  A perfectly reflecting (Dirichlet) boundary condition at the edge of an
impenetrable magnetic-flux-carrying tube of nonzero transverse size is imposed
on the charged massive scalar matter field which is quantized outside the tube.
We show that the vacuum polarization effects outside the tube give rise to a
macroscopic force acting at the increase of the tube radius (if the magnetic
flux is held steady). The Casimir energy and force are periodic in the value of
the magnetic flux, being independent of the coupling to the space-time
curvature scalar. We conclude that a topological defect of the vortex type can
polarize the vacuum of only those quantum fields that have masses which are
much less than a scale of the spontaneous symmetry breaking.
