The concept of the RF phase reference distribution system for SINBAD accelerator research facility

SINBAD — Short Innovative Bunches and Accelerators at DESY — is the accelerator research facility, located in DESY, Hamburg, Germany. It is planned to be the place, where various experiments, related to creating ultra-short electron bunches and high gradient acceleration techniques, will take place. One of planned experiments — ARES — Accelerator Research Experiment at SINBAD — is a conventional S-band electron linac, accelerating ultra-short (single fs) electron bunches to energy of 100 MeV. To ensure proper and stable work of this accelerator, a high frequency phase reference distribution system needs to be designed, manufactured and tested. In this paper the concept of such system for SINBAD is presented. The design is based on authors' experience and knowledge gained during development of similar systems for FLASH, XFEL, REGAE and ESS-ERIC accelerators.