Overview of Final Focus Optics, Collimeter, Final Doublet and Extraction/Dump

1. Overview of Final Focus Optics, Collimeter, Final Doublet and Extraction/Dump • Final Focus Optics • Collimeter • Final Doublet • Extraction/Dump S.Kuroda ( KEK ) MDI meeting at SLAC 1/6/2005

2. Final Focus Optics 1. Beam size blow-up due to energy spread( chromatic effect ) Ds = x d s Generally x is large for FF. (x =103~104, mainly from final Q) 2. Chromaticity correction introducing SX. 3. SX also introduces geometric aberration(GA).  Need another SX and special optics for the GA cancellation Two Cancellation Scheme “Traditional” :GA cancelled by -I optics between SXs “Local Correction” : x corrected locally

3. Traditional Optics TESLA TDR x correction by SX far upstream of IP Transfer matrix of -I between SXs h= h’=0 at IP

4. Local Correction Optics  x corrected locally  GA must be corrected by optics  2nd order h correction also required NLC BDS New TESLA BDS qc=0 Long drift space for dump [J.Payet, O.Napoly] Collimeter in FFS OCT tail folding works good [A.Seryi et al]

5. Summary of Optics Recent design tendency is ‘Local Correction Optics’

6. Collimeter Machine( Detector ) Protection Background to Detector SR of Beam Halo at Final Q Collimation with spoiler+absorber Off-momentum Collimation Betatron Collimation Non-linear field in beam line Simulation is required for performance check [TESLA]

7. Off-Momentum Collimation SR protection x+Lp = (h+L h’)d< r Machine protection High dispersion & low beta section

8. Betatron Collimation High beta & dispersion free section Need iterative collimation for action variable cut in phase space (Optional use) Periodic Optics with DY= 45° emittance measurement SR by e of (x, p) at distance L x+Lp= (in action-angle var.) < aperture

9. Performance of Collimeter Better collimation performance in NLC/CLIC beta+d collimation is better than d +beta ? [A.Drozhdin et al]

10. Other Machine Protection Magnetic Energy Spoiler(MES) OCT+skew SX Large d beam kicked by OCT horizontally large Dx in skew SX x-y coupling & beam blow-up • Fast Extraction Line • Long bunch spacing in • Cold machine • much enough time to detect error and fire kicker [TESLA]

11. Other Issue for Collimeter Spoiler & Absorber Wake field Heat load survivability/life time survivable spoiler [A.Seryi] Muon collimation

12. Final Doublet Crossing angle qc & L* is the critical parameters for design Outgoing beam go inside or outside of the bore Normal Electric Magnet • Established technology • Heat loadcooling

13. Super-conducting Magnet • High gradient/Low power consumption • Large bore radius ( common with outgoing beam ) • Vibration?  He flow in cryostat LHC Various type of SC magnets are proposed Compact SC magnet Small bore/double aperture Flat inner tube

14. Permanent Magnet • High gradient w/o power consumption • Compact/small bore • Adjustability/tunability Hybrid Field compensation mover

15. Summary for Final Doublet

16. Beam Extraction/Dump • Charged beam extraction Boundary condition by qc and L* Machine protection by beamstrahlung g • Dump for beamstrahlung • Material of the dump for e± & beamstrahlung