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Journal Articles

Cutting-edge studies on nuclear data for continuous and emerging need, 4; Nuclear chart; Magnificent landscape of nuclei

Koura, Hiroyuki; Minato, Futoshi; Iimura, Hideki

Nippon Genshiryoku Gakkai-Shi, 60(1), p.35 - 40, 2018/01

no abstracts in English

Journal Articles

The Laser and optical system for the RIBF-PALIS experiment

Sonoda, Tetsu*; Iimura, Hideki; Reponen, M.*; Wada, Michiharu*; Katayama, Ichiro*; Sonnenschein, V.*; Takamatsu, Takahide*; Tomita, Hideki*; Kojima, Takao*

Nuclear Instruments and Methods in Physics Research A, 877, p.118 - 123, 2018/01

 Times Cited Count:2 Percentile:16.17(Instruments & Instrumentation)

In order to produce low-energy RI beams at RIKEN RIBF, a laser ion source, PALIS, is under construction. This ion source is based on resonance ionization of RI atoms captured in Ar gas. Because the ion source is located 70m away from lasers, we have developed an optical system for laser beam transport. This system can be controlled remotely when the ion source is not accessible because of high radiation level. The position of laser beam after transport is reasonably stable, and the transport efficiency is about 50%.

Journal Articles

Laser ablation absorption spectroscopy for isotopic analysis of plutonium; Spectroscopic properties and analytical performance

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

Spectrochimica Acta, Part B, 134, p.42 - 51, 2017/08

 Times Cited Count:5 Percentile:22.02(Spectroscopy)

Spectroscopic properties of atomic species of plutonium were investigated by combining laser ablation and resonance absorption techniques for the analysis of a plutonium oxide sample. For 17 transitions of Pu atoms and ions, the absorbance, isotope shift, and hyperfine splitting were determined via Voigt profile fitting of the recorded absorption spectra. Three transitions were selected as candidates for analytical use. Using these transitions, we investigated the analytical performance that was attainable and determined a correlation coefficient R2 between the absorbance and plutonium concentration of 0.9999, a limit of detection of 30-130 ppm, and a relative standard deviation of approximately 6% for an abundance of $$^{240}$$Pu of 2.4%. These results demonstrate that laser ablation absorption spectroscopy is applicable to the remote isotopic analysis of highly radioactive nuclear fuels and waste materials containing multiple actinide elements.

Journal Articles

Evaluation of nuclear data for application of isotopes

Iimura, Hideki

Isotope News, (746), p.39 - 42, 2016/08

Various nuclear data tables are available for radioisotopes users. In this article properties of these tables are compared. Also, it is explained how the recommended values in these tables are determined from f large amount of experimental data.

Journal Articles

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

 Times Cited Count:14 Percentile:14.06(Spectroscopy)

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$$^{2}$$) 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.

Journal Articles

Charge radii in macroscopic-microscopic mass models

Iimura, Hideki; M$"o$ller, P.*; Ichikawa, Takatoshi*; Sagawa, Hiroyuki*; Iwamoto, Akira*

JPS Conference Proceedings (Internet), 6, p.030102_1 - 030102_4, 2015/06

no abstracts in English

Journal Articles

Development of NRD, 3; Study of a new moderator for compact 14-MeV pulsed neutron sources

Takamine, Jun; Koizumi, Mitsuo; Kureta, Masatoshi; Harada, Hideo; Kitatani, Fumito; Tsuchiya, Harufumi; Seya, Michio; Iimura, Hideki

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-35-Kai Nenji Taikai Rombunshu (Internet), 10 Pages, 2015/01

A prototype device of neutron resonance densitometry (NRD) with a D-T neutron generator was planned for basic studies of actual NRD devices. D-T neutron generators had features of simple handling and compact compared with photo neutron sources driven by electron beam accelerators. But those of D-T neutron are higher energy and lower intensity than those of photo neutron. We designed a new type moderator to compensate for the shortcomings. In the new type moderator, the D-T neutron generator is surrounded by Lead, and Polyethylene is arranged in the beam direction on the surface of Lead. As the result of analysis using Monte Carlo code MCNP5, it was found that the new moderator achieved about four times larger production of low energy neutrons than polyethylene moderator without distorting the energy resolution below at least 100 eV. The lead part in the new moderator are changed to other heavy metals, which is Uranium, and Tungsten. Analysis like the above were performed. We report these results.

Journal Articles

Development of NRD, 2; Investigation on systematic effects due to sample thickness for areal density derived from NRTA

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Kimura, Atsushi; Becker, B.*; Kopecky, S.*; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-35-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2015/01

We are developing neutron resonance densitometry that combines neutron resonance transmission analysis (NRTA) and neutron resonance capture analysis. The aim is to establish a non-destructive technique that can quantify nuclear materials in particle-like debris of melted fuel resulting from severe nuclear accidents like the one at the Fukushima Daiichi Nuclear Power Plant. Systematic effects due to sample thickness and mixed sample for the areal density measurement by NRTA were investigated at a neutron time-of-facility GELINA, IRMM. The experiments were conducted utilizing natural Cu metal discs with different thickness and a B$$_{4}$$C disc. Areal densities were derived with a resonance shape analysis code REFIT. It was found that they were inconsistent with those calculated by mass and area, when using recommended resonance parameters. Hence, a neutron width of resonance parameters was newly evaluated with the NRTA data and we found that derived areal density agreed within 2% with the expected ones. We also discuss the impacts of mixed sample for the areal density derived from NRTA measurement.

Journal Articles

Development of NRD, 1; Developments of a LaBr$$_{3}$$ scintillation detector system for neutron resonance densitometry

Koizumi, Mitsuo; Tsuchiya, Harufumi; Kitatani, Fumito; Harada, Hideo; Takamine, Jun; Kureta, Masatoshi; Seya, Michio; Kimura, Atsushi; Iimura, Hideki; Becker, B.*; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-35-Kai Nenji Taikai Rombunshu (Internet), 8 Pages, 2015/01

We have proposed neutron resonance densitometry (NRD) as a method to quantify special nuclear materials in particle-like debris of melted fuel. NRD is a combination of neutron resonance transmission analysis (NRTA), and neutron resonance capture analysis (NRCA) (and prompt $$gamma$$-ray analysis (PGA)). NRCA/PGA is used to identify contaminant elements, which is difficult to be detected by NRTA. To observe $$gamma$$ rays emitted in neutron capture reaction, a spectrometer consisting of LaBr$$_3$$ scintillation detectors has been constructed. A newly installed data acquisition system enables us to measure 500 k event/s for each 8-channel inputs. In this presentation, the research and development of NRD is introduced and the status of the development of the spectrometer system is given as well.

Journal Articles

Recent progress in research and development in neutron resonance densitometry (NRD) for quantification of nuclear materials in particle-like debris

Koizumi, Mitsuo; Kitatani, Fumito; Tsuchiya, Harufumi; Harada, Hideo; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Seya, Michio; Becker, B.*; Kopecky, S.*; et al.

Nuclear Back-end and Transmutation Technology for Waste Disposal, p.13 - 20, 2015/00

Neutron Resonance Densitometry (NRD) has been proposed for quantification of nuclear materials in melted fuel. NRD is a combined TOF technique of Neutron Resonance Transmission Analysis (NRTA) and Neutron Resonance Capture Analysis (NRCA) or Prompt Gamma ray Analysis (PGA). To establish the method, development of detectors is in progress. Experiments were carried out at a TOF facility, GELINA, under the collaboration with EC-JRC-IRMM. The progress of the project is reported.

Journal Articles

Impact of systematic effects on results of neutron resonance transmission analysis

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Kimura, Atsushi; Becker, B.*; Kopecky, S.*; et al.

Nuclear Instruments and Methods in Physics Research A, 767, p.364 - 371, 2014/12

 Times Cited Count:6 Percentile:36.56(Instruments & Instrumentation)

The impact of systematic effects on the areal density derived from a neutron resonance transmission analysis (NRTA) is investigated by measurements at the time-of-flight facility GELINA. The experiments were carried out at a 25 m station using metallic natural Cu discs with different thicknesses. To derive the areal density from a fit to the experimental transmission, the resonance shape analysis code REFIT was used. Large bias effects were observed using recommended resonance parameters. Therefore, neutron resonance parameters, in particular resonance energies and neutron widths, were derived from the transmission data obtained with a 0.25 mm thick Cu metallic sample. These parameters were used to study the impact of the resonance strength and sample thickness, on the accuracy of the areal density derived by NRTA.

Journal Articles

Thickness and mixed sample effects on areal density measurement with NRTA for particle like debris of melted fuel

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Kimura, Atsushi; Becker, B.*; Kopecky, S.*; et al.

Proceedings of INMM 55th Annual Meeting (Internet), 6 Pages, 2014/07

Journal Articles

Developments of a LaBr$$_3$$ scintillation detector system for neutron resonance densitometry (NRD)

Koizumi, Mitsuo; Tsuchiya, Harufumi; Kitatani, Fumito; Harada, Hideo; Takamine, Jun; Kureta, Masatoshi; Seya, Michio; Kimura, Atsushi; Iimura, Hideki; Becker, B.*; et al.

Proceedings of INMM 55th Annual Meeting (Internet), 7 Pages, 2014/07

Journal Articles

Development of neutron resonance densitometry

Harada, Hideo; Schillebeeckx, P.*; Tsuchiya, Harufumi; Kitatani, Fumito; Koizumi, Mitsuo; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Kimura, Atsushi; Seya, Michio; et al.

Proceedings of INMM 55th Annual Meeting (Internet), 8 Pages, 2014/07

Journal Articles

Neutron resonance densitometry for particle-like debris of melted fuel

Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Takamine, Jun; Kureta, Masatoshi; Tsuchiya, Harufumi; Iimura, Hideki; Seya, Michio; Becker, B.*; Kopecky, S.*; et al.

Nuclear Data Sheets, 118, p.502 - 504, 2014/04

 Times Cited Count:3 Percentile:63.98(Physics, Nuclear)

Journal Articles

A Monte Carlo simulation to study a design of a $$gamma$$-ray detector for neutron resonance densitometry

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki

Nuclear Instruments and Methods in Physics Research A, 729, p.338 - 345, 2013/11

 Times Cited Count:4 Percentile:53.77(Instruments & Instrumentation)

Journal Articles

GEANT4 simulation study of a $$gamma$$-ray detector for neutron resonance densitometry

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki

JAEA-Conf 2013-002, p.119 - 124, 2013/10

We have proposed a system to quantify nuclear materials in melted fuels in the reactors of the Fukushima Daiichi Nuclear Power Plant. The system utilizes non destructive techniques combining neutron resonance transmission analysis (NRTA) and neutron resonance capture analysis (NRCA). This is because the melted fuels are though to involve not only nuclear materials but also impurities such as ${it e.g.}$ Hydrogen, Boron, Zirconium, and Iron. Using the combined system, we would be able to identify those non-nuclear materials by NRCA and accurately measure nuclear materials by NRTA. A $$gamma$$-ray detector for NRCA consists of a cylindrical LaBr$$_{3}$$ scintillation counter and a well-type LaBr$$_{3}$$ one. The well-type counter is served as a back-catcher detector and individual signals recorded in the two counters are summed to aim at reducing the Compton edge originating from $$^{137}$$Cs that generate intense background for the NRCA measurement. According to GEANT4 simulation, It can be seen that the Compton edge is suppressed by the well-type counter. For example, thanks to the well-type counter, a count at an energy of $$^{10}$$B-derived $$gamma$$-rays (478 keV) is reduced by $$sim$$0.15. In this presentation, we show performance of the $$gamma$$-ray detector using GEANT4 simulation. In addition, comparing results based on evaluated cross sections of ENDF-VII.0 with those based on JENDL-4.0, we discuss differences in performance expected for the $$gamma$$-ray detector.

Journal Articles

Investigation on sample thickness effect on nuclear material quantification with NRTA for particle-like debris of melted fuel

Tsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Becker, B.*; Kopecky, S.*; Kauwenberghs, K.*; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 8 Pages, 2013/10

We have no established methods to quantify the amount of nuclear materials in particle-like debris of melted fuel derived from a nuclear accident such as the one occurred at the Fukushima Daiichi Nuclear Power Plant. For this reason, neutron resonance densitometry, combining neutron resonance transmission analysis and neutron resonance capture analysis, is under development. It is expected that such debris have a wide variety of size, shape, and concentration of impurities. Experiments with the Neutron Resonance Transmisson Analysis (NRTA) using three Cu metal disks with different thickness of 0.125 mm, 0.25 mm, and 0.7 mm were made between November 2012 and February 2013 at the Geel Electron LINear Accelerator (GELINA) to investigate sample thickness effect on the transmission analysis. We experimentally derived the areal density for the individual Cu samples with the resonance shape analysis code REFIT, and then compared them with the declared areal density. It was found that the REFIT-evaluated areal density was consistent with declared ones for each sample.

Journal Articles

Recent progress in research and development on the neutron resonance densitometry for particle-like debris of melted fuel

Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Seya, Michio; Becker, B.*; Kopecky, S.*; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 6 Pages, 2013/10

Neutron resonance densitometry (NRD) has been proposed to quantify nuclear materials in particle-like debris of melted fuel formed in severe accidents of nuclear reactors such as Fukushima Daiichi Nuclear Power Plants. NRD is a method combining NRTA (neutron resonance transmission analysis) and NRCA (neutron resonance capture analysis). It relies on neutron TOF (time of flight) technique using a pulsed white neutron source. The use of a special $$gamma$$-ray spectrometer for NRCA and an evaluation of the achievable accuracy are discussed. The discussion is based on results of Monte Carlo simulations combined experimental data from measurements carried out at GELINA. In this contribution, progress made in the development of NRD for the characterization of nuclear materials mixed with highly radioactive nuclides is presented, together with the basic concept and principles.

Journal Articles

Development of basic NDA technologies of nuclear material accountancy of debris of melted fuel formed in severe accidents

Seya, Michio; Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Iimura, Hideki; Kureta, Masatoshi; Takamine, Jun; Hajima, Ryoichi; Hayakawa, Takehito; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nippon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 10 Pages, 2013/10

The forming of MF in severe accidents of nuclear reactors such as Units 1 - 3 of Fukushima-Daiichi NPP (Nuclear Power Plant) inevitably change the category of the nuclear reactor from "item facility" to "bulk-handling facility". At removal of the MF it is necessary to break chunks of MF into relatively small blocks by using some tools, resulting in debris that consists of cut or small rock-like debris and particle (or grain)-like debris in bulk form. This paper presents a categorization of debris of MF and two possible non-destructive assay (NDA) technologies for precise measurement which could be applied to the NM accountancy of MF debris. One of them is Neutron Resonance Densitometry (NRD) for particle-like (or grain-like) debris, and another is NRF (Nuclear Resonance Fluorescence) NDA using LCS (Laser Compton Scattered) $$gamma$$-rays (mono-energetic $$gamma$$-rays) for cut or small rock-like debris. The paper also describes about the recent development of these two technologies.

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