Beam Delivery System / Machine Detector Interface

1
Beam Delivery System / Machine Detector Interface

• BDS Area leaders
• Deepa Angal-Kalinin, Andrei Seryi, Hitoshi
  Yamamoto
• ILC MAC meeting, January 10-12, 2007

2
BDS design optimization and evolutionVancouver
gt MAC(Sep06) gt Valencia gt MAC(Jan07)

• Configuration changes (CCRs) after Vancouver
• Baseline configuration to 14/14, single collider
  hall
• 5m muon walls instead of 918m CCR approved
  23rd Sep
• On surface detector assembly CCR approved 2nd
  Nov
• Evaluations by WWS, MDI panels CCB
• MAC (Sep 06)
• Further cost optimizations studies
• Shorter BDS and shorter extraction lines
• Several optics versions proposed, extraction
  lines shortened
• Single IR evaluation of push-pull
• Task force charged to report at Valencia
• CCR submitted 19th Nov, on 23rd Dec CCB issued
  recommendation for the EC to approve the CCR. The
  EC approved it last Thursday

3
Vancouver baseline to Valencia baseline
Vancouver baseline
Diagnostics BSY tune-up dump
2mr IR
b-collim.
E-collim.
20mr IR
Two collider halls separated longitudinally by
138m
FF
Valencia baseline
14mr IR
14mr IR
One collider hall
4
Valencia 14/14 baseline. Conceptual CFS layout
muon wall tunnel widening
polarimeter laser borehole
9m shaft for BDS access
IP2
10m
IP1
beam dump service hall
alcoves
1km
5
CFS designs for two IRs
Vancouver
Valencia
6
Beam Delivery System tunnels
9m shaft for BDS access service hall
muon wall tunnel widening
alcoves
beam dump service hall
beam dump and its shield
7
Muon walls

• Purpose
• Personnel Protection Limit dose rates in one IR
  when beam sent to other IR or to the tune-up beam
  dump
• Physics Reduce the muon background in the
  detectors

Scheme of a muon wall installed in a tunnel
widening which provides passage around the wall
Baseline configuration 18m and 9m walls in each
beamline
8
5m muon walls instead of 918m

• Reduction of 18m muon spoilers to 5m and
  elimination of 9m muon spoilers CCR submitted
  8th September
• Considered that
• The estimation of 0.1 beam halo population is
  conservative and such high amount is not
  supported by any simulations
• The minimum muon wall required for personnel
  protection is 5m
• Detector can tolerate higher muon flux
• Cost of long muon spoilers is substantial,
  dominated by material cost and thus approximately
  proportional to the muon wall length
• The caverns will be built for full length walls,
  allowing upgrade if higher muons flux would be
  measured
• MDI panel accepted this change
• CCB approved this request on 23rd September
  contingent upon continuation of detailed detector
  studies to ensure that the occupancy due to muons
  does not affect the high precision physics
  measurements

9
On-surface assembly CMS approach

• CMS assembly approach
• Assembled on the surface in parallel with
  underground work
• Allows pre-commissioning before lowering
• Lowering using dedicated heavy lifting equipment
• Potential for big time saving
• Reduces size of required underground hall

10
On-surface detector assembly CCR

• According to tentative CFS schedule worked out
  by M. Gastal, CERN, the detector hall is ready
  for detector assembly after 4y11m after project
  start
• If so, cannot fit into the goal of 7years until
  first beam and 8years until physics run
• Surface assembly allows to save 2-2.5 years and
  allows to fit into this goal
• The collider hall size may be smaller (40-50)
  in this case
• A building on surface is needed, but savings may
  be still substantial
• Discussing possible variations
• pure CMS assembly (config B)
• modified CMS assembly (config A)
• Assemble smaller (than CMS) pieces on surface,
  lower down and perform final assembly underground
• May affect schedule (?), but preliminary looks by
  a small bit less expensive than B
• The change request not intended to specify all
  the details for the schedule, hall sizes,
  capacity of cranes etc.
• Such optimisation is being done in details by
  BDS, CFS and Detector concept groups.
• CCB approved this CCR on 2nd November.

11
CERN LHC-ILC engineering forum Participation by
MDI members (Oct. 12,13)

• Tour of ATLAS, CMS and ALICE
• Presentations on
• Radiation protection issues
• CMS services
• ATLAS installation
• CMS installation infrastructure
• ILC MDI present status and understanding H.
  Yamamoto and A. Seryi
• Assembly and installation of an ILC detector N.
  Meyners
• Extremely useful information from CERN colleagues
  based on real experience.

12
Optimizing the design and tweaking it to
understand its position w.r.to the optimum

• Since Vancouver, incorporated other cost saving
  changes
• redesigned tail folding octupoles, final doublet,
  refined vacuum requirements, redesigned CFS
  tunnels, changed design of water and air cooling
  systems, decimated bends, removed any spares and
  overheads, scrutinized all tech area for cost
  savings, etc.
• Other design optimization studies that were
  performed, but were not included, as not giving
  performance improvement and/or cost savings
• studied shorter BDS or its subsystems
• studied lowering power of tune-up dumps
• studied replacing magnetized muon walls with
  magnetized muon doughnuts

13
Single IR questions

• GDE suggested evaluation of push-pull at the end
  of September.
• Questions to be evaluated
• Organizational and historical questions
• Accelerator design questions
• Detector design questions
• Engineering integration questions
• Detailed list of questions to be studied
  developed
• Technical evaluation of push-pull option by an
  extended task force, which include more than 60
  detector and accelerator experts from ILC
  community and beyond. Detailed summary presented
  at Valencia.
• Conclusions from task force should be feasible,
  provided careful design and sufficient RD
  resources
• Conclusions from detector concept groups do not
  see show stoppers, detailed engineering design
  studies are needed to give confidence, in
  meantime would like to see two IR option kept as
  an alternative
• WWS comments H. Yamamoto (next talk)

http//www-project.slac.stanford.edu/ilc/acceldev/
beamdelivery/rdr/docs/push-pull/
14
Single IR BDS (version 2006e)
e-
e

• Upgrade to 1 TeV CM involves adding magnets only
  no geometry changes
• Total BDS Z-length is 4452 m (2 IRs5100m)
• Removed dedicated energy error dianostics (MPS)
  and replaced with polarimeter chicane (some
  issues)

hybrid BSY (x 2)
14 mrad ILC FF9 hybrid (x 2)
IR 14 mrad
?Z -650 m w.r.t. ILC2006c
2226 m
14 mrad (L 5.5 m) dump lines
M. Woodley et al
15
BDS with single IR
BSY
Sacrificial collimators
b-collim.
E-collimator
Diagnostics
FF
14mr IR
Tune-up dump
Extraction
16
betatron collimation
septa
skew correction / emittance diagnostic
MPS coll
polarimeter
fast kickers
fast sweepers
tuneup dump
beta match
final transformer
polarimeter
energy collimation
IP
primary dump
energy spectrometer
fast sweepers
final doublet
energy spectrometer
17
500GeV gt 1TeV CM upgrade in BSY of 2006e
Magnets and kickers are added in energy upgrade
M. Woodley et al
18
Single IR BDS optics (2006e)
BSY
FF
Polarimeter
E-spectrometer
E-collimator
b-collim.
Diagnostics
19
Concept of single IR Final Doublet
vacuum connection feedback kicker
common stationary cryostat
Detector
QD0
QF1
warm
IP
Original FD and redesigned for push-pull (BNL)
Redesigned FD
20
IR magnets
BNL prototype of sextupole-octupole magnet
BNL prototype of self shielded quad
cancellation of the external field with a shield
coil has been successfully demonstrated at BNL
21
New optics for extraction FD push pull
compatible

• Rearranged extraction quads are shown. Optics
  performance is very similar.
• Both the incoming FD and extraction quads are
  optimized for 500GeV CM.
• In 1TeV upgrade would replace (as was always
  planned) the entire FD with in- and outgoing
  magnets. In this upgrade, the location of
  break-point may slightly move out. (The
  considered hall width is sufficient to
  accommodate this).

Nominal scheme
Push-pull scheme
B.Parker, Y.Nosochkov et al.
http//ilcagenda.cern.ch/conferenceDisplay.py?conf
Id1187
22
Extraction Lines shortened by 100m
For undisrupted beam reliance on beam sweeping on
beam dump window using kickers.
high L parameters (500 GeV CM)
Total loss before and at collimators for High L
parameters is within acceptable levels. Losses
for the nominal case are negligible.
23
Concept of single IR with two detectors
The concept is evolving and details being worked
out
may be accessible during run
detector A
accessible during run
Platform for electronic and services (1088m).
Shielded (0.5m of concrete) from five sides.
Moves with detector. Also provide vibration
isolation.
24
Detector systems connections
25
Push-pull cryo configuration
Optimized for fast switch of detectors in
push-pull and fast opening on beamline
QD0 part
QF1 part
This scheme require lengthening L to 4.5m and
increase of the inner FD drift Opening of
detectors on the beamline (for quick fixes) may
need to be limited to a smaller opening than what
could be done in off-beamline position
door
central part
26
Shielding the IR hall
Self-shielding of GLD
Shielding the 4th with walls
27
Working progress on IR design
Mobile Shield Wall
Illustration of ongoing work Designs are
tentative evolving
Structural Rib
3m Thickness
Overlapping Rib
Mobile Platform 20m x 30m
Electronics/Cryo Shack 1m Shielded
9m Base
25m Height
John Amann
28
CFS layout for single IR central DR
29
CFS layout for single IR
30
Single IR push pull schedule

• The hardware can be designed to be compatible
  with a one day move, and this can be a design
  goal
• Need to study cost and reliability versus the
  move duration
• Need to study regulations in each regions
• A.Yamamoto presented a scheme (which includes
  warming-up the cold-box and disconnecting room T
  lines) and give an estimation of one week (many
  other tasks can be done in parallel with cryo
  work), which can serve as conservative boundary
  of the range
• Recalibration (at Z) may or may not be needed,
  and may be independent on push-pull to be
  studied
• BDS group will study the range between one day
  and one week and optimize the design versus cost,
  performance, reliability, etc.

31
Single IR, push-pull cost

• Cost difference of two IR versus single IR
  push-pull as reported to CCB on Dec.15 (based on
  Valencia wbs)
• baseline 14/14 100
• estimate for single p-p IR 69.1, with further
  updates 67.6
• Estimation of saving, in Value cost, is 31-32 of
  BDS cost
• Using single push-pull IR saves about one third
  of two IR BDS cost, or in other words the two IR
  BDS is by about 50 more expensive than single
  push-pull IR BDS
• Estimation of additional hardware that is needed
  to make push-pull feasible is small fraction of
  the savings

32
From summary of CCB response on Single IR
push-pull

• CCB agrees that .. CCR qualifies as Class-2.
  Consequently, CCB assumes that its role is to
  make recommendation to EC rather than to make a
  decision.
• CCB recommends EC to accept CCR23, whereby
  incorporating the "1IR with two detectors
  push-pull" as Baseline Configuration.
• CCB recommends EC to maintain the previous
  Baseline with "2IR, single hall, two detectors"
  as part of Alternative Configuration.
• CCB recommends EC to reinforce a taskforce on
  Machine-Detector-Interface issues. The taskforce
  should be specifically charged to facilitate
  pertinent design development efforts and
  discussions on relevant executive matters.

33
Briefly on other systems

• Magnets and PS
• Vacuum system
• Crab cavities
• Beam dumps collimators
• IR hall, surface buildings cranes

34
Magnets and PS

• Most of the magnets are rather standard, but
  require good magnetic and mechanical stability
• All PS are high availability design, stability in
  several ppm range (building 40 PS for ATF2 now)
• PS are placed in the service tunnel, cable
  penetrations are every 100m, which reduces heat
  load in the tunnel helping thermal and mechanical
  stability
• All BDS magnets in incoming beamlines except
  bends are on movers with 50nm step
• Special magnets except FD and first extraction
  quads
• SC tail folding octupoles (BNL design)
• beam sweepers
• Kickers with option of DC bends
• Antisolenoids embedded in the detector
• Detector integrated dipoles (part of detector
  solenoid)
• Magnetized muon walls

35
Vacuum system

• Material choice
• is defined by the resistive wall effects for
  off-centered bunch preserving the beam emittance
  discourage use of SS chambers
• Considered Al version and Cu plated SS chambers.
  Chosen the latter as more reliable, keeping Al
  for backup option. Chambers in the places where
  SR is expected (e.g. chicanes) are Cu
• Vacuum pressure
• determined by the need to minimize background due
  to beam-gas.
• Need 1nTorr in 200m upstream of IP (may need in
  situ baking), 10nTorr in 200-800m and 50nTorr
  in the rest of the system

36
Crab cavities

• BDS has two SC 9-cell cavities located 13 m
  upstream of the IP operated at 5MV/m peak
  deflection.
• Based on a Fermilab design for a 3.9GHz TM110
  mode 13-cell cavity.
• The uncorrelated phase jitter between the
  positron and electron crab cavities must be
  controlled to 61 fsec to maintain optimized
  collisions.
• A proof-of-principle test of a 7 cell 1.5GHz
  cavity at the JLab ERL facility has achieved a 37
  fsec level of control.
• Other key issues to be addressed are LLRF
  control and higher-order mode damping.

• Top earlier prototype of 3.9GHz deflecting
  (crab) cavity designed and build by Fermilab.
  This cavity did not have all the needed high and
  low order mode couplers.
• Bottom Cavity modeled in Omega3P, to optimize
  design of the LOM, HOM and input couplers.FNAL
  T. Khabibouline et al., SLAC K.Ko et al.
• Design is being continued by UK-US team

3.9GHz cavity achieved 7.5 MV/m
37
18MW Water Dump design features

• BDS features
• Optics drift to increase undisrupted beam spot
  size on window
• Raster beam in 30mm radius circle in 1 ms
  interlock to MPS
• Hi-power donut collimators to protect vessel
  window
• Vessel
• 6.5m (18X0) water followed by 1m water-cooled Cu
  (22X0)
• 1.5m diameter with vortex flow water, v1.0-1.5
  m/s , at r30cm
• 10 atm to prevent boiling
• 30 cm diameter 1mm Ti vessel window with water
  cooling nozzles
• Rad water system
• 2300 gpm three loop water system
• 18 MW heat exchanger 400HP of pumps per loop
• Catalytic H2-O2 recombiner
• Mixed bed ion exchange column to filter 7Be
• Containment for tritiated water
• Shielding
• 50cm Fe 150cm concrete local protection for
  personnel beamlines
• 200cm site dependent to protect ground water

38
18MW Dump design

• Two companies Fichtner Framatome, design and
  cost estimate for TESLA TDR
• Fichtner design for TESLA reworked by RAL
• Taken into account recent RAL experience with
  industry
• RAL design included additions for window remote
  handling, air exchange and control, air drying
  and recovery, etc.

39
IR surface area
40
Included in IR hall and surface buildings

• IR halls
• finished civil engineering works, plus
• movable concrete intermediate shielding wall in
  two parts (on air pads)
• steel platforms with staircases and all fittings
• two 1.6t elevators between steel platforms plus
  two 2.8t in shafts,
• steel plates on the floor of the Hall
• one 400t and two 20t overhead cranes in Hall
• etc
• Included in surface assembly building
• 400t and 20t overhead cranes
• Requirements for detector assembly are different
  (table on the next slide). Since we cannot tell
  now which detectors will be used, assumed
  Configuration A
• This choice can suite some detectors better than
  other (one size does not fit all) and is the
  reason for concerns
• Further adjustments of IR hall and surface
  building are needed, and detector colleagues
  should be more deeply involved in this design and
  also cost optimization

41
Table of IR assumptions
continued
42
Summary

• Several configuration changes since Vancouver to
  Valencia and final RDR version.
• Single IR with two complementary detectors in
  push-pull configuration has been recommended by
  CCB to EC as a baseline for the RDR. The EC
  approved it last Thursday
• This configuration gives 30 saving compared to
  two IR 14/14 mrad configuration.
• Single IR BDS optics design allows upgrade to 1
  TeV in the same tunnel.
• The on surface detector assembly will save 2-2.5
  years and has been accepted by the MDI panel.
• The engineering details will be carried out in
  the EDR phase.

43
Backup slides
44
500 GeV cm
1 TeV cm
45
continued
46
Power cooling in BDS
Table as of Valencia, 1TeV CM, two IR.
Table is as of 11/26/2006
9.768 0.862 218 MW gt Power from Magnets, PS
Dumps to LCW 0.726 MW gt Cables to Airgt
approximately 60W/m in average 0.712 MW gt PS to
Air gt taken out by Chilled water
47
Cost breakdown for single IR
(Labor person-hours, such as installation, was
converted to dollars to produce this chart)
48
Beam Dump Vessel
49
Beam Dump Service Cavern Layout
50
If detector does not provide any radiation
protection
18MW loss on Cu target 9r.l \at s-8m. No
Pacman, no detector. Concrete wall at 10m. Dose
rate in mrem/hr.

• For 36MW maximum credible incident, the concrete
  wall at 10m from beamline should be 3.1m

Wall
25 rem/hr
10m
Alberto Fasso et al
51
IR hall radiation safety criteria

• BDS produces and uses ILC radiation guidance
  document
• beam containment policies and devices, conditions
  for occupancy
• For IR region, in particular, defines
• Normal operation dose less than 0.05 mrem/hr
  (integrated less than 0.1 rem in a year with 2000
  hr/year)
• allows non-rad workers in IR hall
• Accidents dose less than 25rem/hr and
  integrated less than 0.1 rem for 36MW of maximum
  credible incident (MCI)

52
Detector sizes opening on beamline
SiD (opened)
GLD
Since opening of detectors on the beamline is
intended only for quick fixes, the required width
for opening may be smaller that for opening
off-beamline
53
FD with L4.5m lengthened warm drift section
by 0.7m
Detector opened on beamline (GLD opening reduced
to 1.5m) still leaves 0.5m of not-overlapped
space for config.C
54
Instrumentation

• Laser wire
• Deflecting cavity Y-T
• Loss monitors ion chamber PMT
• Cav BPM C-band, S-band, L-band
• Stripline or button bpm
• X sync light tr. profile imager
• OTR, OTRI
• Current monitors
• Pickup phase monitors
• Feedbacks
• Polarimeter laser upstream downstream
• E-spectrometer

55
IR coupling compensation
When detector solenoid overlaps QD0, coupling
between y x and y E causes large (30 190
times) increase of IP size (greendetector
solenoid OFF, redON)
without compensation sy/ sy(0)32
Even though traditional use of skew quads could
reduce the effect, the local compensation of the
fringe field (with a little skew tuning) is the
most efficient way to ensure correction over wide
range of beam energies
antisolenoid
QD0
SD0
with compensation by antisolenoidsy/ sy(0)lt1.01