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Kokubu, Yoko; Matsubara, Akihiro; Fujita, Natsuko; Nishio, Tomohiro*; Owaki, Yoshio*; Sanada, Katsuki*; Nishizawa, Akimitsu*; Miyake, Masayasu*
no journal, ,
Cosmogenic nuclides of Be and
Al are used for studies such as estimation of exposure age and erosion rate of rock. In order to measure traces of
Be and
Al by accelerator mass spectrometry (AMS) in these studies, reagents with low levels of
Be and
Al are needed. In this study, ratios of
Be/
Be or
Al/
Al in several reagents were compared. The reagents were oxides for evaluation of blank in measurement and standard solutions for atomic absorption spectrometry (AAS) or inductively coupled plasma optical emission / mass spectrometry (ICP) for carrier and evaluation of process blank. The ratios were measured in JAEA-AMS-TONO. The ratios of
Be/
Be in the Be oxides and the Be standard solutions were approximately 10
10
levels. The Be Standard solutions for AAS and ICP supplied by Merck had lower ratios of
Be/
Be than those supplied by Wako and Kanto chemical.
Fujita, Hiroki
no journal, ,
Optically stimulated luminescence (OSL) from natural quartz and feldspar has been used in retrospective dosimetry, dating of sediment and etc. However, in the application target mineral should be extracted with chemical separation which is robust work. Now a days, pulsed optically stimulated luminescence (P-OSL) was developed to separate luminescence signal from between quartz and feldspar as instrumental separation. The purpose of this study tried to apply the P-OSL to Japanese surface soil as retrospective dosimetry with easy physical separation. From our results, it was concluded that P-OSL dosimetry is suitable for accident evaluation although further research is required to improve the protocol using various kinds of Japanese surface soils.
Ishii, Yasuo; Sasaki, Yoshito; Kikuchi, Naoyuki; Watanabe, Takayoshi; Oda, Yoshihiro; Niizato, Tadafumi
no journal, ,
As part of "Long-Term Assessment of Transport of Radioactive Contaminant in the Environment of Fukushima" (F-TRACE project), JAEA have researched to expect the transportation of radioactive caesium from contaminated mountain forests to estuary and coast through dam, pond, river etc. based on survey data in Fukushima prefecture, and to implement technical information and remedial measures to prevent contamination of decontaminated areas and domestic water supply. In the forest area, it is considered that radioactive caesium existed in the tree canopies move to the surface of the ground through litter fall, through fall and stem flow. In this study, we report properties and distribution of radioactive caesium of the surface soils at stem base of Japanese cedar in the Ogi district of Kawauchi-mura to know the influence of the stem flow on soil.
Miyashita, Yuka*; Akiyama, Kazuhiko*; Hatsukawa, Yuichi; Tadai, Tomohiro*; Chiba, Kazuki*; Sato, Yuta*; Kubuki, Shiro*
no journal, ,
To obtain an endohedral metallofullerenes with high specific radioactivity using nuclear recoil phenomena, many experiments have been performed so far. However, production yield of metallofullerene by nuclear recoil using high LET radiation was found to be very small because radiation damages to targeted fullerene molecule were not negligible. In order to increase the yield of radioactive metallofullerenes, it is very promising to employ the recoil of nuclear reaction by fast neutron from the viewpoint of reducing the radiation damage. In this session, we will report the synthesis of Sr@C
using nuclear recoil of
Sr (n,2n)
Sr reaction by 14 MeV fast neutron. Mixture of C
with strontium salts such as Sr(NO
)
and SrC
O
were employed for the target materials. These samples were irradiated by fast neutron in Fusion Neutronics Source at Japan Atomic Energy Agency. After the irradiation, CS
, aniline, and HCl
were passed through the irradiated samples on the filter to dissolve C
, Sr@C
, and strontium salts, respectively. The
-ray from these solutions were measured by Ge detector. As a result, about 0.75% of radioactivity was observed in the aniline solution from SrC
O
sample. This result strongly suggests that Sr@C
was efficiently produced by fast neutron irradiation of SrC
O
/C
target.
Dohi, Terumi; Omura, Yoshihito*; Fujiwara, Kenso; Iijima, Kazuki
no journal, ,
Lichens are symbiotic organisms consisted of fungi and algae. A number of studies were carried out after the nuclear weapons tests and Chernobyl accident, and demonstrated that lichens were useful for indicator of radioactive fallout because they could take up large amount of radionuclides directly from their thallus due to lack of root system and retain them. However, in order to measure radiocaesium concentration in lichen, the lichen sample was collected from their habitat. Therefore, temporal change of radiocaesium concentration in same lichen individual has never reported. In addition, a retention of radiocaesium in lichens in Japan was unknown. The objective of this study is to investigate the temporal change of radiocaesium concentration in individual lichen. Lichen samples were parmelioid lichens which were grown on the trunk of Prunus spp. within Fukushima prefecture. The counting rate of surface of lichen was measured by using Geiger-Mueller (GM) survey meter with a lead collimator to evaluate the radiocaesium concentration. The contamination density in lichens increased from the initial measurement value after one year. It is considered that lichen may receive radiocaesium from stem flow including radiocaesium desorbed from canopy or stem.
Toyoshima, Atsushi; Miyashita, Sunao*; Oe, Kazuhiro*; Kitayama, Yuta*; Lerum, H. V.*; Goto, Naoya*; Kaneya, Yusuke; Komori, Yukiko*; Mitsukai, Akina*; Vascon, A.; et al.
no journal, ,
no abstracts in English
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 -emitter
At which is a prospective candidate for utilization in targeted alpha radiotherapy is produced through the
Bi(
He, 2n)
At reaction. In contrast, our project is focusing on the production in the
Bi(
Li, 5n)
Rn reaction. This enables us to supply
At in a
Rn/
At generator system. The daughter
At (7.2 h half-life) is extracted from the parent
Rn (14h), expanding time-frame for transportation and use of
At. To use astatine and iodine radioisotopes in our project, the excitation functions of
Bi(
Li, xn)
Rn,
Pb(
Li, xn)
At and
Sn(
Li, xn)
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.
Sato, Tetsuya; Asai, Masato; Kaneya, Yusuke; Tsukada, Kazuaki; Toyoshima, Atsushi; Vascon, A.; Takeda, Shinsaku; Mitsukai, Akina*; Nagame, Yuichiro; Ichikawa, Shinichi; et al.
no journal, ,
In order to determine the IP of the heavy elements, we have developed a novel measurement method based on a surface ionization technique by using a surface ionization ion source coupled to a He/CdI gas-jet transport system for an Isotope Separator On-Line (ISOL) at the JAEA tandem accelerator facility. In this work, we have determined IP value of No by using the method. In a surface ionization process, an ionization efficiency of an atom depends on its IP. To obtain a relationship between IP and ionization efficiency in present system, we measured ionization efficiencies of various short-lived isotopes. Ionization efficiency of
No produced in the
Cm(
C, 4n) reaction was also measured. Measured ionization efficiency of
No was 0.8%, which yields IP value of No to be 6.6 eV. This value is in a good agreement with the value which has been evaluated by extrapolation from those of the lighter actinide elements, 6.65 eV.
Asai, Masato; Sato, Tetsuya; Kaneya, Yusuke
no journal, ,
To experimentally determine the first ionization energy of element 103, Lr, we have newly developed a surface ionization method and have investigated its feasibility. We have measured surface ionization efficiencies of various lanthanide elements as a function of the first ionization energy, and investigated whether the surface ionization efficiencies can be reproduced by the Saha-Langmuir equation which is the equation to describe the surface ionization process. We have found that the effect of excited states in atom and ion largely contributes to the surface ionization efficiency in the Saha-Langmuir equation. By taking account of this effect, we have reproduced the measured ionization efficiencies of all the lanthanide elements with good accuracies.
Hashimoto, Kazuyuki; Kawabata, Masako; Saeki, Hideya; Tsukada, Kazuaki; Sato, Nozomi*; Motoishi, Shoji*; Nagai, Yasuki; Watanabe, Satoshi; Ishioka, Noriko
no journal, ,
Copper-67 is an attractive radionuclide for cancer therapy, because of emissions of medium energy particle (a mean energy of 141 keV) and
rays (91, 93, 185 keV) suitable for imaging, and its appropriate half-life (62 hours). However, the use of
Cu for clinical researches has been limited due to the difficulty in obtaining sufficient quantities. In this study, we have investigated the production of
Cu by the
Zn(n,x)
Cu reaction (x = n'p, d) using fast neutrons from
C(d,n) reaction. The highly purified
Cu was obtained by the two columns separation method (chelate resin chelex-100 and anion exchange resin AG1-X8). Furthermore, the labelling of DOTA and TETA which are useful bifunctional ligands for the labelling monoclonal antibodies was succeeded in more than 97% yield.
Aoyagi, Noboru; Watanabe, Masayuki; Kimura, Takaumi; Kirishima, Akira*; Sato, Nobuaki*
no journal, ,
no abstracts in English
Tsukada, Kazuaki; Sato, Nozomi; Watanabe, Satoshi; Ishioka, Noriko; Hatsukawa, Yuichi; Hashimoto, Kazuyuki; Kin, Tadahiro*; Kawabata, Masako; Saeki, Hideya; Nagai, Yasuki
no journal, ,
no abstracts in English
Toh, Yosuke
no journal, ,
no abstracts in English
Yasuda, Kenichiro; Suzuki, Daisuke; Kanazawa, Kazuhito; Miyamoto, Yutaka; Esaka, Fumitaka; Magara, Masaaki
no journal, ,
In order to detect of undeclared activities in nuclear facilities, we develop to technique of safeguards environmental sample analysis in JAEA. As part of this effort, isotope ratio analysis of individual MOX particle was performed using by TIMS without chemical treatment. It is possible to estimate an age determination of plutonium purification by a combination of the plutonium isotope ratios and (Pu-238+Am-241)/(Pu-239+Pu-240) alpha activity ratios were obtained by the alpha spectrometry. Since the plutonium particle size is more than 1m due to the influence of self-absorption, exactly measurement of the activity ratios has been difficult. Therefore, we were examining how to acid dissolution in the plutonium particles on the TIMS filament before alpha spectrometry.
Kimura, Atsushi
no journal, ,
no abstracts in English
Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki
no journal, ,
The authors accomplished the development of technique for sequential separation of U, Th, Pb, and the lanthanides using a single anion-exchange column and mixed media consisting of hydrochloric acid, nitric acid, acetic acid, and hydrofluoric acid in the previous work. Composition of eluents for separation of Pu and Th was optimized to accomplish the sequential separation of multi-elements including Pu. The mixture of Pu and Th was successfully separated by a single anion exchange column with acetic acid-HCl-HF mixed-media.
Furuta, Sadaaki; Ikeda, Koki; Mikake, Shinichiro; Imaeda, Yasuhiro; Nagasaki, Yasushi; Suzuki, Hajime; Nomura, Yukihiro
no journal, ,
no abstracts in English
Takeuchi, Erina; Atarashi-Andoh, Mariko; Nishimura, Shusaku; Nakanishi, Takahiro; Tsuzuki, Katsunori; Koarashi, Jun; Matsunaga, Takeshi
no journal, ,
no abstracts in English
Koma, Yoshikazu
no journal, ,
Due to the accident of Fukushima Daiichi NPS, TEPCO, wide area was contaminated. TEPCO analyzed radioactivity in the soil within the NPS site and reported their concentration in 2011. Based on the data disclosed, transport behavior from the fuel of damaged reactors to the soil for the detected radionuclides was investigated.
Shimada, Asako; Kameo, Yutaka
no journal, ,
no abstracts in English