Laser Irradiated Foam Targets: Absorption and Radiative Properties

Martina Salvadori,Martina Salvadori,Mattia Cipriani,Giorgio Di Giorgio,Danilo Giulietti,Alexander A Rupasov,Pier Luigi Andreoli,Giuseppe Cristofari,Riccardo De Angelis,Fabrizio Consoli,Sergey Yu Gus’Kov,Francesco Ingenito,L Torrisi,M Cutroneo

doi:10.1051/epjconf/201816705003

Abstract

An experimental campaign to characterize the laser radiation absorption of foam targets and the subsequent emission of radiation from the produced plasma was carried out in the ABC facility of the ENEA Research Center in Frascati (Rome). Different targets have been used: plastic in solid or foam state and aluminum targets. The activated different diagnostics allowed to evaluate the plasma temperature, the density distribution, the fast particle spectrum and the yield of the X-Ray radiation emitted by the plasma for the different targets. These results confirm the foam homogenization action on laser-plasma interaction, mainly attributable to the volume absorption of the laser radiation propagating in such structured materials. These results were compared with simulation absorption models of the laser propagating into a foam target.

Highlights

Porous materials of light elements consist of randomly distributed solid fibers or membranes, with transversal size b0 in the range of few microns up to hundreds of microns, separated by voids of similar dimensions
According to their pore size δ0, these materials can be divided in two groups, large pore foams and small pore foams
The first one comprehends porous plastics ([CH]n, [CH2]n), porous Beryllium and agar-agar (C12H18O9), with pore size and thickness of solid elements ranging from 30μm to 100μm and from 0.1 to 1μm respectively; cellulose triacetate (C12H16O8) and trimethylolpropane triacrylate (C15H20O6) are in the small pore group, with pore size ranging from 1 to 10μm and the thickness of solid elements from 0.01 to 0.1μm

Summary

Introduction

Porous materials of light elements consist of randomly distributed solid fibers or membranes, with transversal size b0 in the range of few microns up to hundreds of microns, separated by voids of similar dimensions. According to their pore size δ0, these materials can be divided in two groups, large pore foams and small pore foams. The average density of foams can vary from few mg/cm to several hundreds. This wide variety in characteristic dimensions leads to different behavior under laser irradiation. According to their initial average density ρa, corresponding to an electron density ne

Objectives

Methods

Results

Conclusion