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Ogura, Koichi; Fukumi, Atsushi*; Li, Z.*; Orimo, Satoshi; Sagisaka, Akito; Nishiuchi, Mamiko; Kado, Masataka; Mori, Michiaki; Yogo, Akifumi; Hayashi, Yukio; et al.
Journal of the Vacuum Society of Japan, 52(10), p.570 - 574, 2009/10
For accurate control of relativistic laser-plasma interaction under the repetitive operation, we have to measure and control the laser irradiation conditions such as laser parameters, the target shooting accuracy and so on as well as measuring proton parameter on each laser shot. The displacement of the laser shooting position on a tape target, that are used in the high energy proton generation using an ultra-short Ti:sapphire laser system, is measured by observing an X-ray image from laser plasma with an X-ray pinhole camera for each laser shot. The displacement of the shooting position on the target is about 20micron and the accuracy of the target positioning is within 20micron which is small enough for present laser focusing optics with an F number of 3.6 (f=179mm). The technique contributes to accurate control of a repetitive laser driven proton accelerators.
Li, Z.*; Daido, Hiroyuki; Fukumi, Atsushi*; Bulanov, S. V.; Sagisaka, Akito; Ogura, Koichi; Yogo, Akifumi; Nishiuchi, Mamiko; Orimo, Satoshi; Mori, Michiaki; et al.
Physics Letters A, 369(5-6), p.483 - 487, 2007/10
Times Cited Count:10 Percentile:53.17(Physics, Multidisciplinary)The energy spectra of energetic protons emitted in the normal direction from a 5-m thick copper tape irradiated by p-, circularly-, and s-polarized 55-fs laser pulses with intensity of 8-9
10
W/cm
are measured together with the angular distribution and energy spectra of hot electrons by the target normal direction. The protons with energy up to 1.34 MeV in the rear target normal direction and hot electrons in the laser propagation direction are found. The characters of protons and electrons driven by the circularly-polarized irradiation are close to that driven by the p-polarized one, which is much different from the case at laser intensity of 2-3
10
W/cm
.
Sagisaka, Akito; Daido, Hiroyuki; Ogura, Koichi; Orimo, Satoshi; Hayashi, Yukio; Mori, Michiaki; Nishiuchi, Mamiko; Yogo, Akifumi; Kado, Masataka; Fukumi, Atsushi*; et al.
Journal of the Korean Physical Society, 51(1), p.442 - 446, 2007/07
Times Cited Count:1 Percentile:10.63(Physics, Multidisciplinary)The recent progress of the laser driven accelerators which include high power laser driven electrons and ions are reviewed. The studies at JAEA Kansai are mainly described. Based on the recent progres, the various aspects of the applications are also reviewed.
Yogo, Akifumi; Daido, Hiroyuki; Fukumi, Atsushi*; Li, Z.*; Ogura, Koichi; Sagisaka, Akito; Pirozhkov, A. S.; Nakamura, Shu*; Iwashita, Yoshihisa*; Shirai, Toshiyuki*; et al.
Physics of Plasmas, 14(4), p.043104_1 - 043104_6, 2007/04
Times Cited Count:63 Percentile:87.78(Physics, Fluids & Plasmas)Fast protons are observed by a newly-developed time-of-flight spectrometer, which provides
proton-energy distributions immediately after the irradiation of a laser pulse having an intensity of
W/cm
onto a 5-
m-thick copper foil. The maximum proton energy is found to increase when the intensity of a fs-prepulse arriving 9 ns before the main pulse increases from 10
to 10
W/cm
. Interferometric measurement indicates that the preformed-plasma expansion at the front surface is smaller than 15
m, which corresponds to the spatial resolution of the diagnostics. This sharp gradient of the plasma makes a beneficial effect on increasing the absorption efficiency of the main-pulse energy, resulting in the increase in the proton energy. This is supported by the result that the X-ray intensity from the laser plasma clearly increases with the prepulse intensity.
Noda, Akira*; Nakamura, Shu*; Iwashita, Yoshihisa*; Shirai, Toshiyuki*; Tongu, Hiromu*; Soda, Hikaru*; Daido, Hiroyuki; Mori, Michiaki; Kado, Masataka; Sagisaka, Akito; et al.
International Journal of Modern Physics B, 21(3&4), p.319 - 330, 2007/02
Laser ion production has been studied for downsizing of the accelerator dedicated for cancer therapy. For optimization of various parameters such as pre-pulse condition, target position, laser spot size on target, laser pulse width and so on, time of flight (TOF) measurement utilizing the detected signal by a plastic scintillation counter played an essential role for real time measurement. Protons up to 900 keV and 600 keV are produced from the thin foil targets of Ti 3 micron and 5 micron in thickness, respectively. Modification of the energy distribution of the laser-produced ions with Maxwell distribution by utilizing an RF electric field synchronized to the pulse laser, which is the rotation of the ion beam in the longitudinal phase space (phase rotation), has been demonstrated for the first time.
Sagisaka, Akito; Utsumi, Takayuki*; Daido, Hiroyuki; Ogura, Koichi; Orimo, Satoshi; Takai, Mamiko; Hayashi, Yukio; Mori, Michiaki; Yogo, Akifumi; Kado, Masataka; et al.
Journal of Plasma Physics, 72(6), p.1281 - 1284, 2006/12
Times Cited Count:0 Percentile:0.00(Physics, Fluids & Plasmas)no abstracts in English
Hayashi, Yukio; Fukumi, Atsushi*; Matsukado, Koji*; Mori, Michiaki; Kotaki, Hideyuki; Kando, Masaki; Chen, L.-M.; Daito, Izuru; Kondo, Shuji; Kanazawa, Shuhei; et al.
Radiation Protection Dosimetry, 121(2), p.99 - 107, 2006/12
Times Cited Count:19 Percentile:76.75(Environmental Sciences)The authors obtain a new equation to estimate the forward component of a photon dose which is generated through the interaction between a target and a short pulse high power laser. As the equation is quite simple, it is useful for calculating the photon dose. The equation shows that the photon dose is proportional to the electron temperature for the range of its temperature 3 MeV, and proportional to square of the electron temperature for the range of its temperature
3 MeV. The dose estimated with this method is roughly consistent with the result of Monte Carlo simulation. On someassumptions and corrections, it can reproduce experimental results obtained and the dose result calculated at other laboratories.
Sagisaka, Akito; Pirozhkov, A. S.; Daido, Hiroyuki; Fukumi, Atsushi*; Li, Z.*; Ogura, Koichi; Yogo, Akifumi; Oishi, Yuji*; Nayuki, Takuya*; Fujii, Takashi*; et al.
Applied Physics B, 84(3), p.415 - 419, 2006/09
Times Cited Count:21 Percentile:65.39(Optics)no abstracts in English
Mori, Michiaki; Kando, Masaki; Pirozhkov, A. S.; Hayashi, Yukio; Yogo, Akifumi; Yoshimura, Norihisa; Ogura, Koichi; Takai, Mamiko; Sagisaka, Akito; Orimo, Satoshi; et al.
Plasma and Fusion Research (Internet), 1(9), p.042_1 - 042_4, 2006/09
A new detection device for evaluating ion energy distributions for laser-plasma ion source is demonstrated. The Imaging Plate (IP) with no protective layer as ion detector device for the Thomson Parabola spectrometeris used. The Imaging Plate Thomson Parabola spectrometer (IPTPS) is applicable for the analysis of the energydistribution of the laser-driven ion beam using an opto-electric digitizing technique.
Mori, Michiaki; Pirozhkov, A.; Nishiuchi, Mamiko; Ogura, Koichi; Sagisaka, Akito; Hayashi, Yukio; Orimo, Satoshi; Fukumi, Atsushi*; Li, Z.*; Kado, Masataka; et al.
Laser Physics, 16(7), p.1092 - 1096, 2006/07
Times Cited Count:36 Percentile:79.59(Optics)no abstracts in English
Sagisaka, Akito; Utsumi, Takayuki*; Daido, Hiroyuki; Ogura, Koichi; Orimo, Satoshi; Hayashi, Yukio; Takai, Mamiko; Mori, Michiaki; Yogo, Akifumi; Kado, Masataka; et al.
Reza Enerugigaku Kenkyu Senta Heisei-17-Nendo Kyodo Kenkyu Seika Hokokusho (Heisei-17-Nen 4-Gatsu Heisei-18-Nen 3-Gatsu), p.61 - 62, 2006/07
no abstracts in English
Yogo, Akifumi; Nishiuchi, Mamiko; Fukumi, Atsushi*; Li, Z.*; Ogura, Koichi; Sagisaka, Akito; Orimo, Satoshi; Kado, Masataka; Hayashi, Yukio; Mori, Michiaki; et al.
Applied Physics B, 83(4), p.487 - 489, 2006/06
Times Cited Count:9 Percentile:41.40(Optics)We present experimental results on protons accelerated up to 950 keV from a 3-m thick tantalum foil with a 133-nm thick polystyrene layer on its rear surface, irradiated with a laser pulse having the duration of 70 fs and the intensity of
W/cm
. The energy distribution of fast protons was measured simultaneously with that of the hot-electrons from the rear surface. The proton yield from the polystyrene-coated target is about 10 times as high as that from the uncoated metal target. This enhancement of the proton yield is roughly proportional to the increase of hydrogen atoms given by the 133-nm thick polystyrene layer, assuming a contaminant layer of
10-nm thickness is on the metal surface without coating. This result shows that the polystyrene layer contributes to the yield enhancement.
Sagisaka, Akito; Daido, Hiroyuki; Fukumi, Atsushi*; Takai, Mamiko; Yogo, Akifumi; Li, Z.*; Ogura, Koichi; Orimo, Satoshi; Hayashi, Yukio; Mori, Michiaki; et al.
Proceedings of RCNP-JAEA Workshop on Nuclear Photon Science "Hadron-nuclear physics probed by photon", p.195 - 200, 2006/00
High energy ions, electrons, and X-ray are generated from ultrashort pulse high-intensity laser-matter interactions. High-energy protons are observed with a thin-foil target irradiated with a high intensity Ti:sapphire laser at the peak intensity of 2.7
10
W/cm
. The maximum proton energy is
900 keV.
Fukumi, Atsushi*; Takai, Mamiko; Daido, Hiroyuki; Li, Z.*; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Kado, Masataka; Hayashi, Yukio; Mori, Michiaki; et al.
Physics of Plasmas, 12(10), p.100701_1 - 100701_4, 2005/10
Times Cited Count:45 Percentile:78.46(Physics, Fluids & Plasmas)A study of proton emission from a 3-m thick Ta foil target irradiated by
-,
- and circularly polarized laser pulses with respect to the targetplane has been carried out. Protons with energies up to 880 keV were observed in the target normaldirection under the irradiation by the
-polarized laser pulse, which yieldedthe highest efficiency for proton emission. In contrast,
- and circularlypolarized laser pulses gave the maximum energies of 610 keV and 680 keV,respectively. The difference in the maximum energy between the
- and
-polarized cases was associated with the difference between thesheath fields estimated from electron spectra.
Li, Z.*; Nakamura, Shu; Fukumi, Atsushi*; Hayashi, Yukio; Orimo, Satoshi; Nishiuchi, Mamiko; Sagisaka, Akito; Mori, Michiaki; Shirai, Toshiyuki*; Iwashita, Yoshihisa*; et al.
Japanese Journal of Applied Physics, Part 1, 44(9A), p.6796 - 6800, 2005/09
Times Cited Count:13 Percentile:45.03(Physics, Applied)An electron energy spectrometer for studying the energy spectrum of electrons emitted from solid foils irradiated by a femtosecond intense laser pulse and its calibration with a source is described. The intensity distribution of the magnetic field induced by a dipole magnet and the time decay of the photostimulated luminescence of an imaging plate were determined. Both the energy scale and the electron intensity conversion ratio of the electron energy spectrometer were calibrated with a
Sr-
Y
source. The energy spectrum of hot electrons emitted from a 3-
m-thick Tantalum foil target irradiated by laser pulses with a pulse duration of 50 fs and a peak intensity of 2
10
W/cm
was determined with the calibrated electron energy spectrometer.
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:26 Percentile:70.77(Optics)no abstracts in English
Matsukado, Koji*; Esirkepov, T. Z.; Kinoshita, Kenichi*; Daido, Hiroyuki; Utsumi, Takayuki*; Li, Z.*; Fukumi, Atsushi*; Hayashi, Yukio; Orimo, Satoshi; Nishiuchi, Mamiko; et al.
Physical Review Letters, 91(21), p.215001_1 - 215001_4, 2003/11
Times Cited Count:139 Percentile:95.12(Physics, Multidisciplinary)no abstracts in English
Ogura, Koichi; Fukumi, Atsushi*; Li, Z.*; Orimo, Satoshi; Nakamura, Shu*; Sagisaka, Akito; Nishiuchi, Mamiko; Kado, Masataka; Mori, Michiaki; Hayashi, Yukio; et al.
no journal, ,
no abstracts in English
Orimo, Satoshi; Nishiuchi, Mamiko; Nakamura, Shu*; Fukumi, Atsushi*; Li, Z.*; Sagisaka, Akito; Ogura, Koichi; Mori, Michiaki; Kado, Masataka; Hayashi, Yukio; et al.
no journal, ,
This time, the laser(4TW, pulse duration 70 200fs, contrast 10) of p-pol. of irradiation on the peak power 9
10
W/cm
was made Ta(Tantalum metal) tape target the axis of the F-number 13 outside, and it glared with the 45 degrees of incidence angle using OAP. Spectrum mesurement was performed with Thomson-prabola energy analysis equipment about the proton beam generated by the tape back perpendicular direction at this time, and space propagation and proton imaging measurment was measured using the renge filter and the Cu mesh.
Mori, Michiaki; Ogura, Koichi; Sagisaka, Akito; Kando, Masaki; Hayashi, Yukio; Daito, Izuru; Fukumi, Atsushi*; Yogo, Akifumi; Takai, Mamiko; Orimo, Satoshi; et al.
no journal, ,
The multi-TW laser system "JLITE-X (JAEA Laser system for laser-matter InTeraction Experiment)" was developed for studying on the laser-matter interaction in sub-relativistic regime. Two quasi-monoenergetic charged particle production experiments were conducted after laser system development. The first, we successfully generated quasi-monoenergetic proton beam by using phase rotator which based on the radio-frequency accelerator technique. The quasi-monoenergetic component was observed near 600 keV with 1 TW / 220 fs laser operation mode. The second, we also successfully generated quasi-monoenergetic electron beam with energy of 20 MeV in self-modulated laser-wakefield regime with 3 TW / 70 fs operation mode. These results were indicated that the multi-TW laser is useful for not only plasma physics research but also high-energy particle source and its applications.