Progress and prospects of calculation methods for radiation shielding

Hirayama, Hideo*; Nakashima, Hiroshi; Morishima, Makoto*; Uematsu, Mikio*; Sato, Osamu*

Journal of Nuclear Science and Technology, 52(11), p.1339 - 1361, 2015/11

AA2014-0681.pdf:1.15MB

https://doi.org/10.1080/00223131.2015.1021283

Progress in calculation methods for radiation shielding are reviewed based on basis of the activities of research committees related to radiation shielding fields established in the Atomic Energy Society of Japan. A technological roadmap for the field of radiation shielding, progress and prospects for specific shielding calculation methods such as the Monte Carlo, discrete ordinate Sn transport, and simplified methods, and shielding experiments used to validate calculation methods are presented in this paper.

Numerical predictions on turbulent mixing in two parallel channels with a connecting passage at non-heated supercritical fluid condition

Misawa, Takeharu; Takase, Kazuyuki; Mori, Hideo*

Proceedings of 8th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-8) (USB Flash Drive), 6 Pages, 2012/12

Outline of research and development of thermal-hydraulics and safety of Japanese Supercritical Water Cooled Reactor (JSCWR) project

Nakatsuka, Toru; Mori, Hideo*; Akiba, Miyuki*; Ezato, Koichiro; Yasuoka, Makoto*

Proceedings of 5th International Symposium on Supercritical Water-Cooled Reactors (ISSCWR-5) (CD-ROM), 12 Pages, 2011/03

In the thermal-hydraulic area of Japanese Supercritical Water Cooled Reactor (JSCWR) project, the main objective is to provide high-precision heat transfer and hydraulics resistance correlations of supercritical water which are necessary for the conceptual design of the core and fuel. For this purpose, a database was constructed from literature survey and previous research results. The most suitable correlation applied for circular tubes was selected based on the database and the range of application and predictive accuracy were defined. A thermal-hydraulics analysis code has been developed based on large eddy simulation, which is selected for simulation of the heat transfer deterioration, to give detailed information of thermal-hydraulics phenomena in a fuel bundle.

Proton generation and terahertz radiation from a thin-foil target with a high-intensity laser

Sagisaka, Akito; Pirozhkov, A. S.; Mori, Michiaki; Yogo, Akifumi; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Ma, J.*; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.

Reza Kenkyu, 38(9), p.702 - 705, 2010/09

https://ci.nii.ac.jp/naid/10026690906

High-intensity laser and thin-foil interactions produce high-energy particles, hard X-ray, high-order harmonics, and terahertz (THz) radiation. A proton beam driven by a high-intensity laser has received attention as a compact ion source for medical applications. In this study we have tested simultaneous generation of protons and THz radiation from a thin-foil target. We use a Ti:sapphire laser system (J-KAREN) at JAEA. A laser beam is focused by an off-axis parabolic mirror at the thin-foil target. We observed the high-energy proton in the rear side of the target and THz radiation in the reflected direction. Next, high energy protons are observed by reducing the size of preformed plasma.

Observation of UV harmonics from a thin-foil target in the high-intensity laser-driven proton generation

Sagisaka, Akito; Pirozhkov, A. S.; Ma, J.-L.; Mori, Michiaki; Yogo, Akifumi; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.

Journal of Plasma and Fusion Research SERIES, Vol.8, p.464 - 467, 2009/09

http://www.jspf.or.jp/JPFRS/PDF/Vol8/jpfrs2009_08-0464.pdf

We measure the UV harmonics from a thin-foil target by changing the laser pulse duration in the high-energy proton generation. The maximum proton energies are around 1 MeV. In the case of the 500 fs, the peaks of UV harmonics up to fourth-order clearly appear. The spectra are broadened and shifted at the pulse durations of 100 fs and 30 fs.

Ion acceleration using temporally-controlled high-intensity laser pulses

Yogo, Akifumi; Daido, Hiroyuki; Mori, Michiaki; Kiriyama, Hiromitsu; Bulanov, S. V.; Bolton, P. R.; Esirkepov, T. Z.; Ogura, Koichi; Sagisaka, Akito; Orimo, Satoshi; et al.

Reza Kenkyu, 37(6), p.449 - 454, 2009/06

https://ci.nii.ac.jp/naid/10024748876

The acceleration of protons driven by a high-intensity laser is comprehensively investigated via control of the target density by using ASE just before the time of the main-laser interaction. Two cases were investigated for which the ASE intensity differed by three orders of magnitude: In the low contrast case the beam centre for higher energy protons is shifted closer to the laser-propagation direction of 45, while the center of lower-energy beam remains near the target normal direction. Particle-in-cell simulations reveal that the characteristic proton acceleration is due to the quasistatic magnetic field on the target rear side with the magnetic pressure sustaining a charge separation electrostatic field.

Simultaneous generation of UV harmonics and protons from a thin-foil target with a high-intensity laser

Sagisaka, Akito; Daido, Hiroyuki; Pirozhkov, A. S.; Ma, J.-L.; Yogo, Akifumi; Ogura, Koichi; Orimo, Satoshi; Mori, Michiaki; Nishiuchi, Mamiko; Kawachi, Tetsuya; et al.

IEEE Transactions on Plasma Science, 36(4), p.1812 - 1816, 2008/08

https://doi.org/10.1109/TPS.2008.2000897

We observe UV harmonics and protons with a thin-foil target irradiated with a high-intensity Ti:sapphire laser. The laser intensity dependency of UV harmonics and proton signal is measured by varying the distance between the target surface and the best focus of the laser beam. In the case of appropriate condition for proton generation with a maximum energy of 2.7 MeV, the weak broad spectrum in the UV region is generated. The UV harmonics up to fourth-order are generated as the target is moved away from the best focus position. In this condition the maximum energy of protons is reduced to 1 MeV.

Fluoride complexation of element 104, rutherfordium (Rf), investigated by cation-exchange chromatography

Ishii, Yasuo; Toyoshima, Atsushi; Tsukada, Kazuaki; Asai, Masato; Tome, Hayato; Nishinaka, Ichiro; Nagame, Yuichiro; Miyashita, Sunao*; Mori, Tomotaka*; Suganuma, Hideo*; et al.

Chemistry Letters, 37(3), p.288 - 289, 2008/03

https://doi.org/10.1246/cl.2008.288

We have investigated cation-exchange behavior of Rf together with the lighter homologues of the group-4 elements Zr and Hf, and the tetravalent pseudo-homologue Th, in HF/HNO solution using Automated Ion exchange separation apparatus coupled with the Detection system for Alpha spectroscopy (AIDA). The values of Zr, Hf, Th and Rf in HF/0.1 M HNO were decreased with increasing the concentration of the fluoride ion [F], indicating the formation of the fluoride complexes. The sequence of the fluoride complexation strength is Zr Hf Rf Th.

Laser-driven proton acceleration from a near-critical density target

Yogo, Akifumi; Daido, Hiroyuki; Bulanov, S. V.; Esirkepov, T. Z.; Nemoto, Koshichi*; Oishi, Yuji*; Nayuki, Takuya*; Fujii, Takashi*; Ogura, Koichi; Orimo, Satoshi; et al.

Journal of Physics; Conference Series, 112, p.042034_1 - 042034_4, 2008/00

https://doi.org/10.1088/1742-6596/112/4/042034

In this work, we present a new method to enhance the proton generation by a 10-contrast laser. High-energy protons up to 3.8 MeV are observed with 7.5-m-thick insulator (Polyimide) target irradiated by a laser pulse having energy of 0.8 J and an intensity of 10-W/cm. Using two time-of-flight (TOF) spectrometers simultaneously in different directions, we measure the direction dependency of proton-energy spectra. As a result, we find that high-energy component of proton beam is shifted away from the target normal toward the laser-propagation direction, when the laser is focused with 45 incident angle. The TOF measurements over 130 laser shots confirm that the generation of the high-energy protons, which are steered away from the target normal, depends strongly on the laser-focusing condition.

Angle-resolved photoemission study of the -chain compound [Ni(chxn)Br]Br; Spin-charge separation in hybridized - chains

Fujimori, Shinichi; Ino, Akihiro; Okane, Tetsuo; Fujimori, Atsushi; Okada, Kozo*; Manabe, Toshio*; Yamashita, Masahiro*; Kishida, Hideo*; Okamoto, Hiroshi*

Physical Review Letters, 88(24), p.247601_1 - 247601_4, 2002/06

https://doi.org/10.1103/PhysRevLett.88.247601

We report on the results of angle-resolved photoemission experiments on a quasi-one-dimensional -chain compound [Ni(chxn)Br]Br (chxn = 1,2-cyclohexanediamine), a one-dimensional Heisenberg system with and K, which shows a gigantic non-linear optical effect. A "band" having about 500meV energy dispersion is found in the first half of the Brillouin zone , but disappears at . Two dispersive features, expected from the spin-charge separation, as have been observed in other quasi-one-dimensional systems like SrCuO, are not detected. These characteristic features are well reproduced by the - chain model calculations with a small charge-transfer energy compared with that of one-dimensional Cu-O based compounds. We propose that this smaller is the origin of the absence of clear spin- and charge-seperation in the photoemission spectra and strong non-linear optical effect in [Ni(chxn)Br]Br.