  Observations have shown that the Sun's magnetic field has helical structures.
The helicity content in magnetic field configurations is a crucial constraint
on the dynamical evolution of the system. Since helicity is connected with the
number of links we investigate configurations with interlocked magnetic flux
rings and one with unlinked rings. It turns out that it is not the linking of
the tubes which affects the magnetic field decay, but the content of magnetic
helicity.
