US LHC Accelerator Research Program

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US LHC Accelerator Research Program
US LHC Accelerator Research Program
brookhaven - fermilab - berkeley

• Jim Strait, Fermilab
• For the BNL-FNAL-LBNL LHC Accelerator
  Collaboration
• SLAC
• 23 April 2003

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Outline

• Program Goals and Organization
• RD to Maximize the HEP Output of LHC
• Fundamental Accelerator RD
• LHC Upgrades
• Coordination with CERN
• Possible SLAC Role???

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Goals of the US LARP

• Advance High Energy Physics
• Help bring the LHC on and up to design
  performance quickly.
• Improve LHC performance by advances in
  understanding and instrumentation.
• Use LHC as a tool to gain deeper knowledge of
  accelerator science and technology.
• Extend LHC as a frontier HEP instrument with a
  timely luminosity upgrade.
• Advance U.S. Accelerator Science and Technology
• Keep skills sharp by helping commission the LHC.
• Conduct forefront AP research and development.
• Advance U.S. capabilities to improve the
  performance of our own machines.
• Prepare U.S. accelerator scientists to design the
  next generation of hadron colliders.
• Develop advanced components necessary for the
  next generation of hadron colliders.

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Initial Organization
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RD to maximize the HEP output of the LHCInitial
Instrumentation Suite

• 1) Tune, Chromaticity, Coupling Feedback
• Tune, chromaticity and coupling feedback
  instruments are crucial for efficiency with
  intense beams At LHC but also RHIC and
  Tevatron.
• Such tools are already being developed at CERN
  and at BNL Collaboration meeting on this topic,
  Fermilab, May 9, 2003.
• 2) Real-Time Luminosity Measurements
• Fast luminosity measurements help keep the beams
  in exact collision.
• Two potential technologies ArN2 ionization
  chamber and CdTe.
• Beam test at Fermilab this year, jointly with
  CERN, to allow direct comparison.
• 3) Longitudinal Beam Density Monitor
• Based on the non-linear mixing of synch.
  radiation with light from a pulsed laser.
• These measurements are essential, with 350 MJ of
  stored energy in the beams.
• We plan to begin RD on this to start in FY2005.

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RD for LHC Upgrades

• HEPAP has set its highest priority on RD for a
  luminosity upgrade
• The science of extending exploration of the
  energy frontier with the LHC accelerator and
  detector luminosity upgrades is absolutely
  central. The RD phase for these will need to
  start soon if the upgrades are to be finished by
  the present target date of 2014.
• HEPAP has set lower priority on energy upgrade
• It is possible that the physics found in the
  next decade at the LHC will be such that it will
  demand such an upgrade, but at this point we
  dont know enough yet either about the science or
  about the specifics of the facility that might be
  proposed. It will require an extensive RD phase.
  
• __________________________________________________
  ____
• High-Energy Physics Facilities of the DOE
  Office of Science Twenty-Year Road Map, HEPAP
  report to the Director of the Office of Science,
  17 March 2003.

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Schedule for Upgrades
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Long-range beam-beam interactions are a potential
performance limit. gt Favor larger crossing
angles.
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New IRs The Major US Role in Upgrades
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Accelerator Physics for Luminosity Upgrade

• Accelerator Physics for luminosity upgrades is
  the earliest AP activity.
• It informs the type of upgrade that can take
  place.
• It is necessary to guide the magnet RD program,
  which must be launched soon and must be launched
  on the right path.
• Close cooperation with CERN required.
• Currently planned work
• Interaction region optics.
• Energy deposition.
• Beam-beam calculations.
• Interaction region field error compensation.
• Beam loss scenarios.
• Effects of and requirements for other machine
  upgrades.

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Magnet RD for Luminosity Upgrade

• Magnet RD will eventually become the largest
  part of LARP.
• Plan to pursue RD on both quadrupoles and
  dipoles
• Quads with the largest possible aperture with Gop
  gt 200 T/m. (FNAL LBNL)
• Large-aperture dipoles for the extreme radiation
  environment of a dipole-first IR. (BNL LBNL)
• Deliverables will be successful RD, leading to
  accelerator-ready magnet design(s).
• Fabrication of production magnets is outside the
  scope of LARP and will be considered a\s a
  separate proposal.

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Coordination with CERN

• Many formal and informal meetings with CERN over
  the past ? 1 year to develop the LARP proposal.
• US-CERN Committee combines leaders of the LHC at
  CERN with leaders of the LARP at the US Labs, and
  provides for formal coordination of the US effort
  with the CERN LHC program.
• The US-CERN Committee, at its first meeting on 10
  April, approved our program plans, as documented
  in a letter from Lyn Evans.

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Possible SLAC Role???

• All upgrade scenarios require substantial RF
  upgrades
• 1.2 GHz RF to shorten bunches, or
• Crab cavities (lots of volts), or
• Broadband cavities to form superbunches
• Many hard beam dynamics problems to reach even
  nominal luminosity.
• High intensity beams
• Large number of bunches
• Beam-beam effects
• Electron-cloud, etc.
• Instrumentation, diagnostics, feedback.
• SLAC collaboration on LHC would be most welcome
• Would need to develop specific proposals (working
  with CERN).
• Would need to discuss funding with DOE.