Plasma and Shock Generation by Indirect Laser Pulse Action.

In the paper the results of our experiment with flyer disks, accelerated to high velocities by the PALS iodine laser and subsequently creating craters when hitting massive targets , are presented. We have carried out experiments with the double targets consisted of a disk placed in front of a massive target part at distances of either 200 or 500 μm. Both elements of the targets were made of Al. The following disk irradiation conditions were used: laser energy of 130 J, laser wavelength of 1.315 μm, pulse duration of 0.4 ns, and laser spot diameter of 250 μm. To measure some plasma parameters and accelerated disk velocity a three frame interferometric system was used. Efficiency of crater creation by a disk impact was determined from the crater parameters, which were obtained by means of a crater replica technique. The experimental results concern two main stages: (a) ablative plasma generation and disk acceleration and (b) disk impact and crater creation. Spatial density distributions at different moments of plasma generation and expansion are shown. Discussion of the experimental results on the basis of a 2-D theoretical model of the laser — solid target interaction is carried out. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]