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Beam Delivery configuration materials to start discussion. Andrei Seryi , Deepa Angal-Kalinin, Hitoshi Yamamoto BDS area GDE meeting at KEK, January 19-20, 2006. Progress. RDR work
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Beam Delivery configurationmaterials to start discussion Andrei Seryi, Deepa Angal-Kalinin, Hitoshi Yamamoto BDS area GDE meeting at KEK, January 19-20, 2006
Progress • RDR work • Contacting Technical systems (Magnets, Vacuum, Instrumentation, etc) to establish communication and define scope the work • Start to estimate and request needed resources • Design work • Continue design optimization, e.g. • Finalize optics for tune-up extraction and diagnostics • Consider improvements in 2mrad extraction chicanes (0.7MW SR loss at 1TeV CM) • Will consider low power tune-up dumps • Technical consideration of push-pull requirements • Radiation physics study for single IR hall; self shielded detector; MPS • design for 1TeV compatibility • Any design changes will go through CCB
ILC BDS baseline • Magnets • Vacuum • Collimation and beam dumps • Instrumentations • Civil • RF, cavity package, cryomodule Layout and counts are accurate to better than 10% : anticipate very small change of optics in diagnostics and fast extraction. If will go e.g. to single dump and add a beamline to the main dump – could have some effects on the count as well
Lengths, counts of magnets (for present optics) • Total length of beamlines • 12008 m • Counts of magnets (N Ltotal Laverage) • Bends: 484 3375m 6.97m • Quads: 536 996m 1.86m • Sextup: 40 39.6m 0.99m • Octup: 46 60.8m 1.32m • Kickers 2*50 200m 2m • Total length of magnets (active length) • 4673 m • Active / Total length • 38.9 % • This number (active/total) is underestimation, e.g. length of BPMs is not included (if stick out of magnets) or other instrumentation
Vacuum system • Total length of vacuum system ~12km • about 7500m of drifts with simple vacuum chamber • about 3400m are in bends with moderate SR. Design of chamber need to be evaluated • Several chicanes in extraction with high SR losses. Special chamber design will be needed. • About a thousand of quads and bends and about a thousand of BPMs, with associated vacuum connections • There is instrumentation which require optical windows • The aperture ranges from couple of cm to half a meter in some places in extraction line • Vacuum requirements, about 10nTorr near IR (tbc) • The need for fast valves in several places (e.g. near dumps) • Perhaps one of the biggest single cost items in BDS • Other (minor) questions • narrow gaps from collimators take into account in conductance eval. • Specific requirements for vacuum readout for MPS and BDS diagnostics ? • Accel. phys. tech. group to contacts e.g. for vacuum req. reeval.
Magnets (warm, SC, Pulsed, Special) • Long weak warm dipoles • Warm quads • Magnet movers • Warm large aperture extraction quads • Kickers for fast extraction • Compact direct wind SC IR quads • Compact direct wind sextupole/octupole IR packages • Large aperture SC IR quads • Large aperture SC IR sextupoles • Octupoles for tail folding SC direct wind • Septa for fast extraction • Warm pocket coil IR quad • Warm or SC super septum extraction quads • Magnetized muon spoilers (9 and 18m iron walls) • Detector integrated dipoles in detectors • IR antisolenoids • Related: power supply stability. Location of PS. Alcoves or surface bldg.? Warm quads: cost driver: Large count IR quads: Cost driver: Unique and difficult Muon walls: Cost driver: large cost of material
Muon spoilers • Two magnetized walls 9m and 18m in each branch • Needed to reduce muon flux at IP to below 10muons per 200 bunches • Assume 0.001 of beam lost at collimators • Muon spoilers seem to beone of costly items and needto revisit strategy of theirimplementation • Staging? Start with min set and add if #muons is too high? • Alternatives Older NLC picture
Muon spoiler material cost estimation • 4m*5m (9m+18m) * 4branches * density 8Ton/m3 * 3.3$/kg = 57M$ for the material only • References for iron cost (range from 2.2$kg to 3.5$/kg): • 1) M.Breidenbach et al: 3.48$/kg – SiD muon system (Babar Kawasaki experience. M.B.: “Note iron is a commodity with big fluctuations”) • 2) L.Keller: raw material=0.7$/kg, fabrication=1.5$/kg, total=2.2$/kg • probably obsolete data • 3) F.Asiri: material $1000/ton in US. Cost of prepared, cut, crated and delivered to order is about $3,300/ton. Korean Iron may be purchased for about 30% less in US.
e+ tunnel ? Civil layout ?s • Location of shafts (8?) • at each dump (6) and IP (2) ? • Location of positron go-around tunnel • Do we need service tunnels? • Alcoves for electronics? • Location of power supplies? Shaft also here? Service tunnels?
Beam dump enclosures & service tunnels? • Shafts?
Drawings and other misc. questions • Drawings like those CF layouts shown in previous page – should they be provided to all GDE on password protected web site? • Are there global guidance on what cranes or other transportation machines will be available in the halls, alcoves and in the tunnel? • e.g. if we need to move 12m long magnet, or remove collimator, what is the procedure? Is there global guidance on limits for sizes of components?
Beam dumps and collimations • Full powerdumps (18MW) (6) • Removing tune-up dumps will be considered • Photon (~1-3?MW) dumps (2) • Fixed aperture protection collimators (~60) • Adjustable spoilers and absorbers (~60) • Passive devices to limit betatron aperture (to be designed) • Forming the task force to estimate beam dump cost and understand importance of site and ground water • Beam Dumps and Collimation technical system – 1 name out of 3. Very big issue. Can we solve it in 48hours?
RF, cryomodule, cavity package systems • Crab cavity systems • Based on 3.9GHz deflecting mode cavity developed at Fermilab • Present 3.9GHz CKM cavity not suitable as prototype – it is mechanically too soft, its frequency is 3.925GHz, etc. • Experience with 3.9GHz accelerating mode cavity is also relevant • Fermilab is best positioned to make RDR design and cost estimation, as well as start work on real crab cavity design and prototype, to be built in ~1.5 years • Coordination with UK colleagues and work sharing need to be discussed. E.g. cavity itself – Fermilab, phase stabilization system – UK ?
Instrumentation • BPM and their channels ~ 1100 • Large aperture (r=3cm) – design issues • Laser wire systems • Current monitors, loss monitors (standard) • Feedbacks and fast luminosity monitors, pair monitor • Spectrometer and polarimeter upstream & downstream • Alignment – Civil group & Instrumentation • This week at SLAC – mtg of Instrumentation technical group for discussion of feedbacks in BDS etc
IR systems and magnets • Unique, difficult magnets, integration with detectors, R&D • One of the high cost items (~ X0M$ ?) • Do not have sufficiently detailed sketches that would allow to make technical and engineering evaluation • One of concerns and the area where trying to pull in resources • 20(14)mrad IR magnets – design and cost estimation by BNL • 2mrad IR magnets – design and cost estimation by Fermilab and Saclay • IR instrumentation, LUMI/BEAMCALs, IP BPMs, kickers
20/14mr • BNL • Issue of resources at BNL
Si D Forward Masking, Calorimetry & Tracking 2005-09-1520mrad, L*=3.51m ECAL Muon Yoke HCAL QF1 SD0 QD0 CRAB Lo-Z BeamCal LumCal Q-EXT Support Tube
Conceptual design of 2mrad IR Shared Large Aperture Magnets Disrupted beam & Sync radiations Q,S,QEXF1 SF1 QF1 SD0 QD0 60 m Beamstrahlung Incoming beam pocket coil quad Rutherford cable SC quad and sextupole
Details of zero degree design Design of 20 & 2 mrad IR need to advance to and beyond this level of details
IR hall sizes • Large range (3.5 times in volume) • Parametric studies of cost (~excavated volume) SiD: 48m x 18m x 30m [SiD Collab. Mtg. 16-17 December 2005] GLD: 72m x 32m x 40m [Snowmass data]
Cost of BDS • Two approaches should give about the same answer • Bottom -> top approach (count parts, individual cost) • Top -> bottom (compare with recently built accelerators, scale, and adjust for differences) • With exception of special systems, whose cost could be added, BDS is a lot of kms of warm magnets and vacuum chambers • It should be possible to compare it, for example, with Main Injector cost, scale according to beamline length, length of magnets and add special costly systems (beamdumps, muon walls, IR halls, IR and FD) • There are many caveats (e.g. more precise power supplies could be more expensive) but top-bottom cost should also give correct answer
Possible cost saving strategies • Singe IR (will be chosen when more design and cost information will be available, in ~5month) • Install only fraction (half) of bends at 500GeV CM stage • this will increase difficulty and cost of the energy upgrade • Design all quads as consisting from two halves and install only one half at 500 GeV CM • same difficulty with upgrade • Replace high power tune-up dumps with low power • additional beamline from BDS entrance to main dump => +cost • Consider staging construction and installation of muon walls (e.g. start with min 5m wall). Install more if muon rate is too high • May be difficult to install the wall in operational tunnel • Consider alternative muon spoilers • Undisrupted beam size at dump window - rely not on drift but more on rastering - shorten extraction lines (MPS)
Some milestones • Feb 13-14, GDE mtg at Fermilab – review BDS optics • Bangalore • one more iteration on IR comparison • first report on technical evaluation of push-pull? • evaluation (e.g. rad. physics) of single IR hall • more details on upgrade paths from single IR • including consideration of upgrade to gamma-gamma • Will set up review of beam dump cost and design – end of March? • End of May – full picture of IR performance and cost • possibly, that is when will choose the favorite IR design