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Matsuda, Shohei; Nakashima, Nobuaki*; Yokoyama, Keiichi; Taniguchi, Seiji*; Chosrowjan, H.*; Somekawa, Toshihiro*; Yatsuhashi, Tomoyuki*
Chemical Physics Letters, 802, p.139759_1 - 139759_6, 2022/09
Times Cited Count:0 Percentile:0.01(Chemistry, Physical)no abstracts in English
Matsuda, Shohei; Yokoyama, Keiichi; Yaita, Tsuyoshi; Kobayashi, Toru; Kaneta, Yui; Simonnet, M.; Sekiguchi, Tetsuhiro; Honda, Mitsunori; Shimojo, Kojiro; Doi, Reisuke; et al.
Science Advances (Internet), 8(20), p.eabn1991_1 - eabn1991_11, 2022/05
Times Cited Count:3 Percentile:54.33(Multidisciplinary Sciences)no abstracts in English
Sagisaka, Akito; Daido, Hiroyuki; Nashima, Shigeki*; Orimo, Satoshi; Ogura, Koichi; Mori, Michiaki; Yogo, Akifumi; Ma, J.-L.; Daito, Izuru; Pirozhkov, A. S.; et al.
Applied Physics B, 90(3-4), p.373 - 377, 2008/03
Times Cited Count:62 Percentile:92.91(Optics)High-intensity laser and thin-foil interactions produce high energy ions, electrons, hard X-ray, and terahertz radiation. The simultaneous generation of the protons and terahertz radiation will provide us unique applications. In this study we use a Ti:sapphire laser system (JLITE-X) at JAEA for simultaneous generation of the protons and terahertz radiation. The laser beam is focused by an off-axis parabolic mirror at the Ti target surface. The estimated peak intensity is 210W/cm. The simultaneous generation of the protons and terahertz radiation are observed by reducing the ASE duration.
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*; Nagaoka, Shinji*; Mitamura, Muneki*; et al.
Journal of Environmental Radioactivity, 99(1), p.211 - 217, 2008/01
Times Cited Count:18 Percentile:40.59(Environmental Sciences)In a sediment core of Nishiyama reservoir at Nagasaki, depth profiles of Pu/Pu ratio, Pu and Cs concentrations were determined. Sediments containing plutonium and Cs, which were fallout deposited immediately after a detonation of Nagasaki atomic bomb, were identified in the core. Observed below the sediments were macroscopic charcoals, providing evidence for initial deposit of the fallout. This is the first entire depositional records of plutonium and Cs released from the Nagasaki atomic bomb together with those from atmospheric nuclear tests.
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*
Journal of Radioanalytical and Nuclear Chemistry, 273(1), p.183 - 186, 2007/07
Times Cited Count:7 Percentile:47.42(Chemistry, Analytical)no abstracts in English
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Mitamura, Muneki*; Yoshikawa, Shusaku*
Journal of Geosciences, Osaka City University, 50, p.7 - 13, 2007/03
no abstracts in English
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*
KEK Proceedings 2006-5, p.36 - 40, 2006/11
no abstracts in English
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yoshikawa, Shusaku*; Yamazaki, Hideo*
no journal, ,
no abstracts in English
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Murakami, Akiko*; Inoue, Jun*; Yoshikawa, Shusaku*; Yamazaki, Hideo*; et al.
no journal, ,
no abstracts in English
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yoshikawa, Shusaku*; Yamazaki, Hideo*; Nagaoka, Shinji*
no journal, ,
no abstracts in English
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yoshikawa, Shusaku*; Yamazaki, Hideo*; Nagaoka, Shinji*
no journal, ,
no abstracts in English
Sagisaka, Akito; Daido, Hiroyuki; Pirozhkov, A. S.; Ogura, Koichi; Orimo, Satoshi; Mori, Michiaki; Yogo, Akifumi; Nakamura, Shu*; Iwashita, Yoshihisa*; Shirai, Toshiyuki*; et al.
no journal, ,
no abstracts in English
Kokubu, Yoko
no journal, ,
This presentation is one of the invited talks at a special session of "Advances and future prospect of A-bomb researches" in the 2008 Annual Meeting of the Japan Society of Nuclear and Radiochemical Sciences. Alpha-ray spectrometry of Pu was mainly used to assess plutonium from Nagasaki atomic bomb in the previous studies. However it was difficult to discriminate the plutonium due to atomic explosion in Nagasaki from global fallout by analysis of the -ray spectrum. In this study, Pu/Pu ratio measured by ICP-MS was used to identify the source of Pu and distributions of the Pu in sediment and soils were reported. Depth profile of the Pu in a sediment core collected at Nishiyama reservoir, Nagasaki city was determined to obtain depositional record of the Pu from the atomic bomb for 60 years. The Pu was measured in surface soils collected around the hypocenter of the atomic bomb to identify geological distribution of the Pu from the atomic bomb.
Yamazaki, Hideo*; Kawashima, Asami*; Kokubu, Yoko; Nagaoka, Shinji*; Tsujimoto, Akira*; Murakami, Akiko*; Yoshikawa, Shusaku*
no journal, ,
no abstracts in English
Kokubu, Yoko; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu*; Kimura, Takaumi; Yamazaki, Hideo*; Yoshikawa, Shusaku*; Nagaoka, Shinji*
no journal, ,
Plutonium isotopes were released from Nagasaki atomic bomb which exploded on August 9, 1945. The isotopes are interesting in research on environmental radioactivity, because evident information of the plutonium release provide opportunities to simplify understanding of environmental behavior of Pu. The Nagasaki area is one of the oldest areas that were contaminated with the artificial Pu in the world. As the isotopic composition of Pu depends on its origin, Pu/Pu ratio is a useful tool for the identification of the source of Pu. This paper is intended to report the Pu/Pu ratios in sediments and surface soils and distribution of the Pu from the atomic bomb.
Kando, Masaki; Nashima, Shigeki*; Pirozhkov, A. S.; Hayashi, Yukio; Kotaki, Hideyuki; Bulanov, S. V.
no journal, ,
We irradiated laser pulses with energy of 400 mJ - 1J and the pulse duration of 30 fs onto a helium gas-jet target with the irradiance of 10 W/cm and measured the long wavelength ( THz) electromagnetic radiation with a DTGS detector. Among the known mechanism of THz generation via laser-matter interaction, we focus on the soliton mechanism that the laser pulse depletes its energy and its energy is converted to lower frequency light. With a probe light, we observed soliton-like structures. With the DTGS, many noises were obtained when the laser intensity and laser contrast increases.
Matsuda, Shohei; Nakashima, Nobuaki*; Yokoyama, Keiichi; Yatsuhashi, Tomoyuki*; Chosrowjan, H.*; Taniguchi, Seiji*; Somekawa, Toshihiro*
no journal, ,
The photochemical reactions of lanthanide and actinide ions are expected to be utilized for recovery and recycling of rare earths, and nuclear fuel reprocessing. Heading towards research for implementation of photochemical purification, a unified evaluation of the efficiency of multiphoton processes is required. In this study, we have evaluated the fluence dependence of photoreduction of Eu(III) more precisely than before by measuring the beam profile of the excitation laser. The reduction rate of Eu(III)Eu(II) is proportional to the square of the laser fluence, indicating that the photoreduction of Eu(III) is induced by a two-photon process.
Nakae, Masanori*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Ueda, Akihiko; Machida, Masahiko; Sasaki, Toshiki; Tsuji, Koichi*
no journal, ,
no abstracts in English
Fuchita, Tomoki*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Ueda, Akihiko; Machida, Masahiko; Sasaki, Toshiki; Tsuji, Koichi*
no journal, ,
no abstracts in English
Nakae, Masanori*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Machida, Masahiko; Ueda, Akihiko; Sasaki, Toshiki; Tsuji, Koichi*
no journal, ,
X-ray absorption imaging is a technique in which samples are irradiated with X-rays and the transmitted X-rays are detected by an X-ray camera. Although this method is non-destructive and fast, X-ray cameras generally do not have energy resolution and cannot identify elements. Recently, an X-ray imaging method has been reported to use synchrotron radiation to image the elemental distribution using X-rays with energy around the absorption edge, and analyze the difference between the images. However, it is difficult to change the energy of X-rays in a laboratory. In this study, we studied the method for visualization of only the target element even in the laboratory by using a secondary target and an X-ray filter.