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Kitatani, Fumito; Harada, Hideo; Goko, Shinji*; Iwamoto, Nobuyuki; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*; Igashira, Masayuki*
Journal of Nuclear Science and Technology, 53(4), p.475 - 485, 2016/04
Times Cited Count:2 Percentile:20.83(Nuclear Science & Technology)Kitatani, Fumito; Harada, Hideo; Goko, Shinji*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*
JAEA-Conf 2014-002, p.57 - 62, 2015/02
Kondo, Takeo*; Utsunomiya, Hiroaki*; Goriely, S.*; Iwamoto, Chihiro*; Akimune, Hidetoshi*; Yamagata, Tamio*; Toyokawa, Hiroyuki*; Harada, Hideo; Kitatani, Fumito; Lui, Y.-W.*; et al.
Nuclear Data Sheets, 119, p.310 - 313, 2014/05
Times Cited Count:2 Percentile:19.91(Physics, Nuclear)Omer, M.*; Negm, H.*; Ogaki, Hideaki*; Daito, Izuru*; Hayakawa, Takehito; Bakr, M.*; Zen, H.*; Hori, Toshitada*; Kii, Toshiteru*; Masuda, Kai*; et al.
Nuclear Instruments and Methods in Physics Research A, 729, p.102 - 107, 2013/11
Times Cited Count:6 Percentile:45.27(Instruments & Instrumentation)The performance of LaBr (Ce) to measure nuclear resonance fluorescence (NRF) excitations is discussedin terms of limits of detection and in comparison with high-purity germanium (HPGe)detectors near the 2 MeV region where many NRF excitation levels from special nuclear materials are located. The NRF experiment was performed at the High Intensity Gamma-ray Source (HIGS) facility of Duke University. The incident
-rays, of 2.12 MeV energy, hit a B
C target to excite the
B nuclei to the first excitation level. The statistical-sensitive non-linear peak clipping (SNIP) algorithm was implemented to eliminate theback ground and enhance the limits of detection for the spectra measured with LaBr
(Ce). Both detection and determination limits were deduced from the experimental data.
Ishibashi, Toshihiro*; Tomota, Yo*; Sugaya, Satoshi*; Toyokawa, Hiroyuki*; Hirade, Tetsuya; Horita, Zenji*; Suzuki, Hiroshi
Materials Transactions, 54(9), p.1562 - 1569, 2013/09
Bulky averaged microstructural parameters like vacancy density, texture, intergranular stress, etc. for 99.99% Cu subjected to Equal-Channel Angular Pressing (ECAP) were investigated using Accelerator-based gamma-ray-Induced Positron Annihilation Spectroscopy (AIPAS) and neutron diffraction. The Doppler-broadening parameter (S) for positron annihilation peaks of AIPAS increased by the first ECAP cycle and then decreased slightly with further ECAP cycles. Upon annealing, the S recovered at a lower temperature for the eight-cycle ECAP processed sample than for the one-cycle processed sample. The texture and intergranular stresses generated by ECAP are determined by neutron diffraction analyses. Changes in FWHM and intensity of neutron diffractions monitored in situ during annealing indicate the early onset of recrystallization in the eight-cycle ECAP sample. These bulky averaged data show good agreements qualitatively with local SEM/EBSD observations and the results of mechanical tests.
Utsunomiya, Hiroaki*; Goriely, S.*; Kondo, Takeo*; Iwamoto, Chihiro*; Akimune, Hidetoshi*; Yamagata, Tamio*; Toyokawa, Hiroyuki*; Harada, Hideo; Kitatani, Fumito; Lui, Y.-W.*; et al.
Physical Review C, 88(1), p.015805_1 - 015805_6, 2013/07
Times Cited Count:72 Percentile:96.44(Physics, Nuclear)Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Yamagata, Tamio*; Iwamoto, Chihiro*; Goriely, S.*; Daoutidis, I.*; Toyokawa, Hiroyuki*; Harada, Hideo; Kitatani, Fumito; Iwamoto, Nobuyuki; et al.
Proceedings of 14th International Symposium on Capture -Ray Spectroscopy and Related Topics, p.505 - 514, 2013/05
Shizuma, Toshiyuki; Hayakawa, Takehito; Ogaki, Hideaki; Toyokawa, Hiroyuki*; Komatsubara, Tetsuro*; Kikuzawa, Nobuhiro; Inakura, Tsunenori*; Homma, Michio*; Nakada, Hitoshi*
Physical Review C, 87(2), p.024301_1 - 024301_7, 2013/02
Times Cited Count:15 Percentile:69.33(Physics, Nuclear)Electro-magnetic dipole transitions in Fe were measured in photon scattering experiments with a linearly polarized photon beam. The parity quantum numbers of the excited dipole states were determined by the intensity asymmetry of resonantly scattered
-rays with respect to the polarization plane of the incident photon beam. While the summed magnetic dipole (
) strength was determined as
at excitation energies between 7 and 10 MeV, the summed electric dipole (
) strength below 10 MeV was obtained as
. The observed
strength was compared with shell-model predictions in the
-shell using the GXPF1J and KB3G effective interactions. In addition, the
strength was compared with random-phase approximation calculations with the Skyrme interaction.
Kondo, Takeo*; Utsunomiya, Hiroaki*; Goriely, S.*; Daoutidis, I.*; Iwamoto, Chihiro*; Akimune, Hidetoshi*; Okamoto, Akiyuki*; Yamagata, Tamio*; Kamata, Masaki*; Ito, Osamu*; et al.
Physical Review C, 86(1), p.014316_1 - 014316_7, 2012/07
Times Cited Count:38 Percentile:87.07(Physics, Nuclear)Using quasi-monochromatic laser-Compton scattering rays, total photoneutron cross sections were measured for
Pb near neutron threshold with a high-efficiency 4
neutron detector. Partial
1 and
1 photoneutron cross sections along with total cross sections were determined for
Pb at four energies near threshold by measuring anisotropies in photoneutron emission with linearly-polarized
rays. The
1 strength dominates over the
1 strength in the neutron channel where
1 photoneutron cross sections show extra strength of the pygmy dipole resonance in
Pb near the neutron threshold corresponding to 0.32-0.42% of the Thomas-Reiche-Kuhn sum rule. Several
units of B(
1)
strength were observed in
Pb just above neutron threshold, which correspond to an
1 cross section less than 10% of the total photoneutron cross section.
Shizuma, Toshiyuki; Hayakawa, Takehito; Hajima, Ryoichi; Kikuzawa, Nobuhiro; Ogaki, Hideaki; Toyokawa, Hiroyuki*
Review of Scientific Instruments, 83(1), p.015103_1 - 015103_4, 2012/01
Times Cited Count:8 Percentile:38.43(Instruments & Instrumentation)Nondestructive identification of heavy isotopes concealed in a thick iron box has been demonstrated by using nuclear resonance fluorescence. A quasi-monochromatic photon beam produced by the collision of laser quanta with high energy electrons was used for resonant excitation of nuclear levels in Pb and
Pb. By measuring the resonant
rays emitted from
Pb and
Pb, each of these isotopes were clearly identified. The ratio of the effective thickness, i.e., concentration distribution, of these isotopes was deduced from the relative intensities of the measured NRF strengths.
Utsunomiya, Hiroaki*; Goriely, S.*; Kamata, Masaki*; Akimune, Hidetoshi*; Kondo, Takeo*; Ito, Osamu*; Iwamoto, Chihiro*; Yamagata, Tamio*; Toyokawa, Hiroyuki*; Lui, Y.-W.*; et al.
Physical Review C, 84(5), p.055805_1 - 055805_6, 2011/11
Times Cited Count:43 Percentile:89.94(Physics, Nuclear)Photoneutron cross sections were measured for Sn,
Sn,
Sn,
Sn, and
Sn near neutron threshold with quasi-monochromatic laser-Compton scattering
-rays. A systematic analysis of the present photoneutron data and existing neutron-capture data is made using the
-ray strength function on the basis of the HFB+QRPA model of E1 strength supplemented with a pygmy dipole resonance, which was deduced from a previous study on
Sn and
Sn. Radiative neutron capture cross sections for two radioactive nuclei,
Sn and
Sn, are deduced through the
-ray strength function method.
Utsunomiya, Hiroaki*; Goriely, S.*; Akimune, Hidetoshi*; Yamagata, Tamio*; Kondo, Takeo*; Iwamoto, Chihiro*; Okamoto, Akiyuki*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji*; et al.
AIP Conference Proceedings 1377, p.255 - 259, 2011/10
Times Cited Count:0 Percentile:0.05Ito, Osamu*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Yamagata, Tamio*; Kondo, Takeo*; Kamata, Masaki*; Toyokawa, Hiroyuki*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji*; et al.
AIP Conference Proceedings 1377, p.362 - 364, 2011/10
Times Cited Count:0 Percentile:0.05Utsunomiya, Hiroaki*; Goriely, S.*; Arteaga, D. P.*; Daoutidis, I.*; Akimune, Hidetoshi*; Yamagata, Tamio*; Kondo, Takeo*; Iwamoto, Chihiro*; Kamata, Masaki*; Ito, Osamu*; et al.
AIP Conference Proceedings 1377, p.450 - 452, 2011/10
Times Cited Count:0 Percentile:0.05Kitatani, Fumito; Harada, Hideo; Goko, Shinji*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*
Journal of the Korean Physical Society, 59(2), p.1836 - 1839, 2011/08
Times Cited Count:2 Percentile:20.43(Physics, Multidisciplinary)The photo-nuclear cross section of Se isotopes (Se,
Se,
Se,
Se) were measured with laser-Compton scattering (LCS)
-rays to supply fundamental data for the estimation of the inverse reaction cross sections, i.e., the
Se(
,
)
Se cross section. An enriched Se isotope samples were irradiated with LCS
-rays whose maximum energy was varied from each near neutron separation energy to 16.0 MeV. The energy distributions of LCS
-rays were precisely determined using a high-resolution high-energy photon spectrometer (HHS). Emitted neutrons were detected by a high efficiency 4
-
He detector. The excitation function of the photo-nuclear cross section of Se isotopes were determined for the energy range form each near neutron separation energy to near 16.0 MeV. The energy point corresponding to each cross section was deduced using the accurately determined energy distribution of LCS
-rays.
Utsunomiya, Hiroaki*; Goriely, S.*; Akimune, Hidetoshi*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*; Lui, Y.-W.*
Journal of the Korean Physical Society, 59(2), p.1713 - 1716, 2011/08
Times Cited Count:2 Percentile:20.43(Physics, Multidisciplinary)Kitatani, Fumito; Harada, Hideo; Goko, Shinji*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*
Journal of Nuclear Science and Technology, 48(7), p.1017 - 1024, 2011/07
Times Cited Count:17 Percentile:78.28(Nuclear Science & Technology)Ito, Osamu*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Kondo, Takeo*; Kamata, Masaki*; Yamagata, Tamio*; Toyokawa, Hiroyuki*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji*; et al.
Journal of Nuclear Science and Technology, 48(5), p.834 - 840, 2011/05
Times Cited Count:28 Percentile:88.52(Nuclear Science & Technology)Photoneutron cross section measurements were made for Au in the entire energy range of the (,n) channel based on a direct neutron-counting technique with quasi-monochromatic
-rays produced in inverse Compton-scattering of laser photons with relativistic electrons. The data were analyzed with a least-squares method to deduce photoneutron cross sections. The analysis significantly reduced experimental uncertainties compared with those resulted from the photon difference method. The result is compared with the previous data by direct neutron-counting with
-rays produced in positron annihilation in flight and by photoactivation with bremsstrahlung. The present data are in good agreement with the previous data near neutron threshold, while there remain some discrepancies between the present and the previous data above 10 MeV.
Utsunomiya, Hiroaki*; Goriely, S.*; Akimune, Hidetoshi*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*; Kondo, Takeo*; Ito, Osamu*; et al.
Physical Review C, 82(6), p.064610_1 - 064610_5, 2010/12
Times Cited Count:39 Percentile:87.92(Physics, Nuclear)The -ray strength function method (
SF method) is devised to indirectly determine radiative neutron capture cross sections for radioactive nuclei. This method is applied here to the
Pd case. Photoneutron cross sections were measured for
Pd near neutron threshold with quasi-monochromatic laser-Compton-scattering
-ray beams. These photoneutron cross sections as well as the reverse radiative neutron capture cross sections for
Pd are used to provide constraints on the
Pd(n,
)
Pd cross section.
Utsunomiya, Hiroaki*; Goriely, S.*; Akimune, Hidetoshi*; Yamagata, Tamio*; Kondo, Takeo*; Iwamoto, Chihiro*; Ito, Osamu*; Kamata, Masaki*; Io, Masanori*; Kususe, Koichi*; et al.
AIP Conference Proceedings 1377, p.447 - 449, 2010/10
Times Cited Count:0 Percentile:0.05