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Np and 
Am by accelerator-driven system at Kyoto University Critical AssemblyPyeon, C. H.*; Yamanaka, Masao*; Oizumi, Akito; Fukushima, Masahiro; Chiba, Go*; Watanabe, Kenichi*; Endo, Tomohiro*; Van Rooijen, W. G.*; Hashimoto, Kengo*; Sakon, Atsushi*; et al.
Journal of Nuclear Science and Technology, 56(8), p.684 - 689, 2019/08
Times Cited Count：12 Percentile：79.53(Nuclear Science & Technology)This study demonstrates, for the first time, the principle of nuclear transmutation of minor actinide (MA) by the accelerator-driven system (ADS) through the injection of high-energy neutrons into the subcritical core at the Kyoto University Critical Assembly. The main objective of the experiments is to confirm fission reactions of neptunium-237 (Np) and americium-241 (Am), and capture reactions of Np. Subcritical irradiation of Np and Am foils is conducted in a hard spectrum core with the use of the back-to-back fission chamber that obtains simultaneously two signals from specially installed test (Np or Am) and reference (uranium-235) foils. The first nuclear transmutation of Np and Am by ADS soundly implemented by combining the subcritical core and the 100 MeV proton accelerator, and the use of a lead-bismuth target, is conclusively demonstrated through the experimental results of fission and capture reaction events.
Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.
Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07
Times Cited Count：8 Percentile：55.71(Physics, Multidisciplinary)Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for 
Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.
Tanaka, Taiki*; Narikiyo, Yoshihiro*; Morita, Kosuke*; Fujita, Kunihiro*; Kaji, Daiya*; Morimoto, Koji*; Yamaki, Sayaka*; Wakabayashi, Yasuo*; Tanaka, Kengo*; Takeyama, Mirei*; et al.
Journal of the Physical Society of Japan, 87(1), p.014201_1 - 014201_9, 2018/01
Times Cited Count：18 Percentile：74.14(Physics, Multidisciplinary)Excitation functions of quasielastic scattering cross sections for the 
Ca + 
Pb, 
Ti + Pb, and Ca + 
Cm reactions were successfully measured by using the gas-filled recoil-ion separator GARIS. Fusion barrier distributions were extracted from these data, and compared with the coupled-channels calculations. It was found that the peak energies of the barrier distributions for the Ca + Pb and Ti + Pb systems coincide with those of the 2n evaporation channel cross sections for the systems, while that of the Ca + Cm is located slightly below the 4n evaporation ones. This results provide us helpful information to predict the optimum beam energy to synthesize superheavy nuclei.
Koshimizu, Masanori*; Iwamatsu, Kazuhiro*; Taguchi, Mitsumasa; Kurashima, Satoshi; Kimura, Atsushi; Yanagida, Takayuki*; Fujimoto, Yutaka*; Watanabe, Kenichi*; Asai, Keisuke*
Journal of Luminescence, 169(Part B), p.678 - 681, 2016/01
We analyzed the effects of linear energy transfer (LET) on the scintillation properties of a Li glass scintillator, GS20. The scintillation time profiles were measured by using pulsed ion beams having different LETs. The rise in the scintillation time profiles was faster for higher LET, whereas the decay part was not significantly different for largely different LETs. The LET effects in the rise was ascribed to the effects of excited states interaction during the energy transfer process from the host glass to the luminescent centers, Ce
ions. Supposing that the light yield decreases with LET, the fast rise at high LET was explained in terms of the competition between the energy transfer and the quenching due to the excited states interaction.
Oi, Motoki; Sakai, Kenji; Watanabe, Akihiko; Akutsu, Atsushi; Meigo, Shinichiro; Takada, Hiroshi
JPS Conference Proceedings (Internet), 8, p.036007_1 - 036007_5, 2015/09
This paper reports on upgrading of the monitor and operation (MO) system for a general control system (GCS) of the Materials and Life science experimental Facility (MLF) at J-PARC. The MLF-GCS consists of programmable logic controllers (PLCs), operator interfaces (OPIs) for integral control and interlock systems, shared servers, and so on. It is controlling various components of the pulsed spallation neutron source such as a mercury target and hydrogen moderators. The MO system is used for monitoring, alarm notification and remote control from the MLF control room. The GCS has been working well as expected, but current MO system which consists of the OPIs and data servers based on iFix has some problems in view of sustainable maintenance because of its poor flexibility of supported OS and software version compatibility. To overcome the problems, we upgraded the MO system to be operated using the framework of EPICS, the OPI of Control System Studio (CSS) and the server software of Postgre SQL. This improves versatility of the MO system, enabling to run on various platforms such as Windows, Linux and Mac OS. At first, we made a prototype MO system, which processed 100 points of data and 5 operation screens and verified that the MO system functions correctly. Then we made full spec MO system which processes the data point of 7000 and operation screens of 130. It was operated in parallel with the current system to evaluate its performance with real data such as data transmission speed from PLCs, control functions from OPI, storage capability of servers and long-term reliability. As results, the new MO system achieved the communication speed of 2 Hz and its operability compatible to the current system. Now, we are operating and debugging it in comparison with the current system during the operating period as a preparation for the system replacement at the end of 2014.
SGo, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Kobayashi, Motoki*; Kisamori, Keiichi*; Takaki, Motonobu*; Miya, Hiroyuki*; Ota, Shinsuke*; Michimasa, Shinichiro*; Shimoura, Susumu*; et al.
JPS Conference Proceedings (Internet), 6, p.030005_1 - 030005_4, 2015/06
Z nucleus, 
Ar and high-spin states in A = 30 
40 nucleiIdeguchi, Eiji*; Ota, Shinsuke*; Morikawa, Tsuneyasu*; Oshima, Masumi; Koizumi, Mitsuo; Toh, Yosuke; Kimura, Atsushi; Harada, Hideo; Furutaka, Kazuyoshi; Nakamura, Shoji; et al.
Progress of Theoretical Physics Supplement, (196), p.427 - 432, 2012/10
Sakai, Kenji; Sakamoto, Shinichi; Kinoshita, Hidetaka; Seki, Masakazu; Haga, Katsuhiro; Kogawa, Hiroyuki; Wakui, Takashi; Naoe, Takashi; Kasugai, Yoshimi; Tatsumoto, Hideki; et al.
JAEA-Technology 2011-039, 121 Pages, 2012/03
JAEA-Technology-2011-039.pdf:10.87MB
This report investigates the behavior, damage and restoration of a neutron source station of the MLF at the Great East Japan Earthquake and verified the safety design for emergency accidents in the neutron source station. In the MLF, after an occurrence of the Earthquake, strong quakes were detected at the instruments, the external power supply was lost, all of the circulators shut down automatically, and the hydrogen gas was released. The leakages of mercury, hydrogen and radio-activation gases did not occur. While, the quakes made gaps between the shield blocks and ruptured external pipe lines by subsidence around the building. But significant damages to the components were not found though the pressure drop of compressed air lines influenced on a target trolley lock system and so on. These results substantiated the validity of the safety design for emergency accidents in the source station, and suggested several points of improvement.
Sakai, Kenji; Futakawa, Masatoshi; Takada, Hiroshi; Sakamoto, Shinichi; Maekawa, Fujio; Kinoshita, Hidetaka; Seki, Masakazu; Haga, Katsuhiro; Kogawa, Hiroyuki; Wakui, Takashi; et al.
Proceedings of 20th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-20) (USB Flash Drive), 6 Pages, 2012/03
This report investigates behaviors and damages of each component in a neutron target station of the MLF at the J-PARC at the time of the Great East Japan Earthquake (GEJE). At the date of the GEJE, in the MLF, strong quakes were detected at several instruments, an external power supply were lost, all of the circulation systems were shut down automatically, and a hydrogen gas was released as planned. Leakage of activation liquids and gases did not occur. While, the quakes made gaps between shield blocks and ruptured external pipe lines for air and water by subsidence. But significant damages on the components of the target station were not found though a loss of compressed air supply affected lock systems with air cylinders and pneumatic operation values. These results substantiated a validity of safety design on the target station for emergency accidents.
Iwatsuki, Jin; Watanabe, Yutaka*; Terada, Atsuhiko; Onuki, Kaoru
Kagaku Kogaku Rombunshu, 37(5), p.441 - 446, 2011/09
Times Cited Count：1 Percentile：6.68(Engineering, Chemical)The thermochemical IS process for hydrogen production involves the use of highly corrosive sulfuric and hydriodic acids at high temperature and pressure, and the development of corrosion-resistant materials for main components is therefore crucial to process development. This paper concerns the development of a sulfuric acid transfer pump, an important component in transferring high-temperature concentrated sulfuric acid in the sulfuric acid decomposition step of the IS process. A reciprocating plunger pump made of SiC ceramics and common metal alloys was designed to meet the required corrosion resistance, thermal resistance and compressive strength for the transfer of high-temperature concentrated sulfuric acid. The pump was test-fabricated, and its performance in an IS test plant with a hydrogen production capacity of 30m
/h was verified in terms of the pressure resistance and the transfer performance.
nucleus ArIdeguchi, Eiji*; Ota, Shinsuke*; Morikawa, Tsuneyasu*; Oshima, Masumi; Koizumi, Mitsuo; Toh, Yosuke; Kimura, Atsushi; Harada, Hideo; Furutaka, Kazuyoshi; Nakamura, Shoji; et al.
Physics Letters B, 686(1), p.18 - 22, 2010/03
Times Cited Count：37 Percentile：87.09(Astronomy & Astrophysics)A rotational band with five 
-ray transitions ranging from 2
to 12 states was identified in Ar. The deduced transition quadrupole moment of 1.45 
0.15 eb indicates that the band has a superdeformed shape. The nature of the band is revealed by cranked Hartee Fock Bogoliubov calculations and a multiparticle-multihole configuration is assigned to the band.
-ray irradiation and crevice-like shape on the corrosion of type 316L stainless steel in high-temperature waterNakahara, Yukio; Kato, Chiaki; Yamamoto, Masahiro; Watanabe, Atsushi*; Fuse, Motomasa*
Proceedings of Symposium on Water Chemistry and Corrosion in Nuclear Power Plants in Asia 2009 (CD-ROM), p.226 - 231, 2009/10
The irradiation effect to high-temperature water in nuclear power plant has been regarded as one of important issues for preventing corrosion and stress corrosion cracking of plant materials. However, the effects of surface reaction and configurations of material on irradiated high-temperature water chemistry have been studied little because of the difficulty of measuring the environment. In this work, we have done a series of corrosion tests of Type 316L stainless steel in high-temperature water in order to estimate the effects of -ray irradiation and crevice-like shape on the water chemistry. Test specimens immersed in high-temperature water of 288 
C were -ray irradiated for 500 hours. The absorbed dose rate of -ray irradiation was estimated to be 30 kGy h
. The dimensions of the disk-like specimens were 16 mm in diameter by 0.5 mm in thickness. The surfaces of the specimens were mechanically finished with #800 emery paper. Sets of two specimens attached closely in order to simulate a crevice-like environment were also immersed. The surfaces of the specimens were analyzed using SEM, TEM, and laser Raman spectrometer. The results of surface analyses indicated that -ray irradiation enhanced the precipitation of iron oxide on the surface and the thickness of inner oxide layer became thicker by -ray irradiation. -ray irradiation also changed the morphology of oxide on the surface faced to the crevice-like environment.
Maehara, Tsunehiro*; Kawashima, Ayato*; Iwamae, Atsushi; Mukasa, Shinobu*; Takemori, Toshihiko*; Watanabe, Takashi*; Kurokawa, Kenya*; Toyota, Hiromichi*; Nomura, Shinfuku*
Physics of Plasmas, 16(3), p.033503_1 - 033503_5, 2009/03
Times Cited Count：13 Percentile：44.93(Physics, Fluids & Plasmas)Taguchi, Mitsumasa; Kimura, Atsushi; Watanabe, Ritsuko; Hirota, Koichi
Radiation Research, 171(2), p.254 - 263, 2009/02
Times Cited Count：9 Percentile：32.02(Biology)This article reports the determination of yields of OH (hydroxyl) radicals in water irradiated with He, C, Ne and Ar ions ranging from 2 to 18 MeV/u. The yields of the OH radicals depend on the atomic number and energy of the incident ion, and reaction time just after the irradiation based on the track structure theory. The yields of the OH radicals estimated by analyzing the yields of the irradiation products from phenol were at almost 0 to 3.1 per 100-eV absorbed energy on a time scale from 0.75 to 300 ns and were lower than corresponding ones under low LET radiation. The yields of the OH radicals decreased with the decreasing specific energy for each ion, with the increasing atomic number of each ion at the similar specific energy, and with the average reaction time after irradiation. In addition, Monte Carlo simulations were conducted and compared with the experimentally obtained OH radical yields.
Be halo nucleus from 
Bi at coulomb barrierMazzocco, M.*; Signorini, C.*; Romoli, M.*; De Francesco, A.*; Di Pietro, M.*; Vardaci, E.*; Yoshida, Koichi*; Yoshida, Atsushi*; Bonetti, R.*; De Rosa, A.*; et al.
European Physical Journal A, 28(3), p.295 - 299, 2006/06
Times Cited Count：46 Percentile：90.04(Physics, Nuclear)The scattering of the radioactive, weakly bound, halo nucleus Be from Bi has been studied at 40 MeV. The measurement performed with a low-intensity and a large-emittance secondary beam could be made using an extremely compact, large solid angle ( 2
sr) detecting set-up, based on 8 highly segmented Si telescopes. The 
Be scattering angular distributions, as well as their relative reaction cross-sections, resulted to be rather similar. This may suggest that at Coulomb barrier energies the halo structure and the small weakly binding energy of the Be projectile have no big influence on the reaction dynamics.
Kaminaga, Masanori; Haga, Katsuhiro; Aso, Tomokazu; Kinoshita, Hidetaka; Kogawa, Hiroyuki; Ishikura, Shuichi*; Terada, Atsuhiko*; Kobayashi, Kaoru*; Adachi, Junichi*; Teraoku, Takuji*; et al.
Proceedings of American Nuclear Society Conference "Nuclear Applications in the New Millennium" (AccApp-ADTTA '01) (CD-ROM), 9 Pages, 2002/00
no abstracts in English
Imai, Ryuta*; Arakawa, Chuichi*; Kobayashi, Kenichi*; Hino, Ryutaro; Ishikura, Shuichi*; Kogawa, Hiroyuki; Terada, Atsuhiko*; Haga, Katsuhiro; Watanabe, Tadashi
Dai-14-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Yoshishu, p.C10_1_1 - C10_1_14, 2000/00
no abstracts in English
Kobayashi, Kenichi*; Arakawa, Chuichi*; Imai, Ryuta*; Hino, Ryutaro; Ishikura, Shuichi*; Kogawa, Hiroyuki; Terada, Atsuhiko*; Haga, Katsuhiro; Watanabe, Tadashi
Dai-14-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Yoshishu, p.C10_2_1 - C10_2_3, 2000/00
no abstracts in English
Aso, Tomokazu; Ishikura, Shuichi*; Terada, Atsuhiko*; Teshigawara, Makoto; Watanabe, Noboru; Hino, Ryutaro
Proceedings of 7th International Conference on Nuclear Engineering (ICONE-7) (CD-ROM), 10 Pages, 1999/04
no abstracts in English
Aso, Tomokazu; Ishikura, Shuichi*; Terada, Atsuhiko; Kai, Tetsuya; Teshigawara, Makoto*; Kaminaga, Masanori; Hino, Ryutaro; Watanabe, Noboru*
Proc. of 14th Meeting of the Int. Collaboration on Advanced Neutron Sources (ICANS-14), 2, p.804 - 822, 1998/00
no abstracts in English
