Evidence of complete fusion in the sub-barrier O+U reaction

Nishio, Katsuhisa; Ikezoe, Hiroshi; Nagame, Yuichiro; Asai, Masato; Tsukada, Kazuaki; Mitsuoka, Shinichi; Tsuruta, Kaoru; Sato, Kenichiro; Lin, C. J.; Osawa, Takaaki*

Physical Review Letters, 93(16), p.162701_1 - 162701_4, 2004/10

https://doi.org/10.1103/PhysRevLett.93.162701

The fission fragment angular distributions for reactions using actinide targets such as O+U show anomalously large anisotropy than the prediction of the transition state model. To interprete this phenomenon, the orientation dependent quasi-fission model was proposed. As the U has prolate deformation, the interaction of O with the U in the sub-barrier region is restricted to the tip collisions. Hinde et al. interpreted that the anomalously large angular anisotropy is due to the quasi-fission, that is the complete fusion is not achieved in the sub-barrier region. The presence (or absence) of the complete fision is found by measuring the evaporation residue cross sections. We measured the evaporation residue cross sections for O+U by using the O beams supplied by the JAERI-tandem accelerator. As a result, complete fusion was observed in the sub-barrier region and no significant fusion hindrace was observed.

Adjustment of total delayed neutron yields of U, U and Pu in JENDL-3.2 using benchmark experiments on effective delayed neutron fraction

Sakurai, Takeshi; Okajima, Shigeaki

Journal of Nuclear Science and Technology, 39(1), p.19 - 30, 2002/01

https://doi.org/10.3327/jnst.39.19

The cross section adjustment method was applied to total delayed neutron yields of U, U and Pu of the JENDL-3.2 file by using experimental results of effective delayed neutron fraction at six cores built in two fast critical facilities of the MASURCA and FCA and a thermal critical facility of the TCA to improve these yields. The adjustment was carried out on the yields given at several incident neutron energy points in the file. After the adjustment, the yield of U was almost uniformly decreased by about 3% below 7 MeV. The yield of Pu was increased by 2.6% and that of U was decreased by 0.9% at the thermal energy point, while the change of yield was less than 0.3% at the other energy points for these nuclides. By using these adjusted yields, the uncertainty of calculated was reduced and the agreement of between experiment and calculation was improved.

U Mssbauer study of UPt

Tsutsui, Satoshi; Nakada, Masami; Nasu, Saburo*; Haga, Yoshinori; Yamamoto, Etsuji; Kimura, Noriaki*; Onuki, Yoshichika

Journal of Magnetism and Magnetic Materials, 226-230(Part.1), p.87 - 88, 2001/05

no abstracts in English

Measurement of U Doppler Effect using various samples in FCA XVII-1

Ando, Masaki; Okajima, Shigeaki; Oigawa, Hiroyuki

JAERI-Research 2001-017, 20 Pages, 2001/03

JAERI-Research-2001-017.pdf:0.82MB

U Doppler effect measurements were carried out using 6 uranium samples with various composition or diameter varying self-shielding factors of U. Calculation accuracy of the standard analysis method for fast reactor cores at FCA was investigated.The Doppler effect were measured by the sample-heated and reactivity worth measurement method up to 800 degree in the FCA XVII-1 assembly, which simulated Na-cooled MOX fueled FBR. In the analysis, the Doppler effect was calculated using the effective cross sections obtained by the PEACO-X code. The calculated values based on the diffusion theory agreed well with the experiment for the U-metal and UO samples. The calculation underestimated the experiment from 10% to 30% for the UO samples containing BeO. This underestimation was improved by the use of the transport calculation. The calculation, however, underestimated about 20% for the sample whose background cross section is greater than 300 barns.

U Mssbauer spectrosopic study of UPdAl and URuSi

Tsutsui, Satoshi; Nakada, Masami; Nasu, Saburo*; Haga, Yoshinori; Homma, Tetsuo; Yamamoto, Etsuji; Okuni, Hitoshi*; Onuki, Yoshichika

Physica B; Condensed Matter, 281-282, p.242 - 243, 2000/06

https://doi.org/10.1016/S0921-4526(99)01080-7

no abstracts in English

Isomeric yield ratios of I and I in the proton-, C- and F-induced fission of U, Np and U

Shinohara, Nobuo; Tsukada, Kazuaki; Ichikawa, Shinichi; Magara, Masaaki; Hatsukawa, Yuichi

Radiochimica Acta, 88(1), p.1 - 5, 2000/00

https://doi.org/10.1524/ract.2000.88.1.001

no abstracts in English

U optical potential up to 100MeV incident nucleon energies

Sukhovitskii, E. S.*; Chiba, Satoshi; Iwamoto, Osamu; Fukahori, Tokio

JAERI-Research 99-040, 28 Pages, 1999/06

JAERI-Research-99-040.pdf:1.0MB

no abstracts in English

Neutron data evaluation of U

V.M.Maslov*; Y.V.Porodzinskij*; Hasegawa, Akira; Shibata, Keiichi

JAERI-Research 98-040, 64 Pages, 1998/08

JAERI-Research-98-040.pdf:2.45MB

no abstracts in English

First evidence for a new spontaneous fission decay produced in the reaction Si + U

Ikezoe, Hiroshi; Ikuta, T.*; Mitsuoka, Shinichi; Nagame, Yuichiro; Nishinaka, Ichiro; Tsukada, Kazuaki; Kuzumaki, T.*; J.Lu*; *

European Physical Journal A, 2(4), p.379 - 382, 1998/00

https://doi.org/10.1007/s100500050134

no abstracts in English

Moessbauer study of uranium compounds

Tsutsui, Satoshi*; Nakada, Masami; Kobayashi, Yasuhiro*; ; Saeki, Masakatsu; Nasu, Saburo*; Nakamura, Akio; Haga, Yoshinori; Homma, Tetsuo*; Yamamoto, Etsuji; et al.

Physics of Strongly Correlated Electron Systems (JJAP Series 11), p.266 - 268, 1998/00

no abstracts in English