Support for the Tevatron and Run II

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Support for the Tevatron and Run II

• David Harding
• 4 June 2003

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Fermilab Operates the Highest Energy Particle
Accelerator in the World
1267 Superconducting magnets
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Technical Division Work Supporting Run II

• Magnet measurements
• Characterize performance
• Adjust rebuilt magnets in production
• Certify new, repaired magnets
• Magnet maintenance
• Manage inventory of spare magnets
• Execute repairs as needed
• Magnet upgrades
• Improve performance
• Improve reliability
• Magnet alignment studies
• Miscellaneous mechanical, electrical, and other
  projects

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Superconducting Magnet Program Resources Needed
to Support Run II (1)

• Trained, talented people!
• Engineers familiar with Tevatron devices
• Technicians familiar with Tevatron devices
• Procurement staff able to respond promptly
• Inspectors available as needed
• Measurement and cryogenic personnel with
  experience
• Clerical and computer support
• Committed physicists
• Steady state need for personnel is modest
• Reserve to draw upon in emergency is essential

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Superconducting Magnet Program Resources Needed
to Support Run II (2)

• Good records
• Inventory
• What devices do we have?
• Status, grade
• Engineering documents
• Device drawings
• Documented procedures (travelers)
• Historical records (old travelers)
• Measurement data
• Quench performance
• Field strength and quality
• Special measurements

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Superconducting Magnet Program Resources Needed
to Support Run II (3)

• Components
• Stock of commonly used and long lead time parts
• Reserve of major subassemblies

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Superconducting Magnet Program Resources Needed
to Support Run II (4)

• Facilities
• Production facilities
• Measurement Facilities
• Cryogenic systems
• Power systems
• Instrumentation
• Data storage

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Measurements at MTF

• Purposes of Measurements
• Characterize magnet behavior
• Qualify individual magnets
• Trim magnets in production
• Types of Measurements
• Quench performance
• Harmonic composition of field
• Time dependence of field
• Magnetic center
• Heat leak

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Approach to Maintenance

• Manage a pool of spares
• Good magnets enough for 2 strings, unless both
  are low beta
• Magnets awaiting repair
• When the pool falls below the specified threshold
• Repair enough magnets to restore the level agreed
  upon
• Start with the easiest work, best performing
  devices
• This requires
• Trained technicians, engineers, physicists,
  support staff
• Good records
• An inventory of parts
• Production and test facilities
• Need depth to respond to crisis

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2002 Run II Vulnerabilities Study

• Recommendations relating to TD
• Booster gradient magnets check spares
• Booster orbit bump magnets - study
• Kicker magnets responsibility collect ceramic
  beam tubes
• Tevatron magnets responsibility for tracking
  failures
• Tevatron magnets continue building spares pool
• All devices track with bar codes
• Cryogenic plant change track spool H20 He
  fittings
• Universal understaffed
• Additional concerns
• Loss of institutional knowledge little
  redundancy
• Stability and accessibility of magnet data

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Spool Safety Lead Failure (2001)
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Spool Safety Lead Failure (2003)
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Safety Lead Measures

• Improved design implemented during production
• Operational procedures supposed to prevent
  overheating
• Not practical to retrofit all spools
• Two spools being rebuilt
• Engineering review of operating procedures is
  under way

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Potential Upgrade Project Design of Higher
Strength Tevatron Dipole

• Goal Make more space in Tevatron
• Replace an existing dipole with a shorter,
  stronger one
• Maintain same aperture
• Run on same bus
• Fit in same transverse space
• Match excitation curve
• Build on a tight schedule ? minimize risk so can
  skip prototyping

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Strong Tevatron Dipole Concept

• Design presented to Beams Division
• Two dipoles replace three

• Enough space in ring after all ? will not need
  this for now
• Propose to build prototype since this is a
  recurring question

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Magnet Alignment Issues in Tevatron

• Intersection between magnets and real world
• Many Tevatron dipoles and quadrupoles misaligned
• Important stuff is inside
• Alignment fiducials are outside
• Questions
• Have collared coils moved over 20 years?
• What will happen if we move the yoke?
• What about future movements?

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Tevatron Dipole Cross-section

• Potential changes
• Translation
• Rotation

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Coil Position in Yoke

• Translation ? quadrupole field
• Sample of 80 dipoles in tunnel shows coil
  movement down
• Simple assumption matches measured effect on beam
• Old data problematic
• May lead to reshimming in situ
• Rotation ? horizontal field
• No motion in first several years
• Need to revive old technique
• TD offering advice

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Mechanical Roll Test

• Questions
• Can we realign magnets in the tunnel cold?
• Will anything break?
• Will collared coil move with iron yoke?
• Will adjacent coil or yoke move, too?
• Plan
• First test warm at MTF
• Then test cold at MTF
• TD will offer advice

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Monitoring of Future Movements

• If the Tevatron is realigned, how can we know
  that it stays that way?
• Task force is designing an elaborate monitoring
  system
• Technical Division is helping at the level of one
  engineer and part of one physicist

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Miscellaneous Projects

• Design and build a windowless transfer line
  Main Injector to Recycler
• Build a flying wire beam profile measurement
  system for the Recycler
• Analyze the mechanical vibrations in the Tevatron
  RF cavities and their effect on the beam
• Build additional electrostatic separators for
  Tevatron
• Document the layout and mechanical aperture of
  the AP2 beam line and Debuncher ring
• Assemble kicker pulse forming lines

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Summary

• Support for Run II Is essential
• Magnetic measurements continue to be needed
• Failures happen and magnets must be repaired
• A wide variety of Run II issues can be addressed
  by Technical Division expertise
• A healthy superconducting magnet program is
  necessary to support Run II