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Usuda, Shigekazu; Yasuda, Kenichiro; Sakurai, Satoshi
no journal, ,
The authors have developed phoswich detectors with ZnS(Ag) as an essential component. The phoswich detectors consist of plural scintillators, which have specific sensitivity for each radiation and different decay time from each scintillator, and enable us to count simultaneously alpha, beta(
) rays, thermal and/or fast neutrons emitted, when pulse shape and/or pulse height discrimination techniques are skillfully applied. In addition, if optical filters are suitably applied to the phoswich detectors, discrimination properties are improved. In this presentation, the authors introduce (1) summary of the rise time properties of scintillators and effects of optical techniques such as optical filters obtained under the almost same conditions, and (2) examples of application of optical techniques to improve the discrimination characteristics of the phoswich detectors.
Lee, C. G.; Iguchi, Kazunari; Suzuki, Daisuke; Inagawa, Jun; Esaka, Fumitaka; Magara, Masaaki; Sakurai, Satoshi; Shinohara, Nobuo; Usuda, Shigekazu
no journal, ,
Safeguards environmental sample analysis has implications on the examination of the existence of uranium particles with a higher 235U enrichment in swipe samples. If such uranium particles can be preferentially detected in a sample, this will be significant in simplifying the particle analysis in the safeguards. In this study, a screening method for uranium particles according to their enrichment has been developed by using the characteristics of fission tracks, which depend on the enrichment of the uranium particles. A two-step filtration system that can collect particles with desired diameters was used for the collection of uranium particles from a swipe sample in order to avoid the influence of the differences in the diameter on the etching behavior of fission tracks. It was shown that the enrichment-based screening of the uranium particles is possible by controlling the etching time to detect fission tracks and by comparing fission track morphologies and particle diameters.
Fujiwara, Asako; Kameo, Yutaka; Nakashima, Mikio
no journal, ,
Separation of Th and U in dissolved solution of solidified products of simulated waste with UTEVA resin has been investigated. Thorium and U were separated from the other elements such as Na, Al, Ca, Fe by column chromatography with UTEVA resin and recovered with the solution containing 0.1 M HNO
and 0.05 M oxalic acid. The concentration of Am and Pu in the fraction to recover Th and U was under the detection limit. Although 1% of Np was contaminated to the recovery fraction of Th and U, Np would not interfere the measurement of U. UTEVA resin cartridge system with flow pomp was applied to the separation of Th and U. The result from cartridge system showed good separation of Th and U from Na, Al, Ca, and Fe. The flow rate with cartridge system was 4-5 times faster than that with column system to shorten the operation time.
Hayashi, Takumi; Nakamura, Hirofumi; Isobe, Kanetsugu; Kobayashi, Kazuhiro; Suda, Taichi*; Oya, Yasuhisa*; Okuno, Kenji*; Yamanishi, Toshihiko
no journal, ,
no abstracts in English
Onuki, Toshihiko; Ozaki, Takuo; Kozai, Naofumi; Sakamoto, Fuminori; Suzuki, Yoshinori; Yoshida, Takahiro*
no journal, ,
We investigated the interactions of Pu(VI) with a mixture of Bacillus subtilis and kaolinite clay to determine the role of the microbes in regulating the environmental mobility of Pu. After 48 h, the oxidation state of Pu in the solutions exposed to B. subtilis and the mixture had changed to Pu(V), whereas the oxidation state of Pu associated with B. subtilis and the mixture was Pu(IV). In contrast, there was no change in the oxidation state of Pu in the solution or on kaolinite after exposure to Pu(VI). SEM-EDS analysis indicated that most of the Pu in the mixture was associated with B. subtilis. These results suggest that Pu(IV) is preferably sorbed to bacterial cells in the mixture, and that Pu(VI) is reduced to Pu(V) and Pu(IV).
Se in radioactive waste samplesKameo, Yutaka; Katayama, Atsushi; Nakashima, Mikio
no journal, ,
no abstracts in English
UNishinaka, Ichiro; Tanikawa, Masashi*; Nagame, Yuichiro; Nakahara, Hiromichi*
no journal, ,
Characteristics of neutron multiplicity and nuclear charge polarization have been studied in the 11.5 MeV proton-induced fission of U. Fragment mass and the average neutron multiplicity were measured by a double time-of-flight method. The most probable charges of secondary fragments were evaluated from fractional cumulative and mass yields. The nuclear charge polarization of primary fragments at scission was obtained by correcting the most probable charge of secondary fragments for neutron evaporation. The results show that the nuclear charge polarization at scission is associated with the liquid drop properties of nuclei and the proton shell effect with 
= 50 of heavy fragments.
Matsue, Hideaki; Yoshikawa, Hideki; Matsubayashi, Masahito; Iikura, Hiroshi; Segawa, Mariko
no journal, ,
no abstracts in English
Hatsukawa, Yuichi; Miyamoto, Yutaka; Osawa, Takahito; Toh, Yosuke; Kimura, Atsushi; Oshima, Masumi
no journal, ,
We developed a new technique of trace element analysis based on neutron activation analysis with coincident -ray detection. In order to improve the low efficiency of coincident -ray detection, an array of 16 Ge detectors with BGO Compton suppressors was used for this method. In this study, we try to measure trace elements in presolar grains. Presolar grains are synthesis in the Super nova or Red giant, and found in the primitive meteorite. We obtained nanodiamonds as presolar grains from the Allende meteorite, and try to measure trace elements in the grains using this method. We also measured isotope ratios of some elements in meteorite samples, such as presolar grains, chondrules.
ion between aqueous and organic solution phasesKitatsuji, Yoshihiro; Kimura, Takaumi; Kihara, Sorin*
no journal, ,
no abstracts in English
Cu as a biotracer and applications to in vivo imaging of Cu in a plantWatanabe, Shigeki; Ishioka, Noriko; Katabuchi, Tatsuya*; Watanabe, Satoshi; Suzui, Nobuo; Ishii, Satomi; Matsuhashi, Shimpei
no journal, ,
Positron emitter, Cu has been used in medical applications with positron emission tomography (PET). We have developed a novel method in Cu production to obtain Cu-labelled antibodies as a PET reagent. On the other hand, Cu can be used for in vivo imaging of copper in a living plant by positron emitting tracer imaging system (PETIS). Production of Cu was carried out via the Ni(p,n)Cu nuclear reaction. The produced Cu (330 MBq) was purified by an ion-exchange method from the irradiated NiO target. The Cu was obtained with high yield (89%) and high radionuclidic-purity Cu (
99%). The NiO was recovered in good yield ( 99%). The Cu was added to a plant (soybean) for an imaging experiment and the movement of Cu was visualized by the PETIS. This result shows that Cu can be applied as a useful tracer for not only medical applications and also plant physiological studies.
Br PET-radionuclide and Br-labeled antibody for PET imaging of cancer diagnosisIshioka, Noriko; Iida, Yasuhiko*; Watanabe, Shigeki; Yoshioka, Hiroki*; Hanaoka, Hirofumi*; Suzui, Nobuo; Matsuhashi, Shimpei; Endo, Keigo*
no journal, ,
no abstracts in English
W/Re generator and of the synthesis condition of 
Re-DMSANogawa, Norio*; Ikeda, Keishiro*; Morikawa, Naotake*; Motoishi, Shoji; Matsuoka, Hiromitsu; Hashimoto, Kazuyuki
no journal, ,
Rhenium-186(T
=90h; E
=1.1 MeV; E
=137 keV) and rhenium-188(T=17h; E=2.1 MeV; E=153 keV) are 
particle emitting radionuclides with excellent properties for targeted radiotherapy. Re-188 has the advantages associated with carrier-free, generator-produced radionuclides. PZC generator with many tungsten molecules is expected for as practical generator. This generator was experimented for clarifying a characteristic. Meso-2,3-dimercaptosuccinic acid (DMSA) is applied for palliative treatment of pain associated with disease. Effect of pH is studied on preparation of Re-DMSA.
Kubota, Takumi*; Nakano, Tomoko*; Amano, Hikaru; Suzuki, Takashi; Mahara, Yasunori*
no journal, ,
no abstracts in English
solutionsKasamatsu, Yoshitaka; Tome, Hayato; Toyoshima, Atsushi; Tsukada, Kazuaki; Asai, Masato; Ishii, Yasuo; Nishinaka, Ichiro; Sato, Tetsuya; Shinohara, Nobuo; Nagame, Yuichiro; et al.
no journal, ,
Anion-exchange behavior of 
Db (half-life 
= 34 s) produced in the 
Cm(
F, 5
) reaction at the JAEA tandem accelerator was investigated in the mixed 0.89 M HF/0.3 M HNO solution ([F] = 3 
10
M) with the automated ion-exchange separation apparatus coupled with the detection system for alpha-spectroscopy (AIDA). Anion-exchange behavior of its lighter homologues, Nb and Ta, was also studied under the same conditions using 
Nb ( = 14.3 min) and 
Ta ( = 6.76 min) produced in the 
Ge(F, 
) and Gd(F, ) reactions, respectively. It was found that the adsorption probability on the anion-exchange resin is in the order of Ta Nb 
Db under the present condition.
Kobayashi, Kazuhiro; Hayashi, Takumi; Yamanishi, Toshihiko; Oya, Yasuhisa*; Okuno, Kenji*
no journal, ,
In a fusion reactor of high safety and acceptability, safe confinement of tritium is one of key issues for the fusion reactor. Tritium should be well-controlled and not excessively released to the environment and to prevent workers from excess exposure. Especially, the hot cell and tritium facilities of ITER will use various construction materials. For tritium desorption processes, so-called "soaking" effect is important. This effect is based on sorption of tritiated water vapor on the materials and subsequent desorption from them. Therefore, in order to develop for the optimal desorption technique, the desorption experiment was carried out as a function of water vapor concentration in the purging gas for organic materials. As the result, the effect of adding water vapor was found on the decontamination for organic materials.
Furuta, Etsuko*; Nakahara, Hiromichi*; Oura, Yasuji*; Hatsukawa, Yuichi; Matsue, Hideaki; Sakane, Hitoshi*
no journal, ,
Cosmetics which declared hormesis effects are available through Internet. The existence of a daughter nuclides of Th and U series were observed by measuring the rays with a high purity Ge detector. In this study, in order to clarify the contents of trace elements, the hormesis cosmetics were analyzed using prompt activation analysis and observed by SEM-EDX. Main elements of the hormesis cosmetics are some rare earth elements such as La, Ce, Sm and Gd. The ratio of Gd/Sm included in all the hormesis cosmetics is 0.70, and the ratio is different from general cosmetics. Furthermore, we evaluated a possibility of radiation exposure. The influence of rays to skin surface from some hormesis cosmetics was, for example, over 50 mSv per year. The addition of the radioisotope to cosmetics is prohibited in some countries by the laws. The examination of the object that should prohibit the addition of the radioisotope is necessary.
Suzuki, Yoshinori; Nankawa, Takuya; Onuki, Toshihiko
no journal, ,
We investigated the redox behavior of Ce(IV)/Ce(III) in the presence of nitrilotriacetic acid (NTA) or Desferrioxamine B (DFO) by cyclic voltammetry and column electrolysis. In the presence of these organic acids, the redox potentials of Ce(IV)/Ce(III) was lower than that of the standard redox potential, suggesting that Ce(IV) was stabilized more than Ce(III) by complex formation. The redox reactions of Ce-DFO complex bellow and above pH 11 were different.