Laser-driven proton acceleration in nanoantenna-doped media: toward nuclear nanofusion

• We demonstrate a plasmon-assisted regime of laser-driven proton acceleration in which metallic nanoantennas embedded in hydrogen-rich matter generate localized electric fields exceeding 10 12 –10 13 V/m. • Optimized paired 3λ/2 three-dimensional crossed antennas driven by femtosecond laser pulses at ∼ 10 18 W/cm 2 produce proton energies approaching 0.6 MeV • Plasmon assisted proton and ion acceleration paves road to nuclear-reactions. Plasmonic nanoantennas embedded in hydrogen-rich media can strongly enhance laser-driven proton acceleration through localized near-field amplification and nanoscale sheath formation. Particle-in-cell simulations performed with the EPOCH PIC Code show that optimized paired 3λ/2 three-dimensional crossed antennas irradiated at ∼ 10 18 W/cm 2 generate proton energies up to ∼ 0.6 MeV, significantly exceeding the performance of conventional dipole nanoantennas. Surface plasmon excitation on dipole, crossed, and three-dimensional crossed antennas is analyzed comparatively. Plasmon-enhanced energy absorption and near-field localization vary strongly with antenna geometry. Proton acceleration exceeds the limits observed in the absence of nanoantenna structures. Proton energies saturate at ∼ 0.12 MeV for dipoles under ≥ 10 18 W/cm 2 irradiation, but reach 0.2–0.25 MeV for crossed and 3D-crossed antennas, ∼0.4 MeV for paired 3D crosses, and up to ∼ 0.6 MeV for paired 3λ/2-scale 3D-cross antennas under the same conditions. Comparison with available experimental trends from Extreme Light Infrastructure Attosecond Light Pulse Source (ELI-ALPS) supports the validity of the model. Our results demonstrate that engineered plasmonic resonances in nanostructured media provide a pathway toward nanoscale laser-driven fusion by enabling proton energies approaching relevant nuclear-reaction thresholds.