학술논문

Unstable longitudinal expansion of plasma foils accelerated by circularly polarized laser pulses in non-transparent regimes.
Document Type
Article
Source
Physics of Plasmas. Oct2019, Vol. 26 Issue 10, pN.PAG-N.PAG. 9p. 5 Graphs.
Subject
*LASER pulses
*PONDEROMOTIVE force
*RELATIVISTIC electrons
*ATTOSECOND pulses
*ULTRA-short pulsed lasers
Language
ISSN
1070-664X
Abstract
Relativistic opaqueness has been considered to be a sufficient condition for the stable compression and acceleration of a negligibly thin plasma foil by a circularly polarized laser pulse. However, in our simulations, we observed that finite-thick plasma foils, which are still relativistically nontransparent to the laser pulse, can be subject to sudden and rapid expansion of the foil even when the pulse intensity is expected to be high enough to suppress the electrostatic Coulomb expansion. Analyzing the "distribution" of the ponderomotive force over the finite thickness of a slab-like foil, we found a theoretical condition to avoid the new expansion mechanism. Relations between this expansion and the relativistic electron heating and self-induced transparency are discussed. [ABSTRACT FROM AUTHOR]