Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
10
W/cm
Skobelev, I. Yu.*; Ryazantsev, S. N.*; Kulikov, R. K.*; Sedov, M. V.*; Filippov, E. D.*; Pikuz, S. A.*; Asai, Takafumi*; Kanasaki, Masato*; Yamauchi, Tomoya*; Jinno, Satoshi; et al.
Photonics (Internet), 10(11), p.1250_1 - 1250_11, 2023/11
Times Cited Count：0 Percentile：0(Optics)It is challenging to clearly distinguish the impacts of the optical field and collisional ionization in the evolution of the charge state of a plasma produced when matter interacts with high-intensity laser pulses. In this work, time-dependent calculations of plasma kinetics are used to show that it is possible only when low-density gaseous targets with sufficiently small clusters are used. In the case of Ar plasma, the upper limit of the cluster radius was estimated to be 
m.
Motooka, Takafumi; Yamamoto, Masahiro; Ueno, Fumiyoshi; Ishijima, Yasuhiro; Uchiyama, Gunzo; Nojima, Yasuo*; Fujine, Sachio*; Sakai, Junichi*; Shiimori, Fusae*; Miyasaka, Yuto*
no journal, ,
As a part of studies on ageing behavior of reprocessing plants, the amount of hydrogen gas generated from nitrate solutions under 
irradiation and the amount of hydrogen absorbed to titanium alloy were measured after irradiation in order to evaluate the hydrogen degradation of instruments made of titanium alloy. The amount of hydrogen gas was decreased with increase of nitrate concentration. Only a little hydrogen was absorbed to titanium. It is necessary to consider the long-time prediction model for hydrogen adsorption to evaluate hydrogen degradation.
Mori, Michiaki; Kiriyama, Hiromitsu; Miyasaka, Yasuhiro; Kishimoto, Maki; Kotaki, Hideyuki; Hayashi, Yukio; Kando, Masaki; Kondo, Kiminori
no journal, ,
Improvement of controllability and stability at laser-driven particle beams are important for multi-purpose applications. Improvement of the laser stability is important to improvement such parameters. Especially, compensation of higher order dispersion at a CPA laser system influences stability of laser temporal profile. In this work, we demonstrate new concept of higher order dispersion management by using assist pulse compression. We confirmed 1e-7 prepulse level at sub-ns region and 120 dB/ps slew rate at sub-ps region.
Miyasaka, Yasuhiro; Kiriyama, Hiromitsu; Kishimoto, Maki; Mori, Michiaki; Kando, Masaki; Kondo, Kiminori
no journal, ,
We are developing an optically synchronized low-jitter pump source for stable optical parametric chirped-pulse amplification. Spectrum of laser pulses provided by Ti:Sapphire laser oscillator is expanded to 1064 nm with photonic crystal fiber (PCF). We successfully stabilize fluctuation of PCF-output spectrum in less than 0.1% by feedback control of laser polarization of input pulses. The stabilization provide us with power stability less than 1% after fiber amplification.
Kiriyama, Hiromitsu; Mori, Michiaki; Pirozhkov, A. S.; Ogura, Koichi; Nishiuchi, Mamiko; Kando, Masaki; Sakaki, Hironao; Kishimoto, Maki; Miyasaka, Yasuhiro; Kon, Akira; et al.
no journal, ,
We report on recent progress on the J-KAREN laser upgrade to realize 10
W/cm intensity at 0.1 Hz. Our current high-spatiotemporal-quality broadband pulse from the front end is amplified in the final amplifier to over 55 J. We plan to mention the future prospects. We also introduce ultra-high intensity lasers worldwide.
Mori, Michiaki; Kiriyama, Hiromitsu; Miyasaka, Yasuhiro; Kishimoto, Maki; Kotaki, Hideyuki; Hayashi, Yukio; Kando, Masaki; Kondo, Kiminori
no journal, ,
In higher-order dispersion compensation at chirped pulse amplification laser system, it is progressing studied for a long time. However, almost compensation concepts or systems are placed at a front end, whose are disadvantageous for suppression of the ASE pedestal. In this work, we demonstrate two grating compressor configuration for management of higher order dispersion. We used a 10 TW Ti:Sapphire laser system JLITE-X laser system. We confirmed improvement of temporal profile in the region of less than 10 ps from the main peak. Especially, the steepness within -1ps from the main peak was significantlly improved. This result shows the higher-order dispersion is highly compensated. In particular, a good ASE pedestal (1e-7) condition is kept before installation of this system. These results show the advantage of this compensation concept for another methods.
