  We construct an efficient zero-temperature semi-local density functional to
dynamically simulate an electron bubble passing through superfluid 4He under
various pressures and electric fields up to nanosecond timescale. Our simulated
drift velocity can be quantitatively compared to experiments particularly when
pressure approaches zero. We find that the high-speed bubble experiences
remarkable expansion and deformation before vortex nucleation occurs.
Accompanied by vortex-ring shedding, drastic surface vibration is generated
leading to intense phonon radiation into the liquid. The amount of energy
dissipated by these phonons is found to be greater than the amount carried away
solely by the vortex rings. These results may enrich our understanding about
the vortex nucleation induced energy dissipation in this fascinating system.
