Electron-yield enhancement in a laser-wakefield accelerator driven by asymmetric laser pulses.
The effect of asymmetric laser pulses on electron yield from a laser wakefield accelerator has been experimentally studied using >10(19) cm(-3) plasmas and a 10 TW, >45 fs, Ti:Al2O3 laser. The laser pulse shape was controlled through nonlinear chirp with a grating pair compressor. Pulses (76 fs FWHM) with a steep rise and positive chirp were found to significantly enhance the electron yield compared to pulses with a gentle rise and negative chirp. Theory and simulation show that fast rising pulses can generate larger amplitude wakes that seed the growth of the self-modulation instability, and that frequency chirp is of minimal importance for the experimental parameters.
Leemans
W P
WP
Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA.
Catravas
P
P
Esarey
E
E
Geddes
C G R
CG
Toth
C
C
Trines
R
R
Schroeder
C B
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Shadwick
B A
BA
Van Tilborg
J
J
Faure
J
J