Experimental study of laser penetration in overdense plasmas at relativistic intensities. I: Hole boring through preformed plasmas layers

Abstract

Propagation of a high-contrast subpicosecond ͑400-600 fs͒ relativistic (I 2 up to 2ϫ10 19 W•cm Ϫ2•m 2 ) laser pulse through long preformed overdense plasmas is experimentally studied. Transmission values up to 10% are measured in plasmas with initial peak densities above 10 ϫn c . We compare these results with one-dimensional ͑1D͒ analytical calculations of the hole boring effect. It is shown that the ponderomotive force of the laser beam can push forward the overdense plasma, create a channel, and lead to transmission levels similar to the experimental ones.

Experimental study of laser penetration in overdense plasmas at relativistic intensities. II: Explosion of thin foils by laser driven fast electrons

“…29 As shown in Fig. 10͑b͒, a reduction of the pulse duration by a factor of 2 3 could correspond to the bottom spectrum of Fig. 10͑a͒.…”

“…A description of the 35 TW short-pulse beam we use has been given in the companion paper. 2 Here we will focus on a specific analysis of its contrast ratio in time and on the diagnostics used for this experiment.…”

Comparison of Two Theories for the Relativistic Self Focusing of Laser Beams in Plasma

“…When the power of the beam is very high, then it causes an electron oscillatory velocity comparable to the velocity of light, which modifies the effective dielectric constant of plasma and hence affects the self-focusing of the beam. Relativistic laser plasma interactions have been studied in detail by many workers both theoretically [6][7] and experimentally [8][9][10] and reviewed thoroughly [11][12]. Three dimensional particle in cell (3D PIC) simulations for laser pulse propagation in near critical underdense plasma far above the threshold for relativistic filamentation have also been reported [13].…”

Dynamics of Gaussian spikes on Gaussian laser beam in relativistic plasma

“…The self-focusing is due to the relativistic mass increase of plasma electrons. Relativistic laser-plasma interaction has been studied in detail by many authors, both theoretically (Kruer, 2000;Osman et al, 1999) and experimentally (Tanaka et al, 2000;Fuchs et al, 1999;Monot et al, 1995), and reviewed thoroughly (Umstadter, 2003;Gibbon & Forster, 1996). Nonlinear processes, playing key role in the generation of new ion sources has been recently reported (Laska et al, 2007;Torrisi et al, 2008;Strangio et al, 2007).…”