The Future Circular Collider (FCC) study foresees the construction of a 90.6 km underground ring where, as a first stage, a high-luminosity electron-positron collider (FCC-ee) is envisaged, operating at beam energies from 45.6 GeV (Z pole) to 182.5 GeV (ttbar). In the FCC-ee experimental interaction regions, various physical processes give rise to particle showers that can be detrimental to machine components as well as equipment in the tunnel, such as cables and electronics. In this work, we evaluate the impact of the synchrotron radiation emitted in the dipoles and the beamstrahlung radiation from the interaction point (IP). The Monte Carlo code FLUKA is used to quantify the power deposited in key machine elements, such as the beamstrahlung dump and the dipole and quadrupole magnets, as well as the cumulative radiation levels in the tunnel. We also examine the effect of synchrotron radiation absorbers in the vacuum chamber, in combination with additional shielding. The results are presented for the different operation modes, namely Z pole and ttbar.

The Future Circular Collider (FCC) study foresees the construction of a 90.7 km underground ring where, as a first stage, a high-luminosity electron-positron collider (FCC-ee) is envisaged, operating at beam energies from 45.6 GeV (Z pole) to 182.5 GeV (ttbar). In the FCC-ee experimental interaction regions, various physical processes give rise to particle showers that can be detrimental to machine components as well as equipment in the tunnel, such as cables and electronics. In this work, we evaluate the impact of the synchrotron radiation (SR) emitted in the magnets and the beamstrahlung (BS) radiation from the interaction point (IP). The Monte Carlo code FLUKA is used to quantify the power deposited in key machine elements, such as the BS dump, as well as the cumulative radiation levels in the tunnel. We also examine the effect of SR absorbers in the vacuum chamber and of external tungsten shielding. The results are presented for the different operation modes, namely Z pole and ttbar.

In this paper we discuss the latest developments for the FCC-ee interaction region layout, which represents one of the key ingredients to establish the feasibility of the FCC-ee. The collider has to achieve extremely high luminosities over a wide range of center-of-mass energies with two or four interaction points. The complex final focus hosted in the detector region has to be carefully designed, and the impact of beam losses and of any type of synchrotron radiation generated in the interaction region, including beamstrahlung, have to be evaluated in detail with simulations. We give an overview of the progress of the whole machine-detector-interface-related studies, among which are the updated mechanical model of the interaction region, the plans for a novel R&D activity of a IR mockup which is just starting, the collimation scheme and evaluation of beam induced backgrounds in the detectors, evaluation of radiation dose in the experimental area, and MDI integration with the detector.

We present the optics design of the solenoid compensation scheme at the FCC-ee. The 2T solenoids from the experiments induce coupling on the beams, generating an increase on vertical emittance. This compensation scheme minimizes emittance growth, with a final value of approximately 5% of the nominal.
 A screening solenoid is placed around the Final Focus Quadrupoles to protect them from the experiment’s field. 
A skew quadrupole component is added to the Final Doublet, aligning the magnet axis to the rotated reference frame of the beam. 
Two anti-solenoids placed approximately ±20 m from the IP are used to cancel the field integral. The vertical orbit generated by the horizontal crossing angle in the detector field is compensated by vertical correctors placed right after the beam pipe separation and next to the final focus quadrupoles.
 We describe the IR optics in this scheme, including the detector solenoid and the magnetic elements used for compensation.