Shimada, Mikio*; Tokumiya, Takumi*; Miyake, Tomoko*; Tsukada, Kaima*; Kanzaki, Norie; Yanagihara, Hiromi*; Kobayashi, Junya*; Matsumoto, Yoshihisa*
Journal of Radiation Research (Internet), 64(2), p.345 - 351, 2023/03
Yakushev, A.*; Lens, L.*; Dllmann, Ch. E.*; Khuyagbaatar, J.*; Jger, E.*; Krier, J.*; Runke, J.*; Albers, H. M.*; Asai, Masato; Block, M.*; et al.
Frontiers in Chemistry (Internet), 10, p.976635_1 - 976635_11, 2022/08
Flerovium (Fl, element 114) is the heaviest element chemically studied so far. The first chemical experiment on Fl suggested that Fl is a noble-gas-like element, while the second studies suggested that Fl has a volatile-metal-like character. To obtain more reliable conclusion, we performed further experimental studies on Fl adsorption behavior on Si oxide and gold surfaces. The present results suggest that Fl is highly volatile and less reactive than the volatile metal, Hg, but has higher reactivity than the noble gas, Rn.
Kirishima, Akira*; Terasaki, Mariko*; Miyakawa, Kazuya; Okamoto, Yoshihiro; Akiyama, Daisuke*
Chemosphere, 289, p.133181_1 - 133181_12, 2022/04
no abstracts in English
Matsutani, Takafumi; Sasaki, Yuji; Katsuta, Shoichi*
Analytical Sciences, 37(11), p.1603 - 1609, 2021/11
We investigated the chemical behavior of lanthanides (Ln) using diglycolamide extractant with multistage extraction. We obtained the breakthrough curves for light and middle Ln. Our study reveals that the metal extraction limit depends on their values and metal concentrations used in the experiments. From the multistage extractions of 15 aqueous phases and 15 organic phases, three curves (extraction curves, back-extraction curves, and separation curves) were obtained by changing the nitric acid concentration. As an example, under a condition of the separation curve experiment (aqueous phase: 0.5 M HNO, organic phase: 0.1 M TDDGA (-tetradecyl-diglycolamide) in -dodecane), a recovery of more than 99% of Sm in the organic phase with less than 1% Nd can be obtained.
Simonnet, M.; Kobayashi, Toru; Shimojo, Kojiro; Yokoyama, Keiichi; Yaita, Tsuyoshi
Inorganic Chemistry, 60(17), p.13409 - 13418, 2021/09
Sato, Junya; Shiota, Kenji*; Takaoka, Masaki*
Zairyo, 70(5), p.406 - 411, 2021/05
An aluminosilicate solid is an inorganic material that has the property of immobilizing heavy metals or radionuclides in the matrix. In this study, aluminosilicates with a Si/Al molar ratio of 0.5 was synthesized from a chemical reagent in order to produce aluminosilicate solids with a low Si/Al molar ratio, which were expected to improve the immobilization of heavy metals and radionuclides contained in the matrix. The synthesized Si-Al gel with a Si/Al molar ratio of 0.5 had little impurity content and was in an amorphous phase. In addition, the compressive strength of the aluminosilicate solid produced by the synthesized Si-Al gel showed a 5 MPa or more, confirming that it can be used as a raw material for aluminosilicate solids. The aluminosilicate solid with a Si/Al molar ratio of 1.25 had a dense surface structure from the result of BSE images and had the highest compressive strength among all samples.
Taniguchi, Yoshinori; Udagawa, Yutaka; Amaya, Masaki
Annals of Nuclear Energy, 139, p.107188_1 - 107188_7, 2020/05
Udagawa, Yutaka; Mihara, Takeshi; Taniguchi, Yoshinori; Kakiuchi, Kazuo; Amaya, Masaki
Annals of Nuclear Energy, 139, p.107268_1 - 107268_9, 2020/05
Simonnet, M.; Suzuki, Shinichi; Miyazaki, Yuji*; Kobayashi, Toru; Yokoyama, Keiichi; Yaita, Tsuyoshi
Solvent Extraction and Ion Exchange, 38(4), p.430 - 440, 2020/00
Lederer-Woods, C.*; Battino, U.*; Ferreira, P.*; Gawlik, A.*; Kimura, Atsushi; n_TOF Collaboration*; 128 of others*
Physics Letters B, 790, p.458 - 465, 2019/03
Lens, L.*; Yakushev, A.*; Dllmann, Ch. E.*; Asai, Masato; Ballof, J.*; Block, M.*; David, H. M.*; Despotopulos, J.*; Di Nitto, A.*; Eberhardt, K.*; et al.
Radiochimica Acta, 106(12), p.949 - 962, 2018/12
Online gas-solid adsorption studies with single atom quantities of Hg, Tl, and Pb on SiO and Au surfaces were carried out using short-lived radioisotopes with half-lives in the range of 4-49 s. This is a model study to measure adsorption enthalpies of superheavy elements Cn, Nh, and Fl. The short-lived isotopes were produced and separated by the gas-filled recoil separator TASCA at GSI. The products were stopped in He gas, and flushed into gas chromatography columns made of Si detectors whose surfaces were covered by SiO or Au. The short-lived Tl and Pb were successfully measured by the Si detectors with the SiO surface at room temperature. On the other hand, the Hg did not adsorb on the SiO surface, but adsorbed on the Au surface. The results demonstrated that the adsorption properties of short-lived Hg, Tl, and Pb could be studied with this setup, and that this method is applicable to the experiment for Cn, Nh, and Fl.
Barbagallo, M.*; Andrzejewski, J.*; Mastromarco, M.*; Perkowski, J.*; Damone, L. A.*; Gawlik, A.*; Kimura, Atsushi; n_TOF Collaboration*; 122 of others*
Nuclear Instruments and Methods in Physics Research A, 887, p.27 - 33, 2018/04
Ichikawa, Shoichi; Chiba, Yusuke; Ono, Fumiyasu; Hatori, Masakazu; Kobayashi, Takanori; Uekura, Ryoichi; Hashiri, Nobuo*; Inuzuka, Taisuke*; Kitano, Hiroshi*; Abe, Hisashi*
JAEA-Research 2017-001, 40 Pages, 2017/03
In order to reduce the influence on a plant schedule of the MONJU by the maintenance of dew point hygrometers, The JAEA examined a capacitance type dew point hygrometer as an alternative dew point hygrometer for a lithium-chloride type dew point hygrometer which had been used at the CV-LRT in the MONJU. As a result of comparing a capacitance type dew point hygrometer with a lithium-chloride type dew point hygrometer at the CV-LRT (Atmosphere: nitrogen, Testing time: 24 hours), there weren't significant difference between a capacitance type dew point hygrometer and a lithium-chloride type dew point hygrometer. As a result of comparing a capacitance dew point hygrometer with a high-mirror-surface type dew point hygrometer for long term verification (Atmosphere: air, Testing time: 24 months), the JAEA confirmed that a capacitance type dew point hygrometer satisfied the instrument specification (2.04C) required by the JEAC4203-2008.
Steinegger, P.*; Asai, Masato; Dressler, R.*; Eichler, R.*; Kaneya, Yusuke*; Mitsukai, Akina*; Nagame, Yuichiro; Piguet, D.*; Sato, Tetsuya; Schdel, M.; et al.
Journal of Physical Chemistry C, 120(13), p.7122 - 7132, 2016/04
A new experimental method "vacuum chromatography" has been developed to measure adsorption enthalpy of superheavy elements, and its feasibility has been examined using short-lived thallium isotopes. The short-lived thallium isotopes were produced at the JAEA tandem accelerator. The thallium ion beam prepared with an on-line isotope separator which ionized and mass-separated the thallium isotopes was injected into an isothermal vacuum chromatography apparatus. A temperature-dependent adsorption property of thallium atom on SiO surface were measured. The adsorption enthalpy of thallium was determined to be 158 kJ/mol. The thallium is a homolog of element 113. Thus, the vacuum chromatography developed in this study enables us to perform chemical experiments for short-lived superheavy elements with half-lives of a order of one second.
Zaiton, A.*; Ono, Yutaka
JAEA-Review 2015-037, 120 Pages, 2016/03
This report summarizes Bilateral Cooperative Research between Japan Atomic Energy Agency and Malaysian Nuclear Agency (a representative of the Government of Malaysia) implemented from 2002 to 2012 under "THE IMPLEMENTING ARRANGEMENT BETWEEN THE GOVERNMENT OF MALAYSIA AND THE JAPAN ATOMIC ENERGY AGENCY ON THE RESEARCH COOPERATION IN THE FIELD OF RADIATION PROSSING". The research activities in two Cooperative Research Programs, "Mutation Induction of Orchid Plants by Ion Beams" and "Generating New Ornamental Plant Varieties Using Ion Beams" performed 2002-2007 and 2007-2012, respectively, are contained. The lists of steering committee meetings, irradiation experiments, and publications/presentations of each program are also attached in the Appendixes.
Sasaki, Ichiro; Watanabe, Shigeki; Ohshima, Yasuhiro; Sugo, Yumi; Yamada, Keiichi*; Hanaoka, Hirofumi*; Ishioka, Noriko
Peptide Science 2015, p.243 - 246, 2016/03
Zaiton, A.*; Affrida, A. H.*; Shakinah, S.*; Nurul Hidayah, M.*; Hase, Yoshihiro; Ono, Yutaka
JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 108, 2015/03
Imazono, Takashi; Hirono, Toko*; Kimura, Hiroaki*; Saito, Yuji; Ishino, Masahiko; Muramatsu, Yasuji*; Koike, Masato; Sano, Kazuo*
Review of Scientific Instruments, 76(12), p.126106_1 - 126106_4, 2005/12
Polarizance of a reflection-type polarizer made with a synthetic mica (fluorophlogopite) single crystal was evaluated at the photon energy of 880 eV by means of the rotating-analyzer method in conjunction with the evaluation of the degree of linear polarization of the insertion beamline, SPring-8 BL23SU, featuring an APPLE-2 type variably polarizing undulator. When the undulator was tuned to the horizontal linear polarization mode, the maximum reflectances for s- and p-polarization for a symmetric Bragg reflection of synthetic mica(002) were 2.6% and 0.013%, respectively, at incident angles of near 45. Our analysis based on the rotating-analyzer method gave the polarizance of the polarizer of at least 0.997 0.002 and the degree of linear polarization of 0.993 0.004 in the linear polarization mode.
Kuznetsov, S. A.*; Hayashi, Hirokazu; Minato, Kazuo; Gaune-Escard, M.*
Journal of Nuclear Materials, 344(1-3), p.169 - 172, 2005/09
The knowledge of separation coefficients of actinides and rare-earth metals is important for developing pyrometallurgical process of spent nuclear fuel. Electrochemical experiments were carried out at 723-823 K to estimate separation coefficients in LiCl-KCl eutectic melt containing uranium and lanthanum trichlorides. Uranium and lanthanum separation coefficients is calcurated with the voltammetric peak potentials of U (III) and La (III), their concentration in the melt and kinetic parameters for U(III) discharge such as diffusion coefficients, and standard rate constants of charge transfer. The diffusion coefficients of U (III) were determined by some electrochemical measurements. The standard rate constants of charge transfer for electroreduction of uranium U(III) +3e =U were calculated by impedance spectroscopy method.
Naganawa, Hirochika; Suzuki, Hideya*; Noro, Junji*; Kimura, Takaumi
Chemical Communications, (23), p.2963 - 2965, 2005/06
A "superweak" anion, TFPB-, gives rise to a field effect on the selectivity for Am over Ln in their extraction from aqueous HNO solution into benzene containing a "hard donor" extractant that shows no selectivity for these metal ions in traditional solvent extraction.