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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

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:15 Percentile:50(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

High intensity, high temporal contrast, high repetition-rate laser for laser driven particle acceleration

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

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 7.2$$times$$10$$^{-9}$$ at -150 ps. This novel laser system after further amplification using additional amplifiers can be useful for the laser-driven proton acceleration in future.

Journal Articles

Development of a compact high-spatiotemporal-quality Yb:YAG thin-disk laser system using an optical parametric preamplifier

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 $$sim$$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$$^{-8}$$ have been achieved successfully.

Journal Articles

Hundred mJ, sub-picoseconds, high temporal contrast OPCPA/Yb:YAG ceramic thin disk hybrid laser system

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:28.75(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 7.2$$times$$10$$^-9$$ was obtained. The contrast level is the highest value achieved in Yb:YAG chirped pulse amplification (CPA) laser system with hundred mJ level.

Journal Articles

Report on CLEO Europe EQEC 2011

Suzuki, Masayuki; Kiriyama, Hiromitsu

Reza Kenkyu, 39(8), p.649 - 651, 2011/08

no abstracts in English

Journal Articles

Development of a high-contrast, high beam-quality, high-intensity laser

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki*; Shimomura, Takuya; Sasao, Hajime*; Tanaka, Momoko; Ochi, Yoshihiro; Tanoue, Manabu*; Kondo, Shuji; Kanazawa, Shuhei; et al.

Reza Kenkyu, 38(9), p.669 - 675, 2010/09

This paper reviews the temporal contrast and spatial beam quality improvement techniques in a high intensity Ti:sapphire laser system that is based on chirped-pulse amplification (CPA). We describe a low gain optical parametric chirped-pulse amplification (OPCPA) preamplifier that uses high energy, clean pulse seeding and is shown to significantly improve the contrast to better than 10$$^{-10}$$-10$$^{-11}$$ relative to the peak of the main femtosecond pulse. We also report the use of a diffractive optical element for beam homogenization of a 100 J level Nd:glass green pump laser, achieving a flat-topped spatial profile with a filling factor near 80 %.

Journal Articles

Toward integrated laser-driven ion accelerator systems at the Photo-Medical Research Center in Japan

Bolton, P.; Hori, Toshihiko; Kiriyama, Hiromitsu; Mori, Michiaki; Sakaki, Hironao; Sutherland, K.*; Suzuki, Masayuki; Wu, J.*; Yogo, Akifumi

Nuclear Instruments and Methods in Physics Research A, 620(1), p.71 - 75, 2010/08

 Times Cited Count:11 Percentile:62.45(Instruments & Instrumentation)

Journal Articles

High-contrast (10$$^{10}$$), high-intensity (500 TW) J-KAREN laser system

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Shimomura, Takuya; Sasao, Hajime; Tanaka, Momoko; Ochi, Yoshihiro; Tanoue, Manabu*; Okada, Hajime; Kondo, Shuji; et al.

JAEA-Conf 2010-002, p.18 - 21, 2010/06

We have developed a femtosecond high intensity laser system, which combines both Ti:sapphire chirped-pulse amplification (CPA) and optical parametric chirped-pulse amplification (OPCPA) techniques, that produces more than 30 J broadband output energy, indicating the potential for achieving peak powers in excess of 500 TW. With a cleaned high-energy seeded OPCPA preamplifier as a front-end in the system, for the final compressed pulse (without pumping the booster amplifier) we found that the temporal contrast in this system exceeds 10$$^{10}$$ on the sub-nanosecond timescale, and is near 10$$^{12}$$ on the nanosecond timescale before the main femtosecond pulse. Using diffractive optical elements for beam homogenization of 100-J level high-energy Nd:glass green pump laser in a Ti:sapphire final amplifier, we have successfully generated broadband high-energy output with near-perfect top-hat intensity distributions.

Journal Articles

High temporal and spatial quality petawatt-class Ti:sapphire chirped-pulse amplification laser system

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Shimomura, Takuya; Sasao, Hajime; Tanoue, Manabu*; Kanazawa, Shuhei; Wakai, Daisuke*; Sasao, Fumitaka*; Okada, Hajime; et al.

Optics Letters, 35(10), p.1497 - 1499, 2010/05

 Times Cited Count:85 Percentile:95.22(Optics)

OPCPA (Optical parametric chirped-pulse amplification) operation with low gain by seeding with high energy, clean pulses is shown to significantly improve the contrast to better than $$10^{-10}$$-$$10^{-11}$$ in a high intensity Ti:sapphire laser system that is based on chirped pulse amplification. In addition to the high contrast broadband high energy output from the final amplifier is achieved with a flat-topped spatial profile of filling factor near 77%. This is the result of pump beam spatial profile homogenization with diffractive optical elements. Final pulse energies exceed 30-Joules indicating capability for reaching peak powers in excess of 500-TW.

Journal Articles

High-energy, high-efficiency second-harmonic generation from a Nd-doped laser with high-quality CsB$$_{3}$$O$$_{5}$$ crystal

Suzuki, Masayuki; Kiriyama, Hiromitsu; Nakai, Yoshiki*; Okada, Hajime; Daito, Izuru; Bolton, P.; Daido, Hiroyuki; Kondo, Kiminori; Kawanishi, Shunichi; Kagebayashi, Yoshio*; et al.

Proceedings of Conference on Lasers and Electro-Optics and The Quantum Electronics and Laser Science Conference (CLEO/QELS 2010) (CD-ROM), 2 Pages, 2010/05

We have demonstrated efficient second harmonic generation (SHG) of high energy fundamental Nd:YAG laser pulse energy of the multi-joule (J) level at 10-Hz using high optical quality top-seeded solution growth CsB$$_{3}$$O$$_{5}$$ (TSSG-CBO) crystal. SHG output energy of 1.2 J is obtained with a conversion efficiency of 60%. These results indicate that CBO is a good candidate material for high energy SHG of Nd-doped lasers at the several J level or more with high repetition rate.

Journal Articles

High spatiotemporal-quality petawatt-class laser system

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Shimomura, Takuya; Sasao, Hajime; Tanaka, Momoko; Ochi, Yoshihiro; Tanoue, Manabu*; Okada, Hajime; Kondo, Shuji; et al.

Applied Optics, 49(11), p.2105 - 2115, 2010/04

 Times Cited Count:39 Percentile:83.8(Optics)

We have developed a femtosecond high intensity laser system, which combines both Ti:sapphire chirped-pulse amplification (CPA) and optical parametric chirped-pulse amplification (OPCPA) techniques, that produces more than 30-J broadband output energy, indicating the potential for achieving peak powers in excess of 500-TW. With a cleaned high-energy seeded OPCPA preamplifier as a front-end in the system, for the compressed pulse without pumping the final amplifier we found that the temporal contrast in this system exceeds 10$$^{10}$$ on the sub-nanosecond timescales, and is near 10$$^{12}$$ on the nanosecond timescale prior to the peak of the main femtosecond pulse. Using diffractive optical elements for beam homogenization of 100-J level high-energy Nd:glass green pump laser in a Ti:sapphire final amplifier, we have successfully generated broadband high-energy output with a near-perfect top-hat-like intensity distribution.

Journal Articles

Highly efficient frequency doubling of high-energy Nd:YAG laser using a CsB$$_{3}$$O$$_{5}$$ crystal

Suzuki, Masayuki; Kiriyama, Hiromitsu; Nakai, Yoshiki; Okada, Hajime; Daito, Izuru; Kagebayashi, Yoshio*; Yokota, Toshio*; Bolton, P.; Daido, Hiroyuki; Kawanishi, Shunichi

Optics Communications, 283(3), p.451 - 453, 2010/02

 Times Cited Count:0 Percentile:0(Optics)

We have demonstrated efficient frequency doubling of high energy fundamental Nd:YAG laser pulse energy of the multi-J level at a high repetition rate using high optical quality top-seeded solution growth CsB$$_{3}$$O$$_{5}$$ (TSSG-CBO) crystal. Second-harmonic (532 nm) generation (SHG) output energy of 12 W at 10 Hz is obtained with a conversion efficiency of 60% The numerical calculation SHG efficiency agrees well with the measured results. These results indicate that CBO is a good candidate material for high energy SHG of Nd-doped lasers at the several J level or more with high repetition rate.

Journal Articles

Multi-millijoule, nonlinear preamplifier for high intensity femtosecond Yb:YAG chirped-pulse amplification lasers at 1030 nm

Suzuki, Masayuki; Kiriyama, Hiromitsu; Daito, Izuru; Okada, Hajime; Nakai, Yoshiki; Orimo, Satoshi; Sato, Masatoshi*; Tamaoki, Yoshinori*; Yoshii, Takehiro*; Maeda, Junya*; et al.

Applied Physics B, 97(2), p.379 - 382, 2009/10

 Times Cited Count:7 Percentile:37.62(Optics)

We report the highest energy broadband laser pulses at a center wavelength of 1030 nm based on optical parametric chirped-pulse amplification (OPCPA). We have demonstrated amplification of 1030 nm femtosecond laser pulses from a broadband Yb oscillator to over 6.5 mJ with a total gain of greater than 10$$^{7}$$ achieved in a single pass through only 56 mm of gain material at a 10 Hz repetition rate. The amplified spectral bandwidth of 10.8 nm affords recompression to a 230 fs pulse duration following amplification. As an alternative to the regenerative amplifier (RA) this system is one of the more promising candidates for realizing compact, high intensity, direct diode pumped, high repetition rate femtosecond Yb:YAG chirped-pulse amplification (CPA) in laser systems.

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:109 Percentile:94.78(Physics, Applied)

JAEA Reports

Discharge Monitoring by the Wide Range Radioactive Krypton Detector

Morita, Suguru; Tanizawa, Teruaki*; Masayuki, Morifuji,; Takasaki, Koji; Suzuki, Hideki*; Suzuki, Kazunori; Kobayashi, Hirohide

JNC TN8410 2004-011, 83 Pages, 2004/07

JNC-TN8410-2004-011.pdf:5.88MB

In the Chemical Processing Facility (CPF), after reconstruction was completed, the examination for advanced hydrometallurgy reprocessing was carried out from December 2002 to March 2004. In this examination,$$^{85}$$Kr were discharged from the stack. Discharge of$$^{85}$$Kr was measured and estimated by the wide range radioactive Krypton detector.GM Gas monitor of the CPF stack monitor was exchanged for the wide range radioactive Krypton detector in fiscal 1994. In discharge monitoring of this examination for advanced hydrometallurgy reprocessing,$$^{85}$$Kr gas were detected for the first time by the wide range radioactive Krypton detector of CPF. In this examination, the temporary gas monitor of the conventional GM detector was installed, and the result of measurement and inventory were compared.In this report the discharge of$$^{85}$$Kr is indicated by the wide range radioactive Krypton detector. As a result of comparative evaluation, it was confirmed that the discharge monitoring by the wide range radioactive Krypton detector was appropriate.

Journal Articles

Characterization of preformed plasmas with an interferometer for ultra-short high-intensity laser-plasma interactions

Sagisaka, Akito; Daido, Hiroyuki; Ogura, Koichi; Orimo, Satoshi; Hayashi, Yukio; Nishiuchi, Mamiko; Mori, Michiaki; Matsukado, Koji*; Fukumi, Atsushi*; Li, Z.*; et al.

Applied Physics B, 78(7-8), p.919 - 922, 2004/05

 Times Cited Count:25 Percentile:70.3(Optics)

no abstracts in English

Journal Articles

Time and space-resolved measurement of a gas-puff laser-plasma X-ray source

Suzuki, Masayuki; Daido, Hiroyuki; Choi, I. W.*; Yu, W.*; Nagai, Keiji*; Norimatsu, Takayoshi*; Mima, Kunioki*; Fiedorowicz, H.*

Physics of Plasmas, 10(1), p.227 - 233, 2003/01

 Times Cited Count:16 Percentile:48.4(Physics, Fluids & Plasmas)

no abstracts in English

Journal Articles

Demonstration of a transient-gain nickel-like xenon-ion X-ray laser

Lu, P.; Kawachi, Tetsuya; Kishimoto, Maki; Sukegawa, Kota*; Tanaka, Momoko; Hasegawa, Noboru; Suzuki, Masayuki; Tai, R.; Kado, Masataka; Nagashima, Keisuke; et al.

Optics Letters, 27(21), p.1911 - 1913, 2002/11

 Times Cited Count:8 Percentile:39.84(Optics)

We demonstrate a high gain nickel-like xenon ion x-ray laser using a gas puff target. The elongated x-ray laser plasma column was produced by irradiating the gas puff target with line-focused double picosecond laser pulses with a total energy of 18 J in a travelling-wave excitation scheme. Strong lasing at 9.98 nm was observed, and a high gain coefficient of 17.4 1/cm was measured on the transient collisionally excited 4d ミ 4p, J=0-1 transition for nickel-like xenon ion with target lengths up to 0.45 cm long. A weak nickel-like lasing line at a shorter wavelength of 9.64 nm was also observed with a gain coefficient of 5.9 1/cm.

Journal Articles

Demonstration of a transient high gain soft X-ray laser for neon-like Argon

Lu, P.; Kawachi, Tetsuya; Suzuki, M.*; Sukegawa, Kota*; Namba, Shinichi; Tanaka, Momoko; Hasegawa, Noboru; Nagashima, Keisuke; Daido, Hiroyuki; Arisawa, Takashi; et al.

Japanese Journal of Applied Physics, Part 2, 41(2A), p.L133 - L135, 2002/02

 Times Cited Count:9 Percentile:38.09(Physics, Applied)

no abstracts in English

47 (Records 1-20 displayed on this page)