  We derive the exact analytical solutions to the symmetron field theory
equations in the presence of a one or two mirror system in the case of a
spontaneously broken phase in vacuum as well as in matter. This complements a
similar analysis performed in a previous article [1], in which the symmetron is
in the spontaneously broken phase in vacuum but in the symmetric phase in
matter. Here again, the one dimensional equations of motion are integrated
exactly for both systems and their solutions are expressed in terms of Jacobi
elliptic functions. In the case of two parallel mirrors the equations of motion
provide also in this case a discrete set of solutions with increasing number of
nodes and energies. The solutions obtained herein can be applied to qBOUNCE
experiments, neutron interferometry and to the calculation of the symmetron
field induced "Casimir force" in the Cannex experiment and allow to extend the
investigation to hitherto unavailable regions in symmetron parameter space.
