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Otsubo, Takashi*; Oya, Susumu*; Goto, Jun*; ; Muto, Suguru*; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki
JAERI-Review 99-025, TIARA Annual Report 1998, p.206 - 207, 1999/10
no abstracts in English
; ; ; ; ; ; ; Muto, Suguru*; Osa, Akihiko; Koizumi, Mitsuo; et al.
Hyperfine Interactions, 120-121(1-4), p.695 - 699, 1999/00
no abstracts in English
Sekine, Toshiaki; Ichikawa, Shinichi; Osa, Akihiko; Koizumi, Mitsuo; Iimura, Hideki; Tsukada, Kazuaki; Nishinaka, Ichiro; Hatsukawa, Yuichi; Nagame, Yuichiro; Asai, Masato*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 239(1), p.127 - 131, 1999/00
Times Cited Count：2 Percentile：20.95(Chemistry, Analytical)no abstracts in English
states in 
BaAsai, Masato*; ; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki; ; Yamamoto, Hiroshi*; Kawade, Kiyoshi*
"Fuanteikaku No Rikogaku Oyobi Kaku Keisokuho(II)" Ni Kansuru Semmon Kenkyukai Hokokusho, 0, p.97 - 100, 1997/00
no abstracts in English
- angular correlation measurements for mass-separated short-lived nucleiAsai, Masato*; Kawade, Kiyoshi*; ; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki
Nuclear Instruments and Methods in Physics Research A, 398, p.265 - 275, 1997/00
Times Cited Count：6 Percentile：49.69(Instruments & Instrumentation)no abstracts in English
Asai, Masato*; ; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki; ; Yamamoto, Hiroshi*; Kawade, Kiyoshi*
KURRI-KR-3, 0, p.36 - 40, 1996/00
no abstracts in English
Ba investigated by - angular correlation measurementAsai, Masato*; ; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki; ; Yamamoto, Hiroshi*; Kawade, Kiyoshi*
ENAM 95: Int. Conf. on Exotic Nuclei and Atomic Masses, 0, p.539 - 540, 1995/00
no abstracts in English
PrSekine, Toshiaki; Osa, Akihiko; Koizumi, Mitsuo; ; Asai, Masato*; Yamamoto, Hiroshi*; Kawade, Kiyoshi*
Z. Phys., A, 349, p.143 - 146, 1994/00
no abstracts in English
Es targetAsai, Masato; Tsukada, Kazuaki; Hirose, Kentaro; Toyoshima, Atsushi; Tomitsuka, Tomohiro; Chiera, N. M.; Ito, Yuta; Makii, Hiroyuki; Nagame, Yuichiro; Nishio, Katsuhisa; et al.
no journal, ,
Spontaneous fissions of 
Fm, 
Fm, and 
Lr have been measured using an Es target at the JAEA Tandem Accelerator Facility. These three nuclei show different fission properties: the asymmetric fission, the high total-kinetic-energy (TKE) symmetric fission, and the low TKE symmetric fission, and the mechanisms of these three fissions should be very different. It is of great interest to elucidate how these differences occur. We have produced 
Fm in multinucleon-transfer reactions with a Es target and 
O projectiles, and produced Lr in the 
Cm(
N,4n) fusion-evaporation reaction. The reaction products were mass-separated with a gas-jet-coupled on-line isotope separator, and were delivered into a rotating wheel alpha- and fission-fragment detection system. By comparing the mass and TKE distributions deduced from the present experimental data, we will discuss the differences in fission mechanism among Fm, Fm, and Lr.
Asai, Masato
no journal, ,
Fission-fragment mass distributions and total kinetic energy (TKE) distributions for the spontaneous fission of Fm, Fm, Md, and Lr have been measured precisely. These nuclei were produced in the multinucleon transfer reactions with the O beam and the Es target, and in the fusion-evaporation reaction of Cm(N,4n)Lr at the JAEA tandem accelerator facility. The reaction products were mass-separated with the on-line isotope separator (ISOL), and the kinetic energies of spontaneous-fission fragments were measured with 4 pairs of Si semiconductor detectors. The results revealed that the three types of fission, the high-TKE and low-TKE symmetric fissions and asymmetric fission, compete or coexist in this neutron-rich Fm region.
Asai, Masato
no journal, ,
Fission-fragment mass and total kinetic energy (TKE) distributions for the spontaneous fission (SF) of neutron-rich Fm and transfermium nuclei have been measured precisely. The deduced mass-TKE distributions for the SF of Fm, Md, and Lr revealed that the SF of these nuclei show mixture of three types of fission with different mechanisms: the high-TKE symmetric fission, low-TKE symmetric fission, and asymmetric fission.
MdAsai, Masato; Ishibashi, Yuichi*; Tsukada, Kazuaki; Sato, Tetsuya; Aoki, Ryota*; Ito, Yuta; Uchibaba, Yuta*; Orlandi, R.; Gong, G.-M.*; Suzaki, Fumi; et al.
no journal, ,
Measurement of mass and total kinetic energy (TKE) distribution for the spontaneous fission (SF) of Md has been performed to clarify the fission mechanism in the neutron-rich fermium region. Md nuclei were produced with the Es target and O beam, and mass-separated with an on-line isotope separator (ISOL). We discuss the mechanism of fission observed in the SF of Md on the basis of the observed mass-TKE distribution.
Yokoyama, Keiichi; Kobayashi, Takanori*
no journal, ,
We report a consideration on the non-linear optical response of molecules rotationally excited by impulsive Raman scattering. An ensemble of molecules which are cascadedly excited and de-excited among the rotational levels by a several numbers of Raman transitions is not uniform in spatial coherence and depend on the number of transition the molecule undergoes. Therefore, there is a possibility to obtain signal waveforms which cannot be explained by the conventional analysis method which ignores the non-locality of the density operator. In this study, we adopted non-local density operator to calculate non-linear optical response in such case. As a result, we predicted that significant angular dependence of observed signal appear due to the spherical wave of input pump laser pulse. We qualitatively confirmed the analysis reproduce the observed waveform.
Asai, Masato; Tsukada, Kazuaki; Hirose, Kentaro; Toyoshima, Atsushi*; Tomitsuka, Tomohiro*; Chiera, N. M.*; Ito, Yuta; Makii, Hiroyuki; Nagame, Yuichiro*; Nishio, Katsuhisa; et al.
no journal, ,
We have studied spontaneous fission of neutron-rich Fm and Lr isotopes. The neutron-rich Fm isotopes were produced with the Es target and the O beam delivered by the JAEA tandem accelerator. The neutron-rich Lr isotope were produced with the Cm target and the N beam. Reaction products were mass-separated with an on-line isotope separator (ISOL), which enabled us to obtain non-contaminated samples and to measure fission fragments precisely. From the deduced fission-fragment mass and total kinetic energy distributions, we have obtained a new insight into the competition between the symmetric and asymmetric fission which is characteristic in this neutron-rich region.
Asai, Masato
no journal, ,
Symmetric fission properties of neutron-rich transfermium nuclei have been studied through the measurements of spontaneous fission fragments of Fm, Md, and Lr. These nuclei were produced in the multinucleon transfer reactions with the O beam and the Es target, and in the fusion-evaporation reaction of Cm(N,4n)Lr at the JAEA tandem accelerator facility. The reaction products were mass-separated with the on-line isotope separator (ISOL), and the kinetic energies of spontaneous-fission fragments were measured with 4 pairs of Si semiconductor detectors. The deduced fission-fragment mass distributions and total kinetic energy distributions have revealed the detailed properties of symmetric fissions in this neutron-rich Fm and transfermium nuclei.
