Collimation Opening Remarks Tom Markiewicz SLAC

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CollimationOpening RemarksTom MarkiewiczSLAC
US LHC Accelerator Research Program
bnl - fnal- lbnl - slac

• 19 October 2004

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Meeting Goals

• Institutions involved in LHC Collimation
• CERN, SLAC, FNAL, BNL
• Agreement on how collaborating institutions will
  work together to the best interests of the LHC
• Who does what, by when?
• Improved methods of communication
• 1-1 email, phone
• Meetings phone, video, VRVS, physical
• Progress Reports /or Statement of Plans
• Informal Discussions with all experts present

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Agenda
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Milestones Since February 2004 LARP Meeting

• CERN
• External review of collimation project, June 2004
• Manufacture, installation and beam test of
  prototypes
• Improved energy deposition codes results
• BNL
• Installation of SixTrack / CollTrack package
• Interim Meetings
• May 2004 LARP Collimator Review at BNL
• Phased approach for Phase II
• June 2004 LAPAC at Fermilab
• Blesses project (I think)

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Reminder of the Phase II Issue

• Primary Collimators are 20cm Carbon
• Phase I secondary collimators are 1.0m Carbon
• Survive accident (asynchronous beam abort) eat 8
  bunches
• Adequate system inefficiency (11E-4) and
  impedance for beginning operation
• 7 kW cooling can handle mandated 90kW (1 hr. beam
  lifetime) load
• Mechanical tolerances maintained during 450 kW
  (12 min beam lifetime) excursions lasting lt 10
  sec
• Phase II secondary collimators
• Presumably metal for low impedance
• WILL be damaged in accident, but SLACs
  rotating geometry can provide new surface
  without collimator removal
• Presumably will absorb more of beam
• Is required DC cooling consistent with rotating
  design and required tolerances?
• How do Phase II secondary collimator parameters
  affect system inefficiency?
• What is their role as absorbers? Absorber system
  currently not designed

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Two Possible Approaches Considered

• Engineer best collimator consistent with SLAC
  technology
• Or
• Delay start of engineering until requirements
  better understood
• Early calculations and MISCONCEPTIONS having to
  do with fault scenarios led us to choose second
  path
• Bureaucratic Plan
• January 2005 LHC Review in Chamonix
• Formal status report to CERN
• April 2005 Go/No-Go Decision for SLAC to
  prototype this collimator
• If GO, hire postdoc engineer to cement what
  is currently donated services from SLAC ILC
  group

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SLAC Progress Since February LARP Meeting

• Independent FLUKA analysis of 7 TeV protons in
  SECONDARY collimator jaws, varying Z and L
• Adoption and benchmarking of CERN FLUKA input
  file describing IR7
• Basis of June Review
• FLUKA energy deposition studies of SECONDARY
  collimators for protons lost on PRIMARY 20cm
  collimator varying Z, L120cm
• ANSYS studies of MAXIMUM JAW TEMPERATURE
  MAXIMUM COOLING WATER TEMPERATURE for specified
  fault scenarios for Phase II secondary
  collimators
• 2d at shower max for 90kW, 1 hr. beam lifetime
  specification
• Time dependent calculations for 10sec. excursions
  to 450kW, 12min beam lifetimes
• 3d calculations
• Installation and benchmarking of SixTrack and
  preliminary new results for particle loss and
  system inefficiency for relevant Phase II
  configurations

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FLUKA Input File
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Heating of Phase I Graphite Secondary
CollimatorsLoss Map1, 450kW Total Loss Rate,
Jaws at 10s
Engineer Graphite TCS as 7kW device for 90kW DC
loss(730/5margin) Handle 30kW for 10 sec as
transient
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Heating of 1.2m Cu Secondary Collimators Phase I
Carbon design In-Line with Same Aperture
14kW
130kW
5kW
30kW
SLAC calculations agrees with CERNs to 5 for
the two cases presented
Simulation is for 4E11 p/s lost on TCPV
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Initial Design Paradigm
Replace C Phase I SC with Cu so than Collimation
System Efficiency is the identical but
Collimation System Impedance is Improved to allow
Design Parameters
11 x 10-4
2 x 10-4
AssmannMay 04
28
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SLAC TEAM

• Lew Keller Energy deposition - FLUKA
• Eric Doyle Engineering ANSYS baseline
  engineering
• Yunhai Cai SLAC ARDA Tracking codes
• Tom Markiewicz Synthesizer
• Tor Raubenheimer New ILC Group Leader
  Supporter
• Andrei Seryi Will help with system design
  tweaks eventually
• Josef Frisch Will help with conceptual design
  once problem better defined

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Plans

• Conclusions of current studies will be presented
  in parallel session on Wednesday and summarized
  in Thursday plenary session.
• Non-bureaucratic Work Plan for immediate future
• Upgrade FLUKA model to detailed and extensive
  system developed over last year by CERN put in
  use July 2004
• Fix Z, L, system inefficiency and loss map via
  tracking studies at SLAC
• Zero-th order conceptual design for cooling flow
  and mechanical support backed by ANSYS for heat
  removal distortion