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Journal Articles

Origin of the dramatic change of fission mode in fermium isotope investigated using Langevin equations

Aritomo, Yoshihiro*; Miyamoto, Yuya*; Nishio, Katsuhisa

Nippon Butsuri Gakkai-Shi, 75(10), p.631 - 636, 2020/10

no abstracts in English

Journal Articles

Simultaneous determination of neutron-induced fission and radiative capture cross sections from decay probabilities obtained with a surrogate reaction

P$'e$rez S$'a$nchez, R.*; Jurado, B.*; M$'e$ot, V.*; Roig, O.*; Dupuis, M.*; Bouland, O.*; Denis-Petit, D.*; Marini, P.*; Mathieu, L.*; Tsekhanovich, I.*; et al.

Physical Review Letters, 125(12), p.122502_1 - 122502_5, 2020/09

 Times Cited Count:0

JAEA Reports

Production of the minor actinide sources using the electrodeposition method

Nakamura, Satoshi; Kimura, Takahiro; Ban, Yasutoshi; Tsubata, Yasuhiro; Matsumura, Tatsuro

JAEA-Technology 2020-009, 22 Pages, 2020/08

JAEA-Technology-2020-009.pdf:2.92MB

Partitioning and transmutation technology division is planning to measure fission rate ratios that contribute to validate nuclear data of minor actinides (MA). For this purpose, MA sources for fission chambers were prepared using electrodeposition method. The radioactivity of each MA source was quantified, and its uncertainty was evaluated. Seven types of MA sources with different radioactivity were prepared using four nuclides of $$^{237}$$Np, $$^{241}$$Am, $$^{243}$$Am, and $$^{244}$$Cm. A $$^{244}$$Cm source solution of which radioactivity was quantified by isotope dilution method was used to prepare working standard sources of $$^{244}$$Cm. The radioactivities were quantified as 1461 Bq, 2179 Bq, and 2938 Bq for $$^{237}$$Np sources, 1.428 MBq for $$^{241}$$Am source, 370.5 kBq and 89.57 kBq for $$^{243}$$Am sources, and 2.327 MBq for $$^{244}$$Cm source with, the uncertainty of 0.35% (1$$sigma$$). This report summarizes the method for preparation and quantification of MA sources, and uncertainty evaluation.

Journal Articles

First online operation of TRIGA-TRAP

Grund, J.*; Asai, Masato; Blaum, K.*; Block, M.*; Chenmarev, S.*; D$"u$llmann, Ch. E.*; Eberhardt, K.*; Lohse, S.*; Nagame, Yuichiro*; Nagy, Sz.*; et al.

Nuclear Instruments and Methods in Physics Research A, 972, p.164013_1 - 164013_8, 2020/08

We report on the successful coupling of the Penning-trap mass spectrometry setup TRIGA-TRAP to the research reactor TRIGA Mainz. This offers the possibility to perform direct high-precision mass measurements of short-lived nuclei produced in neutron-induced fission of a $$^{235}$$U target located near the reactor core. An aerosol-based gas-jet system is used for efficient transport of short-lived neutron-rich nuclei from the target chamber to a surface ion source. In conjunction with new ion optics and extended beam monitoring capabilities, the experimental setup has been fully commissioned. The design of the surface ion source, efficiency studies and first results are presented.

Journal Articles

$$beta$$-delayed fission of isomers in $$^{188}$$Bi

Andel, B.*; Andreyev, A. N.; Antalic, S.*; Al Monthery, M.*; Barzakh, A.*; Bissell, M. L.*; Chrysalidis, K.*; 29 of others*

Physical Review C, 102(1), p.014319_1 - 014319_12, 2020/07

Journal Articles

Effects of multichance fission on isotope dependence of fission fragment mass distributions at high energies

Tanaka, Shoya; Aritomo, Yoshihiro*; Miyamoto, Yuya*; Hirose, Kentaro; Nishio, Katsuhisa

Physical Review C, 100(6), p.064605_1 - 064605_6, 2019/12

 Times Cited Count:0 Percentile:100(Physics, Nuclear)

Fission fragment mass distributions of $$^{234-240}$$U, $$^{236-242}$$Np, and $$^{238-244}$$Pu are studied using the Langevin approach in the widely excitation energy range as $$E^{*}$$ = 15-55 MeV. In the present calculation, neutron emission before fission, so called multichance fission, was introduced. The calculated results well demonstrated the experimental data, which shows the double-peak structure up to the highest excitation energies and the clear dependence on the initial fissioning nuclides. The trend is nicely correlated with the neutron binding energy of the compound nucleus that dominates the neutron emission probability before fission.

Journal Articles

Validation of the multinucleon transfer method for the determination of the fission barrier height

Kean, K. R.; Nishio, Katsuhisa; Hirose, Kentaro; Vermeulen, M. J.; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Andreyev, A. N.; Tsekhanovich, I.*; Chiba, Satoshi*

Physical Review C, 100(1), p.014611_1 - 014611_6, 2019/07

 Times Cited Count:0 Percentile:100(Physics, Nuclear)

Journal Articles

Origin of the dramatic change of fission mode in fermium isotopes investigated using Langevin equations

Miyamoto, Yuya*; Aritomo, Yoshihiro*; Tanaka, Shoya; Hirose, Kentaro; Nishio, Katsuhisa

Physical Review C, 99(5), p.051601_1 - 051601_7, 2019/05

 Times Cited Count:4 Percentile:16.29(Physics, Nuclear)

Journal Articles

Disposal and recycling; Safer disposal and reassuring recycling

Nishihara, Kenji

ImPACT Fujita Puroguramu Kokai Seika Hokokukai "Kaku Henkan Niyoru Koreberu Hoshasei Haikibutsu No Ohaba Na Teigen, Shigenka" Seika Hokokusho, Shiryoshu, p.28 - 31, 2019/03

In this project, long-lived fission products (LLFP) contained in conventional high-level radioactive wastes are separated and their life is reduced, and elements that can be used as resources are separated. By shortening the life of LLFP, it has been shown that it may be possible to dispose in intermediate depth of several tens of meters, meeting safety requirements, instead of geological disposal. In addition, for reassuring recycling of usable elements, possible exposure pathways were evaluated to estimate the safe concentration level of radioactivity.

Journal Articles

Investigation of system for volume-reduction and recycling of HLW

Nishihara, Kenji

ImPACT Fujita Puroguramu Kokai Seika Hokokukai "Kaku Henkan Niyoru Koreberu Hoshasei Haikibutsu No Ohaba Na Teigen, Shigenka" Seika Hokokusho, Shiryoshu, p.130 - 133, 2019/03

High level radioactive waste contains elements with various characteristics. It is possible to reduce the load on the disposal site by separating them according to those characteristics and appropriately dealing with them. In this project, we are working to shorten the life span of long-lived fission products (LLFP). When this technology is realized, high-level radioactive wastes will become new radioactive wastes with low radioactivity. As a result of investigation of disposal concept of new radioactive waste, it turned out that intermediate-depth disposal currently considered for low level radioactive waste may be suitable. Intermediate-depth disposal is a method of small-scale disposal in shallow locations as compared to geological disposal for conventional high-level radioactive waste. We conducted a safety assessment when this disposal is applied to new radioactive wastes, and found that it is possible to safely dispose of for the four LLFPs addressed by this project.

Journal Articles

Observation of the competing fission modes in $$^{178}$$Pt

Tsekhanovich, I.*; Andreyev, A. N.; Nishio, Katsuhisa; Denis-Petit, D.*; Hirose, Kentaro; Makii, Hiroyuki; Matheson, Z.*; Morimoto, Koji*; Morita, Kosuke*; Nazarewicz, W.*; et al.

Physics Letters B, 790, p.583 - 588, 2019/03

 Times Cited Count:8 Percentile:5.43(Astronomy & Astrophysics)

Journal Articles

Disposal of radioactive waste and partitioning-transmutation; Consideration of waste disposal from view point of source term

Nishihara, Kenji

Genshiryoku Bakkuendo Kenkyu (CD-ROM), 25(2), p.131 - 134, 2018/12

Impact of reduction of source term on design and safety assessment of disposal concept for high level radioactive waste is considered. Reduction of source term in partitioning and transmutation technology is shown with impact on disposal concept. Moreover, cost and technological readiness is outlined.

Journal Articles

A New detector system for the measurement of high-energy prompt $$gamma$$-rays for low-energy neutron induced fission

Makii, Hiroyuki; Nishio, Katsuhisa; Hirose, Kentaro; Orlandi, R.; L$'e$guillon, R.*; Ogawa, Tatsuhiko; Soldner, T.*; Hambsch, F.-J.*; A$"i$che, M.*; Astier, A.*; et al.

Nuclear Instruments and Methods in Physics Research A, 906, p.88 - 96, 2018/10

 Times Cited Count:3 Percentile:38.72(Instruments & Instrumentation)

We have developed a new setup to measure prompt fission $$gamma$$-ray spectra in neutron induced fission up to energies sufficient to reveal the structure associated with giant dipole resonances of fission fragments. The setup consists of multi-wire proportional counters, to detect both fission fragments in coincidence, and two large volume (101.6 mm in diameter and 127.0 mm in length) LaBr$$_{3}$$(Ce) scintillators, to measure the $$gamma$$-rays. The setup was used to obtain the prompt fission $$gamma$$-ray spectrum for thermal neutron induced fission of $$^{235}$$U at the PF1B cold-neutron beam facility of the Institut Laue-Langevin, Grenoble, France. We have successfully measured the $$gamma$$-ray spectrum up to energies of about 20 MeV, what extends the currently known $$gamma$$-ray spectrum limit to higher energies by approximately a factor of two.

Journal Articles

Role of breakup processes in deuteron-induced spallation reactions at 100-200 MeV/nucleon

Nakayama, Shinsuke; Furutachi, Naoya; Iwamoto, Osamu; Watanabe, Yukinobu*

Physical Review C, 98(4), p.044606_1 - 044606_8, 2018/10

 Times Cited Count:6 Percentile:24.15(Physics, Nuclear)

Use of deuteron-induced spallation reactions at intermediate energies has recently been proposed for transmutation of several long-lived fission products (LLFPs). In the design study of a transmutation system using a deuteron primary beam, accurate cross section data of deuteron-induced reactions on the LLFPs are indispensable. In the present study, production cross sections of residual nuclei in the deuteron-induced reactions on $$^{93}$$Zr and $$^{107}$$Pd at $$100-200$$ MeV/nucleon are analyzed using DEURACS, in which the breakup processes are explicitly taken into account. The calculated values reproduced the experimental data quantitatively well. From a component-by-component analysis, it was found that the components of nucleon absorption make the significant contributions to residual nuclei production. This result strongly indicates that consideration of the breakup processes is essentially important to predict production of residual nuclei in deuteron-induced reactions.

Journal Articles

First accurate normalization of the $$beta$$-delayed $$alpha$$ decay of $$^{16}$$N and implications for the $$^{12}$$C($$alpha$$,$$gamma$$)$$^{16}$$O astrophysical reaction rate

Kirsebom, O. S.*; Tengblad, O.*; Andreyev, A. N.; 41 of others*

Physical Review Letters, 121(14), p.142701_1 - 142701_6, 2018/10

 Times Cited Count:4 Percentile:41.05(Physics, Multidisciplinary)

Journal Articles

Release and transport behaviors of non-gamma-emitting fission products and actinides in steam and hydrogen atmospheres

Miwa, Shuhei; Ducros, G.*; Hanus, E.*; Bottomley, P. D. W.*; Van Winckel, S.*; Osaka, Masahiko

Nuclear Engineering and Design, 326, p.143 - 149, 2018/01

 Times Cited Count:0 Percentile:100(Nuclear Science & Technology)

The release and transport behaviors of 13 non-gamma-emitting fission products (FPs) and actinides in steam and hydrogen atmospheres were investigated based on the chemical analysis of their deposits on the components of VERCORS test loops. The new findings were obtained; strontium release was significantly enhanced in hydrogen atmosphere and a part of released strontium was transported towards the lower temperature region, uranium release was enhanced in steam atmosphere but most of released uranium deposited at high temperature region.

Journal Articles

Nuclear fission; A Review of experimental advances and phenomenology

Andreyev, A.; Nishio, Katsuhisa; Schmidt, K.-H.*

Reports on Progress in Physics, 81(1), p.016301_1 - 016301_61, 2018/01

 Times Cited Count:48 Percentile:7.68(Physics, Multidisciplinary)

Journal Articles

Cutting-edge studies on nuclear data for continuous and emerging need, 3; Recent advancement of fission studies; Experimental and theoretical approaches

Nishio, Katsuhisa; Chiba, Satoshi*

Nippon Genshiryoku Gakkai-Shi, 59(12), p.717 - 721, 2017/12

no abstracts in English

Journal Articles

Four-dimensional Langevin approach to low-energy nuclear fission of $$^{236}$$U

Ishizuka, Chikako*; Usang, M. D.*; Ivanyuk, F. A.*; Maruhn, J. A.*; Nishio, Katsuhisa; Chiba, Satoshi

Physical Review C, 96(6), p.064616_1 - 064616_9, 2017/12

 Times Cited Count:26 Percentile:3.76(Physics, Nuclear)

Journal Articles

Role of multichance fission in the description of fission-fragment mass distributions at high energies

Hirose, Kentaro; Nishio, Katsuhisa; Tanaka, Shoya*; L$'e$guillon, R.*; Makii, Hiroyuki; Nishinaka, Ichiro*; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Vermeulen, M. J.; et al.

Physical Review Letters, 119(22), p.222501_1 - 222501_6, 2017/12

 Times Cited Count:26 Percentile:7.98(Physics, Multidisciplinary)

Fission-fragment mass distributions were measured for $$^{237-240}$$U, $$^{239-242}$$Np and $$^{241-244}$$Pu populated in the excitation-energy range from 10 to 60 MeV by multi-nucleon transfer channels in the reaction $$^{18}$$O + $$^{238}$$U at the JAEA tandem facility. Among them, the data for $$^{240}$$U and $$^{240,241,242}$$Np were observed for the first time. It was found that the mass distributions for all the studied nuclides maintain a double-humped shape up to the highest measured energy in contrast to expectations of predominantly symmetric fission due to the washing out of nuclear shell effects. From a comparison with the dynamical calculation based on the fluctuation-dissipation model, this behavior of the mass distributions was unambiguously attributed to the effect of multi-chance fission.

474 (Records 1-20 displayed on this page)