Development of ultra-low density foam targets for laser–plasma interaction studies

The use of ultra-low density targets in high-power laser–solid interactions has gained attention due to their potential to enhance laser-driven ion acceleration by facilitating near-critical density plasma formation. This work presents a fabrication methodology for ultra-low-density carbon foam targets deposited on thin aluminum foils, characterized via x-ray photoelectron spectroscopy, scanning electron microscopy, and Rutherford backscattering. The influence of ultra-low density carbon on the ablation dynamics was examined by irradiating it with ultrashort laser pulses reaching an intensity of 1013 W cm−2. Fast gated imaging and cylindrical Langmuir probe diagnostics revealed enhanced plasma kinetic energy for foam-coated targets. Complementary two-dimensional hydrodynamic simulations corroborated with experimental findings validate the behavior of the ultra-low density layer, confirming the plasma density, expansion velocity, and the temporal evolution of the plasma plume as observed through intensified CCD fast camera imaging and Langmuir probe methods.