Abstract
The FCC-e+e- injector complex needs to produce and to transport a high-intensity e+/e- beam at a fast repetition rate of about 0.1 Hz for topping up the collider at its collision energy. A basic parameter set exists for all the collider energies, assuming a 10 GeV linac operating with a large number of bunches being accumulated in the existing SPS, which serves as pre-accelerator and damping ring before the bunches are transferred to the high-energy booster. The purpose of this study is to provide the conceptual design of an alternative accelerator ring, replacing the SPS in the present scheme. This ring will have injection energy of 6 GeV and extraction energy of 20 GeV. In this study, the basic parameters of the ring are established, including the optics design and layout. Preliminary consideration for non-linear dynamics optimization and the impact of intra beam scattering are also presented.
Highlights
The initial basic parameters for FCC e+e- pre-injector were established in order to satisfy the demanding collider flux requirements, especially for the full machine filling of the lowest energy collider flavour (45.6 GeV)
The emittance at extraction of the pre-booster damping ring (PBDR) has to satisfy the requirement for the injected emittance in the main booster ring, which in turn is established by the demands of the collider
For a cycle of 1.2 s, the injected emittance obtained is 1.5 nm.rad. This may already point to the direction of needing an extra damping stage with a dedicated damping ring for both species
Summary
The initial basic parameters for FCC e+e- pre-injector were established in order to satisfy the demanding collider flux requirements, especially for the full machine filling of the lowest energy collider flavour (45.6 GeV). This design is based, on a CLIC (Compact Linear Collider) based linac and using the CERN Super Proton Synchrotron (SPS) as a damping and pre-booster Ring. Since there may be issues for using the SPS as pre-injector, such as machine availability, synchrotron radiation and new RF system, just to name a few, a “green field” alternative pre-booster damping ring (PBDR) design was mandatory [2] In parallel, another alternative linac study has started [3], based on the design approaches of the SUPERKEKB pre-injectors. Based on parameter scaling and basic calculations, the extraction energy was established at 20 GeV, for having the lowest circumference within a reasonable energy loss per turn limits of around 50 MeV [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
