Publications

1999

• Multi-MeV Ion Production from High-Intensity Laser Interactions with Underdense Plasmas
  
  • Krushelnick K.
  • Clark E. L.
  • Najmudin Z.
  • Salvati M.
  • Santala M. I. K.
  • Tatarakis M.
  • Dangor A. E.
  • Malka Victor
  • Neely D.
  • Allott R.
  • Danson C.
  Physical Review Letters, American Physical Society, 1999, 83 (4), pp.737. Experiments were performed using high-power laser pulses (greater than 50 TW) focused into underdense helium, neon, or deuterium plasmas (ne∼5×1019cm−3). Ions having energies greater than 300 keV were measured to be produced primarily at 90° to the axis of laser propagation. Ion energies greater than 6 MeV were recorded from interactions with neon. Images of the ion emission were also obtained, and it is possible that spatially resolved measurements of the ion energy spectrum can provide a method to estimate the intensity of the focused radiation in the interaction region. (10.1103/PhysRevLett.83.737)
  DOI : 10.1103/PhysRevLett.83.737
• Formation of plasma channels in the interaction of a nanosecond laser pulse at moderate intensities with helium gas jets
  
  • de Wispelaere E.
  • Malka Victor
  • Hüller S.
  • Amiranoff François
  • Baton S.
  • Bonadio R.
  • Casanova M.
  • Dorchies F.
  • Haroutunian R.
  • Modena A.
  Physical Review E : Statistical, Nonlinear, and Soft Matter Physics [2001-2015], American Physical Society, 1999, 59 (6), pp.7110. (10.1103/PhysRevE.59.7110)
  DOI : 10.1103/PhysRevE.59.7110
• Frequency doubling of multi-terawatt picosecond pulses
  
  • Neely D.
  • Danson C.N.
  • Allott R.
  • Amiranoff François
  • Collier J.L.
  • Dangor A.E.
  • Edwards C.B.
  • Flintoff P.
  • Hatton P.
  • Harman M.
  • Hutchinson M.H.R.
  • Najmudin Z.
  • Pepler D.A.
  • Ross I.N.
  • Salvati M.
  • Winstone T.
  Laser and Particle Beams, Cambridge University Press (CUP), 1999, 17 (02), pp.281. The frequency-doubling efficiency and resultant focal spot quality of a large aperture (140 × 89 mm) subpicosecond, chirped pulse amplified (CPA) 1054-nm beam for laser–matter interaction studies has been investigated using the Vulcan Nd:glass laser system (Danson et al. 1998). The effect of B-integral on the CPA beam quality was studied and is shown not to be the dominant cause of the observed frequency-doubled beam break-up. Conversion efficiency tests were carried out on small aperture KDP (type 1) crystals at a range of incident intensities up to 3 × 1011 W/cm2 giving the optimum crystal thickness for pulses in the 0.3–3 ps region. A large-aperture frequency-doubled beam was commissioned and delivered pulses of over 10 TW onto target for an electron acceleration experiment. (10.1017/S0263034699172136)
  DOI : 10.1017/S0263034699172136
• Electron acceleration in laser wakefield experiment at Ecole Polytechnique
  
  • Dorchies F.
  • Amiranoff François
  • Baton S.
  • Bernard D.
  • Cros B.
  • Descamps D.
  • Jacquet F.
  • Malka Victor
  • Marquès J. R.
  • Matthieussent G.
  • Miné Ph.
  • Modena A.
  • Mora P.
  • Morillo Joseph
  • Najmudin Z.
  • Solodov A.
  Laser and Particle Beams, Cambridge University Press (CUP), 1999, 17 (02), pp.299. An experiment has been performed with the LULI Multi-TeraWatt Laser. The acceleration of electrons injected in a plasma wave generated by the laser wakefield mechanism has been observed with a maximum energy gain of 1.5 MeV. It has been shown that the electrons deflected during the interaction, could scatter on the walls of the experimental chamber, and fake a high-energy signal. A special effort has been given in the electron detection to separate the accelerated electrons signal from the background noise.The experimental results agree with theoretical predictions and numerical simulations when 3D effects on the electron beam are taken into account (10.1017/S0263034699172161)
  DOI : 10.1017/S0263034699172161
• Direct detection of Helicobacter pylori resistance to macrolides by a polymerase chain reaction/DNA enzyme immunoassay in gastric biopsy specimens
  
  • Marais A.
  • Monteiro L
  • Occhialini A.
  • Pina M.
  • Lamouliatte H
  • Mégraud F.
  Gut, BMJ Publishing Group, 1999, 44 (4), pp.463-467. (10.1136/gut.44.4.463)
  DOI : 10.1136/gut.44.4.463
• Laser wakefield acceleration of electrons at ecole polytechnique
  
  • Amiranoff François
  • Baton S.
  • Bernard D.
  • Cros B.
  • Descamps D.
  • Dorchies F.
  • Jacquet F.
  • Malka V.
  • Marques J. R.
  • Matthieussent G.
  • Miné P.
  • Modena A.
  • Mora P.
  • Morillo Joseph
  • Najmudin Z.
  , 1999, 472, pp.303-314. no abstract
• Acceleration of injected electrons in a laser wakefield experiment
  
  • Dorchies F.
  • Amiranoff François
  • Malka Victor
  • Marquès J. R.
  • Modena A.
  • Bernard D.
  • Jacquet F.
  • Miné Ph.
  • Cros B.
  • Matthieussent G.
  • Mora P.
  • Solodov A.
  • Morillo Joseph
  • Najmudin Z.
  Physics of Plasmas, American Institute of Physics, 1999, 6 (7), pp.2903. An electron plasma wave (EPW) has been excited by a short laser pulse (5 J, 400 fs) via the laser wakefield (LWF) mechanism. At the LWF quasi-resonance condition, the 3 MeV injected electrons have been accelerated with a maximum energy gain of 1.5 MeV. The maximum longitudinal electric field is estimated to be 1.5 GV/m. It has been observed that electrons deflected during the interaction, can scatter on the walls of the experimental chamber and fake a high energy signal. A special effort has been given in the electron detection to separate the accelerated electrons signal from the background noise. The experimental data are confirmed with numerical simulations, demonstrating that the energy gain is affected by the EPW radial electric field. The duration of the EPW inferred by the number of accelerated electrons and by the numerical simulations is of the order of 1–10 ps (10.1063/1.873248)
  DOI : 10.1063/1.873248
• Transient collisional excitation x-ray laser experiments on P102 laser at CEA-LV
  
  • Fourcade P.
  • Jamelot G.
  • Dorchies F.
  • Chanteloup J. C.
  • Miquel J. L.
  • Blanchot N.
  • Bonnet L.
  • Jacquemot S.
  • Klisnick A.
  • Kuba J.
  • Ros D.
  , 1999, 3776, pp.24-36. no abstract
• Temporal and Angular Resolution of the Ionization-Induced Refraction of a Short Laser Pulse in Helium Gas
  
  • Chessa P.
  • de Wispelaere E.
  • Dorchies F.
  • Malka Victor
  • Marquès J. R.
  • Hamoniaux G.
  • Mora P.
  • Amiranoff François
  Physical Review Letters, American Physical Society, 1999, 82 (3), pp.552. The refraction of a short and intense laser pulse focused in helium gas has been studied both experimentally and numerically. Using the time-frequency correspondence of a 120 fs laser pulse linearly chirped to 1.8 ps, the ionization-induced refraction is resolved both temporally and angularly. Two-dimensional numerical simulations are performed to calculate the laser propagation, from the focusing lens to the detector. With such a simulation, we get a quantitative agreement with the experiment, both for the refraction of the chirped pulse and for the ionization-induced blueshifted spectrum of the compressed pulse. (10.1103/PhysRevLett.82.552)
  DOI : 10.1103/PhysRevLett.82.552
• Monomode guiding of 10(16) W/cm(2) laser pulses over 100 Rayleigh lengths in hollow capillary dielectric tubes
  
  • Dorchies F.
  • Marques J. R.
  • Cros B.
  • Matthieussent G.
  • Courtois Cédric
  • Velikoroussov T.
  • Audebert P.
  • Geindre J. P.
  • Rebibo S.
  • Hamoniaux G.
  • Amiranoff François
  Physical Review Letters, American Physical Society, 1999, 82 (23), pp.4655-4658. no abstract