Hot electron jets from femtosecond heated plasmas at intensities of 10$^{16}$–10$^{17}$ W/cm$^{2}$

Solid target experiments carried out on copper targets with both p- and s-polarized 130 fs Ti:Sapphire laser pulses at intensities of 3 x 10 16 W/cm 2 indicate the presence of hot electron jets with electron energies of 80 to over 250 keV and cone angles of the order of 10 degrees at the higher energies with directions dependent on the incident polarization. For comparison, studies on an Argon cluster jet targets with 50 fs duration Ti:Sapphire laser pulses at vacuum intensity of 10 17 W/cm 2 indicated no detectable hot electron jet emission with electron energies above 50 keV. A 2D PIC simulation of the p-polarized solid target interaction predicts features similar to those observed experimentally.