Effects of Laser Polarization on Jet Emission of Fast Electrons in Femtosecond-Laser Plasmas

Abstract

Effects of laser polarization on fast electron emission are studied from an aluminum target irradiated by ultrashort laser pulses at 2 3 10 16 W͞cm 2 . Jet emission of outgoing fast electrons collimated in the polarization direction is observed for s-polarized laser irradiation, whereas for p-polarized irradiation highly directional emission of outgoing fast electrons is found in the direction close to the normal of the target. The behavior of ingoing fast electrons into the target for s-and p-polarized irradiation is also investigated by observing x-ray bremsstrahlung radiation at the backside of the target.

Collimated hot electron jets generated from subwavelength grating targets irradiated by intense short-pulse laser

“…[11][12][13][14] These were attributed to the laser excited bulk plasma wave and quasisteady magnetic field. 12,13,15 A low-density corona plasma, very steep gradient scale length, and a very regular flat plasma surface are simultaneously required to generate such hot electron jets.…”

Generation of surface electrons in femtosecond laser-solid interactions

“…The intensity of the hot electrons flowing along the target surface is comparable or even larger than the other two bunches of electrons. The emission characteristics of the hot electrons in the laser plasma interactions depend on the laser intensity [10] , polarization [1] , the density scale length of the plasma [8,11] , etc. In our experiments, the p-polarized laser was focused on the solid target with an intensity of 6×10 17 W/cm 2 .…”

“…Collimated electron beams in the target normal direction and the laser specular direction have been observed under the non-relativistic laser conditions [1][2][3][4] . In the relativistic regime, hot electron bunches with maximum energy of tens of MeV are observed in the target normal direction and the laser propagation direction during the laser-solid interactions [5][6][7][8] .…”

A novel single-shot, spectrally resolved x-ray imaging technique of ICF relevant plasmas

“…This is an important feature of the technique, even in view of the fact that the Bremsstrahlung emission is related to the fast electron beam transport. [37][38][39] As an example, figure 5 (right) shows the 2D image of the emitting source at photon energies E ph > E Kβ .…”