In this contribution, we present the result of an investigation of foam-based targets for laser-driven ion acceleration. The study was performed in collaboration between the Laser-Particle Acceleration group at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the Nanolab group at Politecnico di Milano.
Foam targets used in this experiment are composed of µm-thick solid foils with ultra-low density carbon coating (thickness ~ 4-16 µm, density ~ 0.01 g/cm^3). Foam production and characterization were performed by the Nanolab group using specially developed techniques . Further characterization of the foam density, composition and nanostructure was performed at HZDR. Previous experiments demonstrated an enhancement of ion acceleration performances for foam targets, with a significant increase in the energy and number of accelerated protons with respect to uncoated metal foils in a wide range of laser intensities (5x10^16 – 4x10^20/cm2). This enhancement was attributed to the increased absorption of laser energy in the near-critical plasma produced by the laser-foam interaction, even though a significant role was played by the foam nanostructure, as shown by PIC-simulations .
Here, we present the results of an experimental campaign performed at DRACO 150 TW (HZDR) aimed at achieving a better understanding of the absorption physics and role of foam nanostructure. The effect of laser illumination in the region surrounding the interaction site and neighbouring targets was also investigated in this campaign, as the mechanical properties of cluster assembled foams highlights target damage due to the heat wave and debris produced in laser-matter interaction and laser reflections from the target holder.
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Prencipe, I., et al. "Development of foam-based layered targets for laser-driven ion beam production." Plasma Physics and Controlled Fusion 58.3 (2016): 034019.
Passoni, M., et al. "Toward high-energy laser-driven ion beams: Nanostructured double-layer targets." Physical Review Accelerators and Beams 19.6 (2016): 061301.
|Working group||Laser-driven ion acceleration|