Magnetohydrodynamic Modeling of Diffusive Megagauss Magnetic Fields Generated in Plasma

The spatial and temporal dynamics of a self-generated magnetic field (SMF) in plasma is investigated within the framework of electron magnetohydrodynamics. The equation that governs the generation and evolution of the diffusive magnetic field is solved as an initial value problem for a general source that includes both thermal and radiative sources and by accounting for retardation effects. Analytical expressions for the space-time development of the SMF are obtained in a closed form for both bounded plasmas and plasmas of infinite extent. For a typical laser-produced plasma, using an oscillating Gaussian source with a source strength equal to that of the thermoelectric source, numerical results show generated fields of magnitudes just about 10 MG.