Conveners
FCC-hh accelerator: Design I (review)
- Bruce Strauss
FCC-hh accelerator: Design II (review)
- Barbara Dalena (Université Paris-Saclay (FR))
FCC-hh accelerator: Collimation (review)
- Toms Torims (Riga Technical University (LV))
FCC-hh accelerator: Collective effects I (review)
- Alexander Novokhatski (SLAC National Accelerator Laboratory)
FCC-hh accelerator: Collective effects II (review)
- Mauro Migliorati (University of Rome "LA SAPIENZA")
The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. In this overview we will describe the status and the evolution of the design of optics integration of FCC-hh, focusing on design of the arcs, alternatives, and tuning procedures.
"The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group, and the natural evolution of existing LHC. The evaluation of the various magnets mechanical error and field error tolerances in the arc sections of FCC-hh, as well as an estimation of the correctors...
The remarkably efficient potential operation of the 100 km FCC as a heavy-ion collider was demonstrated right at the inception of the FCC study. Luminosity projections have risen in recent years in line with the higher intensity beams of lead nuclei now being collided in the LHC. Close contact with the physics working group has been maintained to evaluate the interest of heavy Pb-Pb,...
This talk will give an overview of the developments and the achievements of the Experimental Insertions of FCC-hh.
Dynamic aperture studies have been performed on the FCC-hh lattice at different energies to study the stability of the beam and the effect of different errors. Initial studies for the FCC-hh lattice at collision energy with errors on the triplet showed a very low dynamic aperture, most likely affected by the large integrated quadrupole length of the quadrupoles and the high beta function at...
The future circular collider (FCC-hh) with proton beam energy of 50 TeV and total stored energy of 8.4 GJ requires a collimation system with very high cleaning efficiency to prevent quenches of the superconducting magnets. Collimation performance can be strongly affected by collimator imperfections such as gap errors, jaws deformations, tilt and misalignments. Tracking simulations in SixTrack...
The collimation system intercepts the beam halo by absorbing part of the induced shower and retaining the rest in the warm segment of the ring in order to protect the downstream superconducting (SC) magnets from quenching. The FCC-hh betatron cleaning insertion region (2.7 km long) features primary collimators (TCP), secondary collimators (TCSG) and active absorbers (TCLA), whose design have...
The impedance model together with the status of electron cloud simulations for FCC-hh will be presented. Thresholds for transverse coupled bunch instabilities, for mode coupling instabilities and the requirements for Landau damping in FCC-hh will be discussed and compared to LHC.
In comparison to the LHC beamscreen, the FCC beamscreen is more compact, has much larger pumping holes for achieving high vacuum, and incorporates a surface treatment for electron cloud mitigation. All of these factors can dramatically increase coupling impedance of the beamscreen. The impact on the coupled bunch and the single bunch instabilities is analysed. The necessary pumping hole...
Transverse feedback systems are used for injection oscillation damping and transverse coupled bunch instability mitigation. The FCC-hh sets new challenges in comparison to the LHC due to the more rigid beam during the injection and the faster coupled bunch instability growth rate, which mitigation relies increasingly on the transverse feedback system. In this presentation, the performances of...
Electron clouds can cause several unwanted effects, in particular beam instabilities, emittance growth and tune shifts, as well as additional heat load on the cryogenic system and vacuum degradation. These effects can most efficiently be mitigated by suppressing the formation of electron clouds. In this contribution we present the required conditions for sufficient electron cloud suppression...
Electron clouds pose an intensity and luminosity limitation for proton beams in LHC and its upgrades.
The limitations are due to electron cloud induced heat loads, instabilities and also incoherent beam intensity effects. At present, electron cloud induced effects are well controlled in LHC using different counter-measures, like for example coatings and bunch filling pattern, together with...
In proton colliders, Landau octupoles are used to provide the necessary Landau damping of transverse coherent beam instabilities driven by the impedance. During the operational cycle the tune spread provided by the Landau octupoles may be modified when in presence of beam-beam interactions. Transverse beam stability studies for the FCC-hh operational cycle will be explored using Landau...
