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Journal Articles

High power laser developments with femtosecond to nanosecond pulse durations for laser shock science and engineering

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.

Journal Articles

Current status and future prospects of "J-KAREN"; High contrast, high intensity laser for studying relativistic laser-matter interactions

Kiriyama, Hiromitsu; Mori, Michiaki; Okada, Hajime; Shimomura, Takuya; Nakai, Yoshiki*; Tanoue, Manabu; Kondo, Shuji; Kanazawa, Shuhei; Yogo, Akifumi; Sagisaka, Akito; et al.

JPS Conference Proceedings (Internet), 1, p.015095_1 - 015095_5, 2014/03

We present the design and characterization of a high-contrast, petawatt-class Ti:sapphire chirped-pulse amplification (CPA) laser system. Two saturable absorbers and low-gain optical parametric chirped-pulse amplification (OPCPA) preamplifier in the double CPA laser chain have improved the temporal contrast to 1.4$$times$$10$$^{12}$$ on the subnanosecond time scale at 70 terawatt level. Final uncompressed broadband pulse energy is 28 J, indicating the potential for reaching peak power near 600 terawatt. We also discuss our upgrade to over petawatt level at a 0.1 Hz repetition rate briefly.

Journal Articles

Ultra-intense, high spatio-temporal quality petawatt-class laser system and applications

Kiriyama, Hiromitsu; Shimomura, Takuya; Mori, Michiaki; Nakai, Yoshiki*; Tanoue, Manabu; Kondo, Shuji; Kanazawa, Shuhei; Pirozhkov, A. S.; Esirkepov, T. Z.; Hayashi, Yukio; et al.

Applied Sciences (Internet), 3(1), p.214 - 250, 2013/03

 Times Cited Count:13 Percentile:53.78(Chemistry, Multidisciplinary)

This paper reviews techniques for improving the temporal contrast and spatial beam quality in an ultra-intense laser system that is based on chirped-pulse amplification (CPA). We describe the design, performance, and characterization of our laser system, which has the potential for achieving a peak power of 600 TW. We also describe applications of the laser system in the relativistically dominant regime of laser-matter interactions and discuss a compact, high efficiency diode-pumped laser system.

Journal Articles

Characteristic evaluation of colloidal silica grout material developed for a high level radioactive waste geological repository

Kishi, Hirokazu; Kawaguchi, Masanao; Naito, Morimasa; Hatanaka, Koichiro; Nobuto, Jun*; Sugiyama, Hirokazu*

Genshiryoku Bakkuendo Kenkyu (CD-ROM), 19(1), p.3 - 8, 2012/06

To reduce amount of groundwater inflow into a geological repository, the grouting is expected to play a very important role because the geological environment in Japan is often characterized by many fractures and abundant groundwater. Basically, cementitious materials are used for grouting, however the resulting highly alkaline plume released from the materials could influence the long-term performance of barrier system as a consequence of alteration of both the buffer material and the host rock. To minimize such effects, JAEA has carried out research and development on three types of grout material with low-pH performance that decreases influence in the alteration. This paper focuses on the Colloidal silica grout, and presents its unique characteristics obtained from laboratory tests on pH, viscosity, leaching and so on. The results indicate that the grout has good performances in pH and viscosity. It is concluded that the grout can be greatly used for the repository.

Journal Articles

Magnetic-field-induced metallic state in $$beta$$-US$$_2$$

Sugiyama, Kiyohiro*; Hirose, Yusuke*; Enoki, Kentaro*; Ikeda, Shugo*; Yamamoto, Etsuji; Tateiwa, Naoyuki; Haga, Yoshinori; Kida, Takanori*; Hagiwara, Masayuki*; Kindo, Koichi*; et al.

Journal of the Physical Society of Japan, 80(Suppl.A), p.SA104_1 - SA104_3, 2011/07

 Times Cited Count:1 Percentile:12.07(Physics, Multidisciplinary)

Journal Articles

Magnetic and superconducting properties of CeRhGe$$_2$$ and CePtSi$$_2$$

Hirose, Yusuke*; Nishimura, Naoto*; Honda, Fuminori*; Sugiyama, Kiyohiro*; Hagiwara, Masayuki*; Kindo, Koichi*; Takeuchi, Tetsuya*; Yamamoto, Etsuji; Haga, Yoshinori; Matsuura, Masato*; et al.

Journal of the Physical Society of Japan, 80(2), p.024711_1 - 024711_12, 2011/02

 Times Cited Count:6 Percentile:46.09(Physics, Multidisciplinary)

Journal Articles

Magnetic field and pressure phase diagrams of uranium heavy-fermion compound U$$_2$$Zn$$_{17}$$

Tateiwa, Naoyuki; Ikeda, Shugo*; Haga, Yoshinori; Matsuda, Tatsuma; Yamamoto, Etsuji; Sugiyama, Kiyohiro*; Hagiwara, Masayuki*; Kindo, Koichi*; Onuki, Yoshichika*

Journal of the Physical Society of Japan, 80(1), p.014706_1 - 014706_8, 2011/01

 Times Cited Count:8 Percentile:53.36(Physics, Multidisciplinary)

We have performed the magnetization measurements in high magnetic fields up to 53 T on single crystals of an uranium heavy fermion compound U$$_2$$Zn$$_{17}$$. In the antiferromagnetic state below the N$'e$el temperature $$T_{rm N}$$ = 9.7 K, a metamagnetic transition is found at $$H_c$$ $$simeq$$ 32 T for the field along the [11$$bar{2}$$0] direction ($$a$$-axis). The magnetic phase diagram for the field along the [11$$bar{2}$$0] direction is given. We have also carried out high pressure resistivity measurement on U$$_2$$Zn$$_{17}$$ using a diamond anvil cell up to 8.7 GPa. The N$'e$el temperature $$T_{rm N}$$ is almost pressure-independent up to 4.7 GPa and starts to increase at the higher pressure region. The pressure dependences of the coefficient of $$T^2$$ term in the electrical resistivity $$A$$, an antiferromagnetic gap $$Delta$$ and a characteristic temperature $$T_{{rho}{rm max}}$$ are discussed.

Journal Articles

Metamagnetic behavior in heavy-fermion compound YbIr$$_2$$Zn$$_{20}$$

Takeuchi, Tetsuya*; Yasui, Shinichi*; Toda, Masatoshi*; Matsushita, Masaki*; Yoshiuchi, Shingo*; Oya, Masahiro*; Katayama, Keisuke*; Hirose, Yusuke*; Yoshitani, Naohisa*; Honda, Fuminori*; et al.

Journal of the Physical Society of Japan, 79(6), p.064609_1 - 064609_15, 2010/06

 Times Cited Count:39 Percentile:84.44(Physics, Multidisciplinary)

Journal Articles

Stabilization of laser accelerated electron bunch by the ionization-stage control

Mori, Michiaki; Kando, Masaki; Kotaki, Hideyuki; Hayashi, Yukio; Kawase, Keigo; Bulanov, S. V.; Ogura, Koichi; Pirozhkov, A. S.; Kondo, Kiminori; Sugiyama, Akira; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.4062 - 4064, 2010/05

Journal Articles

Magnetic and Fermi surface properties of CePd$$_5$$Al$$_2$$ and PrPd$$_5$$Al$$_2$$

Nakano, Yasunori*; Honda, Fuminori*; Takeuchi, Tetsuya*; Sugiyama, Kiyohiro*; Hagiwara, Masayuki*; Kindo, Koichi*; Yamamoto, Etsuji; Haga, Yoshinori; Settai, Rikio*; Yamagami, Hiroshi*; et al.

Journal of the Physical Society of Japan, 79(2), p.024702_1 - 024702_9, 2010/02

 Times Cited Count:14 Percentile:65.65(Physics, Multidisciplinary)

Journal Articles

Heavy fermion state in YbIr$$_2$$Zn$$_{20}$$

Yoshiuchi, Shingo*; Toda, Masatoshi*; Matsushita, Masaki*; Yasui, Shinichi*; Hirose, Yusuke*; Oya, Masahiro*; Katayama, Keisuke*; Honda, Fuminori*; Sugiyama, Kiyohiro*; Hagiwara, Masayuki*; et al.

Journal of the Physical Society of Japan, 78(12), p.123711_1 - 123711_4, 2009/12

 Times Cited Count:37 Percentile:83.56(Physics, Multidisciplinary)

Journal Articles

Possible existence of magnetic polaron in nearly ferromagnetic semiconductor $$beta$$-US$$_2$$

Ikeda, Shugo*; Sakai, Hironori; Tateiwa, Naoyuki; Matsuda, Tatsuma; Aoki, Dai*; Homma, Yoshiya*; Yamamoto, Etsuji; Nakamura, Akio; Shiokawa, Yoshinobu*; Ota, Yuki*; et al.

Journal of the Physical Society of Japan, 78(11), p.114704_1 - 114704_10, 2009/11

 Times Cited Count:10 Percentile:56.76(Physics, Multidisciplinary)

Journal Articles

Solubility of uranyl nitrate precipitates with $$N$$-Alkyl-2-pyrrolidone derivatives (Alkyl = $$n$$-propyl, $$n$$-butyl, $$iso$$-butyl, and cyclohexyl)

Takao, Koichiro*; Noda, Kyoko*; Nogami, Masanobu*; Sugiyama, Yuichi*; Harada, Masayuki*; Morita, Yasuji; Nishimura, Kenji*; Ikeda, Yasuhisa*

Journal of Nuclear Science and Technology, 46(10), p.995 - 999, 2009/10

 Times Cited Count:12 Percentile:65.67(Nuclear Science & Technology)

We have been developing an advanced reprocessing system for spent FBR fuels based on precipitation method using pyrrolidone derivatives. In the present study, the solubility of UO$$_{2}$$(NO$$_{3}$$)$$_{2}$$(NRP)$$_{2}$$ (NRP = $$N$$-alkyl-2-pyrrolidone, alkyl = $$n$$-propyl, $$n$$-butyl, $$iso$$-butyl and cyclohexyl) in aqueous solutions with HNO$$_{3}$$ has been examined. As a result, the solubility of each species of UO$$_{2}$$(NO$$_{3}$$)$$_{2}$$(NRP)$$_{2}$$ generally decreases with increasing concentrations of HNO$$_{3}$$ and NRP ($$C$$(HNO$$_{3}$$) and $$C$$(NRP), respectively). The solubility of UO$$_{2}$$(NO$$_{3}$$)$$_{2}$$(NRP)$$_{2}$$ also depends on the type of NRP; a higher hydrophobicity of NRP generally leads to a lower solubility of UO$$_{2}$$(NO$$_{3}$$)$$_{2}$$(NRP)$$_{2}$$. The logarithms of effective solubility products ($$K$$$$_{rm eff}$$) of UO$$_{2}$$(NO$$_{3}$$)$$_{2}$$(NRP)$$_{2}$$ at different $$C$$(HNO$$_{3}$$) values and 293 K were evaluated.

Journal Articles

Experimental studies of the high and low frequency electromagnetic radiation produced from nonlinear laser-plasma interactions

Kando, Masaki; Pirozhkov, A. S.; Fukuda, Yuji; Esirkepov, T. Z.; Daito, Izuru; Kawase, Keigo; Ma, J. L.*; Chen, L. M.*; Hayashi, Yukio; Mori, Michiaki; et al.

European Physical Journal D, 55(2), p.465 - 474, 2009/09

 Times Cited Count:17 Percentile:64.98(Optics)

Nonlinear interaction of intense laser beams with plasma causes a number of different regimes of generation of high energy particle beams and of strong radiation with the emitted photon energy from the X-ray to THz frequency range. The review of the first proof-of-principle experiment and the latest progress on the flying mirror is presented. A low frequency EM radiation emission has also been observed in our experiments. The interpretation invokes the relativistic electromagnetic solitons. The solitons are formed in an underdense plasma in the process of the laser pulse frequency downshift. They store a portion of EM wave energy with the polarization inherited from the laser and emit it at the plasma-vacuum interface in a form of the low frequency EM bursts. We present the results of the polarization-resolved measurements.

Journal Articles

Generation of stable and low-divergence 10-MeV quasimonoenergetic electron bunch using argon gas jet

Mori, Michiaki; Kondo, Kiminori; Mizuta, Yoshio*; Kando, Masaki; Kotaki, Hideyuki; Nishiuchi, Mamiko; Kado, Masataka; Pirozhkov, A. S.; Ogura, Koichi; Sugiyama, Hironori*; et al.

Physical Review Special Topics; Accelerators and Beams, 12(8), p.082801_1 - 082801_5, 2009/08

 Times Cited Count:21 Percentile:77.68(Physics, Nuclear)

The pointing stability and divergence of a quasimonoenergetic electron bunch generated in a self-injected laser-plasma acceleration regime using 4 TW laser is studied. A pointing stability of 2.4 mrad root-mean-square (RMS) and a beam divergence of 10.6 mrad (RMS) were obtained using an argon gas-jet target for 50 sequential shots, while these values were degraded by a factor of three at the optimum condition using helium. The peak electron energies were 8.5$$pm$$0.7 MeV and 24.8$$pm$$3.6 MeV using argon and helium, respectively. The experimental results indicate that the different propagation condition could be generated with the different material, although it is performed with the same irradiation condition.

Journal Articles

Application of laser-accelerated protons to the demonstration of DNA double-strand breaks in human cancer cells

Yogo, Akifumi; Sato, Katsutoshi; Nishikino, Masaharu; Mori, Michiaki; Teshima, Teruki*; Numasaki, Hodaka*; Murakami, Masao*; Demizu, Yusuke*; Akagi, Takashi*; Nagayama, Shinichi*; et al.

Applied Physics Letters, 94(18), p.181502_1 - 181502_3, 2009/05

 Times Cited Count:95 Percentile:94.5(Physics, Applied)

Journal Articles

Focusing and spectral enhancement of a repetition-rated, laser-driven, divergent multi-MeV proton beam using permanent quadrupole magnets

Nishiuchi, Mamiko; Daito, Izuru; Ikegami, Masahiro; Daido, Hiroyuki; Mori, Michiaki; Orimo, Satoshi; Ogura, Koichi; Sagisaka, Akito; Yogo, Akifumi; Pirozhkov, A. S.; et al.

Applied Physics Letters, 94(6), p.061107_1 - 061107_3, 2009/02

 Times Cited Count:54 Percentile:87.76(Physics, Applied)

A pair of conventional permanent magnet quadrupoles is used to focus a 2.4 MeV laser-driven proton beam at a 1 Hz repetition rate. The magnetic field strengths are 55 T/m and 60 T/m for the first and second quadrupoles respectively. The proton beam is focused to a spot size (full width at half maximum) of 2.7$$times$$8 mm$$^{2}$$ at a distance of 650 mm from the source. This result is in good agreement with a Monte Carlo particle trajectory simulation.

Journal Articles

High-energy diode-pumped picosecond regenerative amplification at 999 nm in wavelength with a cryogenically cooled Yb:LuLiF$$_{4}$$ crystal

Akahane, Yutaka; Aoyama, Makoto; Sugiyama, Akira; Kubo, Ryoichi; Ogawa, Kanade; Tsuji, Koichi; Yamakawa, Koichi

Optics Letters, 33(5), p.494 - 496, 2008/03

 Times Cited Count:2 Percentile:15.43(Optics)

A diode-pumped, cryogenically-cooled Yb:LuLiF$$_{4}$$ regenerative amplifier has been developed for the first time to our knowledge. A chirped-seed pulse was amplified and compressed in the regenerative amplifier, simultaneously, which generated $$sim$$6-mJ, 13-ps pulses at 999 nm wavelength without a pulse compressor. Simultaneous lasing at 999 nm and 1024 nm, respectively, was demonstrated, which could be used for different frequency generation in the THz region.

Journal Articles

Magnetic properties and crystalline electric field scheme in RRhIn$$_5$$ (R: Rare earth)

Hieu, N. V.*; Takeuchi, Tetsuya*; Shishido, Hiroaki*; Tonohiro, Chie*; Yamada, Tsutomu*; Nakashima, Hiroshi*; Sugiyama, Kiyohiro*; Settai, Rikio*; Matsuda, Tatsuma; Haga, Yoshinori; et al.

Journal of the Physical Society of Japan, 76(6), p.064702_1 - 064702_16, 2007/06

 Times Cited Count:42 Percentile:83.43(Physics, Multidisciplinary)

Journal Articles

Degenerate optical parametric chirped-pulse amplifier pumped by an Yb:YLF chirped-pulse amplification laser

Aoyama, Makoto; Akahane, Yutaka; Ogawa, Kanade; Tsuji, Koichi; Sugiyama, Akira; Harimoto, Tetsuo*; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi

Reza Kenkyu, 35(6), p.398 - 399, 2007/06

We have demonstrated optical parametric chirped-pulse amplification by using a diode-pumped Yb:YLF CPA laser system as a pump source and achieved an ultra-broadband amplification of over 200-nm supporting a 12.6-fs duration (3.7 optical cycles) in spite of being operated around degeneracy. By using a two-stage OPCPA with a higher-energy pump pulse, it should be able to produce a terawatt-class, few-cycle laser pulse without complexly and enlarging the system size. Such a laser is useful for the generation of attosecond pulse generation in the xuv region as well as other high field applications.

70 (Records 1-20 displayed on this page)