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Journal Articles

Complementary characterization of radioactivity produced by repetitive laser-driven proton beam using shot-to-shot proton spectral measurement and direct activation measurement

Ogura, Koichi; Shizuma, Toshiyuki; Hayakawa, Takehito; Yogo, Akifumi; Nishiuchi, Mamiko; Orimo, Satoshi; Sagisaka, Akito; Pirozhkov, A. S.; Mori, Michiaki; Kiriyama, Hiromitsu; et al.

Japanese Journal of Applied Physics, 51(4), p.048003_1 - 048003_2, 2012/04

 Times Cited Count:2 Percentile:8.97(Physics, Applied)

A proton beam driven by a repetitive high-intensity-laser is utilized to induce a $$^{7}$$Li(p,n)$$^{7}$$Be nuclear reaction. The total activity of $$^{7}$$Be are evaluated by two different methods. The activity obtained measuring the decay $$gamma$$-rays after 1912 shots at 1 Hz is 1.7$$pm$$0.2 Bq. This is in good agreement with 1.6$$pm$$0.3 Bq evaluated from the proton energy distribution measured using a time-of-flight detector and the nuclear reaction cross-sections. We conclude that the production of activity can be monitored in real time using the time-of-flight-detector placed inside a diverging proton beam coupled with a high-speed signal processing system.

Journal Articles

Laser-driven proton generation with a thin-foil target

Sagisaka, Akito; Pirozhkov, A. S.; Mori, Michiaki; Yogo, Akifumi; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Ma, J.*; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.

NIFS-PROC-85, p.30 - 33, 2011/02

The experiment of proton generation is performed for developing the laser-driven ion source. We observe proton signals in the laser-plasma interaction by using a thin-foil target. To get higher energy protons the size of the preformed plasma is reduced by changing the laser contrast level. In the high-contrast laser pulse case the maximum energy of the protons generated at rear side of the target increases.

Journal Articles

Proton generation and terahertz radiation from a thin-foil target with a high-intensity laser

Sagisaka, Akito; Pirozhkov, A. S.; Mori, Michiaki; Yogo, Akifumi; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Ma, J.*; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.

Reza Kenkyu, 38(9), p.702 - 705, 2010/09

High-intensity laser and thin-foil interactions produce high-energy particles, hard X-ray, high-order harmonics, and terahertz (THz) radiation. A proton beam driven by a high-intensity laser has received attention as a compact ion source for medical applications. In this study we have tested simultaneous generation of protons and THz radiation from a thin-foil target. We use a Ti:sapphire laser system (J-KAREN) at JAEA. A laser beam is focused by an off-axis parabolic mirror at the thin-foil target. We observed the high-energy proton in the rear side of the target and THz radiation in the reflected direction. Next, high energy protons are observed by reducing the size of preformed plasma.

Journal Articles

Ion acceleration using temporally-controlled high-intensity laser pulses

Yogo, Akifumi; Daido, Hiroyuki; Mori, Michiaki; Kiriyama, Hiromitsu; Bulanov, S. V.; Bolton, P. R.; Esirkepov, T. Z.; Ogura, Koichi; Sagisaka, Akito; Orimo, Satoshi; et al.

Reza Kenkyu, 37(6), p.449 - 454, 2009/06

The acceleration of protons driven by a high-intensity laser is comprehensively investigated via control of the target density by using ASE just before the time of the main-laser interaction. Two cases were investigated for which the ASE intensity differed by three orders of magnitude: In the low contrast case the beam centre for higher energy protons is shifted closer to the laser-propagation direction of 45$$^{circ}$$, while the center of lower-energy beam remains near the target normal direction. Particle-in-cell simulations reveal that the characteristic proton acceleration is due to the quasistatic magnetic field on the target rear side with the magnetic pressure sustaining a charge separation electrostatic field.

Journal Articles

Proton-induced nuclear reactions using compact high-contrast high-intensity laser

Ogura, Koichi; Shizuma, Toshiyuki; Hayakawa, Takehito; Yogo, Akifumi; Nishiuchi, Mamiko; Orimo, Satoshi; Sagisaka, Akito; Pirozhkov, A. S.; Mori, Michiaki; Kiriyama, Hiromitsu; et al.

Applied Physics Express, 2(6), p.066001_1 - 066001_3, 2009/05

 Times Cited Count:14 Percentile:49.88(Physics, Applied)

Protons with energies up to 3.5 MeV have been generated by a 10 Hz compact laser with an intensity of about 10$$^{20}$$ W/cm$$^{2}$$, focused on a 7.5 mm thick polyimide target. These protons were used to induce a nuclear reaction of $$^{11}$$B(p,n)$$^{11}$$C. A total activity of 11.1 Bq was created after 60-shot laser irradiation. The possibility of thin layer activation (TLA) using a high-intensity ultra-short pulsed laser is discussed.

Journal Articles

Focusing and spectral enhancement of a repetition-rated, laser-driven, divergent multi-MeV proton beam using permanent quadrupole magnets

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:57 Percentile:87.53(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 2.7$$times$$8 mm$$^{2}$$ at a distance of 650 mm from the source. This result is in good agreement with a Monte Carlo particle trajectory simulation.

Journal Articles

New method to measure the rise time of a fast pulse slicer for laser ion acceleration research

Mori, Michiaki; Yogo, Akifumi; Kiriyama, Hiromitsu; Nishiuchi, Mamiko; Ogura, Koichi; Orimo, Satoshi; Ma, J.*; Sagisaka, Akito; Kanazawa, Shuhei; Kondo, Shuji; et al.

IEEE Transactions on Plasma Science, 36(4), p.1872 - 1877, 2008/08

 Times Cited Count:7 Percentile:28.59(Physics, Fluids & Plasmas)

A dependence of cut-off proton kinetic energy on laser prepulse duration has been observed. ASE pedestal duration is controlled by a fast electro-optic pulse slicer where the risetime is estimated to be 130 ps. We demonstrate a new correlated spectral technique for determining this risetime using a stretched, frequency chirped pulse.

Journal Articles

Simultaneous proton and X-ray imaging with femtosecond intense laser driven plasma source

Orimo, Satoshi; Nishiuchi, Mamiko; Daido, Hiroyuki; Yogo, Akifumi; Ogura, Koichi; Sagisaka, Akito; Li, Z.*; Pirozhkov, A. S.; Mori, Michiaki; Kiriyama, Hiromitsu; et al.

Japanese Journal of Applied Physics, Part 1, 46(9A), p.5853 - 5858, 2007/09

 Times Cited Count:16 Percentile:53.23(Physics, Applied)

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. At the same time, keV X-ray is also generated at almost the same place where protons are emitted. Here, we show the successful demonstration of simultaneous proton and X-ray projection images of a test sample placed close to the source with a resolution of $$sim$$10$$mu$$m, which is determined from the source sizes. Although the experimental configuration is very simple, the simultaneity is better than a few hundreds of ps. A CR-39 track detector and imaging plate, which are placed as close as possible to the CR-39, are used as detectors of protons and X-ray. The technique is applicable to the precise observation of microstructures.

Journal Articles

Development of laser driven proton sources and their applications

Daido, Hiroyuki; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Mori, Michiaki; Ma, J.-L.; Pirozhkov, A. S.; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.

Proceedings of 7th Pacific Rim Conference on Lasers and Electro-Optics (CLEO-PR 2007) (CD-ROM), p.77 - 79, 2007/00

We are developing a proton accelerator using an intense lasers with a focused intensity of $$>$$ 10$$^{17}$$ W/cm$$^{2}$$. To monitor proton energy spectra as well as plasma parameters at each laser shot, we are using real time detectors. The proton energy of MeV is stably obtained for applications.

Journal Articles

Intense femto-second laser-driven X-ray source coupled with multiple directional quantum beams for applications

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.

Journal Articles

Quasi-monoenergetic electron beam generation during laser pulse interaction with very low density plasmas

Yamazaki, Atsushi; Kotaki, Hideyuki; Daito, Izuru; Kando, Masaki; Bulanov, S. V.; Esirkepov, T. Z.; Kondo, Shuji; Kanazawa, Shuhei; Homma, Takayuki*; Nakajima, Kazuhisa; et al.

Physics of Plasmas, 12(9), p.093101_1 - 093101_5, 2005/09

 Times Cited Count:70 Percentile:88.85(Physics, Fluids & Plasmas)

no abstracts in English

Oral presentation

Optimization of the target parameter for the phase rotation experiment by using proton beam driven by 100-TW class Ti:Sa laser

Mori, Michiaki; Ogura, Koichi; Sagisaka, Akito; Orimo, Satoshi; Takai, Mamiko; Yogo, Akifumi; Kiriyama, Hiromitsu; Ma, J.-L.; Kanazawa, Shuhei; Kondo, Shuji; et al.

no journal, , 

no abstracts in English

Oral presentation

Online real time characterization of fast protons induced by a repetitive high-intensity laser-foil interaction

Yogo, Akifumi; Daido, Hiroyuki; Mori, Michiaki; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Kiriyama, Hiromitsu; Pirozhkov, A. S.; Kanazawa, Shuhei; Nakai, Yoshiki; et al.

no journal, , 

We report the result on a novel online analysis of fast ions generated in an ultraintense laser-foil interaction. Fast protons are observed by a time-of-flight (TOF) detector, which is precisely calibrated using proton beams from an ion accelerator as to its detection efficiency depending on the proton energy. The TOF detector provides shot-to-shot energy distributions of protons immediately after the irradiation of a high-intensity laser pulse of 10$$^{18}$$ W/cm$$^2$$. Definite correlations are found between the prepulse intensity and the high energy cutoff of protons as well as the conversion efficiency of the laser energy into the proton energy, governing the stability of the repetitive proton generation.

Oral presentation

Simultaneous imaging with a proton beam and an X-ray driven by a fs-intense laser

Orimo, Satoshi; Yogo, Akifumi; Ogura, Koichi; Sagisaka, Akito; Mori, Michiaki; Kiriyama, Hiromitsu; Kondo, Shuji; Yamamoto, Yoichi*; Shimomura, Takuya*; Tanoue, Manabu*; et al.

no journal, , 

We are investigating an intense fs-laser driven MeV proton source using a thin foil, and its applications. Simultaneous imaging of a sample with a proton and an X-ray beams has been demonstrated by a ultra-short pulse higt intensity Ti:Sapphire laser systems at JAEA and GIST. For generating a short-pulse proton beams and X-rays, an intense laser pulse irradiates a tape targets. The p-polarized laser pulse with 50 mm diameter is focused onto the cupper tape target at 45 degree incident angle with focal length of 238 mm (F/4.8), giving an intensity on target of 3-9$$times$$10$$^{18}$$W/cm10$$^{2}$$. The cupper and polyimide tape was 5, 7.5 micron in thickness and 20 mm in width. The target system supplies a fresh surface to the focus spot at every shot. We obtained simultaneously the projection image of a Ni mesh pattern having a periodically structured pattern by the proton detected CR39 and X-rays detected on imaging plate.

Oral presentation

Energetic proton beam generation driven by J-KAREN JAEA 100 TW laser

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

Oral presentation

Characterization of fast-proton generation by ultrahigh-intensity laser irradiation

Yogo, Akifumi; Mori, Michiaki; Ogura, Koichi; Sagisaka, Akito; Orimo, Satoshi; Kanazawa, Shuhei; Kondo, Shuji; Nakai, Yoshiki; Akutsu, Atsushi; Yamamoto, Yoichi*; et al.

no journal, , 

no abstracts in English

Oral presentation

Energetic proton beam generation driven by J-KAREN laser

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

Oral presentation

Target position dependence of energy of proton generated with high intensity laser

Ogura, Koichi; Orimo, Satoshi; Sagisaka, Akito; Nishiuchi, Mamiko; Mori, Michiaki; Yogo, Akifumi; Kiriyama, Hiromitsu; Kanazawa, Shuhei; Kondo, Shuji; Nakai, Yoshiki; et al.

no journal, , 

When the high energy proton beam was generated by the high intensity laser system, the image of the plasma produced by the laser system was measured with an X-ray pinhole camera system. The proton beam, which has maximum energy, was generated in the vicinity of the target position where the image size of the plasma was the smallest.

Oral presentation

Improvement of the JAEA J-KAREN laser and its applications to high field science, 4; Phase rotation technique of the intense and short pulse laser driven proton beam by synchronous RF field

Nishiuchi, Mamiko; Daido, Hiroyuki; Yogo, Akifumi; Mori, Michiaki; Kiriyama, Hiromitsu; Kanazawa, Shuhei; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Kondo, Shuji; et al.

no journal, , 

By applying the RF filed to the high intensity short pulse laser-driven $$sim$$MeV proton beam, we have demonstrated the generation of the quasi-monoenegetic proton spectra and modification of the spatial distribution of proton beams. We used J-KAREN laser system at the JAEA. We focused it to Polyimide target. The intensity was 4$$times$$10$$^{18}$$Wcm$$^{-2}$$. We produced repetetively the proton beams with the maximum energy of 2.2 MeV. We guided this proton beam to the cabvity of the RF field. We observed significant energy peaks in the proton energy spectra. The resultant energy concentration was 11 % (FWHM) out of 100 %. At the same time, we could change the divergence of the beam with the RF field. According to the Monte-Carlo simulation, the spatially converging proton beam has energy spectra with the energy spread of 100 %, on the contrary the spatially diverging beam has mono-energetic energy spectra. This method is very useful because it can apply to repetitivelly produced proton beams to control the energy as well as spatial distributions.

Oral presentation

Energetic ion beam generation driven by J-KAREN laser

Mori, Michiaki; Yogo, Akifumi; Kiriyama, Hiromitsu; Sagisaka, Akito; Ma, J.-L.; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Pirozhkov, A. S.; Okada, Hajime; et al.

no journal, , 

no abstracts in English

36 (Records 1-20 displayed on this page)