Powerful nanosecond laser-plasma processes are explored to generate discharge currents of a few 100 kA in coil targets, yielding magnetostatic fields (B-fields) in excess of 0.5 kT. The quasi-static currents are provided from hot electron ejection from the laser-irradiated surface. According to our model, which describes the evolution of the discharge current, the major control parameter is the laser irradiance $I_{\text{las}}{\lambda }_{\text{las}}^2$ . The space-time evolution of the B-fields is experimentally characterized by high-frequency bandwidth B-dot probes and proton-deflectometry measurements. The magnetic pulses, of ns-scale, are long enough to magnetize secondary targets through resistive diffusion. We applied it in experiments of laser-generated relativistic electron transport through solid dielectric targets, yielding an unprecedented 5-fold enhancement of the energy-density flux at 60 μm depth, compared to unmagnetized transport conditions. These studies pave the ground for magnetized high-energy density physics investigations, related to laser-generated secondary sources of radiation and/or high-energy particles and their transport, to high-gain fusion energy schemes, and to laboratory astrophysics.

A simple setup for the generation of ultra-intense quasistatic magnetic fields, based on the generation of electron currents with a predefined geometry in a curved snail (or ‘escargot’) target, is proposed and analyzed. Particle-in-cell simulations and qualitative estimates show that gigagauss scale magnetic fields may be obtained with existent laser facilities. The described mechanism of the strong magnetic field generation may be useful in a wide range of applications, from laboratory astrophysics to magnetized inertial confinement fusion schemes.

Magnetic reconnection in a relativistic electron magnetization regime was observed in a laboratory plasma produced by a high-intensity, large energy, picoseconds laser pulse. Magnetic reconnection conditions realized with a laser-driven several kilotesla magnetic field is comparable to that in the accretion disk corona of black hole systems, i.e., Cygnus X-1. We observed particle energy distributions of reconnection outflow jets, which possess a power-law component in a high-energy range. The hardness of the observed spectra could explain the hard-state x-ray emission from accreting black hole systems.

Strong electromagnetic pulses (EMPs) are generated from intense laser interactions with solid-density targets and can be guided by the target geometry, specifically through conductive connections to the ground. We present an experimental characterization by time- and spatial-resolved proton deflectometry of guided electromagnetic discharge pulses along wires including a coil, driven by 0.5 ps, 50 J, 10¹⁹ W/cm² laser pulses. Proton-deflectometry allows us to time-resolve first the EMP due to the laser-driven target charging and then the return EMP from the ground through the conductive target stalk. Both EMPs have a typical duration of tens of ps and correspond to currents in the kA-range with electric-field amplitudes of multiple GV/m. The sub-mm coil in the target rod creates lensing effects on probing protons due to both magnetic- and electric-field contributions. This way, protons of the 10 MeV-energy range are focused over cm-scale distances. Experimental results are supported by analytical modeling and high-resolution numerical particle-in-cell simulations, unraveling the likely presence of a surface plasma, in which parameters define the discharge pulse dispersion in the non-linear propagation regime.

The rate of linear collisionless damping (Landau damping) in a classical electron gas confined to a heated ionized thin film is calculated. The general expression for the imaginary part of the dielectric tensor in terms of the parameters of the single-particle self-consistent electron potential is obtained. For the case of a deep rectangular well, it is explicitly calculated as a function of the electron temperature in the two limiting cases of specular and diffuse reflection of the electrons from the boundary of the self-consistent potential. For realistic experimental parameters, the contribution of Landau damping to the heating of the electron subsystem is estimated. It is shown that for films with a thickness below about 100 nm and for moderate laser intensities it may be comparable with or even dominate over electron-ion collisions and inner ionization.