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Wang, Y.*; Kajihara, Shun*; Matsuoka, Hideki*; Saika, B. K.*; Yamagami, Kohei*; Takeda, Yukiharu; Wadachi, Hiroki*; Ishizaka, Kyoko*; Iwasa, Yoshihiro*; Nakano, Masaki*
Nano Letters, 22(24), p.9964 - 9971, 2022/12
Times Cited Count:15 Percentile:90.35(Chemistry, Multidisciplinary)Murase, Kiyoka*; Kataoka, Ryuho*; Nishiyama, Takanori*; Nishimura, Koji*; Hashimoto, Taishi*; Tanaka, Yoshimasa*; Kadokura, Akira*; Tomikawa, Yoshihiro*; Tsutsumi, Masaki*; Ogawa, Yasunobu*; et al.
Journal of Space Weather and Space Climate (Internet), 12, p.18_1 - 18_16, 2022/06
Times Cited Count:1 Percentile:19.16(Astronomy & Astrophysics)We identified two energetic electron precipitation (EEP) events during the growth phase of moderate substorms and estimated the mesospheric ionization rate for an EEP event for which the most comprehensive dataset from ground-based and space-born instruments was available. The mesospheric ionization signature reached below 70 km altitude and continued for ~15 min until the substorm onset, as observed by the PANSY radar and imaging riometer at Syowa Station in the Antarctic region. We also used energetic electron flux observed by the Arase and POES 15 satellites as the input for the air-shower simulation code PHITS to quantitatively estimate the mesospheric ionization rate. Combining the cutting-edge observations and simulations, we shed new light on the space weather impact of the EEP events during geomagnetically quiet times, which is important to understand the possible link between the space environment and climate.
Matsuoka, Hideki*; Barnes, S. E.*; Ieda, Junichi; Maekawa, Sadamichi; Bahramy, M. S.*; Saika, B. K.*; Takeda, Yukiharu; Wadachi, Hiroki*; Wang, Y.*; Yoshida, Satoshi*; et al.
Nano Letters, 21(4), p.1807 - 1814, 2021/02
Times Cited Count:14 Percentile:77.78(Chemistry, Multidisciplinary)Nakano, Masaki*; Wang, Y.*; Yoshida, Satoshi*; Matsuoka, Hideki*; Majima, Yuki*; Ikeda, Keisuke*; Hirata, Yasuyuki*; Takeda, Yukiharu; Wadachi, Hiroki*; Kohama, Yoshimitsu*; et al.
Nano Letters, 19(12), p.8806 - 8810, 2019/12
Times Cited Count:57 Percentile:92.26(Chemistry, Multidisciplinary)Kiriyama, Hiromitsu; Mori, Michiaki; Suzuki, Masayuki*; Daito, Izuru*; Okada, Hajime; Ochi, Yoshihiro; Tanaka, Momoko; Sato, Masatoshi*; Tamaoki, Yoshinori*; Yoshii, Takehiro*; et al.
Reza Kenkyu, 42(6), p.441 - 447, 2014/06
We describe three specific high power laser systems that are being developed in our laboratory for many applications in high field science, nonlinear optics and material processing. We report on a femtosecond petawatt-class Ti:sapphire chirped-pulse amplification laser system that can produce a pulse energy of 20 J of 40 fs pulse duration, a picosecond high intensity Yb:YAG chirped-pulse amplification laser system that can generate a pulse energy of 100 mJ of 0.5 ps pulse duration, and a nanosecond high repetition rate Nd:YAG laser system that can provide an average power of 360 W with a pulse duration of 30 ns delivered at a 1 kHz repetition rate. We discuss the basic design aspects and present the results from our experimental investigations of these laser systems.
Suzuki, Masayuki; Kiriyama, Hiromitsu; Daito, Izuru; Okada, Hajime; Ochi, Yoshihiro; Sato, Masatoshi*; Yoshii, Takehiro*; Tamaoki, Yoshinori*; Maeda, Junya*; Matsuoka, Shinichi*; et al.
AIP Conference Proceedings 1465, p.53 - 57, 2012/07
Times Cited Count:0 Percentile:0.13(Physics, Applied)We have reported hundred mJ level, femtosecond pulse duration with the high temporal contrast in an OPCPA/Yb:YAG ceramic thin disk laser system at 10 Hz repetition rate. At an input laser pulse energy of 3.8 mJ from the OPCPA preamplifer the output energy of 130 mJ with spectral bandwidth of 2.5 nm has been obtained from multipass Yb:YAG ceramic thin disk amplifier, and the optical efficiency from LD energy to amplified laser pulse is 9.6%. The recompressed laser pulse duration was measured to be 450 fs. Because the compressor efficiency exceeds 73% the compressed pulse energy can potentially be as high as 95 mJ. The contrast level of this laser pulse was measured to be less than 7.210 at -150 ps. This novel laser system after further amplification using additional amplifiers can be useful for the laser-driven proton acceleration in future.
Kiriyama, Hiromitsu; Suzuki, Masayuki*; Daito, Izuru; Okada, Hajime; Ochi, Yoshihiro; Sato, Masatoshi*; Tamaoki, Yoshinori*; Yoshii, Takehiro*; Maeda, Junya*; Matsuoka, Shinichi*; et al.
Reza Kenkyu, 40(2), p.143 - 145, 2012/02
We demonstrate a compact, high-spatiotemporal-quality, high-intensity diode-pumped Yb:YAG thin-disk chirped-pulse amplification (CPA) laser system that incorporates a nonlinear preamplifier based on optical parametric chirped-pulse amplification (OPCPA). The stretched pulses are amplified in the OPCPA preamplifier and the following Yb:YAG main amplifier to 100 mJ at 10 Hz. The broadband amplified beam quality of 1.1 (horizontal direction) and 1.4 (vertical direction) times diffraction limited and pulse compression down to 470 fs with contrast of better than 10 have been achieved successfully.
Suzuki, Masayuki*; Kiriyama, Hiromitsu; Daito, Izuru; Ochi, Yoshihiro; Okada, Hajime; Sato, Masatoshi*; Tamaoki, Yoshinori*; Yoshii, Takehiro*; Maeda, Junya*; Matsuoka, Shinichi*; et al.
Applied Physics B, 105(2), p.181 - 184, 2011/11
Times Cited Count:5 Percentile:28.53(Optics)We have demonstrated an OPCPA/Yb:YAG ceramic thin disk hybrid laser system having hundred mJ level pulse energy sub-picosecond pulse duration with high temporal contrast. At an input energy of 3.8 mJ from an OPCPA preamplifier an output energy of 130 mJ was obtained from Yb:YAG ceramic thin disk amplifier. A recompressed pulse duration of 450 fs with a contrast level of less than 7.210 was obtained. The contrast level is the highest value achieved in Yb:YAG chirped pulse amplification (CPA) laser system with hundred mJ level.
Funaki, Hironori; Asamori, Koichi; Sanada, Hiroyuki; Hatsuyama, Yoshihiro*; Yamamoto, Takuya*; Ijiri, Yuji*; Matsuoka, Kiyoyuki*; Kimura, Kazuhiro*; Lin, S.*; Kumagai, Toshifumi*
JAEA-Data/Code 2010-002, 151 Pages, 2010/06
JAEA is implementing Horonobe URL Project as research and development of geological disposal. The investigation of the pilot boring was carried out around the Ventilation shaft in order to decide grouting plan and plant of effluent treating. This report summarize as data-code results of geophysical loggings.
Yabuuchi, Satoshi; Kunimaru, Takanori; Ishii, Eiichi; Hatsuyama, Yoshihiro*; Ijiri, Yuji*; Matsuoka, Kiyoyuki*; Ibara, Tetsuo*; Matsunami, Shinjiro*; Makino, Akiya*
JAEA-Data/Code 2008-026, 62 Pages, 2009/02
The Pilot Borehole Investigation of the Ventilation Shaft was conducted in Horonobe, Hokkaido, Japan from October 2007 to March 2008. Main purpose of the investigation is to understand geological, hydrogeological and hydrochemical properties of the formation where the Ventilation Shaft has been excavated. Hydraulic packer tests show that hydraulic conductivity lies in the range from 1.1E-11 to 1.4E-7 m/sec down to 500 m in depth. This heterogeneity mainly depends on the distribution and permeability of groundwater inflow points, which were detected by Fluid Electric Conductivity logging. High conductive zones were found between 263 m and 290 m, 355 m and 370 m of the depth in the pilot borehole. An effective method for reducing groundwater inflow should be considered for the deeper Ventilation Shaft excavation.
Matsuoka, Toshiyuki; Semba, Takeshi; Ishigaki, Koichi; Sugimoto, Yoshihiro*; Tanoue, Masayoshi*; Narita, Norifumi*
Nihon Oyo Chishitsu Gakkai Heisei-18-Nendo Kenkyu Happyokai Koen Rombunshu, p.331 - 334, 2006/11
no abstracts in English
Zegers, R. G. T.*; Sumihama, Mizuki*; Ahn, D. S.*; Ahn, J. K.*; Akimune, Hidetoshi*; Asano, Yoshihiro; Chang, W. C.*; Dat, S.*; Ejiri, Hiroyasu*; Fujimura, Hisako*; et al.
Physical Review Letters, 91(9), p.092001_1 - 092001_4, 2003/08
Times Cited Count:128 Percentile:94.86(Physics, Multidisciplinary)no abstracts in English
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
Times Cited Count:1007 Percentile:99.86(Physics, Multidisciplinary)no abstracts in English
Metoki, Naoto; Koike, Yoshihiro; Matsuoka, Yuki; Kobayashi, Tatsuo*; Yamashita, Masahiro*
Journal of Magnetism and Magnetic Materials, 226-230(Part.1), p.414 - 416, 2001/05
no abstracts in English
Kuriyama, Masaaki; ; Araki, Masanori; ; Hanada, Masaya; Inoue, Takashi; Kawai, Mikito; Kazawa, Minoru; ; Kunieda, Shunsuke; et al.
Fusion Engineering and Design, 26, p.445 - 453, 1995/00
Times Cited Count:43 Percentile:95.62(Nuclear Science & Technology)no abstracts in English
Inoue, Takashi; Hanada, Masaya; Kuriyama, Masaaki; ; Matsuoka, Mamoru; Miyamoto, Kenji; Ohara, Yoshihiro; Okumura, Yoshikazu; Watanabe, Kazuhiro
IAEA-CN-60/F-10, 0, p.687 - 693, 1995/00
no abstracts in English
Okumura, Yoshikazu; Araki, Masanori; Hanada, Masaya; Inoue, Takashi; Kunieda, Shunsuke; Kuriyama, Masaaki; Matsuoka, Mamoru; Mizuno, Makoto; Ohara, Yoshihiro; Tanaka, Masanobu*; et al.
Production and Neutralization of Negative Ions and Beams; AIP Conference Proceedings 287, p.839 - 848, 1994/00
no abstracts in English
Kuriyama, Masaaki; Kunieda, Shunsuke; Matsuoka, Mamoru; Mizuno, Makoto; Ohara, Yoshihiro; Ohara, Hiroshi; Mogaki, Kazuhiko
JAERI-M 93-059, 13 Pages, 1993/03
no abstracts in English
Kuriyama, Masaaki; ; Araki, Masanori; ; Hanada, Masaya; Inoue, Takashi; Kawai, Mikito; Kazawa, Minoru; ; Kunieda, Shunsuke; et al.
15th IEEE/NPSS Symp. on Fusion Engineering,Vol. 1, 0, p.470 - 473, 1993/00
no abstracts in English
Kuriyama, Masaaki; Ohara, Yoshihiro; ; ; Hanada, Masaya; Inoue, Takashi; ; ; Ito, Takao; Kawai, Mikito; et al.
Fusion Technology 1992, Vol.1, p.564 - 568, 1993/00
no abstracts in English