Magnetic field amplification in relativistic-laser-driven implosion of a preformed cylindrical shock wave structure in a gas*

Laser-driven generation and amplification of quasistatic magnetic fields have seen an increased interest in the last few years. Using three-dimensional particle-in-cell simulations, we demonstrate the amplification of a seed magnetic field in a converging cylindrical shock-wave structure at gas densities. The shock wave is formed by ionizing a gas jet with a structured laser beam of sub-relativistic intensity (high-order Bessel beam at 10¹⁵ W/cm²) and subsequently heated by a relativistic-intensity laser pulse (>10¹⁸ W/cm² at 800 nm wavelength). Our simulation results suggest that considerable enhancement of magnetic fields may be possible with this renewable, debris-free approach.