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Journal Articles

A Knowledge-sharing activity on the environmental radiation monitoring results affected by the Fukushima-Daiichi Nuclear Power Plant Accident at Tokai-Oarai area in Ibaraki Prefecture

Nakano, Masanao; Hosomi, Kenji; Nishimura, Shusaku; Matsubara, Natsumi; Okura, Takehisa; Kuramochi, Akihiko; Kawasaki, Masatsugu; Takeuchi, Erina; Fujii, Yutaka*; Jinno, Tsukasa*; et al.

Hoken Butsuri (Internet), 55(2), p.102 - 109, 2020/06

After the Fukushima-Daiichi Nuclear Power Station (1F) Accident in March 2011, the increase was significantly observed in a part of the result of the environmental radiation monitoring in Ibaraki prefecture. "The review meeting of the environmental effect from 1F accident" was established to discuss technically the fluctuation of monitoring data. The review meeting collected the monitoring data from the four nuclear operators, and discussed a fluctuating trend, $$^{134}$$Cs/$$^{137}$$Cs activity ratio, and so on. In this report, the results of the dose rate and $$^{137}$$Cs in fallout, surface soil, flatfish and seabed sediment are introduced. Also the problem solving in the review meeting is introduced.

Journal Articles

Spallation and fragmentation cross sections for 168 MeV/nucleon $$^{136}$$Xe ions on proton, deuteron, and carbon targets

Sun, X. H.*; Wang, H.*; Otsu, Hideaki*; Sakurai, Hiroyoshi*; Ahn, D. S.*; Aikawa, Masayuki*; Fukuda, Naoki*; Isobe, Tadaaki*; Kawakami, Shunsuke*; Koyama, Shumpei*; et al.

Physical Review C, 101(6), p.064623_1 - 064623_12, 2020/06

 Times Cited Count:2 Percentile:35.83(Physics, Nuclear)

The spallation and fragmentation reactions of $$^{136}$$Xe induced by proton, deuteron and carbon at 168 MeV/nucleon were studied at RIKEN Radioactive Isotope Beam Factory via the inverse kinematics technique. The cross sections of the lighter products are larger in the carbon-induced reactions due to the higher total kinetic energy of carbon. The energy dependence was investigated by comparing the newly obtained data with previous results obtained at higher reaction energies. The experimental data were compared with the results of SPACS, EPAX, PHITS and DEURACS calculations. These data serve as benchmarks for the model calculations.

Journal Articles

Enhancement of element production by incomplete fusion reaction with weakly bound deuteron

Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.

Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07

 Times Cited Count:5 Percentile:62.37(Physics, Multidisciplinary)

Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for $$^{107}$$Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.

Journal Articles

Production and separation of astatine isotopes in the $$^7$$Li + $$^{nat}$$Pb reaction

Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Maeda, Eita*; Watanabe, Shigeki; Hashimoto, Kazuyuki; Ishioka, Noriko; Makii, Hiroyuki; Toyoshima, Atsushi; Yamada, Norihiro*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 304(3), p.1077 - 1083, 2015/06

 Times Cited Count:9 Percentile:69.75(Chemistry, Analytical)

Production cross sections of astatine isotopes $$^{207-211}$$At in the 29-57 MeV $$^7$$Li induced reaction with $$^{nat}$$Pb target have been measured by $$alpha$$- and $$gamma$$-ray spectrometry. Excitation functions of production cross sections have been compared with a statistical model calculation to study the reaction mechanism of $$^7$$Li + $$^{nat}$$Pb. Considerably small experimental cross sections of $$^{210}$$At and $$^{209}$$At compared with the calculation were clearly observed at incident energies higher than 44 MeV, indicating that the effects of breakup reaction play a role. A chemical separation of astatine from an irradiated lead target has been studied with a dry-distillation method. A complementary way to produce astatine isotopes has been developed.

Journal Articles

Extraction of astatine isotopes for development of radiopharmaceuticals using a $$^{211}$$Rn-$$^{211}$$At generator

Maeda, Eita*; Yokoyama, Akihiko*; Taniguchi, Takumi*; Washiyama, Koshin*; Nishinaka, Ichiro

Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1465 - 1468, 2015/02

 Times Cited Count:8 Percentile:60.95(Chemistry, Analytical)

The $$^{211}$$At isotope has gathered attention as a promising $$alpha$$-emitter for radionuclide therapy. We report the dependence of the distribution ratio of astatine on the concentration of HCl, and on the polarity of the organic solvent. The results will be useful for development of the $$^{211}$$Rn-$$^{211}$$At generator.

Oral presentation

Production of astatine radioisotopes in the $$^7$$Li+$$^{nat}$$Pb reaction and simple chemical separation of astatine

Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Ri, Keiko*; Yamada, Norihiro*; Ishiguro, Rika*; Maeda, Eita*; Makii, Hiroyuki; Hashimoto, Kazuyuki; et al.

no journal, , 

We have started to study production and utilization of an $$alpha$$ radioactive nuclide $$^{211}$$At which is a prospective candidate for targeted alpha radiotherapy. We determined production cross sections of astatine radioisotopes in the reaction of 29-48 MeV $$^7$$Li+$$^{nat}$$Pb by $$alpha$$-ray and $$gamma$$-ray spectrometry at the tandem accelerator of JAEA-Tokai. Besides, we developed a simple dry-chemical method for separation of astatine.

Oral presentation

Nuclear and radiochemical study of production and utilization of radioactive astatine isotopes in the Li + $$^{nat}$$Pb reaction

Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Yamada, Norihiro*; Makii, Hiroyuki; Watanabe, Shigeki; Ishioka, Noriko; Hashimoto, Kazuyuki

no journal, , 

Oral presentation

Nuclear and radiochemical study of production and utilization of radioactive astatine isotopes in the Li+$$^{nat}$$Pb reaction; Aim at the new cancer medical treatment by $$alpha$$-emitting radioisotopes

Nishinaka, Ichiro; Makii, Hiroyuki; Toyoshima, Atsushi; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Yamada, Norihiro*; Taniguchi, Takumi*; Watanabe, Shigeki; et al.

no journal, , 

no abstracts in English

Oral presentation

Production and utilization of radioactive astatine isotopes in the $$^7$$Li + $$^{nat}$$Pb reaction

Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Yamada, Norihiro*; Makii, Hiroyuki; Toyoshima, Atsushi; Watanabe, Shigeki; Ishioka, Noriko; et al.

no journal, , 

Production cross sections of astatine in 29-57 MeV $$^7$$Li + $$^{rm nat}$$Pb have been measured by $$alpha$$- and $$gamma$$-ray spectrometry. Excitation functions of production cross sections have been compared with a statistical model calculation to study the reaction mechanism of the $$^7$$Li + $$^{rm nat}$$Pb reaction. It indicates that the breakup of $$^7$$Li plays a rule in the $$^7$$Li + $$^{rm nat}$$Pb reaction. Besides, we have developed a dry-distillation method which separates carrier-free astatine from an irradiated lead target.

Oral presentation

Production and separation of radioactive astatine isotopes in the $$^7$$Li+$$^{nat}$$Pb reaction

Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Yamada, Norihiro*; Makii, Hiroyuki; Toyoshima, Atsushi; Watanabe, Shigeki; Ishioka, Noriko; et al.

no journal, , 

To promote utilization of a radioactive nuclide $$^{211}$$At which draws increasing attention as a promissing $$alpha$$-emitter for targeted alpha therapy, we have measured production cross sections of astatine isotopes in the 29-57 MeV$$^7$$Li+$$^{nat}$$Pb reaction using the tandem accelerator of JAEA-Tokai, providing nuclear data for production. For pharmaceutical study and so on, beside, we have developed a new separation procedure based on a dry-distillation method which separates carrier free astatine isotopes from lead targets with high radiochemical and chemical purity and high yields.

Oral presentation

Production and utilization of astatine radioisotopes using $$^{7}$$Li ion beams

Nishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Taniguchi, Takumi*; Murakami, Kento*; Watanabe, Shigeki; Suzuki, Hiroyuki; Ishioka, Noriko; et al.

no journal, , 

In general, an $$alpha$$-emitter $$^{211}$$At which is a prospective candidate for utilization in targeted alpha radiotherapy is produced through the $$^{209}$$Bi($$^{4}$$He, 2n)$$^{211}$$At reaction. In contrast, our project is focusing on the production in the $$^{209}$$Bi($$^{7}$$Li, 5n)$$^{211}$$Rn reaction. This enables us to supply $$^{211}$$At in a $$^{211}$$Rn/$$^{211}$$At generator system. The daughter $$^{211}$$At (7.2 h half-life) is extracted from the parent $$^{211}$$Rn (14h), expanding time-frame for transportation and use of $$^{211}$$At. To use astatine and iodine radioisotopes in our project, the excitation functions of $$^{209}$$Bi($$^{7}$$Li, xn)$$^{216-x}$$Rn, $$^{nat}$$Pb($$^{7}$$Li, xn)$$^{nat-x}$$At and $$^{nat}$$Sn($$^{7}$$Li, xn)$$^{nat-x}$$I reactions have been measured. In addition to that, separation techniques have been developed. We report not only on the production and separation of astatine and iodine radioisotopes in the reactions but also on the utilization of those radioisotopes.

Oral presentation

Characterization including removal factor of materials used for smear method on radiation protection, 2

Iwasa, Atsutoshi; Nakayama, Naoto; Maeda, Eita; Usui, Toshihide; Kano, Yutaka; Takashima, Hideki; Irokawa, Hiroyuki

no journal, , 

no abstracts in English

Oral presentation

Development of $$^{211}$$Rn/$$^{211}$$At generator for targeted alpha therapy

Washiyama, Koshin*; Maeda, Eita*; Yokoyama, Akihiko*; Nishinaka, Ichiro; Taniguchi, Takumi*; Yamada, Norihiro*; Makii, Hiroyuki; Toyoshima, Atsushi; Amano, Ryohei*

no journal, , 

A $$^{211}$$Rn/$$^{211}$$At generator for targeted alpha therapy has been developed.

Oral presentation

Production of $$^{211}$$At for alpha radiotherapy via $$^{209}$$Bi($$^7$$Li,5n)$$^{211}$$Rn

Nishinaka, Ichiro; Washiyama, Koshin*; Yokoyama, Akihiko*; Maeda, Eita*; Hashimoto, Kazuyuki; Makii, Hiroyuki

no journal, , 

A $$^{211}$$Rn/$$^{211}$$At generator has been proposed to supply a radiotracer $$^{211}$$At with a half-life (T$$_{1/2}$$ = 7.2 h) for medical applications. To establish a technology of the $$^{211}$$Rn/$$^{211}$$At generator, $$^{211}$$Rn (T$$_{1/2}$$ = 14.7 h) has to be produced through the $$^{209}$$Bi($$^7$$Li, 5n)$$^{211}$$Rn reaction without melting bismuth metal targets due to heat produced by the irradiation of 60 MeV $$^7$$Li ion beams. In this work, we have studied the effects of a He gas cooling system of an irradiation chamber constructed for the production of $$^{211}$$Rn. Irradiations were carried out at the JAEA tandem accelerator using the irradiation chamber equipped with the He gas cooling system. The results show that the He gas effectively cools the targets and the cooling efficiency is nearly independent of the pressure ($$>$$ 1 kPa) and the flow rate ($$sim$$20 L/min) of the He gas.

Oral presentation

Production of alpha-emitting radioisotopes using the cyclotron facilities at Osaka University and JAEA Takasaki, and the Tandem accelerator at Tokai, JAEA

Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Yokoyama, Akihiko*; Nishinaka, Ichiro; Takahashi, Naruto*; Shinohara, Atsushi*; Watanabe, Shigeki; Ishioka, Noriko

no journal, , 

In order to use of an alpha emitter for targeted alpha therapy, we have started the production and the utilization of $$^{211}$$At using 30 MeV $$^4$$He particle in the $$^{209}$$Bi($$^4$$He, 2n)$$^{211}$$At nuclear reaction at cyclotron facilities of Osaka University and JAEA Takasaki. In addition to that, we have been developing a $$^{211}$$Rn/$$^{211}$$At generator to expand the availability of $$^{211}$$At to wide range of populations far away from cyclotron facilities. The results of studies on the At-chemistry for clinical use and on the development of the $$^{211}$$Rn/$$^{211}$$At generator will be presented. And a review of current status of targeted alpha therapy in Japan will be also introduced.

Oral presentation

Contamination at Plutonium Fuel Research Facility of Oarai Research and Development Center, 3; Measurement and data aggregation of radiation contamination for workers' dose evaluation

Kato, Yoshinari; Hashimoto, Makoto; Miyauchi, Hideaki; Yasumune, Takashi; Maeda, Eita; Takasaki, Koji; Yoshizawa, Michio; Momose, Takumaro

no journal, , 

no abstracts in English

Oral presentation

JAEA's activities about communication with local residents and the young generation

Ayame, Junko; Maeda, Eita; Koike, Yuko; Mitsumoto, Rika; Nakano, Minako; Uehara, Shieru

no journal, , 

Atomic Energy Society of Japan for 2018 Oral Presentation the winning a prize contents of "excellent active prize" in 2016 Fall Meeting. We were awarded the Outstanding Active Award of Social and Environmental Division, Atomic Energy Society of Japan in the 2018 Annual Meeting. We will present the award lecture at the Planning Session of Social and Environmental Division in the 2018 Fall Meeting.

Oral presentation

Contamination at Plutonium Fuel Research Facility of Oarai Research and Development Center; Evaluation of the activity median aerodynamic diameter of plutonium and americium particles by using imaging plates

Yasumune, Takashi; Kato, Yoshinari; Maeda, Eita; Miyauchi, Hideaki; Hashimoto, Makoto; Takasaki, Koji

no journal, , 

no abstracts in English

Oral presentation

Study on environmental radiation monitoring results for nine years after the accident at THE TEPCO Fukushima Daiichi Nuclear Power Plant at JAEA Oarai Research and Development Institute

Inoue, Yuki; Yamada, Junya; Maeda, Eita; Hatakeyama, Takumi; Miyauchi, Hideaki; Hashimoto, Makoto

no journal, , 

no abstracts in English

Oral presentation

Development of a portable high-resolution gamma-ray spectrometer for nuclear facilities, 1; Research plan

Maeda, Shigetaka; Nogami, Mitsuhiro*; Ito, Chikara; Watanabe, Kenichi*; Hitomi, Keitaro*

no journal, , 

A portable high-resolution gamma-ray spectrometer for nuclear facilities is developing. The research plan will be outlined, and the applicability to OLGM for fast reactor fuel failure detection and the required performance will be reported.

23 (Records 1-20 displayed on this page)