The future circular collider study

At the end of 2018, a large worldwide collaboration, withcontributors from more than 350 institutes completed theconceptual design of the Future Circular Collider (FCC),a∼100 km accelerator infrastructure linked to the existingCERN complex, that would open up the way to the post-LHC era in particle physics. We present an overview of thetwo main accelerator options considered in the design study,namely the lepton collider (FCC-ee), serving as highest-luminosity Higgs and electroweak factory, and the 100-TeVenergy-frontier hadron collider (FCC-hh), along with theongoing technological R&D efforts and the planned nextsteps. A recently approved EU co-funded project, the FCCInnovation Study (FCCIS), will refine the design of the lep-ton collider and prepare the actual implementation of theFCC, in collaboration with European and global partners,and with the local authorities

Influence of Different Beam Energies on the Micro-Bunching Instability

During the operation of an electron synchrotron with short electron bunches, the beam dynamics are influenced by the occurrence of the micro-bunching instability. This collective instability is caused by the self-interaction of a short electron bunch with its own emitted coherent synchrotron radiation (CSR). Above a certain threshold bunch current dynamic micro-structures start to occur on the longitudinal phase space density. The resulting dynamics depend on various parameters and were previously investigated in relation to, amongst others, the momentum compaction factor and the acceleration voltage. In this contribution, the influence of the energy of the electrons on the dynamics of the micro-bunching instability is studied based on measurements at the KIT storage ring KARA (Karlsruhe Research Accelerator)

Miniature, High Strength Transport Line Design for Laser Plasma Accelerator-Driven FELs

Laser-plasma acceleration is an outstanding candidate to drive the next-generation compact light sources and FELs. To compensate large chromatic effects using novel compact beam optic elements in the beam transport line is required. We aim at designing miniature, high strength, normal conducting and superconducting transport line magnets and optics for capturing and matching LPA-generated electron bunches to given applications. Our primary application case is a demonstration experiment for transverse gradient undulator (TGU) FELs, to be performed at the JETI laser facility, Jena, Germany. In this contribution, we present the current design of the beam transport line magnets and the beam optics calculations

Impedance studies of a corrugated pipe for KARA

It is planned to install an impedance manipulation struc-ture in a versatile chamber at the KIT storage ring KARA(KArlsruhe Research Accelerator) to study and eventuallycontrol the influence of an additional impedance on the beamdynamics and the emitted coherent synchrotron radiation.For this purpose the impedance of a corrugated pipe is underinvestigation. In this contribution we present first results ofsimulations showing the impact of different structure param-eters on its impedance and wake potential

Thermal Transition Design and Beam Heat-load Estimation for the COLDDIAG Refurbishment

The COLDDIAG (cold vacuum chamber for beam heat load diagnostics) developed at Karlsruhe Institute of Technology has been modified for more studies at cryogenic temperatures different from the previous operations at 4 K in a cold bore and at 50 K in a thermal shield. The key components in this campaign are two thermal transitions connecting both ends of the bore at 50 K with the shield at the same or higher temperature. In this paper, we present design efforts for the compact transitions, allowed heat intakes to the cooling power margin and mechanical robustness in the cryogenic environment. A manufacture scheme for the transition and its peripheral is also given. In addition, the beam heat loads in the refurbished COLDDIAG are estimated in terms of the accelerator beam parameters