Interaction of a smoothed laser beam with supercritical-density porous targets on the ABC facility

• Published in: Quantum electronics (Woodbury, N.Y.) Vol. 36; no. 5; pp. 424 - 428
• Main Authors: Strangio, C, Caruso, A, Gus'kov, Sergei Yu, Rozanov, Vladislav B, Rupasov, A A
• Format: Journal Article
• Language: English
• Published: United States IOP Publishing 31.05.2006
• Subjects: BEAMS; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CROSS SECTIONS; DENSITY; ELECTROMAGNETIC RADIATION; LASER RADIATION; LASER TARGETS; LASERS; LIGHT TRANSMISSION; MATERIALS; NEODYMIUM LASERS; OPTICAL SYSTEMS; ORGANIC COMPOUNDS; ORGANIC POLYMERS; PETROCHEMICALS; PETROLEUM PRODUCTS; PHOTOGRAPHY; PHOTON BEAMS; PHYSICAL PROPERTIES; PLASMA; PLASTICS; POLYMERS; POROUS MATERIALS; RADIATIONS; SOLID STATE LASERS; SYNTHETIC MATERIALS; TARGETS; TIME DEPENDENCE; TRANSMISSION
• DOI: 10.1070/QE2006v036n05ABEH013241
• ISSN: 1063-7818

We present the results of experiments on the interaction of laser radiation with low-density porous targets performed on the ABC facility at the ENEA Research Centre (Frascati, Italy). Porous plastic targets with densities of 5 and 20 mg cm{sup -3} were irradiated by a focused neodymium-laser beam at the fundamental frequency ({lambda} = 1.054 {mu}m) at a radiation intensity of 10{sup 13} W cm{sup -2} at the target. The beam was preliminarily allowed to pass through an optical system intended to spatially smooth the radiation intensity over the beam cross section. The use a smoothed beam was important to discover in the plasma and in the accelerated dense material the features related to the porous structure of the target under conditions which rule out the effect of the inhomogeneities of the heating beam itself. The spatial plasma structure in the laser beam-target interaction region and at the rear side of the target were investigated by using optical schlieren plasma photography. The time dependent transmission of the laser radiation through the target was also investigated by imaging the target in transmitted radiation to a properly masked photodiode. (interaction of laser radiation with matter. laser plasma)