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M. Nishiuchi,
H. Daido,
A. Sagisaka,
K. Ogura,
S. Orimo, M. Kado,
A. Yogo,
M. Mori,
Y. Hayashi,
S. Bulanov,
A. Fukumi,
Z. Li,
A. Noda,
S. Nakamura
[show abstract]
[hide abstract]
ABSTRACT: A highly collimated sub-MeV proton beam with the divergence angle of 10 degrees is obtained during the interaction of a few
terawatt pulse from a table-top Ti:sapphire laser with a thin metallic foil. This beam is used for proton shadowgraphy. The
quality of the 107 laminar protons per bunch is sufficient for good quality projection imaging of a micrometer size mesh structure, giving a
quantitative characterization of the proton beam, such as the transverse emittance of less than 0.1π mm mrad. These experimental
results open up a new perspective in imaging techniques.
Applied Physics B 04/2012; 87(4):615-621. · 2.19 Impact Factor
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A. Sagisaka,
H. Daido,
K. Ogura,
S. Orimo,
Y. Hayashi,
M. Nishiuchi,
M. Mori,
A. Yogo, M. Kado,
T. Morita, [......],
Y. Oishi,
T. Nayuki,
T. Fujii,
K. Nemoto,
S. Nakamura,
A. Noda,
S. V. Bulanov,
T. Zh. Esirkepov,
A. S. Pirozhkov,
T. Utsumi
[show abstract]
[hide abstract]
ABSTRACT: Intense laser driven thin foil target acts as a double layered coulomb system that produces collimated ions as well as high-order
harmonics, hard X-ray, and so on. From this point of view, we observed the electron density distribution of preformed plasmas
of a tantalum foil target with two-color probe beams as an interferometer. The preformed plasma at the front side of the target
was generated by a prepulse with a high-intensity Ti:sapphire laser pulse. On the other hand, the preformed plasma at the
rear side was not observed. In our experimental condition, high-energy electrons and protons were observed. The characterization
of preformed plasmas will contribute to describe the high-intensity laser-thin foil interactions.
05/2010: pages 273-277;
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T. Kawachi,
M. Kishimoto, M. Kado,
N. Hasegawa,
M. Tanaka,
Y. Ochi,
M. Nishikino,
M. Ishino,
T. Imazono,
T. Ohba, [......],
Y. Fukuda,
H. Kotaki,
A. Pirozhkov,
J. Ma,
A. Sagisaka,
M. Mori,
J. Koga,
S. Bulanov,
H. Daido,
T. Tajima
[show abstract]
[hide abstract]
ABSTRACT: Recent progress in x-ray laser (XRL) research in Japan Atomic Energy Agency (JAEA) is reviewed. The repetition-rate of the
x-ray laser has been improved from each0 minutes to0 seconds (0.1 Hz) by installing new driver laser, TOPAZ, which allows
us to promote the applications of fully spatial coherent3.9 nm laser in the wide variety of research fields such as material
science, single-shot x-ray holography and atomic physics. In order to improve the present performance of the x-ray lasers,
we have investigated the possibilities of the enhancement of the peak brilliance using v-groove target and the generation
of circularly polarized x-ray laser under a strong magnetic field. Towards shorter wavelength x-ray lasers, we have investigated
several schemes. One is the use of reflection of the light by relativistic plasma mirror driven by laser-wake-field, and the
other is photo-pumping scheme using Kα emission from a solid target.
12/2008: pages 3-12;
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A. Sagisaka,
A.S. Pirozhkov,
H. Daido,
A. Fukumi,
Z. Li,
K. Ogura,
A. Yogo,
Y. Oishi,
T. Nayuki,
T. Fujii, [......],
M. Nishiuchi,
Y. Hayashi,
M. Mori, M. Kado,
S. Nakamura,
A. Noda,
I.W. Choi,
J.H. Sung,
D.-K. Ko,
J. Lee
[show abstract]
[hide abstract]
ABSTRACT: A two-color interferometer for preformed plasma characterization is developed. We observe the electron density distribution of preformed plasmas on a 5μm-thick copper target irradiated with a high-intensity Ti:sapphire laser. The two-color interferometer extended the observable electron density region using a fundamental (800nm) probe beam to cover the lower density region and a second harmonic (400nm) probe beam to cover the higher density region, simultaneously. This characterization of the electron density distribution of preformed plasmas with femtosecond time resolution significantly contributes to the understanding of high-intensity laser–thin-foil interactions during high-energy electron, ion, and X-ray generation.
Applied Physics B 08/2006; 84(3):415-419. · 2.19 Impact Factor
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M. Mori,
A. Pirozhkov,
M. Nishiuchi,
K. Ogura,
A. Sagisaka,
Y. Hayashi,
S. Orimo,
A. Fukumi,
Z. Li, M. Kado,
H. Daido
[show abstract]
[hide abstract]
ABSTRACT: We developed a beam-pointing stabilizer for a 10-TW Ti:sapphire laser system to study laser-induced ion acceleration. We confirmed
the improvement in the laser beam pointing stability by using a 10-TW laser system (we call it JLITE-X) at JAERI-APRC. The
original long-term pointing stability on a 10-TW laser system is ∼70 μrad without beam stabilizing. By using a beam-pointing
stabilizer, the laser beam stability was improved within 10 μrad. If f/1 focusing optics and a target which is tilted 45° to the target normal is used, the fluctuation of the laser intensity at
the focus will be improved from 80% without stabilizing to <0.4% with it.
Laser Physics 06/2006; 16(7):1092-1096. · 3.61 Impact Factor
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Z. Li,
H. Daido,
A. Fukumi,
A. Sagisaka,
K. Ogura,
M. Nishiuchi,
S. Orimo,
Y. Hayashi,
M. Mori, M. Kado,
S. V. Bulanov,
T. Zh. Esirkepov,
Y. Oishi,
T. Nayuki,
T. Fujii,
K. Nemoto,
S. Nakamura,
A. Noda
[show abstract]
[hide abstract]
ABSTRACT: The energy spectra and angular distributions of hot electrons as well as protons emitted from a 3-μm-thick tantalum foil irradiated by a 70-fs laser pulse with an intensity of ∼ 1018 W/cm2 are measured. Three hot electron flows are found, in the rear target normal, specular, and target surface directions. The angular distribution of hot electrons is found to depend on the polarization of the incident light. The measured energy spectrum of hot electrons in the rear target normal direction can explain the generated proton beam.
Physics of Plasmas 04/2006; 13(4):043104-043104-6. · 2.15 Impact Factor
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H. Daido,
M. Nishiuchi,
A. Fukumi,
Z. Li,
A. Sagisaka,
K. Ogura,
S. Orimo, M. Kado,
Y. Hayashi,
M. Mori, [......],
T. Kimura,
T. Tajima,
K. Nemoto,
Y. Oishi,
T. Nayuki,
T. Fujii,
A. Noda,
Y. Iwashita,
T. Shirai,
S. Nakamura
[show abstract]
[hide abstract]
ABSTRACT: We have studied the ion emission from a thin‐foil target irradiated by p, s and circularly polarized laser pulses in order to clarify the mechanism of ion acceleration using a Titanium Sapphire laser with a peak irradiance of 3 × 1018 W/cm2. A tape target driver provided a fresh surface of a tantalum foil with the thickness of 3 micro‐meters during the measurements. The laser polarization was changed from p to s‐ and to circular polarization by using the 1/2 and 1/4 wave plates made of mica. To obtain the ion energy spectra and to resolve the ion species, a Thomson parabola ion analyzer was placed behind the target along the target normal direction. The energy spectra close to 1MeV were obtained. Possible explanation of the experimental result is described. Finally, we describe the phase rotation technique to obtain a monochromatic proton beam. © 2006 American Institute of Physics
AIP Conference Proceedings. 04/2006; 827(1):203-214.
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Z. Li,
H. Daido,
A. Fukumi,
S. Orimo,
A. Sagisaka,
K. Ogura,
Y. Oishi,
T. Nayuki,
M. Nishiuchi,
Y. Hayashi,
M. Mori, M. Kado,
T. Zh. Esirkepov,
S. V. Bulanov,
S. Nakamura,
A. Noda,
T. Fujii,
K. Nemoto
[show abstract]
[hide abstract]
ABSTRACT: The experimental study on hot electrons emitted from a 3‐μm thick tantalum foil irradiated by s‐ and p‐polarized intense femtosecond laser pulses with a peak intensity of ∼1018 W/cm2 are reported here. Three hot electron flows are found along the rear target normal, specular and target surface directions. The characters of hot electrons are discussed and applied to explain the experimental results of bremsstrahlung X‐rays and generation of protons. © 2006 American Institute of Physics
AIP Conference Proceedings. 04/2006; 827(1):308-319.
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A. Noda,
S. Nakamura,
Y. Iwashita,
S. Sakabe,
M. Hashida,
T. Shirai,
S. Shimizu,
H. Tongu,
H. Ito,
H. Souda, [......],
A. Yogo,
S. Bulanov,
T. Esirkepov,
A. Nagashima,
T. Kimura,
T. Tajima,
T. Takeuchi,
K. Matsukado,
A. Fukumi,
Z. Li
[show abstract]
[hide abstract]
ABSTRACT: In order to widely spread out particle beams utilized in cancer therapy, laser-produced ions are developed as the injection
beam for an ion synchrotron dedicated for cancer therapy. Such a laser ion source is expected to contribute largely to the
realization of compactness of the size and low cost of the cancer therapy accelerator. The energy spectrum of the laser-produced
ions, however, has no peak, but their intensities decrease exponentially according to the increase of the energy. For the
purpose of modifying such a situation, we have proposed a scheme to rotate the beam in the longitudinal phase space with the
use of the RF electric field, which is phase-adjusted with the pulse laser. We aim for a reduction of the energy spread of
± 5% selected by an energy analyzer and slits to ±1% by such phase rotation. For this purpose, a quarter wavelength resonator
with two gaps with the same resonant frequency as the source laser has already been fabricated, together with its RF power
source. The above phase rotation system and its recent experimental realization are presented.
Laser Physics 03/2006; 16(4):647-653. · 3.61 Impact Factor
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Y Hayashi,
A Fukumi,
K Matsukado,
M Mori,
H Kotaki,
M Kando,
L M Chen,
I Daito,
S Kondo,
S Kanazawa,
A Yamazaki,
K Ogura,
M Nishiuchi, M Kado,
A Sagisaka,
S Nakamura,
Z Li,
S Orimo,
T Homma,
H Daido
[show abstract]
[hide abstract]
ABSTRACT: The authors obtain a new equation to estimate the forward component of a photon dose 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 in the range>3 MeV and proportional to the square of the electron temperature in the range<3 MeV. The dose estimated with this method is roughly consistent with the result of Monte Carlo simulation. With some assumptions and corrections, it can reproduce experimental results obtained and the dose result calculated at other laboratories.
Radiation Protection Dosimetry 02/2006; 121(2):99-107. · 0.82 Impact Factor
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A. Fukumi,
M. Nishiuchi,
H. Daido,
Z. Li,
A. Sagisaka,
K. Ogura,
S. Orimo, M. Kado,
Y. Hayashi,
M. Mori,
S. V. Bulanov,
T. Esirkepov,
K. Nemoto,
Y. Oishi,
T. Nayuki,
T. Fujii,
A. Noda,
S. Nakamura
[show abstract]
[hide abstract]
ABSTRACT: A study of proton emission from a 3‐μm-thick Ta foil target irradiated by p-, s-, and circularly polarized laser pulses with respect to the target plane has been carried out. Protons with energies up to 880 keV were observed in the target normal direction under the irradiation by the p-polarized laser pulse, which yielded the highest efficiency for proton emission. In contrast, s- and circularly polarized laser pulses gave the maximum energies of 610 and 680 keV, respectively. The difference in the maximum energy between the p- and s-polarized cases was associated with the difference between the sheath fields estimated from electron spectra.
Physics of Plasmas 10/2005; 12(10):100701-100701-4. · 2.15 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: We have recently reported the successful development of a fully coherent X-ray laser (XRL) at 13.9 nm by an oscillator-amplifier configuration with two targets. In the experiment, a seed XRL beam from the first target is injected into a plasma amplifier at the second target. The observed XRL beam has full spatial coherence and 0.2 mrad of nearly diffraction-limited divergence. In order to improve the output fluence, the amplification properties of the XRL beam have been investigated using various plasma lengths of the second amplifier target. The output energy has been improved by a factor of ten, increasing the length of the gain region to 10 mm, resulting in about 0.2 μJ of output energy.
IEEE Journal of Selected Topics in Quantum Electronics 12/2004; · 3.78 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: We have measured temporal durations of Ni-like transient collisional excitation X-ray lasers (4d4p, J=01) using a high-speed X-ray streak camera coupled with a flat field grating spectrometer. The pumping laser pulse consisted of a 400-ps prepulse and a 4.8-ps main pulse derived from a Nd:glass laser system with chirped pulse amplification. A quasi-traveling-wave pumping using a six-step mirror was adopted to synchronize the X-ray laser pulse and the onset of gain in a plasma medium. The X-ray laser outputs from three different materials, silver (Z=47), palladium (Z=46) and molybdenum (Z=42), showed that the X-ray laser duration became shorter as the atomic number decreased.
Applied Physics B 04/2004; 78(7):961-963. · 2.19 Impact Factor
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K. Nagashima,
M. Tanaka,
M. Nishikino,
M. Kishimoto, M. Kado,
T. Kawachi,
N. Hasegawa,
Y. Ochi,
K. Sukegawa,
R. Tai,
Y. Kato
[show abstract]
[hide abstract]
ABSTRACT: We have succeeded in developing a laser-pumped X-ray laser with full spatial coherence at 13.9nm. The X-ray laser beam with a very small divergence of 0.2mrad was generated from double target experiments, where a seeding light from the first laser medium was amplified in the second laser medium. The observed divergence was close to the diffraction limit value within a factor of two. The seeding light was amplified in the second medium without refraction influence and the gain coefficient was 7.9cm-1. From the measurement of visibility, it was found that the spatial coherent length was longer than the beam diameter.
Applied Physics B 01/2004; 78(7):927-932. · 2.19 Impact Factor
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H. Tang,
O. Guilbaud,
G. Jamelot,
D. Ros,
A. Klisnick,
D. Joyeux,
D. Phalippou, M. Kado,
M. Nishikino,
M. Kishimoto,
K. Sukegawa,
M. Ishino,
K. Nagashima,
H. Daido
[show abstract]
[hide abstract]
ABSTRACT: X-ray interference microscopy diagnostics of a nanosecond-pulse pumped Al (Z=13) plasma are presented. A transient picosecond Ni-like Ag X-ray laser (13.9nm) is used as the probe beam and a wavefront division bi-mirror interferometer is adopted as the diagnosis tool. From the fringe shifts, the two-dimensional plasma density profile at 1ns after the peak of the heating pulse is deduced. Opposite fringe shifts during the plasma development are observed and possible explanations for this behavior are discussed. This study will contribute to the validation of 1D and 2D hydrodynamic codes as well as to the better understanding of the physics during the development of laser produced plasmas.
Applied Physics B 01/2004; 78(7):975-977. · 2.19 Impact Factor
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R Z Tai,
K Namikawa,
M Kishimoto,
M Tanaka,
K Sukegawa,
N Hasegawa,
T Kawachi, M Kado,
P Lu,
K Nagashima,
H Daido,
H Maruyama,
A Sawada,
M Ando,
Y Kato
[show abstract]
[hide abstract]
ABSTRACT: A picosecond x-ray laser speckle has been conducted to study the dynamics of a disordered surface domain structure (BaTiO3 with 90 degrees c/a domains) as a function of temperature for the first time. The transient surface structures induced by ferroelectric domains decrease as temperature increases towards the Curie temperature T(c) and completely disappear above T(c). The dramatic change of the spatial configuration of the c/a domains was observed to occur from a temperature 2 degrees C below T(c), near which the average correlated domain size at equilibrium decreases as (T(c)-T)(0.37+/-0.02).
Physical Review Letters 01/2003; 89(25):257602. · 7.37 Impact Factor
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T. Kawachi, M. Kado,
N. Hasegawa,
M. Tanaka,
K. Sukegawa,
K. Takahashi,
S. Namba,
P. Lu,
H. Tang,
K. Nagashima,
A. Sasaki,
A. Nagashima,
A. Koike,
H. Daido,
Y. Kato
[show abstract]
[hide abstract]
ABSTRACT: The nickel-like silver x-ray laser in the transient
collisional-excitation scheme is demonstrated. The gain coefficient, the
intensity ratio to the background signal, the beam divergence and the
size of the gain region are investigated
Lasers and Electro-Optics, 2001. CLEO/Pacific Rim 2001. The 4th Pacific Rim Conference on; 02/2001
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[show abstract]
[hide abstract]
ABSTRACT: We observed the spatial profile of the transient collisional
excitation Ni-like Ag 13.9 nm laser in various plasma lengths using the
near field imaging method. The gain region was 50 μm crescent shape
and included a localized high gain area
Lasers and Electro-Optics, 2001. CLEO/Pacific Rim 2001. The 4th Pacific Rim Conference on; 02/2001
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T. Kawachi,
M. Tanaka,
N. Hasegawa, M. Kado,
K. Nagashima,
M. Kishimoto,
A. Sasaki,
K. Sukegawa,
P. Lu,
K. Takahashi,
S. Namba,
R. Tai,
H.-J. Tang,
M. Koike,
H. Daido,
Y. Kato
[show abstract]
[hide abstract]
ABSTRACT: A 1 mm thick silver slab target was irradiated by one beam line of
our chirped pulse amplification (CPA) Nd:glass laser system. The x-ray
laser output from the nickel-like silver plasma was observed by use of a
grazing incidence spectrometer. In this spectrometer, we used a laminar
type grating and the detector was a back-illuminated charged couple
device
Lasers and Electro-Optics Society, 2001. LEOS 2001. The 14th Annual Meeting of the IEEE; 02/2001
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O Guilbaud,
M Edwards,
A. Klisnick,
D. Ros,
G. Jamelot,
D Joyeux,
D. Phalippou,
H Tang,
P Neumeyer,
D. Ursescu, [......],
M Kishimoto,
M Ishino,
K Nagashina,
H. Daido,
W Seelig,
S Borneis,
EW Gaul,
W Geithner,
C Haffner,
PP Wiewior
