Physics
Scientific paper
Mar 2012
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012njph...14c3025k&link_type=abstract
New Journal of Physics, Volume 14, Issue 3, pp. 033025 (2012).
Physics
Scientific paper
Recent experiments with 100 terawatt-class, sub-50 femtosecond laser pulses show that electrons self-injected into a laser-driven electron density bubble can be accelerated above 0.5 gigaelectronvolt energy in a sub-centimetre-length rarefied plasma. To reach this energy range, electrons must ultimately outrun the bubble and exit the accelerating phase; this, however, does not ensure high beam quality. Wake excitation increases the laser pulse bandwidth by red-shifting its head, keeping the tail unshifted. Anomalous group velocity dispersion of radiation in plasma slows down the red-shifted head, compressing the pulse into a few-cycle-long piston of relativistic intensity. Pulse transformation into a piston causes continuous expansion of the bubble, trapping copious numbers of unwanted electrons (dark current) and producing a poorly collimated, polychromatic energy tail, completely dominating the electron spectrum at the dephasing limit. The process of piston formation can be mitigated by using a broad-bandwidth (corresponding to a few-cycle transform-limited duration), negatively chirped pulse. Initial blue-shift of the pulse leading edge compensates for the nonlinear frequency red-shift and delays the piston formation, thus significantly suppressing the dark current, making the leading quasi-monoenergetic bunch the dominant feature of the electron spectrum near dephasing. This method of dark current control may be feasible for future experiments with ultrahigh-bandwidth, multi-joule laser pulses.
Beck Alexander
Davoine X.
Kalmykov Yu. S.
Lefebvre Eric
Shadwick B. A.
No associations
LandOfFree
Laser plasma acceleration with a negatively chirped pulse: all-optical control over dark current in the blowout regime does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Laser plasma acceleration with a negatively chirped pulse: all-optical control over dark current in the blowout regime, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Laser plasma acceleration with a negatively chirped pulse: all-optical control over dark current in the blowout regime will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1057774