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[show abstract]
[hide abstract]
ABSTRACT: In this work, we demonstrate that the contrast of high intensity laser pulses is a key issue for many problems dealing with
high-field interaction with solid-density matter. As an example, we will discuss the interaction of an Ultra-High-Contrast
(UHC), Ultra-Intense, 65 fs laser pulse with an overdense plasma through the proton acceleration from ultra-thin foils (from
0.08 μm to 105 μm). The symmetric feature of the ion beams emitted from both faces of the target will be demonstrated as well
as the dominant role of the p component of the electric field rather than the ponderomotive force. Simulations performed with a 2D particle-in-cell code
are in close agreement with all experimental data. UHC experiments prove to be a good as benchmarks for theories and models.
The European Physical Journal Special Topics 04/2012; 175(1):111-116. · 1.56 Impact Factor
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A Gamucci,
N Bourgeois,
T Ceccotti,
X Davoine,
S Dobosz,
P D'Oliveira,
M Galimberti,
J Galy,
A Giulietti,
D Giulietti, [......],
D J Hamilton,
L Labate,
E Lefebvre,
J R Marques,
P Martin,
P Monot, H Popescu,
F Reau,
G Sarri,
P Tomassini
Radiation Effects and Defects in Solids 01/2010; 165(6-10):774-779. · 0.40 Impact Factor
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A Gamucci,
N Bourgeois,
T Ceccotti,
X Davoine,
S Dobosz,
P D'Oliveira,
M Galimberti,
J Galy,
A Giulietti,
D Giulietti, [......],
D J Hamilton,
L Labate,
E Lefebvre,
J R Marques,
P Monot, H Popescu,
F Reau,
G Sarri,
P Tomassini,
Ph. Martin
2ND INTERNATIONAL CONFERENCE ON ULTRA-INTENSE LASER INTERACTION SCIENCE; 01/2010
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A Lévy,
R Nuter,
T Ceccotti,
P Combis,
M Drouin,
L Gremillet,
P Monot, H Popescu,
F Réau,
E Lefebvre,
P Martin
[show abstract]
[hide abstract]
ABSTRACT: Energies of laser-accelerated ions from thin foils in the so-called 'ultra-high-contrast' regime have been measured for various preformed plasma sizes on the non-irradiated foil surface. Whereas energies of protons accelerated in the laser counter-propagating direction remain almost constant for plasma scale length up to 300 nm, we found that plasmas as short as a few tens of nanometers reduce the maximum energy of ions accelerated in the laser direction. These experimental measurements are numerically confirmed with two-dimensional particle-in-cell simulations coupled to hydrodynamic calculation. Moreover, our experimental results, supported by simulations, provide evidence for the occurrence of ion wave breaking, and demonstrate its ability to mitigate the ion energy reduction due to the plasma gradient. This wave breaking is observed and characterized for both proton and carbon ion components.
New Journal of Physics 09/2009; 11(9):093036. · 4.18 Impact Factor
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D. Batani,
S. D. Baton,
M. Manclossi,
D. Piazza,
M. Koenig,
A. Benuzzi-Mounaix, H. Popescu,
C. Rousseaux,
M. Borghesi,
C. Cecchetti,
A. Schiavi
[show abstract]
[hide abstract]
ABSTRACT: We present the results of experiments performed at the LULI laboratory, using the 100 TW laser facility, on the study of the propagation of fast electrons in gas targets. The implemented diagnostics included chirped shadowgraphy and proton imaging. Proton images showed the presence of very large fields in the gas (produced by charge separation). In turn, these imply a strong inhibition of propagation, and a slowing down of the fast electron cloud as it penetrates in the gas. Indeed chirped shadowgraphy images show a reduction in time of the velocity of the electron cloud from the initial value, of the order of a fraction of c, over a time scale of a few picoseconds.
Physics of Plasmas 03/2009; 16(3):033104-033104-6. · 2.15 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: We present some of the results obtained when an ultra-high-intensity (~5 × 1018W cm−2), ultra-high contrast (>1010) laser pulse interacts with thins foils. Under such conditions, protons accelerated by the target normal sheat acceleration mechanism are observed from both sides of the target and show quasi-symmetric features which have been corroborated by extensive 1D and 2D particle-in-cell simulations. Moreover, we show that due to the very steep gradient of the laser-irradiated surface, the Brunel effect is the main laser energy coupling mechanism.
Plasma Physics and Controlled Fusion 11/2008; 50(12):124006. · 2.42 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: We investigate the interaction of a high-intensity (~5.10<sup>18</sup> W/cm<sup>2</sup>) and short (~65 fs) laser pulse with thin foils (from 0.08 to 105 mum) in a regime of ultrahigh contrast (> 10<sup>10</sup>). This paper shows that for thicknesses less than about 10 mum, proton acceleration from both sides of the target presents quite symmetric features. Proton bunches emitted from each side show similar maximum energies and spatial characteristics. Moreover, we show that for ultrahigh-contrast pulses, the efficient acceleration mechanism is related to the Brunei effect and not to the ponderomotive force. Simulations performed with a 2-D particle-in-cell code are in close agreement with all experimental data.
IEEE Transactions on Plasma Science 09/2008; · 1.17 Impact Factor
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A. Gamucci,
N. Bourgeois,
T. Ceccotti,
S. Dobosz,
P. D'Oliveira,
M. Galimberti,
J. Galy,
A. Giulietti,
D. Giulietti,
L. A. Gizzi,
D. J. Hamilton,
L. Labate,
J.-R. Marques,
P. Monot, H. Popescu,
F. Reau,
G. Sarri,
P. Tomassini,
P. Martin
[show abstract]
[hide abstract]
ABSTRACT: In this paper, the interaction of 10-TW laser pulses, focused at moderately relativistic intensity, with a supersonic helium gas-jet has been investigated by varying gas density and jet nozzle. We have successfully tested several advanced diagnostic devices to characterize the plasma and the accelerated electron bunches. Plasma densities have been measured by means of a femtosecond high-resolution interferometer, while the electron beams were analyzed with a stack of radiochromic films, a beam-profile monitor, a magnetic spectrometer, and a nuclear activation setup based on gamma-ray generation via electron bremsstrahlung. We present the results as well as the basic features and relevant details of such diagnostics whose performances can fit a large class of experiments.
IEEE Transactions on Plasma Science 09/2008; · 1.17 Impact Factor
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A Giulietti,
N Bourgeois,
T Ceccotti,
X Davoine,
S Dobosz,
P D'Oliveira,
M Galimberti,
J Galy,
A Gamucci,
D Giulietti, [......],
D J Hamilton,
E Lefebvre,
L Labate,
J R Marquès,
P Monot, H Popescu,
F Réau,
G Sarri,
P Tomassini,
P Martin
[show abstract]
[hide abstract]
ABSTRACT: A gamma-ray source with an intense component around the giant dipole resonance for photonuclear absorption has been obtained via bremsstrahlung of electron bunches driven by a 10-TW tabletop laser. 3D particle-in-cell simulation proves the achievement of a nonlinear regime leading to efficient acceleration of several sequential electron bunches per each laser pulse. The rate of the gamma-ray yield in the giant dipole resonance region (8<E{gamma}<17.5 MeV) was measured, through the radio activation of a gold sample, to be 4 x 10;{8} photons per joule of laser energy. This novel all-optical, compact, and efficient electron-gamma source is suitable for photonuclear studies and medical uses.
Physical Review Letters 09/2008; 101(10):105002. · 7.37 Impact Factor
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A Ya Faenov,
A I Magunov,
T A Pikuz,
I Yu Skobelev,
D Giulietti,
S Betti,
M Galimberti,
A Gamucci,
A Giulietti,
L A Gizzi, [......],
T Ceccotti,
P Monot,
F Reau, H Popescu,
Oliveira,
Ph Martin,
Y Fukuda,
A S Boldarev,
S V Gasilov,
V A Gasilov
[show abstract]
[hide abstract]
ABSTRACT: We used X-ray spectroscopy as a diagnostic tool for investigating the properties of laser-cluster interactions at the stage in which non-adiabatic cluster expansion takes place and a quasi-homogeneous plasma is produced. The experiment was carried out with a 10 TW, 65 fs Ti:Sa laser focused on CO 2 cluster jets. The effect of different laser-pulse contrast ratios and cluster concentrations was investigated. The X-ray emission associated to the Rydberg transitions allowed us to retrieve, through the density and temperature of the emitting plasma, the time after the beginning of the interaction at which the emission occurred. The comparison of this value with the estimated time for the "homogeneous" plasma formation shows that the degree of adiabaticity depends on both the cluster concentration and the pulse contrast. Interferometric measurements support the X-ray data concerning the plasma electron density.
Laser and Particle Beams 02/2008; 26:69. · 1.62 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: We report on simultaneous measurements of backward- and forward-accelerated protons spectra when an ultrahigh intensity (approximately 5 x 10(18) W/cm(20), ultrahigh contrast (>10(10)) laser pulse interacts with foils of thickness ranging from 0.08 to 105 microm. Under such conditions, free of preplasma originating from ionization of the laser-irradiated surface, we show that the maximum proton energies are proportional to the p component of the laser electric field only and not to the ponderomotive force and that the characteristics of the proton beams originating from both target sides are almost identical. All these points have been corroborated by extensive 1D and 2D particle-in-cell simulations showing a very good agreement with the experimental data.
Physical Review Letters 11/2007; 99(18):185002. · 7.37 Impact Factor
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A. Ya. Faenov,
A. I. Magunov,
T. A. Pikuz,
I. Yu. Skobelev,
D. Giulietti,
S. Betti,
M. Galimberti,
A. Gamucci,
A. Giulietti,
L. A. Gizzi, [......],
T. Ceccotti,
P. Monot,
F. Reau, H. Popescu,
P. D’Oliveira,
Ph. Martin,
Y. Fukuda,
A. S. Boldarev,
S. V. Gasilov,
V. A. Gasilov
[show abstract]
[hide abstract]
ABSTRACT: X-ray spectroscopic diagnostics of laser-cluster interaction at the stage of nonadiabatic scattering of clusters and formation
of a spatially uniform plasma channel has been performed. The experimental investigations have been carried out on a Ti:Sa
laser setup with a pulse duration of about 65 fs and an energy up to 600 mJ. It has been shown that, within 10 ps from the
beginning of a laser femtosecond pulse, the laser-cluster interaction forms a uniform plasma channel with a length of 0.4
to 1 mm with the parameters N
e ∼ 1019−1020 cm−3 and T
e ∼ 100 eV.
JETP Letters 09/2007; 86(3):178-183. · 1.35 Impact Factor
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A.Ya. Faenov,
A.I. Magunov,
T. Pikuz,
I.Yu. Skobelev,
D. Giulietti,
S. Betti,
M. Galimberti,
A. Gamucci,
A. Giulietti,
L.A. Gizzi, [......],
T. Ceccotti,
P. Monot, H. Popescu,
F. Reau,
P. D'Oliveira,
Ph. Martin,
Y. Fukuda,
A.S. Boldarev,
S.V. Gasilov,
V.A. Gasilov
[show abstract]
[hide abstract]
ABSTRACT: X-ray spectroscopic diagnostics of laser–cluster interaction at the stage of nonadiabatic scattering of clusters and formation of a spatially uniform plasma channel has been performed. The experimental investigations have been carried out on a Ti:Sa laser setup with a pulse duration of about 65 fs and an energy up to 600 mJ. It has been shown that, within 10 ps from the beginning of a laser femtosecond pulse, the laser-cluster interaction forms a uniform plasma channel with a length of 0.4 to 1 mm with the parameters Ne~10^19-10^20 cm^-3 and Te~100 eV.
JETP Letters 05/2007; 86:178. · 1.35 Impact Factor
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J Fuchs,
Y Sentoku,
T E Cowan,
J Cobble,
P Audebert,
A Kemp,
A Nikroo,
P Antici,
E Brambrink,
A Blazevic, [......],
J -C Gauthier,
M Geissel,
M Hegelich,
S Karsch, H Popescu,
N Renard-LeGalloudec,
M Roth,
J Schreiber,
R Stephens,
H Pepin
[show abstract]
[hide abstract]
ABSTRACT: The maximum energy of protons that are accelerated forward by high-intensity, short-pulse lasers from either the front or rear surfaces of thin metal foils is compared for a large range of laser intensities and pulse durations. In the regime of moderately long laser pulse durations (300-850 fs), and for high laser intensities [(1-6)x10(19) W/cm(2)], rear-surface acceleration is shown experimentally to produce higher energy particles with smaller divergence and a higher efficiency than front-surface acceleration. For similar laser pulse durations but for lower laser intensities (2x10(18) W cm(-2)), the same conclusion is reached from direct proton radiography of the electric fields associated with proton acceleration from the rear surface. For shorter (30-100 fs) or longer (1-10 ps) laser pulses, the same predominance of rear-surface acceleration in producing the highest energy protons is suggested by simulations and by comparison of analytical models with measured values. For this purpose, we have revised our previous analytical model of rear-surface acceleration [J. Fuchs et al., Nat. Phys. 2, 48 (2006)] to adapt it to the very short pulse durations. Finally, it appears, for the explored parameters, that rear-surface acceleration is the dominant mechanism. (C) 2007 American Institute of Physics.
Physics of Plasmas 05/2007; 14(5). · 2.15 Impact Factor
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S D Baton,
D Batani,
M Manclossi,
A Morace,
D Piazza,
A Benuzzi-Mounaix,
M Koenig,
P Guillou,
B Loupias,
J Fuchs,
F Amiranoff,
M Rabec Le Gloahec, H Popescu,
C Rousseaux,
M Borghesi,
C Cecchetti,
R Kodama,
T Norimatsu,
M Nakatsutsumi,
Y Aglitskiy
[show abstract]
[hide abstract]
ABSTRACT: We present the results of some recent experiments performed at the LULI laboratory using the 100 TW laser facility concerning the study of the propagation of fast electrons in gas and solid targets. Novel diagnostics have been implemented including chirped shadowgraphy and proton radiography. Proton radiography images did show the presence of very strong fields in the gas probably produced by charge separation. In turn these imply a slowing down of the fast electron cloud as it penetrates in the gas and a strong inhibition of propagation. Indeed chirped shadowgraphy images show a strong reduction in time of the velocity of the electron cloud from the initial value, which is of the order of a fraction of c. We also performed some preliminary experiments with cone targets in order to verify the guiding effect and fast electron propagation in presence of the cone. Finally we compared results obtained by changing the target size.Here we only give a first presentation and preliminary analysis of data, which will be addressed in detail in a following paper.
Plasma Physics and Controlled Fusion 11/2005; 47(12B):B777. · 2.42 Impact Factor
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M. Manclossi,
D Batani,
D. Piazza,
S Baton,
Francois Amiranoff,
M Koenig, H. Popescu,
P Audebert,
J J Santos,
Emanuele Martinolli,
A Benuzzi-Mounaix,
M. Rabec Le Gloahec,
A Antonicci,
C Rousseaux,
M Borghesi,
C Cecchetti,
Victor Malka,
T Hall
[show abstract]
[hide abstract]
ABSTRACT: This paper reports the results of some recent experiments performed at the LULI laboratory (Palaiseau, France) concerning the propagation of large relativistic electron currents in a gas jet. We present our experimental results according to the type of diagnostics used in the experiments: (1) time resolved optical shadowgraphy and (2) proton imaging. Proton radiography images did show the presence of very strong fields in the gas probably produced by charge separation. In turn, these imply a slowing down of the fast electron cloud as it penetrates in the gas. Indeed, shadowgraphy images show a strong inhibition of propagation and a strong reduction in time of the velocity of the electron cloud from the initial value, which is of the order of a fraction of c.
Radiation Effects and Defects in Solids 10/2005; · 0.40 Impact Factor
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H. Popescu,
S.D. Baton,
F. Amiranoff,
C. Rousseaux,
M. Rabec Le Gloahec,
J.J. Santos,
L. Gremillet,
M. Koenig,
E. Martinolli,
T. Hall,
J.C. Adam,
A. Heron,
D. Batani,
Bruyeres-le-Cha circumflex tel Commisariat a l'Energie Atomique,
LULI, UMR CNRS-CEA-Ecole Polytechnique-Paris Palaiseau,
Department of Physics, University of Essex, Colchester,
CPhT, UMR CNRS-Ecole Polytechnique, Palaiseau,
Universita di Milano-Bicocca Dipartimento di Fisica 'G. Occhialini' and INFM
[show abstract]
[hide abstract]
ABSTRACT: Harmonics of the laser light have been observed from the rear side of solid targets irradiated by a laser beam at relativistic intensities. This emission evidences the acceleration of subfemtosecond electron bunches by the laser pulse in front of the target. These bunches emit coherent transition radiation (CTR) when passing through the back surface of the target. The spectral features of the signal recorded for targets of thicknesses up to several hundred microns are consistent with the electrons being accelerated by both the laser electric field--via vacuum heating and/or resonance absorption,--and the vxB component of the Lorentz force. The spatial study of the radiation shows that the relativistic electrons causing the CTR radiation are coherent and propagate ballistically through the target, originating from a source with a size of the order of the laser focal spot.
Physics of Plasmas 06/2005; 12(6). · 2.15 Impact Factor
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H. Popescu,
S. D. Baton,
F. Amiranoff,
C. Rousseaux,
M. Rabec Le Gloahec,
J. J. Santos,
L. Gremillet,
M. Koenig,
E. Martinolli,
T. Hall,
J. C. Adam,
A. Heron,
D. Batani
[show abstract]
[hide abstract]
ABSTRACT: Harmonics of the laser light have been observed from the rear side of solid targets irradiated by a laser beam at relativistic intensities. This emission evidences the acceleration of subfemtosecond electron bunches by the laser pulse in front of the target. These bunches emit coherent transition radiation (CTR) when passing through the back surface of the target. The spectral features of the signal recorded for targets of thicknesses up to several hundred microns are consistent with the electrons being accelerated by both the laser electric field—via vacuum heating and/or resonance absorption,—and the v×B component of the Lorentz force. The spatial study of the radiation shows that the relativistic electrons causing the CTR radiation are coherent and propagate ballistically through the target, originating from a source with a size of the order of the laser focal spot.
Physics of Plasmas 06/2005; 12(6):063106-063106-8. · 2.15 Impact Factor
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J Fuchs,
Y Sentoku,
S Karsch,
J Cobble,
P Audebert,
A Kemp,
A Nikroo,
P Antici,
E Brambrink,
A Blazevic, [......],
J-C Gauthier,
M Geissel,
M Hegelich,
H Pépin, H Popescu,
N Renard-LeGalloudec,
M Roth,
J Schreiber,
R Stephens,
T E Cowan
[show abstract]
[hide abstract]
ABSTRACT: The comparative efficiency and beam characteristics of high-energy ions generated by high-intensity short-pulse lasers (approximately 1-6 x 10(19) W/cm2) from both the front and rear surfaces of thin metal foils have been measured under identical conditions. Using direct beam measurements and nuclear activation techniques, we find that rear-surface acceleration produces higher energy particles with smaller divergence and a higher efficiency than front-surface acceleration. Our observations are well reproduced by realistic particle-in-cell simulations, and we predict optimal criteria for future applications.
Physical Review Letters 03/2005; 94(4):045004. · 7.37 Impact Factor
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D. Batani,
S. D. Baton,
M. Manclossi,
F. Amiranoff,
M. Koenig,
J. J. Santos,
E. Martinolli,
L. Gremillet, H. Popescu,
A. Antonicci,
C. Rousseaux,
M. Rabec Le Gloahec,
T. Hall,
V. Malka,
T. E. Cowan,
R. Stephens,
M. Key,
J. King,
R. Freeman
[show abstract]
[hide abstract]
ABSTRACT: This paper reports the results of several experiments performed at the LULI laboratory (Palaiseau, France) concerning the propagation of large relativistic currents in matter from ultra‐high‐intensity laser pulse interaction with target. We present our results according to the type of diagnostics used in the experiments: 1) Kα emission and Kα imaging, 2) study of target rear side emission in the visible region, 3) time resolved optical shadowgraphy. © 2004 American Institute of Physics
AIP Conference Proceedings. 11/2004; 740(1):446-457.
