Beam Transfer to the FCC-hh Collider from a 3.3 TeV Booster in the LHC Tunnel

Transferofthehighbrightness3.3TeVprotonbeamsfrom the High Energy Booster (HEB) to the 100 TeV centre-ofmass proton collider in a new tunnel of 80‐100 km circumference will be a major challenge. The extremely high stored beam energy means that machine protection considerations will constrain the functional design of the transfer, for instance in the amount of beam transferred, the kicker rise and fall times and hence the collider filling pattern. In addition the transfer lines may need dedicated insertions for passive protection devices. The requirements and constraints are described, and a first concept for the 3.3 TeV beam transfer between the machines is outlined. The resulting implications on the parameters and design of the various kicker systems are explored, in the context of the available technologies. The general features of the transfer lines between the machines are described, with the expected constraints on the collider layout and insertion lengths. MACHINE PROTECTION LIMITS Present investigations of the feasibility of absorber blocks for the LHC injection protection for High Luminosity-LHC (HL-LHC) beam parameters show two limitations. The foreseen high brigthness beams could cause mechanical stresses intheabsorbersbeyondtheirdamagelevel. Also, attenuation of primary particles to provide protection of downstream elements would not be guaranteed with the present design [1‐3]. The beam energy at the HEB to FCC transfer is a factor 130 higher than in case of the SPS to LHC transfer. Thus, a staggered transfer of batches with a reduced number of bunches is envisaged. The reachable bunch filling as a function of the injection kicker rise time for dierent transferred beam