DAFNE injection system upgrade

High luminosity in DAFNE needs very high electron and positron currents stored. A full energy (510 MeV) injection system composed by a full energy electron and positron linac and an accumulator-damping ring is presently used. The electron and positron beams, alternatively accelerated by the linac, are injected and stacked in the accumulator with high efficiency thanks to its large acceptance and short damping time. The damped beams are extracted and transferred to the main ring through a long transfer line that has been built inside already existing buildings. The refill time of the collider is limited by the transfer line set-up change between the two different beams modes. In this paper a transfer line modification is proposed in order to reduce the switch time. A possible injection scheme for the main rings is also described.