KeV-region analysis of the neutron capture cross-section of Np

Rovira Leveroni, G.; Katabuchi, Tatsuya*; Tosaka, Kenichi*; Matsuura, Shota*; Kodama, Yu*; Nakano, Hideto*; Iwamoto, Osamu; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Nobuyuki

Journal of Nuclear Science and Technology, 59(1), p.110 - 122, 2022/01

https://doi.org/10.1080/00223131.2021.1954104

Neutron beam filter system for fast neutron cross-section measurement at the ANNRI beamline of MLF/J-PARC

Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Katabuchi, Tatsuya*; Terada, Kazushi*; Kodama, Yu*; Nakano, Hideto*; et al.

Nuclear Instruments and Methods in Physics Research A, 1003, p.165318_1 - 165318_10, 2021/07

https://doi.org/10.1016/j.nima.2021.165318

XUV-FEL spectroscopy; He two-photon ionization cross-sections

Sato, Takahiro*; Iwasaki, Atsushi*; Ishibashi, Kazuki*; Okino, Tomoya*; Yamanouchi, Kaoru*; Adachi, Junichi*; Yagishita, Akira*; Yazawa, Hiroki*; Kannari, Fumihiko*; Aoyama, Makoto; et al.

Europhysics News, 42(5), P. 10, 2011/09

The resonant and non-resonant two-photon single ionization processes of He were investigated using intense free electron laser light in the extreme ultraviolet (XUV) region (53.4-61.4 nm) covering the 1s-2p and 1s-3p resonant transitions of He. On the basis of the dependences of the yield of He on the XUV light-field intensity at 53.4, 58.4, 56.0 and 61.4 nm, the absolute values of the two-photon ionization cross sections of He at the four different wavelengths and their dependence on the light-field intensity were determined for the first time.

Extreme ultraviolet free electron laser seeded with high-order harmonic of Ti:sapphore laser

Togashi, Tadashi*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Okino, Tomoya*; Yamanouchi, Kaoru*; et al.

Optics Express (Internet), 19(1), p.317 - 324, 2011/01

https://doi.org/10.1364/OE.19.000317

The 13th harmonic of a Ti:sapphire (Ti:S) laser in the plateau region was injected as a seeding source to a 250-MeV free-electron-laser (FEL) amplifier. When the amplification conditions were fulfilled, strong enhancement of the radiation intensity by a factor of 650 was observed. The random and uncontrollable spikes, which appeared in the spectra of the Self-Amplified Spontaneous Emission (SASE) based FEL radiation without the seeding source, were found to be suppressed drastically to form to a narrow-band, single peak profile at 61.2 nm. The properties of the seeded FEL radiation were well reproduced by numerical simulations. We discuss the future precept of the seeded FEL scheme to the shorter wavelength region.

Two-body Coulomb explosion and hydrogen migration in methanol induced by intense 7 and 21 fs laser pulses

Itakura, Ryuji; Liu, P.*; Furukawa, Yusuke*; Okino, Tomoya*; Yamanouchi, Kaoru*; Nakano, Hidetoshi*

Journal of Chemical Physics, 127(10), p.104306_1 - 104306_5, 2007/09

https://doi.org/10.1063/1.2768958

Coulomb explosion of methanol induced by intense laser pulses with t = 7 and 21 fs is investigated by coincidence momentum imaging. When t = 7, the angular distribution of recoil vectors for the direct C-O bond breaking exhibits a peak deflected from the laser polarization direction by 30-45 deg., and the corresponding angular distribution for the migration pathway exhibits almost the same profile. When the laser pulse is stretched to t = 21 fs, the angular distributions for the direct and migration pathways exhibit a broad peak along the laser polarization direction. However, the extent of the anisotropy in the migration pathway is smaller than that in the direct pathway, exhibiting a substantial effect of hydrogen atom migration.

The Relationship between the Surface Current Offshore Tokai and the Wind Field

Nakano, Masanao; Isozaki, Hisaaki; Isozaki, Tokuju; Ao, Hidetoshi*; Nemoto, Masashi *

JNC TN8400 2005-030, 189 Pages, 2005/09

JNC-TN8400-2005-030.pdf:136.62MB

The marine observation has been performed along the coast of JNC Tokai Reprocessing Plant (TRP) that discharges low level radioactive effluent. Recently the underslung electromagnetic flow-meter measured the current field at the very surface layer (depth: 0.5m, 1.0m, 3.0m). Then, the characteristic of the surface current field was analysed with correlation to the wind field that observed at 20m above sea level in Tokai Works. The tidal component is apparently detected by the harmonic analysis since the diel contents (land and sea breeze) is included in the wind that drives the surface seawater. However it is not the tidal current but the wind current. As the result, it made sure that the surface current is induced by the wind. Especially the wind current develops at the thin surface (skin) layer with pycnocline. The effluent from TRP has no salt and relatively high temperature, and it induces pycnocline near the discharge port. Assessing the marine diffusion of the radioactive materials from TRP, it is important to consider wind current especially.

Data Book on the Current of Tokai Reprocessing Plant; From January to December in 2000

Takeishi, Minoru; Naoto, Miyagawa,; Nakano, Masanao; Isozaki, Hisaaki; Isozaki, Tokuju; Ao, Hidetoshi*; Nemoto, Masashi *

JNC TN8450 2004-005, 139 Pages, 2004/06

JNC-TN8450-2004-005.pdf:12.13MB

Current direction, velocity, water temperature, salinity and etc. were observed by the current meters which were set near the outlet (36 26' 51" N, 140 39' 02"E)of the discharge pipe of the reprocessing plant in JNC Tokai Works. Besides, the horizontal (26 points) and vertical (14 points) observation of water temperature and salinity were executed using the monitoring ship (Seikai). The observation region ranged from 36 22' N to 36 30' N and from 140 37' E to 140 42'E. The data, which were observed in 2000, were described in this report.

Evidence for a narrow = +1 Baryon resonance in photoproduction from the neutron

Nakano, Takashi*; Ahn, D. S.*; Ahn, J. K.*; Akimune, Hidetoshi*; Asano, Yoshihiro; Chang, W. C.*; Date, S.*; Ejiri, Hiroyasu*; Fujimura, Hisako*; Fujiwara, Mamoru; et al.

Physical Review Letters, 91(1), p.012002_1 - 012002_4, 2003/07

https://doi.org/10.1103/PhysRevLett.91.012002

no abstracts in English

Powder eutectic coating of SUS316 for the purpose of improvement of corrosion resistance in Pb-Bi

Sato, Hidetomo*; Nakano, Hiromasa*; Yokota, Hitoshi*; Suzuki, Tetsuya*; Maekawa, Katsuhiro*; Kurata, Yuji

no journal, , 

Liquid lead-bismuth is a candidate material used for accelerator driven systems and fast reactors. One of difficulties to apply Pb-Bi to nuclear systems is the corrosiveness of liquid Pb-Bi to structural steels. For this reason the study has been focused on improvement of corrosion resistance due to addition of Si and Al to steels. In this study, type 316 stainless steel was coated by Al-Ti-Fe eutectic alloy layer to enhance corrosion resistance in liquid lead-bismuth. The coating was conducted by a powder eutectic method using laser heating. The optimum condition to produce good coating layers was obtained concerning laser pulse energy and chemical composition of powders.

Application of aluminum powder alloy coating to nuclear system

Sato, Hidetomo*; Nakano, Hiromasa*; Yokota, Hitoshi*; Suzuki, Tetsuya*; Maekawa, Katsuhiro*; Kurata, Yuji

no journal, , 

Liquid lead-bismuth is a candidate material used for accelerator driven systems and fast reactors. One of difficulties to apply Pb-Bi to nuclear systems is the corrosiveness of liquid Pb-Bi to structural steels. Recently, an Al alloy coating technique using Al and Ti powders was developed. In this study, type 316 stainless steel was coated with Al-Ti-Fe alloy layer to enhance corrosion resistance in liquid lead-bismuth. As a result of the corrosion test of the Al alloy coated specimens in liquid lead-bismuth, it was found that the coated layer exhibited good corrosion resistance to lead-bismuth.