2017 CAS Erice case study Design of a

2017 CAS Erice case study: Design of a beam dumping system for FCC Oliver Georges-Henry Lorena Luca Nuria Vincenzo 1

100 km FCC Layout 8. 8 GJ stored in each beam. Requirements for a dumping system: • Fast • Reliable • 1. 5 km for extraction available. Injection team provided the injection kicker rise time (280 ns < 12 e buckets) and filling pattern: 1 batch (with margin) = trise, inj+full buckets = 12 empty+90 bunches Possible no. of batches in max number of buckets (considering 80% filling factor) = 10667/(12+90)= 104 Total nr. of bunches = 104 x 90 = 9360 Parameter EBeam 50 Te. V Max. Bunches 9360* Proton/Bunch 1. 1 e 11 Stored energy per beam 8. 8 GJ *Minimum 7095 from (head-on) peak luminosity requirement of 5 x 1034 cm-2 s-1 CAS 2017 Erice case study 2

FCC horizontal dumping system Parameter βKicker 100 m σ3. 3 Te. V@Kicker 0. 25 mm βSeptum 3600 m σ3. 3 Te. V@Septum 1. 5 mm Dump line Diluting kicker Kicker Collimator Septum Collimator 500 mm 25 mm thick 1. 5 km CAS 2017 Erice case study 3

FCC (horizontal) dumping system Kicker deflection: 0. 133 mrad Kicker to Septum: 1050 m Opening at the septum: 2. 5 cm aperture + 2. 5 cm septum thickness + 10σ + margin = 8 cm Septum deflection: 0. 9 mrad Septum to QF: 450 m 3. 3 Te. V@septum Septum CAS 2017 Erice case study 4

Abort gaps and extraction kicker functions Total space for abort gap(s) = Total nr. of buckets (100% ring circumference)– nb, min = (13351 -9360) = 3991 buckets = 3991 x 25 ns ~ 100 ms Up to 33 x 3 ms possible abort gaps Fast rise/falling time of the kickers: 1μs to 3 μs 1μs possibility to add spare kicker modules for Field Uniformity Kicker Control corrective feedback (if erratic occurs) Short rise time reduces the lost bunches during asynchronous beam dump. Less stress for absorbers. Flat top time from 8 μs (selective extraction of minimum 3 batches) up to 340 μs (revolution period for total abort). CAS 2017 Erice case study Field Uniformity Kicker Control 5

FCC dump painting the beam Dilution kickers paint the beam on the dump (spiraling out) many for redundancy Distance d between two bunches depend on the shower behavior! d ~ 1. 6 mm distance spiral 3 cm [1] Rmax gives max diluter kick. Complex dump layout • Different materials (liquid dump possibility) for optimal energy deposition. Segmented diluter kickers 2. 5 km upstream of the dump block. Max deflection kick: 240 μrad Large beta at dump block ~ 10 km Reduction of the beam density. What about liquid dump? [1] F. Burkart, A. Lechner CAS 2017 Erice case study 6

Thank you for your attention! CAS 2017 Erice case study 7