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Journal Articles

Behavior of light elements in iron-silicate-water-sulfur system during early Earth's evolution

Iizuka, Riko*; Goto, Hirotada*; Shito, Chikara*; Fukuyama, Ko*; Mori, Yuichiro*; Hattori, Takanori; Sano, Asami; Funakoshi, Kenichi*; Kagi, Hiroyuki*

Scientific Reports (Internet), 11(1), p.12632_1 - 12632_10, 2021/06

 Times Cited Count:0 Percentile:0.01(Multidisciplinary Sciences)

The Earth's core consist of Fe-Ni alloy with some light elements (H, C, O, Si, S etc.). Hydrogen (H) is the most abundant element in the universe and one of the promising candidates. In this study, we have investigated the effects of sulfur(S) on hydrogenation of iron-hydrous silicate system containing saturated water in the ideal composition of the primitive Earth. We observed a series of phase transitions of Fe, dehydration of the hydrous mineral, and formation of olivine and enstatite with increasing temperature. The FeS formed as the coexisting phase of Fe under high-pressure and temperature condition, but its unit cell volume did not increase, suggesting that FeS is hardly hydrogenated. Recovered samples exhibited that H and S can be incorporated into solid Fe, which lowers the melting temperature as Fe(H$$_{x}$$)-FeS system. No detection of other light elements (C, O, Si) in solid Fe suggests that they dissolve into molten iron hydride and/or FeS in the later process of Earth's core-mantle differentiation.

Journal Articles

Online chemical adsorption studies of Hg, Tl, and Pb on SiO$$_{2}$$ and Au surfaces in preparation for chemical investigations on Cn, Nh, and Fl at TASCA

Lens, L.*; Yakushev, A.*; D$"u$llmann, 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

 Times Cited Count:2 Percentile:33.17(Chemistry, Inorganic & Nuclear)

Online gas-solid adsorption studies with single atom quantities of Hg, Tl, and Pb on SiO$$_{2}$$ 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$$_{2}$$ or Au. The short-lived Tl and Pb were successfully measured by the Si detectors with the SiO$$_{2}$$ surface at room temperature. On the other hand, the Hg did not adsorb on the SiO$$_{2}$$ 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.

Journal Articles

Complex chemistry with complex compounds

Eichler, R.*; Asai, Masato; Brand, H.*; Chiera, N. M.*; Di Nitto, A.*; Dressler, R.*; D$"u$llmann, Ch. E.*; Even, J.*; Fangli, F.*; Goetz, M.*; et al.

EPJ Web of Conferences, 131, p.07005_1 - 07005_7, 2016/12

 Times Cited Count:1 Percentile:48.51

In recent years gas-phase chemical studies assisted by physical pre-separation allowed for the productions and investigations of fragile single molecular species of superheavy elements. The latest highlight is the formation of very volatile hexacarbonyl compound of element 106, Sg(CO)$$_{6}$$. Following this success, second-generation experiments were performed to measure the first bond dissociation energy between the central metal atom and the surrounding ligand. The method using a tubular decomposition reactor was developed and successfully applied to short-lived Mo(CO)$$_{6}$$, W(CO)$$_{6}$$, and Sg(CO)$$_{6}$$.

Journal Articles

Sulfate complexation of element 104, Rf, in H$$_{2}$$SO$$_{4}$$/HNO$$_{3}$$ mixed solution

Li, Z.*; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Sato, Tetsuya; Sato, Nozomi; Kikuchi, Takahiro; Nagame, Yuichiro; Sch$"a$del, M.; Pershina, V.*; et al.

Radiochimica Acta, 100(3), p.157 - 164, 2012/03

 Times Cited Count:10 Percentile:65.97(Chemistry, Inorganic & Nuclear)

Journal Articles

Fluorido complex formation of element 104, rutherfordium (Rf)

Ishii, Yasuo; Toyoshima, Atsushi; Tsukada, Kazuaki; Asai, Masato; Li, Z.*; Nagame, Yuichiro; Miyashita, Sunao*; Mori, Tomotaka*; Suganuma, Hideo*; Haba, Hiromitsu*; et al.

Bulletin of the Chemical Society of Japan, 84(9), p.903 - 911, 2011/09

 Times Cited Count:15 Percentile:49.37(Chemistry, Multidisciplinary)

The cation-exchange behavior of element 104, rutherfordium (Rf), was investigated together with its lighter group-4 homologues Zr and Hf, and the tetravalent pseudo-homologue Th in HF/HNO$$_{3}$$ mixed solution. The results demonstrate that distribution coefficients ($$K_{d}$$) of Rf in HF/0.10 M HNO$$_{3}$$ decrease with increasing concentration of the fluoride ion [F$$^{-}$$], indicating the consecutive formation of fluorido complexes of Rf. We also measured the $$K_{d}$$ values of Rf and the homologues as a function of the hydrogen ion concentration [H$$^{+}$$]. The log $$K_{d}$$ values decrease linearly with an increase of log [H$$^{+}$$] with slopes between -2.1 and -2.5. This indicates that these elements are likely to form the same chemical compounds: mixture of [MF]$$^{3+}$$ and [MF$$_{2}$$]$$^{2+}$$ (M = Rf, Zr, Hf and Th) in the studied solution. It is also ascertained that sequence in the fluoride complex formation is Zr $$sim$$ Hf $$>$$ Rf $$>$$ Th.

Journal Articles

Observation of itinerant Ce 4$$f$$ electronic states in CeIrSi$$_3$$ studied by angle-resolved Ce 3$$drightarrow 4f$$ resonance photoemission spectroscopy

Okochi, Takuo*; Toshimitsu, Takafumi*; Yamagami, Hiroshi; Fujimori, Shinichi; Yasui, Akira; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Fujimori, Atsushi; Miyauchi, Yuichiro*; et al.

Journal of the Physical Society of Japan, 78(8), p.084802_1 - 084802_6, 2009/08

 Times Cited Count:8 Percentile:50.92(Physics, Multidisciplinary)

We have applied angle-resolved Ce 3$$d{rightarrow}$$4$$f$$ resonance photoemission spectroscopy to the non-centrosymmetric pressure-induced superconductor CeIrSi$$_3$$ and obtained the 4$$f$$ band-structure and Fermi surfaces. We have found that the Ce 4$$f$$ states are located mainly near the Fermi level and that the photoemission intensity derived from the dispersive conduction bands across the Fermi level shows considerable resonant enhancement. In addition, the band structure and Fermi surfaces of CeIrSi$$_3$$ are different from those of the non-$$f$$ reference compound, LaIrSi$$_3$$ and the difference is well explained by the band structure calculated within the local density approximation (LDA). These results strongly suggest that the Ce 4$$f$$ electrons in CeIrSi$$_3$$ are well hybridized with conduction bands and form itinerant electronic states.

Journal Articles

Fluoride complexation of element 104, rutherfordium (Rf), investigated by cation-exchange chromatography

Ishii, Yasuo; Toyoshima, Atsushi; Tsukada, Kazuaki; Asai, Masato; Tome, Hayato; Nishinaka, Ichiro; Nagame, Yuichiro; Miyashita, Sunao*; Mori, Tomotaka*; Suganuma, Hideo*; et al.

Chemistry Letters, 37(3), p.288 - 289, 2008/03

 Times Cited Count:18 Percentile:54.69(Chemistry, Multidisciplinary)

We have investigated cation-exchange behavior of Rf together with the lighter homologues of the group-4 elements Zr and Hf, and the tetravalent pseudo-homologue Th, in HF/HNO$$_{3}$$ solution using Automated Ion exchange separation apparatus coupled with the Detection system for Alpha spectroscopy (AIDA). The ${it K}$ $$_{d}$$ values of Zr, Hf, Th and Rf in HF/0.1 M HNO$$_{3}$$ were decreased with increasing the concentration of the fluoride ion [F$$^{-}$$], indicating the formation of the fluoride complexes. The sequence of the fluoride complexation strength is Zr $$sim$$ Hf $$>$$ Rf $$>$$ Th.

Journal Articles

A Water radiolysis code for the irradiation loop system

Hanawa, Satoshi; Sato, Tomonori; Mori, Yuichiro; Ogiyanagi, Jin; Kaji, Yoshiyuki; Uchida, Shunsuke

Journal of Power and Energy Systems (Internet), 1(2), p.123 - 133, 2007/00

In order to evaluate the water chemistry in the irradiation field during IASCC irradiation test, a water radiolysis code for IASCC irradiation loop system was developed. In the water radiolysis code, a multiple node model was introduced since the irradiation loop system has a wide rage temperature distribution as well as the dose distribution. To investigate the applicability of developed water radiolysis code, water chemistry at the water sampling point of the irradiation loop system was measured and compared with analytical results under several water chemistry conditions. Further, water chemistry distribution in the in-pile region as well as in the out-pile region was calculated by the developed water radiolysis code.

Journal Articles

Development of water radiolysis code for the JMTR IASCC test loop

Hanawa, Satoshi; Sato, Tomonori; Mori, Yuichiro; Ogiyanagi, Jin; Kaji, Yoshiyuki; Uchida, Shunsuke*

Proceedings of 14th International Conference on Nuclear Engineering (ICONE-14) (CD-ROM), 9 Pages, 2006/07

no abstracts in English

Journal Articles

Water chemistry of the JMTR IASCC irradiation loop system

Hanawa, Satoshi; Ogiyanagi, Jin; Mori, Yuichiro*; Saito, Junichi; Tsukada, Takashi

JAEA-Conf 2006-003, p.350 - 357, 2006/05

no abstracts in English

JAEA Reports

Design study of water chemistry control system for IASCC irradiation test

Mori, Yuichiro*; Ide, Hiroshi; Nabeya, Hideaki; Tsukada, Takashi

JAERI-Tech 2002-003, 32 Pages, 2002/02

JAERI-Tech-2002-003.pdf:2.24MB

In relation to the aging of Light Water Reactor (LWR), the Irradiation Assisted Stress Corrosion Cracking (IASCC) has been regarded as a significant and urgent issue for the reliability of in-core components of LWR, and the irradiation research on the IASCC is now under schedule. With the progress of the irradiation research on reactor materials, well-controlled environment conditions during irradiation testing are required. Especially for irradiation testing of IASCC studies, water chemistry control is essential in addition to the control of neutron fluence and irradiation temperature.According to these requirements, at the Japan Atomic Energy Research Institute (JAERI), an irradiation testing facility that simulates in-core environment of Boiling Water Reactor (BWR) has been designed to be installed in the Japan Materials Testing Reactor (JMTR). This facility is composed of the Saturated Temperature Capsules (SATCAP) that are installed into the JMTR's core to irradiate material specimens, the Water Control Unit that is able to supply high-temperature and high-pressure chemical controlled water to SATCAP, and other components.This report describes the design study of water chemistry control system of the Water Control Unit. The design work has been performed in the fiscal year 1999.

JAEA Reports

Design of water feeding system for IASCC irradiation tests at JMTR

Kanno, Masaru; Nabeya, Hideaki; Mori, Yuichiro*; Matsui, Yoshinori; Tobita, Masahiro*; Ide, Hiroshi; Itabashi, Yukio; Komori, Yoshihiro; Tsukada, Takashi; Tsuji, Hirokazu

JAERI-Tech 2001-080, 57 Pages, 2001/12

JAERI-Tech-2001-080.pdf:2.34MB

no abstracts in English

Oral presentation

Water chemistry in JMTR in-pile loop, 2; Calculation result of water chemistry in the loop

Mori, Yuichiro*; Hanawa, Satoshi; Sato, Tomonori; Ogiyanagi, Jin; Nabeya, Hideaki; Uchida, Shunsuke*

no journal, , 

no abstracts in English

Oral presentation

Water chemistry in JMTR in-pile loop, 3

Hanawa, Satoshi; Ogiyanagi, Jin; Sato, Tomonori; Mori, Yuichiro*; Miwa, Yukio; Uchida, Shunsuke*

no journal, , 

no abstracts in English

Oral presentation

Cation-exchange behavior of Rf in HNO$$_{3}$$/HF mixed solution, 2

Ishii, Yasuo; Tome, Hayato; Toyoshima, Atsushi; Asai, Masato; Nishinaka, Ichiro; Tsukada, Kazuaki; Nagame, Yuichiro; Miyashita, Sunao*; Mori, Tomotaka*; Suganuma, Hideo*; et al.

no journal, , 

Chemical properties of rutherfordium (Rf, the element 104) in HNO$$_{3}$$/HF mixed solutions have been investigated using cation-exchange chromatography. Distribution coefficients of Rf on the cation-exchange resin as a function of hydrofluoric-acid and nitric-acid concentrations have been measured precisely, and it was found that the strength of the fluoride complex formation of Rf is much weaker than those of lighter group 4 homologs Zr and Hf. The same result was obtained through the anion-exchange chromatography. These results enabled us to quantitatively account for the fluoride complexation of Rf.

Oral presentation

Fluoride complexation of Rf in HNO$$_3$$/HF solution

Ishii, Yasuo; Tome, Hayato; Toyoshima, Atsushi; Asai, Masato; Nishinaka, Ichiro; Tsukada, Kazuaki; Nagame, Yuichiro; Miyashita, Sunao*; Mori, Tomotaka*; Suganuma, Hideo*; et al.

no journal, , 

The cation-exchange behavior of rutherfordium(Rf) in HNO$$_3$$/HF solution has been studied based on an atom-at-a-time scale. In the symposium, we will discuss the fluoride complexation of rutherfordium in comparison with that of Zr, Hf and Th.

Oral presentation

Electronic structure of CeIrSi$$_3$$ studied by angle-resolved resonant photoemission spectroscopy

Toshimitsu, Takafumi; Okochi, Takuo; Yasui, Akira; Kobayashi, Masaki*; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Fujimori, Atsushi*; Yamagami, Hiroshi*; Miyauchi, Yuichiro*; et al.

no journal, , 

We performed angle-resolved resonant photoemission spectroscopy on CeIrSi$$_3$$. CeIrSi$$_3$$ is said to be the superconductor which lacks inversion symmetry and therefore the measurements of electronic conductivity, magnetoresistance, dHvA, and so on, have been made on so far. In this study, we observed extremely clear 4$$f$$ derived band dispersions and Fermi surfaces. By these obtained profiles and comparison with those predicted by LDA calculation, Ce 4$$f$$ electrons in CeIrSi$$_3$$ have relatively itinerant electronic states.

Oral presentation

Electronic structure of CeIrSi$$_{3}$$ and LaIrSi$$_{3}$$ by angle-resolved photoemission spectroscopy

Toshimitsu, Takafumi; Okochi, Takuo; Yasui, Akira; Kobayashi, Masaki*; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Fujimori, Atsushi; Yamagami, Hiroshi; Miyauchi, Yuichiro*; et al.

no journal, , 

no abstracts in English

Oral presentation

4f band structure and Fermi surfaces of CeIrSi$$_3$$ by soft X-ray angle-resolved resonant photoemission spectroscopy

Okochi, Takuo; Yasui, Akira; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Fujimori, Atsushi*; Yamagami, Hiroshi; Miyauchi, Yuichiro*; Okuda, Yusuke*; Settai, Rikio*; et al.

no journal, , 

We have investigated the bulk 4$$f$$ electronic structure of the non-centrosymmetric superconductor, CeIrSi$$_3$$ by soft X-ray angle-resolved photoemission spectroscopy. We have performed the angle-resolved 3$$d$$-4$$f$$ resonant photoemission and the comparison of the angle-resolved photoemission spectra of CeIrSi$$_3$$ with those of non-$$f$$ reference compound, LaIrSi$$_3$$ and revealed that the 4$$f$$ states of CeIrSi$$_3$$ well hybridized with the non-$$f$$ conduction bands.

Oral presentation

Sulfate complexation of element 104, Rf, in H$$_{2}$$SO$$_{4}$$/HNO$$_{3}$$ mixed solution ([H$$^{+}$$] = 1.0 M)

Li, Z.; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Sato, Tetsuya; Sato, Nozomi; Kikuchi, Takahiro; Sch$"a$del, M.*; Nagame, Yuichiro; Liang, X. H.*; et al.

no journal, , 

Cation-exchange behavior of $$^{261}$$Rf (T$$_{1/2}$$ = 78 s) produced in the $$^{248}$$Cm($$^{18}$$O, 5n) reaction was studied on a "one-atom-at-a-time" scale in H$$_{2}$$SO$$_{4}$$ (0.15-0.69 M)/HNO$$_{3}$$ mixed solutions ([H$$^{+}$$] = 1.0 M) using an automated ion-exchange separation apparatus coupled with the detection system for alpha-spectroscopy. It was found that adsorption probability (%ads) of $$^{261}$$Rf on cation-exchange resin decreases with increasing [HSO$$_{4}$$$$^{-}$$], showing a successive formation of its sulfate complexes. Rf exhibited much weaker formation of the complexes than the lighter homologues Zr and Hf, which is qualitatively in good agreement with theoretical calculations including relativistic effects.

32 (Records 1-20 displayed on this page)