Overview of Beam Delivery System Final Focus Optics Collimator Final Doublet Extraction/Dump Others S.Kuroda ( KEK ) MDI meeting at SLAC 1/6/2005

Final Focus Optics 1. Beam size blow-up due to energy spread( chromatic effect )  Generally  is large for FF. (  =10 3 ~10 4, 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” :  corrected locally

Traditional Optics TESLA TDR  correction by SX far upstream of IP Transfer matrix of -I between SXs  =  ’=0 at IP

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

Summary of Optics ‘Traditional Optics’‘Local Correction Optics’ Easy to understand Tested at FFTB Wide momentum band width Expandability to high energy Compact beam line Recent design tendency is ‘Local Correction Optics’

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

Energy Collimation SR protection x+Lp = (  +L  ’)  < r Detector protection  Background study High dispersion & low beta section

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

Performance of Collimator Better collimation performance in NLC/CLIC  (beta+  collimation+local correction FF is better than (  +beta)collimation+traditional FF ? [A.Drozhdin et al]

Other Machine Protection Magnetic Energy Spoiler(MES) OCT+skew SX Large  beam kicked by OCT horizontally large  x 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]

Other Issue for Collimator Spoiler & Absorber Wake field Heat load  survivability/life time Muon collimation survivable spoiler [A.Seryi] Fast emergency extraction line is necessary

Final Doublet Normal Electric Magnet Established technology Heat load  cooling Crossing angle  c & L* is the critical parameters for design Outgoing beam go inside or outside of the bore [T.Mihara,O.Napoly 1st ILCWS]

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

Permanent Magnet High gradient w/o power consumption Compact/small bore Fine tuning for temperature/ rad. Damage Adjusting for big E change( e.g. Z-pole )  Hybrid Field compensation mover

Summary for Final Doublet EMSCPM Established technology Power consumption  cooling High gradient Large bore( generally ) Vibration? High gradient Compact/small bore Adjustability / tunability

Beam Extraction/Dump Charged beam extraction Boundary condition by  c and L* Diagnostic section 1) Energy 2) Polarization ……  Chicane for photon separation 2nd focusing point for Laser collision Machine protection by beamstrahlung  Dump for beamstrahlung? Background( neutron ) study from the extraction/dump ……

TESLA Extraction Head-on scheme Irradiation of septum magnet No beam diagnostic after collision is considered optics Beam size when no collision

GLC Extraction Geometry optics 7mrad crossing Superconducting final Q is assumed (out-going particle goes inside of Q ) Diagnostic section is considered. Transmission and background study  need more to do [K.Kubo]

Extraction for 20mrad crossing 2nd focal point in vertical chicane for beam diagnosis Good transmission for disrupted beam [Y.Nosochkov]

Others Straw-man layout for ILC BDS Yuri’s ILC 20 mrad dump lines IR1 20 mrad IR2 2 mrad Andrei’s 20 mrad ILC FF (x 4) NLC BSY dump lines 11 mrad NLC-style Big Bends 200 m drifts IP separation: 150 m (Z), 22 m (X) Design done except Pre-IP E-spectrometer FEXL Extraction for 2mrad [M.Woodley]

Solenoid Field Compensation LD model,  = 20 mrad LD model,  = 0 Solenoid field at FD  beam size blow-up ( independent on crossing angle ) With antisolenoids and linear knobs,  y = 0.9% Total field with and w/o antisolenoids Anti-solenoids provide good compensation, and it is considered as a part of detector More effective with skew Q [ Y. Nosochkov, A. Seryi ] Anti-solenoid compensation