Two typical collective behaviors of the heavy ions expanding in cold
plasma with ambient magnetic field
Abstract
We have studied the evolution of the heavy ions that expand in a cold
background plasma. Two typical conditions are considered where only the
debris ion’s initial total mass is significantly different. The work
aims to illustrate the complex scaling behavior of the debris evolution
in the early time of the High Altitude Nuclear Explosions (HANE). The
simulation is performed via the hybrid model, in which the ions and
electrons are treated as classical particles and mass-less fluid,
respectively. Due to the imbalance of the electric and magnetic force on
the debris ions, these debris particles will evolve into different
collective patterns at the later times. These patterns manifest a rather
different stopping behavior of the debris ions and an opposite drifting
direction of the electron fluid. Further numerical and analytical
calculations demonstrate that the imbalance depends not only on the
number densities of the plasma ions, but also on the spatial variations
of the magnetic fields. Our work reveals that the behavior of the debris
ions scales non-linearly with their initial total mass, and this
non-linearity complicates the scaling from laser experiment to HANE.