Hall Effects during Spherical Laser-Plasma Cloud Expansion into a Magnetized Background Plasma (Laboratory Experiments and Numerical Simulations)

We report a comprehensive study of Hall effects during the sub-Alfvén expansion of a spherical plasma cloud into a magnetized background plasma in the weakly magnetized ion regime. A laboratory experiment on the KI-1 large-scale laser-plasma facility and kinetic numerical simulations using the IPIC3D hybrid code demonstrate that the Hall effects are suppressed with increasing background plasma concentration, yielding good agreement between the experiment and simulations. This is evident in the nature and rate of magnetic field re-penetration into the displaced volume during the diamagnetic cavity collapse phase.