Acceleration of injected electrons in a laser wakefield experiment

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.

[1]  Thomas M. Antonsen,et al.  Laser wakefield: Experimental study of nonlinear radial electron oscillations , 1998 .

[2]  Nakajima,et al.  Observation of ultrahigh gradient electron acceleration by a self-modulated intense short laser pulse. , 1995, Physical review letters.

[3]  N. Ebrahim.  OPTICAL MIXING OF LASER LIGHT IN A PLASMA AND ELECTRON ACCELERATION BY RELATIVISTIC ELECTRON PLASMA WAVES , 1994 .

[4]  Joyce,et al.  Propagation and guiding of intense laser pulses in plasmas. , 1992, Physical review letters.

[5]  Zulfikar Najmudin,et al.  Observation of Electron Energies Beyond the Linear Dephasing Limit from a Laser-Excited Relativistic Plasma Wave , 1998 .

[6]  G. Matthieussent,et al.  Coupling between electron and ion waves in Nd‐laser beat‐wave experiments , 1994 .

[7]  T. Tajima,et al.  Laser Electron Accelerator , 1979 .

[8]  Dyson,et al.  Ultrahigh-gradient acceleration of injected eletrons by laser-excited relativistic electron plasma waves. , 1993, Physical review letters.

[9]  N. Andreev,et al.  Resonant excitation of wakefields by a laser pulse in a plasma , 1992 .

[10]  Clayton,et al.  Propagation of intense subpicosecond laser pulses through underdense plasmas. , 1995, Physical review letters.

[11]  Thomas M. Antonsen,et al.  Kinetic modeling of intense, short laser pulses propagating in tenuous plasmas , 1997 .

[12]  White,et al.  Subpicosecond, electromagnetic pulses from intense laser-plasma interaction. , 1993, Physical review letters.

[13]  Gauthier,et al.  Temporal and spatial measurements of the electron density perturbation produced in the wake of an ultrashort laser pulse. , 1996, Physical review letters.

[14]  D. Rogers,et al.  EGS4 code system , 1985 .

[15]  Electron acceleration in a relativistic electron plasma wave , 1989 .

[16]  Eric H. Esarey,et al.  Laser wakefield acceleration and relativistic optical guiding , 1988 .

[17]  Thomas M. Antonsen,et al.  Self-focusing and Raman scattering of laser pulses in tenuous plasmas. , 1992 .

[18]  D. Meyerhofer,et al.  Tunneling ionization of noble gases in a high-intensity laser field. , 1989, Physical review letters.

[19]  Acceleration and scattering of injected electrons in plasma beat wave accelerator experiments , 1994 .

[20]  G. Mourou,et al.  Nonlinear Optics in Relativistic Plasmas and Laser Wake Field Acceleration of Electrons , 1996, Science.

[21]  S. P. Le Blanc,et al.  Laser wakefield excitation and measurement by femtosecond longitudinal interferometry , 1996, Summaries of papers presented at the Conference on Lasers and Electro-Optics.

[22]  G. Matthieussent,et al.  The plasma beat-wave acceleration experiment at Ecole Polytechnique , 1995 .

[23]  Eric Esarey,et al.  Overview of plasma-based accelerator concepts , 1996 .

[24]  G. Matthieussent,et al.  A summary of the beat-wave experiments at Ecole Polytechnique , 1996 .

[25]  Matsumoto,et al.  Beat-wave excitation of plasma wave and observation of accelerated electrons. , 1992, Physical review letters.

[26]  A. E. Dangor,et al.  Electron acceleration from the breaking of relativistic plasma waves , 1995, Nature.