Interaction of ISI smoothed laser beams with low-density supercritical foam targets at AEEF ABC facility

Abstract

The results of a preliminary experiment on laser foam interaction performed at the ABC installation of the Associazione EURATOM-ENEA sulla Fusione are presented. Plastic foams with density of 5 - 20 mg/cm3 were irradiated with light produced from the neodymium laser of ABC (λ = 1.054 μm) and processed through a proper optical system to produce near field ISI smoothed radiation at ≈1013W/cm2 on the target. The use of a smoothed beam was essential to detect in the plasma and in the accelerated dense phase evolving features related to the target foam structure without mixing with those of the irradiating beam. Structures in the plasma corona and in the dense phase were detected by optical shadography of foam slabs. In the same experiment time-dependent transmission of laser light through slabs of foams was measured by target imaging and masking on a photodiode (bandwidth of the system 5 GHz).