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Janulewicz, K. A.*; Kim, C. M.*; Steil, H.*; Kawachi, Tetsuya; Nishikino, Masaharu; Hasegawa, Noboru
X-Ray Lasers and Coherent X-Ray Sources; Development and Applications XI (Proceedings of SPIE, Vol.9589), p.95890N_1 - 95890N_7, 2015/09
Times Cited Count：0 Percentile：0(Optics)We describe measurement results on the polarization state of amplified spontaneous emission signal from a collisionally pumped Ni-like Ag soft X-ray laser with a transient inversion. The result obtained with a calibrated membrane beam splitter as a polarization state (P-state) selector shows that dominance one of the mutually perpendicular electric field components (p- or s-) in the output signal depends on the hydrodynamic state of the plasma medium. Two different hydrodynamic states were referred as a low gain and high gain regimes and the allocated P-states had dominant s- and p-component, respectively. It was also shown that due to correlations between p- and s-components in the process of coherent amplification of noise, correct description of the polarization state requires applying the generalized theory of polarization and formulated there the generalized degree of polarization.
Choi, I. W.*; Kim, I. J.*; Pae, K. H.*; Nam, K. H.*; Lee, C.-L.*; Yun, H.*; Kim, H. T.*; Lee, S. K.*; Yu, T. J.*; Sung, J. H.*; et al.
Applied Physics Letters, 99(18), p.181501_1 - 181501_3, 2011/11
Times Cited Count：17 Percentile：57.65(Physics, Applied)We report the manufacturing of a thin foil target made of conjugated polymer, and the simultaneous observation of laser accelerated ions and second harmonic radiation, when irradiated with ultrahigh-contrast laser pulse at a maximum intensity of 4
10
W/cm
. Maximum proton energy of 8 MeV is achieved along the target normal direction. Strong second harmonic with over 6% energy ratio compared to fundamental is emitted along the specular direction. Two-dimensional particle-in-cell simulations confirm the simultaneous generation of protons and high-order harmonics, which demonstrates the feasibility of applications requiring particle and radiation sources at once, effectively using the same laser and target.
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：59 Percentile：87.48(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 2.78 mm at a distance of 650 mm from the source. This result is in good agreement with a Monte Carlo particle trajectory simulation.
Nishiuchi, Mamiko; Daido, Hiroyuki; Yogo, Akifumi; Orimo, Satoshi; Ogura, Koichi; Ma, J.-L.; Sagisaka, Akito; Mori, Michiaki; Pirozhkov, A. S.; Kiriyama, Hiromitsu; et al.
Physics of Plasmas, 15(5), p.053104_1 - 053104_10, 2008/05
Times Cited Count：45 Percentile：83.73(Physics, Fluids & Plasmas)High-flux energetic protons whose maximum energies are up to 4 MeV are generated by an intense femtosecond Titanium Sapphire laser pulse interacting with a 7.5, 12.5, and 25
m thick Polyimide tape targets. The laser pulse energy is 1.7 J, duration is 34 fs, and intensity is 310Wcm
. The amplified spontaneous emission (ASE) has the intensity contrast ratio of 410
. The conversion efficiency from laser energy into proton kinetic energies of 
3% is achieved, which is comparable or even higher than those achieved in the previous works with nanometer-thick targets and the ultrahigh contrast laser pulses (10
).
Jeong, T.*; Choi, I. W.*; Sung, J. H.*; Kim, H.*; Hong, K.*; Yu, T.*; Kim, J.-H.*; Noh, Y.*; Ko, D.-K.*; Lee, J.*; et al.
Journal of the Korean Physical Society, 50(1), p.34 - 39, 2007/01
no abstracts in English
Daido, Hiroyuki; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Yogo, Akifumi; Mori, Michiaki; Li, Z.*; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.
X-Ray Lasers 2006; Springer Proceedings in Physics, Vol.115, p.595 - 605, 2007/00
At present, using ultra-short high intensity lasers at APRC, JAEA Kansai photon research institute, we are developing laser driven multiple quantum beams such as protons, X-rays, electrons and THz waves. These beams are perfectly synchronized with each other. The pulse duration of each beam is lass than a pico-second. They have sharp directionality with high brightness. If we properly combined these, we have new pump-probe techniques for various applications.
Mori, Michiaki; Yogo, Akifumi; Orimo, Satoshi; Ogura, Koichi; Sagisaka, Akito; Nakamura, Shu*; Shirai, Toshiyuki*; Iwashita, Yoshihisa*; Noda, Akira*; Nemoto, Koshichi*; et al.
no journal, ,
no abstracts in English
Mori, Michiaki; Yogo, Akifumi; Orimo, Satoshi; Ogura, Koichi; Sagisaka, Akito; Nakamura, Shu*; Shirai, Toshiyuki*; Iwashita, Yoshihisa*; Noda, Akira*; Oishi, Yuji*; et al.
no journal, ,
no abstracts in English
Nishiuchi, Mamiko; Daido, Hiroyuki; Yogo, Akifumi; Orimo, Satoshi; Ogura, Koichi; Ma, J.-L.; Sagisaka, Akito; Mori, Michiaki; Pirozhkov, A. S.; Kiriyama, Hiromitsu; et al.
no journal, ,
The efficient proton beam whose maximum energy of up to 4 MeV was produced by the 50TW short pulse intensity Ti:Sap laser irradiated on the polyimide target [(C
H
O
N
)n] with the thicknesses of 7.5m, 12.5m, 25m, which is transparent to the 800 nm laser. The laser parameters are energy of 1.7J, pulse width of 35fs and the intensity of 310 Wcm. The contrast of the ASE component is 410. The conversion efficiency from laser energy into the proton kinetic energy is up to 3%. This conversion efficiency is comparable or even higher than the results obtained with the same level laser ( J energy) interacts with the nano-meter level ultra thin target. In this paper we discuss on the comparison between our results and other experimental results obtained in other facilities.
MeV proton beamNishiuchi, Mamiko; Daito, Izuru; Ikegami, Masahiro; Mori, Michiaki; Orimo, Satoshi; Ogura, Koichi; Sagisaka, Akito; Yogo, Akifumi; Pirozhkov, A. S.; Ma, J.*; et al.
no journal, ,
A laser-driven proton beam with a maximum energy of a few MeV is stably obtained using an ultra-short and high-intensity Titanium Sapphire laser. As compared with the proton beam from the conventional accelerator, this proton beam exhibits peculiar characteristics, such as, more than 10
protons per bunch are produced within a short pulse duration of ps at a source, resulting in a very high peak current. It also exhibits a very low transverse emittance. The proton beam has a divergence angle of 10 degrees and energy spread of 100%. It accompanies electrons and X-rays, which is produced simultaneously. Making the best use of these peculiar characteristics, many possible applications of the laser-driven proton are proposed. In order to make practical laser-driven proton beam for the applications, we carry out series of experiments. We have successfully obtained simultaneous imaging of the target with proton and X-ray or proton and electron beams. In the course of practical use of the proton beam for specific applications, characteristics above should be optimized based on the variations of the applications. For example, in order to apply the laser-driven proton beam for the proton irradiation system, such as used in the medical or the industrial applications, we should obtain focused or parallel proton beam. One of our plans to alter the orbits of the laser-driven protons from the planer tape target is using permanent quadrupole magnets.
Nishiuchi, Mamiko; Daito, Izuru; Mori, Michiaki; Orimo, Satoshi; Ogura, Koichi; Sagisaka, Akito; Sakaki, Hironao; Hori, Toshihiko; Yogo, Akifumi; Pirozhkov, A. S.; et al.
no journal, ,
From our previous research, we have successfully produce MeV proton beam by 1Hz repetition rate stabely from the interaction between the femto-second TW laser with solid target. Produced proton beam exhibits lower emittance. The number of proton beam is 10. However, it shows large divergence angle of 10 degree. The energy spectrum exhibits 100% energy spread. These are problematic for some specific applications. In this study we transported the laser-driven proton beam with permanent quadrapole magnet for the future application. We successfully obtain focused proton beam as well as the monochromatic proton beam. Those spatial distribution at the focus point as well as the spectral information is well reproduced by the montecalro simulation.
Mori, Michiaki; Ogura, Koichi; Yogo, Akifumi; Nishiuchi, Mamiko; Kiriyama, Hiromitsu; Pirozhkov, A. S.; Sagisaka, Akito; Orimo, Satoshi; Tampo, Motonobu; Daito, Izuru; et al.
no journal, ,
Experimental studies of laser-driven ion acceleration aimed at ion therapy for cancer treatment are being conducted at the PMRC of JAEA using the J-KAREN Ti:Sapphire laser system at JAEA's APRC. In recent experiments thin foil targets have been irradiated with focused 38 fs laser pulses at the 1.8J laser energy. The energy spectrum of the proton beam is observed to extend to a cut-off value in excess of 7-MeV. Our results expose the prospects and challenges associated with developing a laser-driven ion therapy facility.
Mori, Michiaki; Ogura, Koichi; Yogo, Akifumi; Nishiuchi, Mamiko; Kiriyama, Hiromitsu; Pirozhkov, A. S.; Sagisaka, Akito; Orimo, Satoshi; Tampo, Motonobu; Daito, Izuru; et al.
no journal, ,
no abstracts in English
