Beam Delivery configurationmaterials to start
discussion
Andrei Seryi, Deepa Angal-Kalinin, Hitoshi YamamotoBDS area
GDE meeting at KEK, January 19-20, 2006
19-20 Jan 06A.Seryi 2
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
19-20 Jan 06A.Seryi 3
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
19-20 Jan 06A.Seryi 4
Lengths, counts of magnets (for present optics)• Total length of beamlines
– 12008 m
• Counts of magnets (N Ltotal Laverage)– Bends: 484 3375m6.97m– 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
19-20 Jan 06A.Seryi 5
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.
19-20 Jan 06A.Seryi 6
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
19-20 Jan 06A.Seryi 7
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
19-20 Jan 06A.Seryi 8
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.
19-20 Jan 06A.Seryi 9
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?
e+ tunnel ?
19-20 Jan 06A.Seryi 10
Beam dump enclosures & service tunnels?• Shafts?
19-20 Jan 06A.Seryi 11
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?
19-20 Jan 06A.Seryi 12
Beam dumps and collimations• Full power dumps (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?
19-20 Jan 06A.Seryi 13
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 ?
19-20 Jan 06A.Seryi 14
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
19-20 Jan 06A.Seryi 15
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
19-20 Jan 06A.Seryi 16
20/14mr• BNL• Issue of
resources at BNL
19-20 Jan 06A.Seryi 17
Si D Forward Masking, Calorimetry & Tracking 2005-09-1520mrad, L*=3.51m
Q-EXT
CRAB
QF1SD0QD0
ECAL
HCAL Muon Yoke
Support Tube
Lo-Z
LumCal
BeamCal
19-20 Jan 06A.Seryi 18
QD0SD0 QF1
SF1 Q,S,QEXF1
Disrupted beam & Sync radiations
BeamstrahlungIncoming beam
60 m
Shared Large Aperture Magnets
Rutherford cable SC quad and sextupole
pocket coil quad
Conceptual design of 2mrad IR
19-20 Jan 06A.Seryi 19
Details of zero degree design
Design of 20 & 2 mrad IR need to advance to and beyond this level of details
19-20 Jan 06A.Seryi 20
-40 -35 -30 -25 -20 -15 -10 -5 0 5 10
01
23
45
67
89
10
IR hall sizes
GLD: 72m x 32m x 40m [Snowmass data]
SiD: 48m x 18m x 30m [SiD Collab. Mtg. 16-17 December 2005]
• Large range (3.5 times in volume)
• Parametric studies of cost (~excavated volume)
19-20 Jan 06A.Seryi 21
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
19-20 Jan 06A.Seryi 22
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)
19-20 Jan 06A.Seryi 23
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