Synchronization between Linac4 and the PS Booster

Linac4 will be equipped with a low energy chopper and an energy modulation system to tailor the beam structure to the needs of the PS Booster. This allows optimizing the PS Booster machine performance and reducing beam losses around the injection. In particular, an active longitudinal painting scheme becomes possible for the most demanding high brightness and high intensity beams. This implies that an interface between the low level RF systems of the two machines has to be designed carefully to make sure that the beam generated by Linac4 suits the challenging timing requirements. This reports summarizes the requirements from the Booster side to make full use of the possibilities provided by the chopper and the energy ramping system. Functional descriptions of possible interfaces between the two machines involved are sketched and the arguments to choose one of the schemes as baseline for implementation are given.