Peculiar properties of hot plasma formation under the influence of intense femtosecond pulses on the surface of molten metal

Femtosecond laser-plasma interaction with prepulse-generated liquid metal microjets

“…2 A significant absorption of the s-polarized laser pulses indicates a strong modification of the target surface. In our previous study, we already observed a local recession of melted Ga level in the vicinity of the focal spot, while the mean melt level was the same, 17 i.e., a small crater is formed in the interaction area under the effect of a sequence of laser pulses and the local surface becomes curved. Another phenomenon that could lead to enhanced absorption is surface rippling due to the laser prepulse.…”

“…For instance, a melted gallium target exhibited exceptionally good stability and enhanced hard x-ray yield compared with solid targets. 16,17 Liquid metal jets 19,20 have also been examined for x-ray production with ps/fs laser pulses. Quite high efficiency along with average-stable long-term operation was demonstrated.…”

“…This difficulty motivates the search for other solid target designs: rotating disks and cylinders, running wires, cluster jet targets, etc. [7][8][9][10][11] In addition, liquid targets have been tested: water, 12 mercury, 13 vacuum oil, 14 and melted gallium, [15][16][17] indium, and bismuth. 17,18 The key advantage of a liquid target is the rapid "self-healing" ability of the liquid-vacuum interface after each laser pulse.…”