Investigating the role of magnetic flux compression in the formation of helical structures in axially magnetized implosions

Helical structures have been observed in axially magnetized liner implosions on the Z facility despite the azimuthal driving magnetic field being orders of magnitude larger than the applied axial magnetic field. One hypothesis to explain this result is magnetic flux is compressed by low density plasma against the surface of the target, resulting in an axial field that is much larger than the applied value. To test this hypothesis, experiments were conducted with a smaller volume of available flux, which simulations indicated would reduce the axial component of the magnetic field at the target surface. A comparison of the observed helical structures between the two cases will be presented.