James T Volk

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NLC - The Next Linear Collider Project
Report on Magnet Group Status May 7th 2002 J
Volk, C Spencer, B Parker
10/03/2001

• James T Volk

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Topics

• BBA alignment
• PM quad Measurement
• EM Quad Measurement
• Radiation Issues
• Vibration
• Final Focus Magnets
• Operations Costing and Availability

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BBA

• Continuing to measure the Wedge quad and EM to
  understand center stability
• Working on new ideas to improve center stability
• Tuning rod adjustment schemes
• Passive adjustment to wedge quad poles
• Low flux issues for EM and PM quads
• Working with PT to refine requirements

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SLAC Rotating Coil Data
May 2002
James T Volk
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New data on the electromagnetic quad with
improved magnetic measuring set-up
The SLAC rotating coil measuring set-up has been
improved a 5kW electric direct immersion water
heater with an SCR controller has been put in the
incoming cooling water circuit. Variations of
4C in LCW temp reduced to /- 0.1 C . Above
plots show water temperatures during a 2.5 day
run at 80 amps.
James T Volk
May 2002
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Radiation Damage

• Investigating SLC radiation measurements and NLC
  predictions on rates as it impacts Permanent
  Magnets
• Measuring SLC radiation fields ID particle type
  and rates
• Starting measurements on radiation damage at SLAC
  and FNAL
• Continuing literature search
• International collaboration with Japanese groups
  already doing radiation damage studies

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Vibration

• Doing measurements on EM quad and water flow
• Working with ground motion group to understand
  sources
• And Accelerator groups to understand
  requirements imposed on magnets due to vibration

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Developing Methodologies to Estimate Overall
Magnet Costs- including repair costs

• Use real failure data of magnets from similar
  accelerator to predict how often there will be
  failures of the magnets in the NLC. Estimate for
  a particular failure scenario how much it will
  cost to fix the failure accounting for all
  aspects of the repair and the lost opportunity
  costs (for those failures happening during
  operations, when the accelerator is un-useable
  have to ascribe an opportunity cost per hour).
• For real failure data took all the magnet
  failures that brought down any beamline in SLAC
  during 5 year period. Using downtime reporting
  database we scrutinized every one of 75 failures
  as to its cause, type of magnet, length of time
  to detect and repair.
• Calculated number of SLAC magnets running during
  any period and how many hours they ran to
  calculate mean time between failures.
• Calculate availability values and extrapolate
  them to known number of NLC magnets running for
  30 years. Estimate cost to fix all failures.

James T Volk
May 2002
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Final Focus Magnet
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Final Focus Magnet