JAEA
  • help
  • PC | SP
  • JP | EN
          
Refine your search：     
Report No.
 - 
Clear All
Search Results: Records 1-13 displayed on this page of 13
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

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

https://doi.org/10.1051/epjconf/201613107005
 Times Cited Count：3 Percentile：72.98(Chemistry, Inorganic & Nuclear)

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

Decomposition studies of group 6 hexacarbonyl complexes, 1; Production and decomposition of Mo(CO)$$_6$$ and W(CO)$$_6$$

Usoltsev, I.*; Eichler, R.*; Wang, Y.*; Even, J.*; Yakushev, A.*; Haba, Hiromitsu*; Asai, Masato; Brand, H.*; Di Nitto, A.*; D$"u$llmann, Ch. E.*; et al.

Radiochimica Acta, 104(3), p.141 - 151, 2016/03

https://doi.org/10.1515/ract-2015-2445
 Times Cited Count：31 Percentile：95.03(Chemistry, Inorganic & Nuclear)

Conditions of the production and decomposition of hexacarbonyl complexes of short-lived Mo and W isotopes were investigated to study thermal stability of the heaviest group 6 hexacarbonyl complex Sg(CO)$$_6$$. A tubular flow reactor was tested to decompose the hexacarbonyl complexes and to extract the first bond dissociation energies. A silver was found to be the most appropriate reaction surface to study the decomposition of the group 6 hexacarbonyl. It was found that the surface temperature at which the decomposition occurred was correlated to the first bond dissociation energy of Mo(CO)$$_6$$ and W(CO)$$_6$$, indicating that the first bond dissociation energy of Sg(CO)$$_6$$ could be determined with this technique.

Journal Articles

In situ synthesis of volatile carbonyl complexes with short-lived nuclides

Even, J.*; Ackermann, D.*; Asai, Masato; Block, M.*; Brand, H.*; Di Nitto, A.*; D$"u$llmann, Ch. E.*; Eichler, R.*; Fan, F.*; Haba, Hiromitsu*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 303(3), p.2457 - 2466, 2015/03

https://doi.org/10.1007/s10967-014-3793-7
 Times Cited Count：15 Percentile：77.56(Chemistry, Analytical)

Rapid In situ synthesis of metal carbonyl complexes has been demonstrated using short-lived isotopes produced in nuclear fission and fusion reactions. The short-lived isotopes with high recoil energy directly react with carbon-monoxides and form carbonyl complexes. Only highly volatile complexes were fast transported in a gas stream to counting and chemistry devices. Short-lived Mo, Tc, Ru, Rh, W, Re, Os, and Ir were found to form volatile carbonyl complexes, while no volataile complex of Hf and Ta were detected. This technique has been applied to a chemical investigation of the superheavy element Sg (atomic number 106), and will be applicable to various fields of nuclear science with short-lived transition metal isotopes.

Journal Articles

Synthesis and detection of a Seaborgium carbonyl complex

Even, J.*; Yakushev, A.*; D$"u$llmann, Ch. E.*; Haba, Hiromitsu*; Asai, Masato; Sato, Tetsuya; Brand, H.*; Di Nitto, A.*; Eichler, R.*; Fan, F. L.*; et al.

Science, 345(6203), p.1491 - 1493, 2014/09

https://doi.org/10.1126/science.1255720
 Times Cited Count：63 Percentile：83.28(Multidisciplinary Sciences)

A new superheavy element complex, a seaborgium carbonyl, has been successfully synthesized, and its adsorption property has been studied using a cryo-thermochromatography and $$alpha$$-detection apparatus COMPACT. Nuclear reaction products of short-lived $$^{265}$$Sg preseparated with a gas-filled recoil ion separator GARIS at RIKEN were directly injected into a gas cell filled with He/CO mixture gas, and chemical reaction products of volatile carbonyl complexes were trasported to COMPACT. The Sg carbonyl complex detected with COMPACT was found to be very volatile with adsorption enthalpy of $$-$$50 kJ/mol, from which we have concluded that this complex should be a Sg hexacarbonyl Sg(CO)$$_{6}$$. This is the first synthesis of organometallic compounds of transactinide elements for which only simple inorganic comounds have been synthesized so far.

JAEA Reports

Chaotic behavior in a system simulating the pressure balanced injection system; Analysis of passive safety reactor behavior, JAERI's nuclear research promotion program, H12-012 (Contract research)

Madarame, Haruki*; Okamoto, Koji*; Tanaka, Gentaro*; Morimoto, Yuichiro*; Sato, Akira*; Kondo, Masaya

JAERI-Tech 2003-017, 156 Pages, 2003/03

JAERI-Tech-2003-017.pdf:5.31MB

no abstracts in English

Oral presentation

$$alpha$$-$$gamma$$ coincidence spectroscopy of $$^{259}$$Rf using a mixed Cf target

Asai, Masato; Tsukada, Kazuaki; Kasamatsu, Yoshitaka*; Sato, Tetsuya; Toyoshima, Atsushi; Ishii, Yasuo; Takahashi, Ryuta; Nagame, Yuichiro; Ishii, Tetsuro; Nishinaka, Ichiro; et al.

no journal, , 

$$gamma$$ rays following the $$alpha$$ decay of $$^{259}$$Rf have been observed for the first time by means of $$alpha$$-$$gamma$$ coincidence spectroscopy. $$^{259}$$Rf was produced via the $$^{251}$$Cf($$^{12}$$C,4n)$$^{259}$$Rf reaction at the JAEA tandem accelerator. Two $$gamma$$ lines were observed at 97.3 and 146.7 keV in coincidence with the 8770 keV $$alpha$$ transition of $$^{259}$$Rf. The energy differences and intensities of these $$gamma$$ transitions, which are very similar to those in the $$alpha$$ decay of $$^{257}$$No with the same neutron number N = 155, allow us to assign the 3/2$$^{+}$$[622] configuration to the 146.7 keV level in $$^{255}$$No as well as to the ground state of $$^{259}$$Rf. This result indicates that the order of neutron orbitals should be inverted between $$^{255}$$Fm and $$^{257}$$No in $$N=155$$ isotones.

Oral presentation

Alpha-decay spectroscopy of Rf and Lr isotopes

Asai, Masato; Haba, Hiromitsu*; Tsukada, Kazuaki; Sato, Nozomi; Kasamatsu, Yoshitaka*; Kaji, Daiya*; Morimoto, Koji*; Morita, Kosuke*; Sato, Tetsuya; Toyoshima, Atsushi; et al.

no journal, , 

Alpha-decay spectroscopy of odd-mass Rf and Lr isotopes was performed to establish proton and neutron single-particle orbitals. $$gamma$$ rays following the $$alpha$$ decay of $$^{259}$$Rf were observed for the first time through the $$alpha$$-$$gamma$$ coincidence measurement, and the neutron configuration of the ground state of $$^{259}$$Rf was assigned. It was found that the ground-state configuration of $$^{259}$$Rf is different from those of the lighter N = 155 isotones $$^{255}$$Fm and $$^{253}$$Cf. For the Lr isotopes, the proton configurations of the ground and isomeric states in $$^{255}$$Lr and the ground states of $$^{257}$$Lr and $$^{259}$$Lr were definitely identified through the high-resolution $$alpha$$ fine structure spectroscopy. Theoretical calculations based on the macroscopic-microscopic model revealed that the change of the ground-state configuration in the N = 155 isotones is strongly associated with the rapidly decreasing hexadecapole deformation with increasing atomic number.

Oral presentation

$$alpha$$-$$gamma$$ and high-resolution $$alpha$$ fine-structure spectroscopy for the heaviest nuclei

Asai, Masato; Haba, Hiromitsu*; Tsukada, Kazuaki; Sato, Nozomi; Kasamatsu, Yoshitaka*; Kaji, D.*; Morimoto, Koji*; Morita, Kosuke*; Sato, Tetsuya; Toyoshima, Atsushi; et al.

no journal, , 

Alpha-gamma and high-resolution $$alpha$$ fine-structure spectroscopy of Rf and Lr isotopes was performed to clarify the nuclear structure of superheavy nuclei. $$gamma$$ rays following the $$alpha$$ decay of $$^{259}$$Rf were observed for the first time through the $$alpha$$-$$gamma$$ coincidence measurement, and the neutron configuration of the ground state of $$^{259}$$Rf was assigned. It was found that the ground-state configuration of $$^{259}$$Rf is different from those of the lighter N = 155 isotones $$^{255}$$Fm and $$^{253}$$Cf. For the Lr isotopes, the proton configurations of the ground and isomeric states in $$^{255}$$Lr and the ground states of $$^{257}$$Lr and $$^{259}$$Lr were definitely identified through the high-resolution $$alpha$$ fine structure spectroscopy. Theoretical calculations based on the macroscopic-microscopic model revealed that the change of the ground-state configuration in the N = 155 isotones is strongly associated with the rapidly decreasing hexadecapole deformation with increasing atomic number.

Oral presentation

High-resolution $$alpha$$ fine-structure spectroscopy for studying nuclear structure of heavy nuclei

Asai, Masato; Haba, Hiromitsu*; Sato, Nozomi; Kasamatsu, Yoshitaka*; Kaji, Daiya*; Morimoto, Koji*; Morita, Kosuke*; Shima, Yosuke*; Shibata, Michihiro*; Tsukada, Kazuaki; et al.

no journal, , 

We have developed high-resolution $$alpha$$ fine-structure spectroscopy for studying nuclear structure of short-lived heavy actinide nuclei. It has been demonstrated that spin-parities and single-particle configurations of the ground state of a parent nucleus as well as excited states in a daughter nucleus can be determined only through the measured $$alpha$$ singles spectrum. To achieve a good $$alpha$$ energy resolution of $$sim$$11 keV, conditions to make a thin $$alpha$$ source have been optimized. Using this technique, we have identified proton single-particle configurations of $$^{rm 255g}$$Lr, $$^{rm 255m}$$Lr, $$^{257}$$Lr, and $$^{259}$$Lr for the first time.

Oral presentation

Fission properties of $$^{258}$$Md produced in the $$^{4}$$He+$$^{254}$$Es reaction

Nishio, Katsuhisa; Hirose, Kentaro; Makii, Hiroyuki; Orlandi, R.; Kean, K. R.*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi*; Sato, Tetsuya; Ito, Yuta; et al.

no journal, , 

no abstracts in English

Oral presentation

Fission experiment using Es-254 at JAEA Tokai tandem accelerator facility

Hirose, Kentaro; Nishio, Katsuhisa; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Asai, Masato; Sato, Tetsuya; Ito, Yuta; Suzaki, Fumi; Nagame, Yuichiro*; et al.

no journal, , 

A specific phenomenon was found in fission-fragment mass distributions for nuclides around A=258 by spontaneous fission measurements. Fm256 splits into light and heavy fragments, like uranium isotopes, making two peaks in their mass distribution, whereas a sharp single peak was found in that of Fm258 which has only two more neutrons. In order to study such a specific phenomenon more widely, we performed an experiment of the multinucleon transfer fission in the O18+Es254 reaction at JAEA Tokai tandem accelerator facility.

Oral presentation

Fission of $$^{258}$$Md produced in the $$^{4}$$He + $$^{254}$$Es reaction

Nishio, Katsuhisa; Hirose, Kentaro; Makii, Hiroyuki; Orlandi, R.; Kean, K. R.*; Tsukada, Kazuaki; Toyoshima, Atsushi*; Asai, Masato; Sato, Tetsuya; Chiera, N. M.*; et al.

no journal, , 

no abstracts in English

Oral presentation

Fission of $$^{258}$$Md produced in the $$^{4}$$He + $$^{254}$$Es reaction

Nishio, Katsuhisa; Hirose, Kentaro; Makii, Hiroyuki; Orlandi, R.; Kean, K. R.*; Tsukada, Kazuaki; Toyoshima, Atsushi*; Asai, Masato; Sato, Tetsuya; Chiera, N. M.*; et al.

no journal, , 

no abstracts in English

13 (Records 1-13 displayed on this page)
  • 1