Magnetized Plasmas

In indirect-drive inertial confinement fusion experiments, high power laser beams interact within a hohlraum (a cylindrical gold can) to produce plasmas which radiate x-rays causing compression of a capsule located in the centre of the hohlraum. The production of magnetic fields in these situations can significantly affect the dynamics of the interaction. We have made the first detailed studies of such effects in multiple laser beam geometries using the VULCAN laser facility at the Rutherford Appleton Laboratory in the UK. We have characterized the ablation dynamics and plasma outflows using optical probing and have observed B-field null formation using rear-projection proton probing (see Figure 1). We have also measured strong electron heating via Thomson scattering. The plasma dynamics and estimated magnetic reconnection rates appear consistent with theoretical models. Further experiments are planned using the recently constructed OMEGA EP laser system at the Laboratory for Laser Energetics (LLE) at the University of Rochester. High energy ns pulse magnetized plasmas can require kinetic modeling, which we do using an implicit Vlasov-Fokker-Planck code.