LARP Magnet Progress

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LARP Magnet Progress
US LHC Accelerator Research Program
bnl - fnal - lbnl - slac

• Michael Lamm
• For the LARP Collaboration

All Experimenters Meeting Monday, October 8, 2007
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US Accelerator Research Program (LARP)

• ?What is LARP ?
• US Accelerator Specialist to play role in LHC
  Accelerator, commissioning, operation and
  performance upgrades
• Fermilab AD/APC/TD play major role

• ?Magnet LARP Motivation
• Existing 70 mm NbTi IR quads will likely be
  replaced after 4-7 years of operation to increase
  luminosity
• We want to play a major role with CERN in
  developing these magnets

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IR Higher Luminosity Replacement Magnets

• IR Environment (low b, more interactions)
• Wider beam profile, Larger Gdl, Higher energy
  deposition, More Radiation

• Implications for Magnet Design
• Wider Aperture, Higher Gradient ? Higher field
  on conductor, SC Temperature Margin, Rad
  Hardened Materials

• Utilize Nb3Sn Superconductor
• Improved Nb3Sn magnet technology
• Improved Nb3Sn conductor
• Rad Hardened structure

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Nb3Sn has been around for a while.

• 1960-1990 Nb3Sn/NbTi on parallel path
  
• Alternative for Isabelle
• SSC development
• LHC 4.2 K Nb3Sn vs. 1.9K NbTi

NbTi Wins!

• 1990s Generic RD to push envelope
• Twente, LBNL, achieve up to 14. 7 T

Nb3Sn Tape BNL W. B. Sampson, circa 1967

• 21st Century, Nb3Sn revisited for future VLHC,
  LHC upgrade
• Conductor improvements in Nb3Sn vs. Field
  limitations in NbTi
• Several participants by now... BNL, FNAL,
  LBNL,TAMU, CEA, Twente, KEK
• 10s of 1 meter models magnets successfully
  built,
• mostly in the US.

But never used in an actual accelerator
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LARP 2009 Challenge

• Demonstrate that Nb3Sn magnets are a viable
  choice for an LHC IR upgrade

Milestone set in agreement with CERN

• ? Technological Quadrupoles (TQ) for performance
  reproducibility
• 1 m long, 90 mm aperture Cos(2q), Gnom gt 200 T/m,
  Bcoil gt 12T
• ? Scale up to 4 meter long (LQ)
• TQs-like cross section and mechanical structure,
  experience from two long magnet intermediate
  studies

• ? High gradient quadrupoles (HQ) to explore
  performance limits
• 1 m long, 90 mm aperture, Gnom gt 250 T/m,
  Bcoil gt 15 T

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Technological Quadrupoles

• Two mechanical designs are under development
• Same coils / Aperture 90 mm / Gradient gt 200
  T/m _at_ 4.2K

TQC using collars Collar laminations from LHC-IR
quads 1st time applied to Nb3Sn coils
TQS using Al-shell Pre-loaded by bladders and
keys 1st time applied to shell-type coils
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Recent TQ Test Results at Fermilab
TQE02 Build a TQC magnet with TQS02 coils Direct
comparison of mechanical structures To be tested
early Oct (this week!)
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Plan for Length Scale-Up
LENGTH SCALE-UP CHALLENGE No Nb3Sn accelerator
magnet longer than 1m has ever been built LARP
should make a successful 4m long quadrupole by
end of 09
Scale up quad (LQ) will be a 4 meter longer
version of the TQ with TQS, TQC or hybrid
structure

• Design Inputs to LQ
• TQ results and design studies
• Long mirror
• 2 m/4 m Nb3sn Cos (q) Dipole with COLLAR
  structure
• Long race track
• 4 m Nb3Sn Racetrack coil with SHELL Structure

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LARP Long Racetrack
Reported in Sept 7, 2007 Fermilab Today

• The goals of the Long Racetrack (LR)
• fabricate and test long Nb3Sn racetrack coils
• test an Al-shell-based supporting structure
• (preloaded using bladders and keys)

• Results
• Iqgt 90 ssl

LBNL Designed BNL Built/tested
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FNAL Long Mirror

• This magnet is a base program contribution in
  support of LARP
• FNAL Mirror magnet is a Nb3Sn cos(Q) dipole
  where a coil is substituted by iron blocks.
• Long cos(Q) coils fabrication/reaction and collar
  mechanics prior to LQ

LM02 quench history at 4.5K compared with 1m
model
Front view of mirror magnet
Successful 2m mirror magnet test in May 2007 4m
mirror magnet will be tested in November
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LQ Status/Future Plans

• We are developing a plan whose goal is to produce
  2 4-meter long LQs by the end of CY 2009
• Program leader for LQ has been chosen (Giorgio
  Ambrosio)
• Program will involve all three participating LARP
  Magnet Labs
• Major issue to be decided is the mechanical
  structure
• There will be an external review of the LQ
  program in late November

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LARP Magnet Status

• Several TQ Magnets have been built. All of them
  work well. Performance improves with successive
  rebuilt due to increased understand of mechanics
  and coil fabrication.
• Scaleup to 4 meters is underway. 4 meter long
  racetrack and 2 meter long mirror dipole (4 meter
  test soon) LQ plan for 4 meter long cos(Q)
  underway
• Beyond LQ several LARP activities toward final
  goal of Nb3Sn accelerator magnets (local leaders)
• Conductor Studies for higher Jc better conductor
  stability (Barzi)
• Join AP/Magnet IR studies (Zlobin)
• HQ quad model program (project leaders at LBNL
  but with contributions from Fermilab on magnetic
  design for e.g.)
• 1.9K Test facility and instrumentation upgrades