Speaker
Description
Nanostructured targets significantly enhance laser-matter interaction by coupling the laser pulse into the target, due to the increased surface area, resulting in higher proton energy cut-off, yield, X-ray or gamma ray emission. However, enhanced coupling is highly dependent on the correlation of the target parameters to the laser pulse characteristics (as laser contrast, wavelength, and pulse duration). Therefore, the diameter and gap between the structures, along with their height and substrate thickness, were controlled via the target fabrication methods. Highly ordered metallic (gold and nickel) nanowires and nanotubes on thin substrates were used as targets for proton acceleration and x-ray emission studies. These targets were irradiated by the 1 PW HPLS from ELI-NP, ultra-short laser pulse, with an intensity of 1021W/cm2, using a single plasma mirror system for pulse cleaning. Radiochromic film stacks and a Thompson parabola were employed as ion diagnostics, and CsI scintillators for the electron and photon signal. An enhancement in the proton yield and in the photon signal, from the nanostructured targets, is discussed and presented, compared to that of flat targets, as well as the dependencies on the target characteristics.
