Konstantin Zsukovszki

Abstract

Recent advancements theoretical research and experiments on laser-induced fusion demonstrate that resonating dopes in matter can significantly enhance absorption of laser radiation. This may have multiple applications; among them laser-driven inertial confinement fusion (ICF). Using a kinetic model, implemented in EPOCH numerical software, we simulate and study the interaction of laser pulses with hydrogen rich matter doped with gold nanoparticles of various shapes and sizes. We examine the response of such gold-doped matter to short, intense (~1018 W/cm²) bursts of infrared radiation (~800 nm, ~100 fs), and model the dynamics of electron ejection and ionization, as well as the energy transfer with focus on the energy of protons, which appear upon ionization of matter. Among various shapes, dipole and crossed antennas stand out for their resonance efficiency. Cross-based nanoantennas maintain resonance regardless of orientation, unlike dipole based antennas, which require alignment with the polarization vector E. The infrared laser intensity ~1017 - 1018 W/cm² yields best results in terms of ion energy. The gain in the ion energy over that in the field 4×1015 W/cm² is more than an order-of-magnitude. Further increase of the laser field intensity over ~4×1018 W/cm² does not yield significant energy gain for protons. Energy saturation is observed due to ejection of conduction electrons, disrupting the antenna resonance. Our theoretical results for dipole antenna dopes agree with the experiments, conducted at ELI-ALPs laboratories at Szeged (HU), confirming their validity. We have identified the double 3D crossed sextuples as most energy efficient nanoantenna; the Yagi-based nanoantennas also provide high energy for protons, exceeding three times the ion energy around dipole antennas. These advanced antenna configurations especially in the close placement enhance the near field between them and prove to be most efficient at producing high-energy protons at high intensities, outperforming optimally aligned dipoles. Our discoveries suggest that nanoantenna doping optimizes energy absorption in laser- matter interactions, making crossed quadrupoles especially in 3D configuration and paired placement a promising candidate for enhancing ICF fuel ignition and other high-intensity laser applications.