Abstract
In response to the 2013 Update of the European Strategy for Particle Physics, the Future Circular Collider (FCC) study was launched, as an international collaboration hosted by CERN. This study covers a highest-luminosity high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh), which could, successively, be installed in the same 100 km tunnel. The scientific capabilities of the integrated FCC programme would serve the worldwide community throughout the 21st century. The FCC study also investigates an LHC energy upgrade, using FCC-hh technology. This document constitutes the second volume of the FCC Conceptual Design Report, devoted to the electron-positron collider FCC-ee. After summarizing the physics discovery opportunities, it presents the accelerator design, performance reach, a staged operation scenario, the underlying technologies, civil engineering, technical infrastructure, and an implementation plan. FCC-ee can be built with today’s technology. Most of the FCC-ee infrastructure could be reused for FCC-hh. Combining concepts from past and present lepton colliders and adding a few novel elements, the FCC-ee design promises outstandingly high luminosity. This will make the FCC-ee a unique precision instrument to study the heaviest known particles (Z, W and H bosons and the top quark), offering great direct and indirect sensitivity to new physics.
Highlights
One of the major issues for the Future Circular Collider (FCC)-ee lepton collider is the collective effects due to electromagnetic fields generated by the interaction of the beam with the vacuum chamber, which can produce instabilities, tune shifts and spread, bunch lengthening etc., limiting the machine operation and performance
This chapter focusses on the impedance model and collective effects at Z running: some important sources of impedance have been included in the model to study both single bunch and multi bunch instabilities, to predict their effects on the beam dynamics and to find a possible solution for their mitigation
It has been observed [204] that the thickness of the coating plays a fundamental role in the beam dynamics while the conductivity of the material only plays a marginal role: the resistive wall (RW) impedance decreases for a thinner coating; this results in higher single-bunch instability thresholds, improving the beam stability during machine operation
Summary
One of the major issues for the FCC-ee lepton collider is the collective effects due to electromagnetic fields generated by the interaction of the beam with the vacuum chamber, which can produce instabilities, tune shifts and spread, bunch lengthening etc., limiting the machine operation and performance. The level of detail corresponds to the conceptual development stage requirements as defined in the European Strategy for Research Infrastructures (ESFRI) methodology roadmap [605,606] At this level, a number of concepts are presented that can be screened by experts in the domain, funding agencies and other stakeholders. The subsequent preparatory phase will focus on the development of the implementation plans, relying on credible designs that need to be based on a set of technologies that enable the research infrastructure to be built At this stage, any project of such scale, ambition and with a long-term vision spanning many decades, comprises a number of uncertainties with different probabilities and potential impact. The immediate step, the design phase, will include the development of a technically achievable and coherent blueprint, which successfully responds to the requirements and concepts presented at this first stage
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
