plasma basics heating experiment

Kawakami, Tomohiko*; Abe, Yuta; Spaziani, F.*; Nakano, Natsuko*; Nakagiri, Toshio

no journal, , 

no abstracts in English

Oral presentation

Establishment of evaluation method using material analysis of simulated fuel assembly heating test, 3; Evaluation method of oxygen and boron using LIBS

Okazaki, Kodai*; Abe, Yuta; Spaziani, F.*; Nakano, Natsuko*; Kawakami, Tomohiko*

no journal, , 

no abstracts in English

25 (Records 1-20 displayed on this page)