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Si investigated by decay spectroscopy of AlSteiger, K.*; Nishimura, Shunji*; Li, Z.*; Gernh
user, R.*; Utsuno, Yutaka; Chen, R.*; Faestermann, T.*; Hinke, C.*; Kr
cken, R.*; Nishimura, Mitsuki*; et al.
European Physical Journal A, 51(9), p.117_1 - 117_9, 2015/09
Times Cited Count：10 Percentile：57.9(Physics, Nuclear)no abstracts in English
Oe, Kazuhiro*; Attallah, M. F.*; Asai, Masato; Goto, Naoya*; Gupta, N. S.*; Haba, Hiromitsu*; Huang, M.*; Kanaya, Jumpei*; Kaneya, Yusuke*; Kasamatsu, Yoshitaka*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1317 - 1320, 2015/02
Times Cited Count：10 Percentile：64.26(Chemistry, Analytical)A new technique for continuous dissolution of nuclear reaction products transported by a gas-jet system was developed for superheavy element (SHE) chemistry. In this technique, a hydrophobic membrane is utilized to separate an aqueous phase from the gas phase. With this technique, the dissolution efficiencies of short-lived radionuclides of 
Mo and 
W were measured. Yields of more than 80% were observed for short-lived radionuclides at aqueous-phase flow rates of 0.1-0.4 mL/s. The gas flow-rate had no influence on the dissolution efficiency within the studied flow range of 1.0-2.0 L/min. These results show that this technique is applicable for on-line chemical studies of SHEs in the liquid phase.
Nakamura, Hiroo; Agostini, P.*; Ara, Kuniaki; Cevolani, S.*; Chida, Teruo*; Ciotti, M.*; Fukada, Satoshi*; Furuya, Kazuyuki*; Garin, P.*; Gessii, A.*; et al.
Fusion Engineering and Design, 83(7-9), p.1007 - 1014, 2008/12
Times Cited Count：19 Percentile：75.95(Nuclear Science & Technology)This paper describes the latest design of liquid lithium target system in IFMIF. Design requirement of the Li target is to provide a stable Li jet with a speed of 20 m/s to handle an averaged heat flux of 1 GW/m
. A double reducer nozzle and a concaved flow are applied to the target design. On Li purification, a cold trap and two kinds of hot trap are applied to control impurities below permissible levels. Nitrogen concentration shall be controlled below 10 wppm by one of the hot trap. Tritium concentration shall be controlled below 1 wppm by an yttrium hot trap. To maintain reliable continuous operation, various diagnostics are attached to the target assembly. Among the target assembly, a back-plate made of RAFM is located in the most severe region of neutron irradiation (50 dpa/y). Therefore, two design options of replaceable back wall and their remote handling systems are under investigation.
Miyashita, Makoto; Yutani, Toshiaki*; Sugimoto, Masayoshi
JAEA-Technology 2007-016, 62 Pages, 2007/03
JAEA-Technology-2007-016.pdf:3.2MB
This report describes investigation on structure of a high neutron flux test module (HFTM) for the International Fusion Materials Irradiation Facilities (IFMIF). The HFTM is aimed for neutron irradiation of a specimen in a high neutron flux domain of the test cell for irradiation ground of IFMIF. We investigated the overall structure of the HFTM that was able to include specimens in a rig and thermocouple arrangement, an interface of control signal and support structure. Moreover, pressure and the amount of the bend in the module vessel (a rectangular section pressure vessel) were calculated. The module vessel did a rectangular section from limitation of a high neutron flux domain. Also, we investigated damage of thermocouples under neutron irradiation, which was a temperature sensor of irradiation materials temperature control demanded high precision. Based on these results, drawings on the HTFM structure.
Nakamura, Hiroo; Ida, Mizuho; Miyashita, Makoto; Yoshida, Eiichi; Ara, Kuniaki; Nishitani, Takeo; Okumura, Yoshikazu; Horiike, Hiroshi*; Kondo, Hiroo*; Terai, Takayuki*; et al.
no journal, ,
no abstracts in English
Miyashita, Yuta*; Nakazawa, Takanori*; Obara, Satoshi; Yamazaki, Masayoshi*; Hongo, Hiromichi*
no journal, ,
no abstracts in English
Obara, Satoshi; Wakai, Takashi; Asayama, Tai; Mogi, Masaru*; Miyashita, Yuta*; Nakazawa, Takanori*
no journal, ,
no abstracts in English
Oe, Kazuhiro; Tsukada, Kazuaki; Asai, Masato; Sato, Tetsuya; Toyoshima, Atsushi; Miyashita, Sunao; Nagame, Yuichiro; Schdel, M.; Kaneya, Yusuke*; Lerum, H. V.*; et al.
no journal, ,
We are planning to investigate the redox behavior of element 106, seaborgium (Sg). For the Sg study, we newly developed a continuous dissolution apparatus which dissolves the gas-jet transported nuclides produced in nuclear reactions into aqueous solution. The new apparatus has a hydrophobic membrane filter for separation of aqueous solution from the gas. We investigated the dissolution efficiencies with the apparatus for short-lived nuclides of molybdenum and tungsten which are lighter homologues of Sg. In the meeting, the dependence of the efficiencies on the aqueous- and gas-flow rates will be reported.
Miyashita, Sunao; Oe, Kazuhiro; Toyoshima, Atsushi; Sato, Tetsuya; Asai, Masato; Tsukada, Kazuaki; Nagame, Yuichiro; Schdel, M.; Kaneya, Yusuke*; Omtvedt, J. P.*; et al.
no journal, ,
For the experiments of the redox potentials of Sg, rapid separation between different oxidation states of Sg is needed. In this study, solvent extraction of hexavalent Mo and W, as the lighter homologues of Sg, from 1.0 mol/L hydrochloric acid solution into di-(2-ethylhexyl)phosphoric acid (HDEHP), 1-phenyl-3-metyl-4-benzoyl-5-pyrazolone (PMBP), N-benzoyl-N-pheny-hydroxylamine (BPHA) and 4-isopropyl-tropolone (HT) in toluene was carried out. When HDEHP and PMBP were used as extractant, extraction equilibrium of 
W was achieved within 5 and 1 hours respectively. On the other hand, when BPHA and HT were used, extraction equilibrium of W was quickly achieved within 1 minute in both extractants. Extraction kinetics of 
Mo using BPHA and HT was examined. Extraction kinetics of Mo was slower than that of W. Extraction equilibrium of Mo was achieved within 10 by BPHA and 3 minutes by HT. We concluded that HT is a suitable extractant for the Sg reduction experiment.
Miyashita, Sunao; Toyoshima, Atsushi; Oe, Kazuhiro*; Asai, Masato; Sato, Tetsuya; Tsukada, Kazuaki; Nagame, Yuichiro; Schdel, M.; Kaneya, Yusuke; Haba, Hiromitsu*; et al.
no journal, ,
Solvent extraction of 
Mo and W using 4-isopropyltropolone (Hinokitiol, HT) was investigated. Extraction mechanism of Mo and W with HT was examined by slope analysis. The slopse of the distribution ratio of Mo and W vs. [HT] in logarithmic scale are 1.88 and 1.54, respectively.
Miyashita, Sunao; Toyoshima, Atsushi; Oe, Kazuhiro*; Sato, Tetsuya; Asai, Masato; Tsukada, Kazuaki; Nagame, Yuichiro; Schdel, M.; Kaneya, Yusuke; Haba, Hiromitsu*; et al.
no journal, ,
The extraction behavior of hexavalent and reduced Mo and W were investigated when aqueous phase was 0.1 M HCl/0.9 M LiCl solution. The D value of Mo was changed from 10 to 1 when applied potential was near 0 to -0.2 V. On the other hand, the D value of W was not changed at all applied potentials in this experimental condition. Those results indicated that Mo was reduced by FEC, and the extraction behavior of reduced Mo was different from hexavalent Mo. In the case of W, W was not reduced or the D values of reduced W was same as hexavalent W.
Toyoshima, Atsushi; Miyashita, Sunao*; Asai, Masato; Sato, Tetsuya; Kaneya, Yusuke; Tsukada, Kazuaki; Kitatsuji, Yoshihiro; Nagame, Yuichiro; Schdel, M.; Lerum, H. V.*; et al.
no journal, ,
To carry out a continuous reduction experiment of Sg with the low production rates and the short half-life, we are developing a new chemistry assembly consisting of a membrane degasser (MDG), a flow electrolytic column (FEC), the continuous liquid-liquid extraction apparatus, and the liquid scintillation counting system (SISAK). Recently, we have begun preparatory studies with Mo and W isotopes. Aqueous solution dissolving Mo and W was successfully separated from a carrier gas. Redox couples of Mo(VI)/Mo(V) and W(VI)/W(V) in HCl have been characterized for their macro amounts. Extraction behavior of Mo(VI) and W(VI) between toluene containing hinokitiol (HT) and HCl was successfully observed by a batch method. On-line extractions of short-lived Mo and W were also carried out using SISAK and MDG. In the symposium, our present status of the preparation with Mo and W will be presented.
Sr@C60 by nuclear recoil using high energy neutronsMiyashita, Yuka*; Akiyama, Kazuhiko*; Hatsukawa, Yuichi; Chiba, Kazuki*; Tadai, Tomohiro*; Sato, Yuta*; Kubuki, Shiro*
no journal, ,
Metallofullerene is one of promising material for the drug delivery system transporting useful encapsulated atoms, such as radioisotopes, with their characteristic cage-like structure. The methods to synthesize radioactive metallofullerenes are, for example, to irradiate cold metallofullerenes by thermal neutrons in a nuclear reactor and to prepare metallofullerene by an arc discharge method using radioisotopes created by an accelerator. However, the radioactive metallofullerenes synthesized these methods are including many amount of non-radioactive carriers and radioisotopes are dispersed into not only targeted fullerene species but also various kind of other species. In this study, we tried to synthesize radioactive metallofullerenes of carrier-free and single molecular species using the nuclear recoil technique by high energy neutron irradiation.
Toyoshima, Atsushi; Asai, Masato; Attallah, M. F.*; Goto, Naoya*; Gupta, N. S.*; Haba, Hiromitsu*; Huang, M.*; Kanaya, Jumpei*; Kaneya, Yusuke; Kasamatsu, Yoshitaka*; et al.
no journal, ,
Towards electrolytic reduction of Sg, batch-wise electrolytic reduction of carrier-free Mo and 
W radiotracers was studied using a flow electrolytic column (FEC). The electrolyzed samples from a FEC were chemically analyzed by solvent extraction with TOA and HDEHP to separate and identify reduced species from the stable Mo(VI) and W(VI) ones based on their different extraction behavior. Mo and 
W were applied as radiotracers. We also performed cyclic voltammetry and UV/Vis absorption spectrometry of macro amounts of Mo and W in acidic solutions to obtain information on redox reactions of these elements under given conditions. In the conference, the present status of the preparatory reduction experiments with Mo and W will be presented.
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 SrCO
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 SrCO sample. This result strongly suggests that Sr@C was efficiently produced by fast neutron irradiation of SrCO/C target.
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
Toyoshima, Atsushi; Oe, Kazuhiro*; Asai, Masato; Attallah, M. F.*; Goto, Naoya*; Gupta, N. S.*; Haba, Hiromitsu*; Kaneko, Masashi*; Kaneya, Yusuke; Kasamatsu, Yoshitaka*; et al.
no journal, ,
Due to short half-lives less than 10 s and extremely low production rates, transactinide elements heavier than seaborgium (Sg) are produced on an atom per hour scale. Therefore, a continuous rapid chemistry assembly is required to study aqueous-phase chemistry of these heaviest elements. In the present study, we started developments of a continuous chemistry assembly. Our first attempt was made in on-line experiments with Mo and W, lighter homologs of Sg, to optimize a chemistry assembly consisting of a newly developed membrane degasser as an interface between gas-jet and aqueous phase, a flow electrolytic column apparatus utilized to control oxidation states of Mo and W ions, and the continuous liquid-liquid extraction apparatus of SISAK for separation. In the conference, present status of the developments will be presented.
