Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 23

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

A Novel technique for monitoring the reproducibility of laser tape-target interactions using an X-ray pinhole camera

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.

Journal Articles

Protons and electrons generated from a 5-$$mu$$m thick copper tape target irradiated by s-, circularly-, and p-polarized 55-fs laser pulses

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:9 Percentile:52.55(Physics, Multidisciplinary)

The energy spectra of energetic protons emitted in the normal direction from a 5-$$mu$$m thick copper tape irradiated by p-, circularly-, and s-polarized 55-fs laser pulses with intensity of 8-9$$times$$10$$^{18}$$W/cm$$^{2}$$ 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$$times$$10$$^{18}$$W/cm$$^{2}$$.

Journal Articles

Characterization of an intense laser-produced preformed plasma for proton generation

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:11.47(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.

Journal Articles

Laser prepulse dependency of proton-energy distributions in ultraintense laser-foil interactions with an online time-of-flight technique

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:59 Percentile:89.69(Physics, Fluids & Plasmas)

Fast protons are observed by a newly-developed $textit{online}$ time-of-flight spectrometer, which provides $textit{shot-to-shot}$ proton-energy distributions immediately after the irradiation of a laser pulse having an intensity of $$sim 10^{18}$$ W/cm$$^2$$ onto a 5-$$mu$$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$$^{14}$$ to 10$$^{15}$$ W/cm$$^2$$. Interferometric measurement indicates that the preformed-plasma expansion at the front surface is smaller than 15 $$mu$$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.

Journal Articles

High quality laser-produced proton beam generation by phase rotation

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.

Journal Articles

Characterization of preformed plasmas using a multi-dimensional hydrodynamic simulation code in the study of high-intensity laser-plasma interactions

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:0.01(Physics, Fluids & Plasmas)

no abstracts in English

Journal Articles

Estimation of photon dose generated by a short pulse high power laser

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:15 Percentile:73.49(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.

Journal Articles

Development of a two-color interferometer for observing wide range electron density profiles with a femtosecond time resolution

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:20 Percentile:66.49(Optics)

no abstracts in English

Journal Articles

New detection device for Thomson parabola spectrometer for diagnosis of the laser-plasma ion beam

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.

Journal Articles

Development of beam-pointing stabilizer on a 10-TW Ti:Al${tiny 2}$O${tiny 3}$ laser system JLITE-X for laser-excited ion accelerator research

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:81.82(Optics)

no abstracts in English

Journal Articles

Characterization of preformed plasmas using a hydrodynamic simulation code in the study of high-intensity laser-plasma interactions

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 $$sim$$ Heisei-18-Nen 3-Gatsu), p.61 - 62, 2006/07

no abstracts in English

Journal Articles

Enhancement of high energy proton yield with a polystyrene-coated metal target driven by a high-intensity femtosecond laser

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:43.61(Optics)

We present experimental results on protons accelerated up to 950 keV from a 3-$$mu$$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 $$2.7times10^{18}$$ W/cm$$^{2}$$. 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 $$sim$$10-nm thickness is on the metal surface without coating. This result shows that the polystyrene layer contributes to the yield enhancement.

Journal Articles

Characterization of a laser-driven proton beam

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 $$sim$$2.7$$times$$10$$^{18}$$ W/cm$$^{2}$$. The maximum proton energy is $$sim$$900 keV.

Journal Articles

Laser polarization dependence of proton emission from a thin foil target irradiated by a 70 fs, intense laser pulse

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:43 Percentile:80.54(Physics, Fluids & Plasmas)

A study of proton emission from a 3-$$mu$$m thick Ta foil target irradiated by$$p$$-, $$s$$- 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 $$p$$-polarized laser pulse, which yieldedthe highest efficiency for proton emission. In contrast, $$s$$- and circularlypolarized laser pulses gave the maximum energies of 610 keV and 680 keV,respectively. The difference in the maximum energy between the $$p$$- and$$s$$-polarized cases was associated with the difference between thesheath fields estimated from electron spectra.

Journal Articles

Electron energy spectrometer for laser-driven energetic electron generation

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:47.14(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 $$beta$$ 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 $$^{90}$$Sr-$$^{90}$$Y $$beta$$ source. The energy spectrum of hot electrons emitted from a 3-$$mu$$m-thick Tantalum foil target irradiated by laser pulses with a pulse duration of 50 fs and a peak intensity of 2$$times$$10$$^{18}$$ W/cm$$^{2}$$ was determined with the calibrated electron energy spectrometer.

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:24 Percentile:70.62(Optics)

no abstracts in English

Journal Articles

Energetic protons from a few-micron metallic foil evaporated by an intense laser pulse

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:134 Percentile:95.57(Physics, Multidisciplinary)

no abstracts in English

Oral presentation

Proton generation from a metal thin foil irradiated with a high intensity ultra-short pulse laser

Sagisaka, Akito; Yogo, Akifumi; Daido, Hiroyuki; Fukumi, Atsushi*; Li, Z.*; Ogura, Koichi; Takai, Mamiko; Orimo, Satoshi; Hayashi, Yukio; Mori, Michiaki; et al.

no journal, , 

no abstracts in English

Oral presentation

Proton generation with a high intensity ultra-short pulse laser 1; Preformed plasma dependence

Sagisaka, Akito; Nakamura, Shu; Mori, Michiaki; Daido, Hiroyuki; Fukumi, Atsushi*; Ogura, Koichi; Orimo, Satoshi; Hayashi, Yukio; Takai, Mamiko; Yogo, Akifumi; et al.

no journal, , 

no abstracts in English

Oral presentation

Proton beam spectrum and beam transport from Ta tape target irradiated by intense ultra-short laser pulse

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$$^{-6}$$) of p-pol. of irradiation on the peak power 9$$times$$10$$^{17}$$W/cm$$^{2}$$ 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.

23 (Records 1-20 displayed on this page)