80 likes | 181 Vues
CLIC Drive beam BPM. Requirements and cost estimate. CLIC module, Type 1. Wake Field Monitors*8. MB-BPM. Beams. Main Beam. DB -BPM. Drive Beam. DB-BPM. Module types. 1 BPM per quadrupole 1WFM per accelerating structure. 78 0? 4 5 5. 8374 154 634 477 731.
E N D
CLIC Drive beam BPM Requirements and cost estimate
CLIC module, Type 1 Wake Field Monitors*8 MB-BPM Beams Main Beam DB-BPM Drive Beam DB-BPM
Module types 1 BPM per quadrupole 1WFM per accelerating structure 78 0? 4 5 5 8374 154 634 477 731 In total 10462 modules per Linac
Drive beam parameters Standard BPM coupling impedance of -40dB would pump 300W! 40000 BPMs would dissipate 12MW!!
Specifications Nominal beam parameters: Charges/bunch: 5.2*1010;Nb of Bunches: 2922; Bunch length: 1mm; Train length: 243.7ns ; Bunch spacing: 0.0833ns Difficult / Expensive 80dB Feasible Commission beam parameters: Nominal bunch-charge, with 9/10 buckets empty ( 10% of nom. Current); Bunch length: 1mm; Max train length: 243.7ns; Bunch spacing: 0.0833ns
Beam spectrum HOM Current modulation? Chamber cutoff frequency 7.6GHz!!! HOM from PETS with several kilo Watt’s Introduce current modulation at e.g. 2GHz? Measure with button, strip line or inductive BPM at baseband Use other (unknown) spectral lines
Cost estimation • Button BPM , simple and cheapest. • Do not expect a 50% price reduction going from 1000 to 10000 pc!!. • Cable costs should/can be reduced by ~50%, but precise machining of BPM will • compensate this increase. • Radiation hardness of cables and electronics could increase the costs.
Conclusion • Drive beam BPM very complicated and study needed. Performance + cost. • There is a lot of power in the drive beam. • 40000 BPMs of 15KchF each: ~600MCHF • Reduction in total numbers is essential.