Volume 107, Number 4, August 2014
|Number of page(s)||6|
|Section||Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics|
|Published online||25 August 2014|
Dynamics of the wakefield of a multi-petawatt, femtosecond laser pulse in a configuration with ultrarelativistic electrons
1 Institute of Physics, University of Belgrade - Pregrevica 118, 11080 Belgrade (Zemun), Serbia
2 Dipartimento di Fisica, Università di Napoli “Federico II”, Complesso Universitario di M.S. Angelo - Napoli, Italy
3 INFN Sezione di Napoli - Napoli, Italy
4 Texas A&M University at Qatar - P.O. Box 23874 Doha, Qatar
Received: 13 January 2014
Accepted: 4 August 2014
The wakefield excitation in an unmagnetized plasma by a multi-petawatt, femtosecond, pancake-shaped laser pulse is described both analytically and numerically in the regime with ultrarelativistic electron jitter velocities, when the plasma electrons are almost expelled from the pulse region. This is done, for the first time, in fluid theory, using a novel mathematical model that does not break down for very intense pump strengths, in contrast to the standard approach that uses the laser field envelope and the ponderomotive guiding center averaging. A three-timescale description is introduced, with the intermediate scale associated with the nonlinear phase of the electromagnetic wave and with the bending of its wave front. The evolution of the pulse and of its electrostatic wake are studied by the numerical solution in a two-dimensional geometry, with the spot diameter . It has revealed that the nonlocal plasma response stretches very short pulses and that those with the length of 1–2 laser wavelengths, favored by the analytic estimates obtained in the local limit, are unstable. The optimum initial pulse length exceeds .
PACS: 41.75.Jv – Laser-driven acceleration / 52.38.-r – Laser-plasma interactions / 52.35.Mw – Nonlinear phenomena: waves, wave propagation, and other interactions (including parametric effects, mode coupling, ponderomotive effects, etc.)
© EPLA, 2014
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.