  Non-linear effects have become increasingly relevant in modern circular
particle accelerators, and in recent years a change of paradigm has appeared,
the attitude towards nonlinear effects having shifted from fighting them to
exploiting them with the goal of devising new beam manipulations, such as the
splitting of the beam in the transverse phase space by crossing a stable
resonance. In the field of hadron accelerators, well-established operational
techniques based on nonlinear effects exist, whereas for the case of
synchrotron light sources these new techniques are only beginning their way
into the field. In this paper, we discuss novel techniques aimed at providing
split beams in synchrotron light sources that are obtained by using stable
islands in the transverse phase space or unsplit beams with AC dipoles to
generate periodic closed orbits. The results of detailed numerical simulations,
which support the proposed methods, are presented and discussed in this paper,
together with possible applications.
