JAEA
  • help
  • PC | SP
  • JP | EN
          
Refine your search：     
Report No.
 - 
Clear All
Search Results: Records 1-20 displayed on this page of 81

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

JAEA Reports

Fuel unloading work in decommissioning of the prototype fast breeder reactor Monju; First stage of Monju decommissioning project

Shiota, Yuki; Kudo, Junki; Tsuno, Hiromi; Takeuchi, Ryotaro; Ariyoshi, Hideo; Shiohama, Yasutaka; Hamano, Tomoharu; Takagi, Tsuyohiko; Nagaoki, Yoshihiro

JAEA-Technology 2023-002, 87 Pages, 2023/06

JAEA-Technology-2023-002.pdf:8.53MB

In the first stage of Monju decommissioning project, fuel unload work began to be carried out. There are two tasks in this work. One is Fuel Treatment and Storage work that gets rid of sodium on the fuel assemblies unloaded from Ex-Vessel fuel Storage Tank (EVST) and carries it in the storage pool, and the other is Fuel Unloading that the fuel assemblies in the reactor core is replaced with dummy fuels and stored in EVST. Fuel Treatment and Storage work and Fuel Unloading work are performed alternately, and 370 fuel assemblies in the core and 160 fuel assemblies in EVST are all carried to the storage pool. Monju had a large amount of sodium in the reactor vessel and EVST, and there was a residual risk of fuel failure due to the superposition of a large scale sodium fire. Therefore, in the first stage of the Monju decommissioning project, it was decided to take about 5.5 years to remove the residual risk by storing all the fuel rods in the fuel storage pool. There are few Fuel handling system of Sodium Fast Reactor in the world, so the driving record and experience are not enough. So, events that occur even if taken measure are assumed. The following three events apply to this; first, events that are difficult to prevent, events. Second, that are due to lack of experience, and final, events optimization of system is not enough. Plans were taken to suppress these events. This report summarizes the "Monju decommissioning project" work conducted so far in all four campaigns.

Journal Articles

Production of $$^{266}$$Bh in the $$^{248}$$Cm($$^{23}$$Na,5$$n$$)$$^{266}$$Bh reaction and its decay properties

Haba, Hiromitsu*; Fan, F.*; Kaji, Daiya*; Kasamatsu, Yoshitaka*; Kikunaga, Hidetoshi*; Komori, Yukiko*; Kondo, Narumi*; Kudo, Hisaaki*; Morimoto, Koji*; Morita, Kosuke*; et al.

Physical Review C, 102(2), p.024625_1 - 024625_12, 2020/08

https://doi.org/10.1103/PhysRevC.102.024625
 Times Cited Count：6 Percentile：59.56(Physics, Nuclear)

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

Production of $$^{88}$$Nb and $$^{170}$$Ta for chemical studies of element 105, Db, using the GARIS gas-jet system

Huang, M.*; Haba, Hiromitsu*; Murakami, Masashi*; Asai, Masato; Kaji, Daiya*; Kanaya, Jumpei*; Kasamatsu, Yoshitaka*; Kikunaga, Hidetoshi*; Kikutani, Yuki*; Komori, Yukiko*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 304(2), p.845 - 849, 2015/05

https://doi.org/10.1007/s10967-014-3877-4
 Times Cited Count：3 Percentile：25.85(Chemistry, Analytical)

A technique to utilize radioisotopes of Nb and Ta was developed for chemical studies of element 105, Db, by coupling a gas-jet transport system to the RIKEN gas-filled recoil ion separator (GARIS). The short-lived $$^{88}$$Nb and $$^{170}$$Ta were produced with nuclear reactions using a $$^{19}$$F beam whose energy was the same as that to produce $$^{262}$$Db. Then, they were separated with GARIS and extracted to a chemistry laboratory with the gas-jet transport system. By changing only magnetic field of GARIS and inserting an energy degrader and a shutter for recoil ions, we could deliver the $$^{88}$$Nb and $$^{170}$$Ta to a chemistry device for $$^{262}$$Db without changing other experimental conditions.

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

Solid-liquid extraction of Mo and W by Aliquat 336 from HCl solutions toward extraction chromatography experiments of Sg

Komori, Yukiko*; Yokokita, Takuya*; Kasamatsu, Yoshitaka*; Haba, Hiromitsu*; Toyoshima, Atsushi; Toyomura, Keigo*; Nakamura, Kohei*; Kanaya, Jumpei*; Huang, M.*; Kudo, Yuki*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1385 - 1388, 2015/02

https://doi.org/10.1007/s10967-014-3476-4
 Times Cited Count：2 Percentile：17.57(Chemistry, Analytical)

We studied solid-liquid extraction behavior of carrier-free Mo and W radiotracers onto an Aliquat 336-loaded resin from HCl solutions toward extraction chromatography experiments of element 106, seaborgium(Sg). Distribution coefficients ($${it K}$$$$_{d}$$) of Mo and W on the resin were determined as a function of HCl concentration by a batch method. On-line extraction chromatography of Mo and W was also carried out in 2-8 M HCl solutions with an automated rapid chemistry apparatus. The order of extraction probability from 2 to 8 M HCl was Mo$$>$$W, which reflected the order of the $${it K}$$$$_{d}$$ values in the batch experiment.

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.

Journal Articles

Production of $$^{262}$$Db in the $$^{248}$$Cm($$^{19}$$F,5$$n$$)$$^{262}$$Db reaction and decay properties of $$^{262}$$Db and $$^{258}$$Lr

Haba, Hiromitsu*; Huang, M.*; Kaji, Daiya*; Kanaya, Jumpei*; Kudo, Yuki*; Morimoto, Koji*; Morita, Kosuke*; Murakami, Masashi*; Ozeki, Kazutaka*; Sakai, Ryutaro*; et al.

Physical Review C, 89(2), p.024618_1 - 024618_11, 2014/02

https://doi.org/10.1103/PhysRevC.89.024618
 Times Cited Count：25 Percentile：82.3(Physics, Nuclear)

Journal Articles

Excitation functions for production of Rf isotopes in the $$^{248}$$Cm + $$^{18}$$O reaction

Murakami, Masashi*; Goto, Shinichi*; Murayama, Hirofumi*; Kojima, Takayuki*; Kudo, Hisaaki*; Kaji, Daiya*; Morimoto, Koji*; Haba, Hiromitsu*; Kudo, Yuki*; Sumita, Takayuki*; et al.

Physical Review C, 88(2), p.024618_1 - 024618_8, 2013/08

https://doi.org/10.1103/PhysRevC.88.024618
 Times Cited Count：15 Percentile：66.57(Physics, Nuclear)

Production cross sections of Rf isotopes in the $$^{248}$$Cm + $$^{18}$$O reaction were measured at the beam energy range of 88.2 to 101.3 MeV by use of a gas-filled recoil ion separator. The excitation functions of $$^{260}$$Rf, $$^{261a}$$Rf, and $$^{262}$$Rf were obtained together with those of spontaneously fissioning nuclides which have few-second half-lives and have been assigned to $$^{261b}$$Rf and a longer-lived state of $$^{262}$$Rf. The excitation function of few-second spontaneously fissioning nuclide exhibited the maximum cross section at the $$^{18}$$O beam energy of 94.8 MeV. The shape of the excitation function was almost the same as that of $$^{261a}$$Rf, whereas it was quite different from those of $$^{260}$$Rf and $$^{262}$$Rf. A few-second spontaneously fissioning nuclide previously reported as $$^{261b}$$Rf and $$^{262}$$Rf observed in$$^{248}$$Cm + $$^{18}$$O reaction was identified as $$^{261b}$$Rf.

Journal Articles

New result in the production and decay of an isotope, $$^{278}$$113 of the 113th element

Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sumita, Takayuki*; Wakabayashi, Yasuo*; Yoneda, Akira*; Tanaka, Kengo*; et al.

Journal of the Physical Society of Japan, 81(10), p.103201_1 - 103201_4, 2012/10

https://doi.org/10.1143/JPSJ.81.103201
 Times Cited Count：167 Percentile：97.27(Physics, Multidisciplinary)

An isotope of the 113th element, $$^{278}$$113, was produced in a nuclear reaction with a $$^{70}$$Zn beam on a $$^{209}$$Bi target. We observed six consecutive $$alpha$$ decays following the implantation of a heavy particle in nearly the same position in the semiconductor detector, in extremely low background condition. The fifth and sixth decays are fully consistent with the sequential decays of $$^{262}$$Db and $$^{258}$$Lr both in decay energies and decay times. This indicates that the present decay chain consisted of $$^{278}$$113, $$^{274}$$Rg (Z = 111), $$^{270}$$Mt (Z = 109), $$^{266}$$Bh (Z = 107), $$^{262}$$Db (Z = 105), and $$^{258}$$Lr (Z = 103) with firm connections. This result, together with previously reported results from 2004 and 2007, conclusively leads the unambiguous production and identification of the isotope $$^{278}$$113, of the 113th element.

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

https://doi.org/10.1524/ract.2012.1898
 Times Cited Count：13 Percentile：69.01(Chemistry, Inorganic & Nuclear)

Journal Articles

Production of $$^{265}$$Sg in the $$^{248}$$Cm($$^{22}$$Ne,5$$n$$)$$^{265}$$Sg reaction and decay properties of two isomeric states in $$^{265}$$Sg

Haba, Hiromitsu*; Kaji, Daiya*; Kudo, Yuki*; Morimoto, Koji*; Morita, Kosuke*; Ozeki, Kazutaka*; Sakai, Ryutaro*; Sumita, Takayuki*; Yoneda, Akira*; Kasamatsu, Yoshitaka*; et al.

Physical Review C, 85(2), p.024611_1 - 024611_11, 2012/02

https://doi.org/10.1103/PhysRevC.85.024611
 Times Cited Count：52 Percentile：91.35(Physics, Nuclear)

Two isomeric states in $$^{265}$$Sg, i.e, $$^{265}$$Sg$$^{a}$$ and $$^{265}$$Sg$$^{b}$$ were produced in the $$^{248}$$Cm($$^{22}$$Ne,5$$n$$) reaction. Decay properties of $$^{265}$$Sg$$^{a,b}$$ were investigated with a rotating-wheel apparatus for $$alpha$$ and spontaneous fission (SF) spectrometry under low background condition attained by a gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator. Based on genetically correlated $$alpha$$-$$alpha$$ (-$$alpha$$) and $$alpha$$-SF decay chains, 18 and 24 events were assigned to $$^{265}$$Sg$$^{a}$$ and $$^{265}$$Sg$$^{b}$$, respectively. The half-life and $$alpha$$-particle energy of $$^{265}$$Sg$$^{a}$$ were measured to be $$8.5^{+2.6}_{-1.6}$$ s and $$8.84 pm 0.05$$ MeV, respectively, and those of $$^{265}$$Sg$$^{b}$$ were $$14.4^{+3.7}_{-2.5}$$ s and $$8.69 pm 0.05$$ MeV.

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

https://doi.org/10.1246/bcsj.20110126
 Times Cited Count：17 Percentile：49.33(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

Production and decay properties of $$^{264}$$Hs and $$^{265}$$Hs

Sato, Nozomi; Haba, Hiromitsu*; Ichikawa, Takatoshi*; Kaji, Daiya*; Kudo, Yuki*; Morimoto, Koji*; Morita, Kosuke*; Ozeki, Kazutaka*; Sumita, Takayuki*; Yoneda, Akira*; et al.

Journal of the Physical Society of Japan, 80(9), p.094201_1 - 094201_7, 2011/09

https://doi.org/10.1143/JPSJ.80.094201
 Times Cited Count：15 Percentile：65.33(Physics, Multidisciplinary)

Decay properties of $$^{264}$$Hs and $$^{265}$$Hs produced in the $$^{207,208}$$Pb($$^{58}$$Fe, $$xn$$) [$$x$$=1, 2] reactions were studied using a gas-filled recoil ion separator at the linear accelerator facility of RIKEN. A total of 6 decay chains were assigned to $$^{264}$$Hs. Cross sections for the $$^{264}$$Hs production in the $$^{208}$$Pb($$^{58}$$Fe,$$2n$$) and $$^{207}$$Pb($$^{58}$$Fe,$$n$$) reactions were measured to be $$2.8^{+6.5}_{-2.3}$$pb and $$6.9^{+4.4}_{-3.1}$$pb, respectively. The isotope $$^{264}$$Hs decayed with a half-life of $$0.751^{+0.518}_{-0.218}$$ms by $$alpha$$-particle emission and spontaneous fission. The $$alpha$$-particle energy of $$^{264}$$Hs was observed at 10.61$$pm$$0.04 and 10.80$$pm$$0.08 MeV. The spontaneous fission branch of $$^{264}$$Hs was found to be $$17^{+38}_{-14}%$$.

Journal Articles

Extraction of chromatographic behavior of Rf, Zr, and Hf in HCl solution with styrenedivinylbenzene copolymer resin modified by TOPO (trioctylphosphine oxide)

Toyoshima, Atsushi; Kasamatsu, Yoshitaka*; Tsukada, Kazuaki; Asai, Masato; Ishii, Yasuo; Tome, Hayato*; Nishinaka, Ichiro; Sato, Tetsuya; Nagame, Yuichiro; Sch$"a$del, M.; et al.

Journal of Nuclear and Radiochemical Sciences, 11(1), p.7 - 11, 2010/06

https://doi.org/10.14494/jnrs.11.7

The extraction behavior of rutherfordium (Rf) into trioctylphosphine oxide (TOPO) from 2.0 - 7.0 M HCl solution was studied together with that of the homologues Zr and Hf. The extracted yields of Rf, Zr, and Hf increased with an increase of HCl concentration, and the sequence of their extraction was Zr $$>$$ Hf $$geq$$ Rf. It is suggested that the stability of the RfCl$$_{4}$$$$cdot$$2(TOPO) complex is lower than that of the corresponding species of the homologues.

Journal Articles

Recent progress in the energy recovery linac project in Japan

Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05

http://accelconf.web.cern.ch/AccelConf/IPAC10/papers/tupe091.pdf

Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.

Journal Articles

Anionic fluoro complex of element 105, Db

Kasamatsu, Yoshitaka*; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Li, Z.; Ishii, Yasuo; Tome, Hayato*; Sato, Tetsuya; Kikuchi, Takahiro; Nishinaka, Ichiro; et al.

Chemistry Letters, 38(11), p.1084 - 1085, 2009/10

https://doi.org/10.1246/cl.2009.1084
 Times Cited Count：15 Percentile：48.93(Chemistry, Multidisciplinary)

We report on the characteristic anion-exchange behavior of the superheavy element dubnium (Db) with atomic number Z = 105 in HF/HNO$$_{3}$$ solution at the fluoride ion concentration [F$$^{-}$$] = 0.003 M. The result clearly demonstrates that the fluoro complex formation of Db is significantly different from that of the group-5 homologue Ta in the 6th period of the periodic table while the behavior of Db is similar to that of the lighter homologue Nb in the 5th period.

Journal Articles

Decay properties of $$^{266}$$Bh and $$^{262}$$Db produced in the $$^{248}$$Cm + $$^{23}$$Na reaction

Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sato, Nozomi*; Sumita, Takayuki*; Yoneda, Akira*; Ichikawa, Takatoshi*; et al.

Journal of the Physical Society of Japan, 78(6), p.064201_1 - 064201_6, 2009/06

https://doi.org/10.1143/JPSJ.78.064201
 Times Cited Count：30 Percentile：78.34(Physics, Multidisciplinary)

Decay properties of an isotope $$^{266}$$Bh and its daughter nucleus $$^{262}$$Db produced by the $$^{248}$$Cm($$^{23}$$Na,5$$n$$) reaction were studied by using a gas-filled recoil separator coupled with a position-sensitive semiconductor detector. $$^{266}$$Bh was clearly identified from the correlation of the known nuclide, $$^{262}$$Db. The obtained decay properties of $$^{266}$$Bh and $$^{262}$$Db are consistent with those observed in the $$^{278}$$113 chain, which provided further confirmation of the discovery of $$^{278}$$113.

Journal Articles

Production of a new hassium isotope $$^{263}$$Hs

Kaji, Daiya*; Morimoto, Koji*; Sato, Nozomi*; Ichikawa, Takatoshi*; Ideguchi, Eiji*; Ozeki, Kazutaka*; Haba, Hiromitsu*; Koura, Hiroyuki; Kudo, Yuki*; Ozawa, Akira*; et al.

Journal of the Physical Society of Japan, 78(3), p.035003_1 - 035003_2, 2009/03

https://doi.org/10.1143/JPSJ.78.035003

A new hassium isotopes $$^{263}$$Hs is directly produced for the first time. The experiment was performed at the linear accelerator (RILAC) facility in RIKEN (the Institute of Physical and Chemical Research) from Jun. 19 to 25. In the 25-h irradiation of $$^{58}$$Fe on $$^{206}$$Pb and 46-h irradiation of $$^{56}$$Fe on $$^{208}$$Pb, 8 decay chains and 1 decay chain, respectively, were observed. All decay chains were assigned to subsequent decays from $$^{263}$$Hs. The half-life of $$^{263}$$Hs is 0.60$$^{+0.30}_{-0.15}$$ ms. In this experiment, the total beam dose was $$4.1times10^{17}$$ ions for $$^{58}$$Fe and $$6.2times10^{17}$$ ions for $$^{56}$$Fe. The production cross section corresponding to 8 decay events and 1 decay chain was deduced to be 21$$^{+10}_{-8}$$ pb and 1.6$$^{+3.7}_{-1.3}$$ pb by assuming that the transmission of the system is 80%.

81 (Records 1-20 displayed on this page)