Open Access Version

Abstract:
A multi-turn energy recovery linac -based light source is under discussion. Using the superconducting Linac technology, the Femto-Science-Factory (FSF) will provide its users with ultra-bright photon beams of angstrom wavelength. The FSF is intended to be a multi-user facility and offer a variety of operation modes. The driver of the facility is a 6 GeV multiturn energy recovery linac with a split linac. In this talk we discuss designs of the optic in the linac and compare different schemes of beam acceleration: a direct injection scheme with acceleration in a 6 GeV linac, a two-stage injection with acceleration in a 6 GeV linac, and a multi-turn (3-turn) scheme with a two-stage injection and two main 1 GeV linacs. Construction costs and beam break up instability were the key points for comparison.