The Galactic Dynamo and Superbubbles
  In previous galactic dynamo theories of the origin of the magnetic field in
our galaxy, the subject of flux-freezing has been omitted. As a consequence,
the equation of mass flow has generally also been omitted, particularly in the
halo where the galactic gravitational field will operate on the mass flow. In
this paper it has been shown that this neglect could have serious consequences
for the results obtained from those galactic dynamo simulations that include
the halo. A modification of these dynamo theories is proposed which involves
the expulsion of very small bits of the magnetic field lines, rather than the
wholesale expulsion of the complete magnetic lines encapsulated in the previous
theories. This expulsion is accomplished by a spike instability that arises
from superbubbles, when they break out of the galactic disc and their shell
fragment. This leads to a {\it cut } in the lines of force that still remain in
the disc. Subsequently, normal disc turbulence rotates the {\it cut} lines and
thus dissipates their mean flux removing them from a role in the dynamo theory.
This new process takes a length of time comparable, but a little longer than
the previous growth time of the disc dynamo, but avoids the previous
difficulties associated with flux-freezing and flux expulsion.
