Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 67

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

Journal Articles

Partial photoneutron cross sections for $$^{207,208}$$Pb

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:1 Percentile:85.28(Physics, Nuclear)

Journal Articles

Photoneutron cross sections for Mo isotopes; A Step toward a unified understanding of($$gamma$$,n) and (n,$$gamma$$)reactions

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:38 Percentile:5.5(Physics, Nuclear)

Journal Articles

Development of small specimen test techniques for the IFMIF test cell

Wakai, Eiichi; Kim, B. J.; Nozawa, Takashi; Kikuchi, Takayuki; Hirano, Michiko*; Kimura, Akihiko*; Kasada, Ryuta*; Yokomine, Takehiko*; Yoshida, Takahide*; Nogami, Shuhei*; et al.

Proceedings of 24th IAEA Fusion Energy Conference (FEC 2012) (CD-ROM), 6 Pages, 2013/03

Journal Articles

Development of lithium target system in engineering validation and engineering design activity of the International Fusion Materials Irradiation Facility (IFMIF/EVEDA)

Wakai, Eiichi; Kondo, Hiroo; Sugimoto, Masayoshi; Fukada, Satoshi*; Yagi, Juro*; Ida, Mizuho; Kanemura, Takuji; Furukawa, Tomohiro; Hirakawa, Yasushi; Watanabe, Kazuyoshi; et al.

Purazuma, Kaku Yugo Gakkai-Shi, 88(12), p.691 - 705, 2012/12

no abstracts in English

Journal Articles

Total and partial photoneutron cross sections for Pb isotopes

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:26 Percentile:13.83(Physics, Nuclear)

Using quasi-monochromatic laser-Compton scattering $$gamma$$ rays, total photoneutron cross sections were measured for $$^{206,207,208}$$Pb near neutron threshold with a high-efficiency 4$$pi$$ neutron detector. Partial $$E$$1 and $$M$$1 photoneutron cross sections along with total cross sections were determined for $$^{207,208}$$Pb at four energies near threshold by measuring anisotropies in photoneutron emission with linearly-polarized $$gamma$$ rays. The $$E$$1 strength dominates over the $$M$$1 strength in the neutron channel where $$E$$1 photoneutron cross sections show extra strength of the pygmy dipole resonance in $$^{207,208}$$Pb near the neutron threshold corresponding to 0.32-0.42% of the Thomas-Reiche-Kuhn sum rule. Several $$mu$$$$_N^{2}$$ units of B($$M$$1)$$uparrow$$ strength were observed in $$^{207,208}$$Pb just above neutron threshold, which correspond to an $$M$$1 cross section less than 10% of the total photoneutron cross section.

Journal Articles

Determination of the number of pulsed laser-Compton scattering photons

Kondo, Takeo*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Yamagata, Tamio*; Okamoto, Akiyuki*; Harada, Hideo; Kitatani, Fumito; Shima, Tatsushi*; Horikawa, Ken*; Miyamoto, Shuji*

Nuclear Instruments and Methods in Physics Research A, 659(1), p.462 - 466, 2011/12

 Times Cited Count:18 Percentile:12.26(Instruments & Instrumentation)

We measured pulse-height spectra of 16.7 MeV laser-Compton scattering photons with a 6"$$times$$5" NaI(Tl) detector for blank and three lead materials of 75.8, 50.9, and 25.9% transmissions at the NewSUBARU facility to investigate how the original Poisson distribution of the pulsed photons is modified after passing through thick-target materials. We present a well-prescribed method of determining the number of incident photons within 3.5% accuracy based on the response of the NaI(Tl) detector to the pulsed photon beams.

Journal Articles

Photoneutron cross sections for $$^{118-124}$$Sn and the $$gamma$$-ray strength function method

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:31 Percentile:10.37(Physics, Nuclear)

Photoneutron cross sections were measured for $$^{118}$$Sn, $$^{119}$$Sn, $$^{120}$$Sn, $$^{122}$$Sn, and $$^{124}$$Sn near neutron threshold with quasi-monochromatic laser-Compton scattering $$gamma$$-rays. A systematic analysis of the present photoneutron data and existing neutron-capture data is made using the $$gamma$$-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 $$^{116}$$Sn and $$^{117}$$Sn. Radiative neutron capture cross sections for two radioactive nuclei, $$^{121}$$Sn and $$^{123}$$Sn, are deduced through the $$gamma$$-ray strength function method.

Journal Articles

The $$gamma$$SF 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

 Percentile:100

Journal Articles

Photoneutron cross sections for Au

Ito, 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

 Percentile:100

Journal Articles

Application of the $$gamma$$SF method to palladium

Utsunomiya, 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

 Percentile:100

Journal Articles

Measurement of reaction rates in Li/V-alloy assembly with 14 MeV neutron irradiation

Tanaka, Teruya*; Sato, Satoshi; Kondo, Keitaro; Ochiai, Kentaro; Murata, Isao*; Takakura, Kosuke; Sato, Fuminobu*; Kada, Wataru*; Iida, Toshiyuki*; Konno, Chikara; et al.

Fusion Science and Technology, 60(2), p.681 - 686, 2011/08

 Percentile:100(Nuclear Science & Technology)

Irradiation experiments of 14 MeV neutrons have been performed on a Li block assembly of 46 $$times$$ 51 $$times$$ 51 cm$$^3$$ with a 5 cm thick V-alloy layer inside to examine the accuracy of neutronics calculations for the Li/V-alloy blanket design. Foils of Nb, Ni, In and Au for reaction rate measurements of $$^{93}$$Nb(n,2n)$$^{rm 92m}$$Nb, $$^{58}$$Ni(n,p)$$^{58}$$Co, $$^{115}$$In(n,n')$$^{rm 115m}$$In, $$^{197}$$Au(n,$$gamma$$)$$^{198}$$Au reactions and $$^6$$Li enriched ($$^6$$Li: 95.5%) and $$^7$$Li enriched ($$^7$$Li: 99.9%) Li$$_2$$CO$$_3$$ pellets for tritium production rate measurements were installed in the assembly. Results of the measurements were compared with those of calculations with MCNP5, JENDL-3.3 and JENDL/D-99. The comparisons for the reaction rates in the Nb, Ni and In foils indicate that measurements and calculations of the fast neutron transport are consistent almost within 10%. In the comparison for the reaction rates in the Au foils, the underestimation of 15% was found at a surface of the V-alloy layer. There is a possibility that this is due to the elastic scattering cross section of V around 4 keV as previously reported. The comparisons for tritium production rates in the $$^6$$Li enriched and $$^7$$Li enriched Li$$_2$$CO$$_3$$ pellets indicate that calculated rates were larger than results of the measurements by 2-8% and 1-4%, respectively.

Journal Articles

Measurement of charged-particle emission double-differential cross section of fluorine for 14.2 MeV neutrons

Kondo, Keitaro; Murata, Isao*; Ochiai, Kentaro; Kubota, Naoyoshi*; Miyamaru, Hiroyuki*; Konno, Chikara; Nishitani, Takeo

Journal of Nuclear Science and Technology, 48(8), p.1146 - 1157, 2011/08

We carried out a detailed measurement of the double-differential cross sections of fluorine for emitted protons, deuterons, tritons and $$alpha$$-particles with 14.2 MeV neutron incidence. An improved charged-particle spectrometer with a pencil DT-neutron beam furnished at the FNS facility of Japan Atomic Energy Agency enabled us to obtain precise data with a fine energy resolution in wide energy range and angular range from 15 to 150 $$^{circ}$$. The obtained data were compared with the nuclear data evaluated in JENDL-3.3 and ENDF/B-VII.0. As a result, large differences in the energy and angular distributions of emitted particles and the charged-particle production cross sections were found between the measured and evaluated data. Angular-differential cross sections for several discrete peaks corresponding to excited states of residual nuclei were extracted to discuss the reaction mechanism of charged-particle emission. The obtained data suggest that the charged-particle emission reaction of fluorine has a quite complicated mechanism where both the direct reaction process and the pre-equilibrium process contribute. The present experiment is the first simultaneous measurement of the four different kinds of charged particles and would provide useful data to confirm previous experimental data as well as to establish a nuclear reaction model of fluorine.

Journal Articles

Photoneutron cross sections for Au revisited; Measurements with laser Compton scattering $$gamma$$-rays and data reduction by a least-squares method

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

Photoneutron cross section measurements were made for Au in the entire energy range of the ($$gamma$$,n) channel based on a direct neutron-counting technique with quasi-monochromatic $$gamma$$-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 $$gamma$$-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.

Journal Articles

Development of measurement technique for surface waves on high-speed liquid lithium jet for IFMIF target

Kondo, Hiroo; Kanemura, Takuji*; Sugiura, Hirokazu*; Yamaoka, Nobuo*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; Muroga, Takeo*; Horiike, Hiroshi*

Fusion Engineering and Design, 85(7-9), p.1102 - 1105, 2010/12

 Times Cited Count:10 Percentile:32.4(Nuclear Science & Technology)

This paper reports a measurement technique for surface waves on a liquid lithium jet for a Li target of the International Fusion Materials Irradiation Facility. The characteristic of the waves was successfully clarified by a contact-type liquid level detector. As a result, it was found that the wave distributions in the all jet velocity range up to 15 m/s were conformed each other in normalized form and Rayleigh distribution which is one of popular model to show irregular water wave.

Journal Articles

$$gamma$$-ray strength function method and its application to $$^{107}$$Pd

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:30 Percentile:11.17(Physics, Nuclear)

The $$gamma$$-ray strength function method ($$gamma$$SF method) is devised to indirectly determine radiative neutron capture cross sections for radioactive nuclei. This method is applied here to the $$^{107}$$Pd case. Photoneutron cross sections were measured for $$^{105,106,108}$$Pd near neutron threshold with quasi-monochromatic laser-Compton-scattering $$gamma$$-ray beams. These photoneutron cross sections as well as the reverse radiative neutron capture cross sections for $$^{104,105}$$Pd are used to provide constraints on the $$^{107}$$Pd(n,$$gamma$$) $$^{108}$$Pd cross section.

Journal Articles

Striking behavior of photoneutron cross sections for $$^{90}$$Zr near threshold

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

 Percentile:100

Journal Articles

Photoneutron cross sections for $$^{96}$$Zr; A Systematic experimental study of photoneutron and radiative neutron capture cross sections for zirconium isotopes

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, 81(3), p.035801_1 - 035801_5, 2010/03

 Times Cited Count:32 Percentile:10.02(Physics, Nuclear)

This manuscript presents photoneutron cross sections for $$^{96}$$Zr. Combining the present data with the previously published Zr data, we investigated the $$gamma$$-ray strength function for zirconium isotopes systematically. We present a unified picture of the $$gamma$$-ray strength function that consists of the HFB + QRPA model of E1 strength accompanied by an extra M1 strength attributable to giant M1 resonance. It is shown that the $$gamma$$-ray strength function reproduces both (g,n) and (n,g) cross sections for Zr isotopes consistently.

Journal Articles

Direct neutron spectrum measurement to validate $$^{rm nat}$$Zr(n,2n) reaction cross-section at 14 MeV

Murata, Isao*; Shiken, Kimiaki*; Kondo, Keitaro; Matsunaka, Masayuki*; Ota, Masayuki*; Miyamaru, Hiroyuki*; Ochiai, Kentaro; Konno, Chikara; Nishitani, Takeo

Fusion Engineering and Design, 84(7-11), p.1376 - 1379, 2009/06

 Percentile:100(Nuclear Science & Technology)

Lithium zirconate, Li$$_{2}$$ZrO$$_{3}$$, is known as a candidate blanket material in a fusion reactor. According to the independent benchmark studies for zirconium by JAERI, Kyoto University and Osaka University, the neutron spectrum calculations show fairly large overestimation for most evaluated nuclear data libraries. The author's group expects that the overestimation be due to a problem of evaluation for the (n,2n) reaction, because the (n,2n) reaction cross section is not well determined experimentally. In the present study, two neutrons emitted from $$^{rm nat}$$Zr(n,2n) reaction have been measured directly to reveal the problem. As a result of measurements, the cross section obtained for energies above 1 MeV, which is the lower measurable limit energy, shows a little larger than JENDL-3.3. This is an opposite result to the benchmark analysis. However, an extrapolation for the low energy region by the evaporation spectrum with the nuclear temperature of 1 MeV brought the smaller total (n,2n) reaction cross section than JENDL-3.3, which is comparable to ENDF/B-VI. This result suggests that the discrepancies reported previously might be due to inappropriate evaluation of nuclear temperature.

Journal Articles

Thickness distribution of high-speed free-surface lithium flow simulating IFMIF target

Kondo, Hiroo*; Kanemura, Takuji*; Sugiura, Hirokazu*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; Muroga, Takeo*; Horiike, Hiroshi*

Fusion Engineering and Design, 84(7-11), p.1086 - 1090, 2009/06

 Times Cited Count:6 Percentile:50.95(Nuclear Science & Technology)

A liquid lithium(Li) target of International Fusion Materials Irradiation Facility (IFMIF) is formed as flat plane free-surface flow by a nozzle and flows at high speed around 15 m/s. This paper focuses on flatness of the liquid Li target. A Li flow experiment was conducted in Osaka University Li Loop with a test section which was 1/2.5 scaled model of IFMIF. A thickness of the Li flow was measured and obtained by a contact method which was developed for the measurement. Analytical study on Kelvin wake and numerical calculation on wakes near side walls of the flow channel were also conducted and compared with the experimental results. As the results, positions of wake crest obtained from both of the experiment and numerical calculation assuming contact angle 140$$^{circ}$$ agreed well with an iso-phase line of the analytical model. Generation of the wake are likely depends on wettability between Li and a structural material which is 304SS in the present study.

Journal Articles

Development of velocity measurement on a liquid lithium flow for IFMIF

Sugiura, Hirokazu*; Kondo, Hiroo*; Kanemura, Takuji*; Niwa, Yuta*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; Muroga, Takeo*; et al.

Fusion Engineering and Design, 84(7-11), p.1803 - 1807, 2009/06

 Times Cited Count:3 Percentile:69.9(Nuclear Science & Technology)

To develop a diagnostics system in view of its application on International Fusion Materials Irradiation Facility (IFMIF) liquid lithium (Li) target, velocity measurements on a liquid Li flow were performed in a Li circulation loop at Osaka University with a test section having a contraction nozzle 1/2.5 scale of IFMIF and producing a flat plane jet of 70 mm width and 10 mm thickness. Based on the Particle Image Velocimetry (PIV) technique, a local Li flow velocity distribution was measured by tracking brightness intensity patterns of surface waves generated on the flow. Measured surface velocity showed good agreement with a surface velocity obtained in previous water experiments, and had an insignificant effect at an area corresponding to a deuteron beam irradiation area on the IFMIF target.

67 (Records 1-20 displayed on this page)