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Journal Articles

Quick measurement of continuous absorption spectrum in ion beam pulse radiolysis; Application of optical multi-channel detector into transient species observation

Iwamatsu, Kazuhiro*; Muroya, Yusa*; Yamashita, Shinichi*; Kimura, Atsushi; Taguchi, Mitsumasa; Katsumura, Yosuke*

Radiation Physics and Chemistry, 119, p.213 - 217, 2016/02

 Times Cited Count:1 Percentile:14.27(Chemistry, Physical)

A quick measurement system of a continuous absorption spectrum covering a wide range from 200 to 950 nm was constructed by employing an optical multi-channel detector. Ion beam pulse radiolysis with 12.5 MeV/u He, 18.3 MeV/u C and 17.5 MeV/u Ne ions were performed with the measurement system. Transient absorption spectrum of (SCN)$$_{2}$$$$^{-}$$ was clearly observed in KSCN aqueous solutions within a few minutes in spite of their very small absorbance, demonstrating high sensitivity of 0.001-0.003 in absorbance in the range from 260 to 660 nm as well as short measurement time of a few minutes. Two different absorption peaks attributed to Br$$_{2}$$$$^{-}$$ and Br$$_{3}$$$$^{-}$$ were observed simultaneously in NaBr aqueous solutions, showing powerfulness of the measurement system in overviewing chemical kinetics under ion beam irradiation especially in not well investigated chemical systems.

Journal Articles

Influence of linear energy transfer on the scintillation decay behavior in a lithium glass scintillator

Koshimizu, Masanori*; Iwamatsu, Kazuhiro*; Taguchi, Mitsumasa; Kurashima, Satoshi; Kimura, Atsushi; Yanagida, Takayuki*; Fujimoto, Yutaka*; Watanabe, Kenichi*; Asai, Keisuke*

Journal of Luminescence, 169(Part B), p.678 - 681, 2016/01

We analyzed the effects of linear energy transfer (LET) on the scintillation properties of a Li glass scintillator, GS20. The scintillation time profiles were measured by using pulsed ion beams having different LETs. The rise in the scintillation time profiles was faster for higher LET, whereas the decay part was not significantly different for largely different LETs. The LET effects in the rise was ascribed to the effects of excited states interaction during the energy transfer process from the host glass to the luminescent centers, Ce$$^{3+}$$ ions. Supposing that the light yield decreases with LET, the fast rise at high LET was explained in terms of the competition between the energy transfer and the quenching due to the excited states interaction.

Journal Articles

Linear energy transfer effects on time profiles of scintillation of Ce-doped LiCaAlF$$_{6}$$ crystals

Yanagida, Takayuki*; Koshimizu, Masanori*; Kurashima, Satoshi; Iwamatsu, Kazuhiro*; Kimura, Atsushi; Taguchi, Mitsumasa; Fujimoto, Yutaka*; Asai, Keisuke*

Nuclear Instruments and Methods in Physics Research B, 365(Part B), p.529 - 532, 2015/12

 Times Cited Count:9 Percentile:69.75(Instruments & Instrumentation)

We measured temporal profiles of scintillation of Ce-doped LiCaAlF$$_{6}$$ scintillator crystals at different linear energy transfers (LETs). Based on the comparison of the high-LET temporal profiles with those at low LET, we found that a fast component was observed only at low LET. The disappearance of the fast component at high LET is tentatively ascribed to quenching of excited states at defects owing to the interaction between excited states via Auger process. In addition, the rise and the initial decay behavior was dependent on the LET. This LET-dependent behavior is explained by a seeming acceleration process and a slowing down process in energy transfer at high LET. The LET-dependent temporal profiles provide a basis of discrimination technique of $$gamma$$-ray and neutron detection events using these scintillators based on the nuclear reaction, $$^{6}$$Li(n,$$alpha$$)t.

Journal Articles

Sequential radiation chemical reactions in aqueous bromide solutions; Pulse radiolysis experiment and spur model simulation

Yamashita, Shinichi*; Iwamatsu, Kazuhiro; Maehashi, Yuki*; Taguchi, Mitsumasa; Hata, Kuniki; Muroya, Yusa*; Katsumura, Yosuke*

RSC Advances (Internet), 5(33), p.25877 - 25886, 2015/02

 Times Cited Count:11 Percentile:42.31(Chemistry, Multidisciplinary)

Pulse radiolysis experiments were carried out to observe transient absorptions of reaction intermediates produced in N$$_{2}$$O$$^{-}$$ and Ar-saturated aqueous solutions containing 0.9-900 mM NaBr. The most important species among the reaction intermediates are BrOH $$^{cdot -}$$ and Br$$_{2}$$ $$^{cdot -}$$, which commonly have absorption peaks around 360 nm. The experimental results were compared with the results of simulation based on a spur diffusion model. Each of several complicated sequential radiation-induced chemical reactions was carefully considered, optimizing its rate constant within a range of reported values. All the experimental results were able to be universally reproduced by the simulation, assuming a reaction not yet reported, 2BrOH$$^{cdot -}$$ $$rightarrow$$ Br$$_{2}$$ + 2OH$$^{-}$$, with a rate constant of 3.8 $$times$$ 10$$^{9}$$ M$$^{-1}$$ s$$^{-1}$$, which is significant only within 10 micro-s for rather high bromide concentrations ($$>$$ 10 mM). Primary $$G$$ values, which are yields after sufficient diffusion from the spur to the perimeter region during 100 ns, of major water decomposition products, as well as of the reaction intermediates, were calculated for N$$_{2}$$O$$^{-}$$ and Ar-saturated conditions as a function of NaBr concentration.

Journal Articles

System for measuring temporal profiles of scintillation at high and different linear energy transfers by using pulsed ion beams

Koshimizu, Masanori*; Kurashima, Satoshi; Taguchi, Mitsumasa; Iwamatsu, Kazuhiro; Kimura, Atsushi; Asai, Keisuke*

Review of Scientific Instruments, 86(1), p.013101_1 - 013101_5, 2015/01

 Times Cited Count:9 Percentile:47.26(Instruments & Instrumentation)

We have developed a system for measuring the temporal profiles of scintillation at high linear energy transfer (LET) by using pulsed ion beams from a cyclotron. The half width at half maximum time resolution was estimated to be 1.5-2.2 ns, which we attributed mainly to the duration of the pulsed ion beam and timing jitter between the trigger signal and the arrival of the ion pulse. The temporal profiles of scintillation of BaF$$_{2}$$ at different LETs were successfully observed. These results indicate that the proposed system is a powerful tool for analyzing the LET effects in temporal profiles of scintillation.

Journal Articles

Concentration and incident energy dependences of transient species in water by H$$^{+}$$ ion irradiation

Iwamatsu, Kazuhiro; Taguchi, Mitsumasa; Sugo, Yumi; Kurashima, Satoshi; Katsumura, Yosuke

Transactions of the Materials Research Society of Japan, 36(3), p.329 - 332, 2011/09

This article reports a transient absorbance measurement system using energetic pulsed ions, and chemical reactions in aqueous NaBr solutions. Dose in pulse was evaluated by using GAF film dosimeter for the quantitative analysis of reactive species. NaBr aqueous solution was selected as a probe of chemical reactions in irradiated water samples because chemical reactions of Br$$^{-}$$ with hydroxyl radicals produced by water radiolysis are well investigated by low LET radiation. The samples were irradiated with pulsed 20 MeV H$$^{+}$$ ion provided by the AVF cyclotron. The formation and decomposition of Br$$_{2}$$$$^{-}$$ were observed at 375 nm. The formation yield of Br$$_{2}$$$$^{-}$$ slightly increased from 0.73 to 0.85 per 100eV absorbed energy with the increase in the concentration of NaBr from 1 to 1000 mM. The formation yield of Br$$_{2}$$$$^{-}$$ for 1000 mM NaBr aqueous solution decreased from 0.85 to 0.27 per 100eV absorbed energy with the decrease in the incident energy from 19.4 MeV to 8.8 MeV, in other words increase of LET from 4.79 to 8.81 eV/nm.

JAEA Reports

Plan and reports of coupled irradiation (JRR-3 and JOYO of research reactors) and hot facilities work (WASTEF, JMTR-HL, MMF and FMF); R&D project on irradiation damage management technology for structural materials of long-life nuclear plant

Matsui, Yoshinori; Takahashi, Hiroyuki; Yamamoto, Masaya; Nakata, Masahito; Yoshitake, Tsunemitsu; Abe, Kazuyuki; Yoshikawa, Katsunori; Iwamatsu, Shigemi; Ishikawa, Kazuyoshi; Kikuchi, Taiji; et al.

JAEA-Technology 2009-072, 144 Pages, 2010/03

JAEA-Technology-2009-072.pdf:45.01MB

"R&D Project on Irradiation Damage Management Technology for Structural Materials of Long-life Nuclear Plant" was carried out from FY2006 in a fund of a trust enterprise of the Ministry of Education, Culture, Sports, Science and Technology. The coupled irradiations or single irradiation by JOYO fast reactor and JRR-3 thermal reactor were performed for about two years. The irradiation specimens are very important materials to establish of "Evaluation of Irradiation Damage Indicator" in this research. For the acquisition of the examination specimens irradiated by the JOYO and JRR-3, we summarized about the overall plan, the work process and the results for the study to utilize these reactors and some facilities of hot laboratory (WASTEF, JMTR-HL, MMF and FMF) of the Oarai Research-and-Development Center and the Nuclear Science Research Institute in the Japan Atomic Energy Agency.

Journal Articles

Ratio of transverse diffusion coefficient to mobility of electrons in high-pressure xenon and xenon doped with hydrogen

Kobayashi, Shingo*; Hasebe, Nobuyuki*; Hosojima, Takehiro*; Ishizaki, Takeshi*; Iwamatsu, Kazuhiro*; Mimura, Mitsuteru*; Miyachi, Takashi*; Miyajima, Mitsuhiro*; Pushkin, K.*; Tezuka, Chikara*; et al.

Japanese Journal of Applied Physics, Part 1, 45(10A), p.7894 - 7900, 2006/10

 Times Cited Count:11 Percentile:41.69(Physics, Applied)

We have obtained the ratio of transverse diffusion coeffcient to mobility of electrons multiplied by the elementary charge, in Xe and Xe+H$$_{2}$$ under electric fields at a higher pressure of 1 MPa in comparison with preceding experiments. The result shows that the density effect (non-linear effect) of the ratio in both of pure Xe and Xe+H$$_{2}$$ is $$<$$15% below 1 MPa over the reduced electric field range from 0.08 to 0.6$$times$$10$$^{-17}$$V$$cdot$$cm$$^{2}$$. We also found that the diffusion of an electron swarm is suppressed by adding trace of hydrogen to high-pressure xenon gas. Discussion is made of Xe+H$$_{2}$$ gas to a new $$gamma$$-ray camera. Trace of hydrogen to high-pressure xenon gas. Discussion is made of Xe+H$$_{2}$$ gas to a new $$gamma$$-ray camera.

Oral presentation

R&D project on irradiation damage management technology for structural materials of long-life nuclear plant, 2; Plan and execution of coupling irradiation (JRR-3 and JOYO) and Hot facilities work (WASTEF, JMTR-HL, MMF and FMF)

Matsui, Yoshinori; Nabeya, Hideaki; Kusunoki, Tsuyoshi; Takahashi, Hiroyuki; Aizawa, Masao; Nakata, Masahito; Numata, Masami; Usami, Koji; Endo, Shinya; Ito, Kazuhiro; et al.

no journal, , 

We are proceeding with the study of "R&D Project on Irradiation Damage Management Technology for Structural Materials of Long-life Nuclear Plant". For the study, it is important that the irradiated specimens are gotten by the coupling of JRR-3 and JOYO. This reports the total irradiation plan in the study, and the executed work for the coupling irradiation (JRR-3 and JOYO) including the Hot facilities work of Tokai and Oarai in the 2006 fiscal year.

Oral presentation

R&D project on irradiation damage management technology for structural materials of long-life nuclear plant, 2; Reports of coupling irradiation (JRR-3 and JOYO) and hot facilities work (WASTEF, JMTR-HL, MMF and FMF)

Matsui, Yoshinori; Takahashi, Hiroyuki; Ichise, Kenichi; Usami, Koji; Endo, Shinya; Iwamatsu, Shigemi; Yonekawa, Minoru; Ito, Kazuhiro; Yamamoto, Masaya; Soga, Tomonori; et al.

no journal, , 

"R&D Project on Irradiation Damage Management Technology for Structural Materials of Long-life Nuclear Plant" was carried out from 2006 fiscal year in a fund of a trust enterprise of the Ministry of Education, Culture, Sports, Science and Technology. The coupling irradiations or single irradiations by JOYO fast reactor and JRR-3 fission reactor were performed for about two years. The irradiation specimens are the very important materials to establish of "Evaluation of Irradiation Damage Indicator" in this research. For the acquisition of the examination specimens irradiated by the JOYO and JRR-3, we will present about the overall plan, work process and the results for the study to utilize these reactors and some facilities of hot laboratory (WASTEF, JMTR-HL, MMF and FMF) of the Oarai Research-and-Development Center and the Nuclear Science Research Institute in the Japan Atomic Energy Agency.

Oral presentation

Observation of heavy ion induced transient species in water by spectroscopic technique

Taguchi, Mitsumasa; Sugo, Yumi; Iwamatsu, Kazuhiro; Kimura, Atsushi; Kurashima, Satoshi; Katsumura, Yosuke*

no journal, , 

no abstracts in English

Oral presentation

Observation of transient species produced by heavy-ion irradiation with spectroscopic method

Iwamatsu, Kazuhiro; Taguchi, Mitsumasa; Sugo, Yumi; Kimura, Atsushi; Kurashima, Satoshi; Katsumura, Yosuke

no journal, , 

no abstracts in English

Oral presentation

Investigation of chemical reactions induced by heavy ion using spectroscopic method

Iwamatsu, Kazuhiro; Taguchi, Mitsumasa; Sugo, Yumi; Kimura, Atsushi; Kurashima, Satoshi; Katsumura, Yosuke

no journal, , 

no abstracts in English

Oral presentation

Observation of transient species in water under pulsed heavy ion irradiation

Taguchi, Mitsumasa; Iwamatsu, Kazuhiro; Sugo, Yumi; Kurashima, Satoshi; Katsumura, Yosuke

no journal, , 

no abstracts in English

Oral presentation

Concentration and incident energy dependences of transient species in water by H$$^{+}$$ ion irradiation

Iwamatsu, Kazuhiro; Taguchi, Mitsumasa; Sugo, Yumi; Kurashima, Satoshi; Katsumura, Yosuke

no journal, , 

no abstracts in English

Oral presentation

Possibility of production and condensation of hydrogen from boiling water under irradiation in the Fukushima Daiichi F4 fuel storage pool

Yamashita, Shinichi; Hirade, Tetsuya; Matsuura, Chihiro*; Iwamatsu, Kazuhiro; Taguchi, Mitsumasa; Katsumura, Yosuke*

no journal, , 

Fukushima Daiichi Nuclear Power Plant Unit-4 was under an inspection on the day of Tohoku earthquake, and all of the fuels were cooled in the fuel storage pool. However, the explosion occurred only four days after the cooling of the pool stopped. Later, the pool was investigated and it was clarified that the fuels were not so damaged and the water was not contaminated with radioisotopes. There are several explanations of the cause of the explosion. We picked up one possibility that the radiolysis of the water was the source of the hydrogen and that the vapor condensation could make the high hydrogen density behind the cold roof or walls, and investigated by an experiment of boiled water radiolysis by $$gamma$$-rays. The results can explain some of the typical things happened on the explosion of Unit-4.

Oral presentation

Pulse radiolysis of water by energetic heavy ion

Taguchi, Mitsumasa; Iwamatsu, Kazuhiro; Sugo, Yumi; Kurashima, Satoshi; Yamaguchi, Makoto*; Katsumura, Yosuke

no journal, , 

no abstracts in English

Oral presentation

Ion beam pulse radiolysis studies of water radiolysis probed with chloride and bromide ions

Iwamatsu, Kazuhiro*; Taguchi, Mitsumasa; Sugo, Yumi; Kurashima, Satoshi; Katsumura, Yosuke*

no journal, , 

no abstracts in English

Oral presentation

Ion beam pulse radiolysis study of water probed with chloride and bromide ions

Iwamatsu, Kazuhiro; Taguchi, Mitsumasa; Sugo, Yumi; Kurashima, Satoshi; Yamashita, Shinichi; Katsumura, Yosuke

no journal, , 

no abstracts in English

Oral presentation

Radiolysis of boiling water and hydrogen enrichment; A Mystery of the hydrogen explosion at No.4 reactor in Fukushima Daiichi Nuclear Power Station

Katsumura, Yosuke; Yamashita, Shinichi; Hirade, Tetsuya; Matsuura, Chihiro*; Iwamatsu, Kazuhiro*; Taguchi, Mitsumasa

no journal, , 

no abstracts in English

35 (Records 1-20 displayed on this page)