Abstract
Strong magnetic fields (B > 10⁴ T) have been measured in previous experiments involving interactions between intense pulsed lasers and solid-density foil targets. These fields are generated by the expanding flow of hot electrons and are related to the formation of electric sheaths used in ion acceleration studies. Such fields have also been employed in fundamental plasma physics investigations, including relativistic magnetic reconnection and magnetised shocks.
Here, the electric and magnetic fields generated on the surface of a dense plasma by hot electrons are analysed using relativistic fluid theory applied to quasi-steady-state solutions. Both isothermal and isentropic models are considered, together with conservation laws for electron flows expressed in terms of the four-potential and specific enthalpy.
Analytic solutions for the electric and magnetic field profiles are obtained and compared with particle-in-cell simulations, showing good agreement. The model clearly delineates regimes of electron refluxing and surface confinement. These results are relevant to ion acceleration and the generation of strong magnetic fields in laser-plasma interactions.