• Europe/Zurich
  • English
  • Login
Filter
 
Focus on:  Hide Contributions
iCal export

LHC Collimation Review 2011

chaired by Ralph Assmann (CERN), Mike Seidel (PSI)
from to (Europe/Zurich)
at CERN
Description The "phase 1" of LHC collimation has been fully commissioned, allowing a stored beam energy in the LHC of more than 80 MJ. Its performance has been characterized with beam at 3.5 TeV. This review is considering the present performance, possible limitations in future operation and plans for the upgrade of the system. In particular, it should be reviewed whether the upgrade work in the IR3 dispersion suppressors can be delayed by three years without limiting the LHC performance at 7 TeV.

Review Committee:
Mike Seidel (PSI, chair), Tiziano Camporesi (CERN), Wolfram Fischer (BNL), Brennan Goddard (CERN), Mike Lamont (CERN), Thomas Markiewicz (SLAC), Nikolai Mokhov (FNAL), Andrzej Siemko (CERN), Johannes Wessel (U. Muenster)

Charge:
Review collimation status and upgrade plans. Advise on the following questions:
  1. Are collimation performance and limitations properly analyzed and adequately addressed by upgrade plans?
  2. Can the collimation upgrade in the IR3 dispersion suppressors, presently foreseen for the 2013/4 shutdown, be delayed by three years without limiting LHC performance at 7 TeV?
  3. Have any issues or risks been overlooked that should be addressed in the collimation upgrade plan?
Produce a report, summarizing the recommendations and findings. The committee report is linked as document in the "MATERIAL" section.
Material:
document pdf file
Contact Email: ralph.assmann@cern.ch
Go to day
  • Tuesday, 14 June 2011
    • 09:00 - 09:30 Executive session (closed)
      Location: 40-S2-A01 - Salle Andersson
    • 09:30 - 12:30 Presentations: Overview on collimation system and present results
      Convener: Dr. Ralph Assmann (CERN)
      Location: 40-S2-A01 - Salle Andersson
      • 09:30 Welcome 5'
        Speaker: Dr. Ralph Wolfgang Assmann (CERN)
      • 09:35 Introduction to LHC collimation 20' 
        Collimation system description: multi-stage cleaning, different planes, betatron and momentum. Definition of cleaning efficiency. Introduction quench limit. Hierarchy. Limiting physics processes: single-diffractive p scattering, ion fragmentation, ... Comments on hollow e-beam scrapers.
        Speaker: Dr. Stefano Redaelli (CERN)
        Material: Slides powerpoint file pdf filedown arrow
      • 09:55 Discussion 5'
      • 10:00 Collimation setup and performance 20' 
        How is it adjusted? How does it perform in LHC (loss maps: measurement and simulation). MD results at 3.5TeV and performance reach at 7TeV. Losses in luminosity production (dispersion suppressors). Measurement protons vs ions. Minimum beam lifetime. First SPS results BPM’s in jaws.
        Speaker: Daniel Wollmann (CERN)
        Material: Slides powerpoint file pdf file
      • 10:20 Discussion 5'
      • 10:25 Coffee Break 25'
      • 10:50 Radiation to electronics 15' 
        Issues with radiation to electronics in LHC, with focus on collimation insertions. IR7 versus IR3 sensitivity. Benefit of moving losses from IR7 to IR3.
        Speaker: Markus Brugger (CERN)
        Material: Slides powerpoint file pdf file
      • 11:05 Discussion 5'
      • 11:10 Collimation margins and beta* 15' 
        Stability of LHC machine (orbit, beta). Required margins for collimation setup. Connection collimation to beta*. What beta* can be achieved? Origins of limitations: protection condition, infrequent collimation setups, machine drifts.
        Speaker: Roderik Bruce (CERN)
        Material: Slides powerpoint file pdf file
      • 11:25 Discussion 5'
      • 11:30 Beam-machine interaction: simulation benchmarking vs first LHC experience 15' 
        FLUKA models and predictions. Comparison between measurements and simulations. Safety margins.
        Speaker: Mr. Anton Lechner (Atomic Institute of the Austrian Universities, TU Vienna)
        Material: Slides pdf file
      • 11:45 Discussion 5'
      • 11:50 Collimator design: phase 1 and beyond 20' 
        Short description phase 1 design. Second generation collimators. Improved jaw materials. Collimators for cryogenic regions (warm/cold solution).
        Speaker: Alessandro Dallocchio (CERN)
        Material: Slides powerpoint file pdf file
      • 12:10 Discussion 5'
      • 12:15 Collimation remote handling 10' 
        Highlights from work for collimation remote handling and remote survey. Plans.
        Speaker: Keith Kershaw (CERN)
        Material: Slides powerpoint file pdf file
      • 12:25 Discussion 5'
    • 12:30 - 14:00 Lunch
    • 14:00 - 17:40 Presentations: Motivation and plans for collimation upgrade (with ATS management)
      Convener: Steve Myers (CERN)
      Location: 13-2-005
      • 14:00 Expectations from Review 5'
        Speaker: Steve Myers (CERN)
      • 14:05 Collimation project upgrade plan and questions 25' 
        Outline of collimation upgrade plan. What is planned when and why? What are the questions arising for this upgrade plan?
        Speaker: Dr. Ralph Assmann (CERN)
        Material: Slides powerpoint file
      • 14:30 Discussion 5'
      • 14:35 Dispersion-suppressor upgrade IR3 15' 
        Foreseen work in IR3 for first long shutdown? Short description. Planning aspects.
        Speaker: Vittorio Parma (CERN)
        Material: Slides powerpoint file pdf file
      • 14:50 Discussion 5'
      • 14:55 Proton beam performance with and without IR3 upgrade 15' 
        What is lost when not doing the IR3 upgrade? Gain from DS collimators. Performance reach without (see also morning presentation) and with dispersion suppressor collimators for protons.
        Speaker: Adriana Rossi (CERN)
        Material: Slides powerpoint file pdf file
      • 15:10 Discussion 5'
      • 15:15 Ion beam performance with and without IR3 upgrade 15' 
        Ion performance reach without and with dispersion-suppressor collimators in IR3. Other ion limitations (IR2, ...). Possible impact from delay of IR3 work on IR2 upgrade of dispersion suppressors.
        Speaker: Giulia Bellodi (CERN)
        Material: Slides powerpoint file pdf filedown arrow
      • 15:30 Coffee Break 20'
      • 15:50 Energy deposition with and without IR3 upgrade 15' 
        Predicted energy deposition with and without IR3 dispersion suppressor collimators. Gain from collimators. Performance reach from comparing peak heat deposition with quench limit. Comparison with MD results.
        Speaker: Dr. Vittorio Boccone (CERN)
        Material: Slides powerpoint file pdf file
      • 16:05 Discussion 5'
      • 16:10 Impedance without IR3 upgrade 15' 
        Impedance from tight collimation settings as achieved in MD. Will the beams be stable with impedance, taking into account stabilization from transverse damper and octupoles?
        Speaker: Nicolas Mounet (Ecole Polytechnique Federale de Lausanne (EPFL)-Unknown-Unknown)
        Material: Slides pdf file
      • 16:25 Discussion 5'
      • 16:30 Outcome Risk Review for IR3 Work 20' 
        Conclusions from May review in EN/TE departments. Technical feasibility? Major risks? Any show-stoppers identified?
        Speaker: Philippe Lebrun (CERN)
        Material: Slides powerpoint file pdf file
      • 16:50 Discussion 5'
      • 16:55 Activation issues in dispersion suppressors 15' 
        Expected activation levels. Are additional limits expected on work in dispersion suppressors during later shutdowns?
        Speaker: Stefan Roesler (CERN)
        Material: Slides powerpoint file pdf file
      • 17:10 Discussion 5'
      • 17:15 Radiation damage in dispersion-suppressor magnets 15' 
        Can the radiation dose on unprotected magnets in the dispersion suppressors be accepted? What is the radiation hardness and can unacceptable damage to magnets be excluded, for protons and ions?
        Speaker: Dr. Davide Tommasini (CERN)
        Material: Slides powerpoint file pdf file
      • 17:30 Discussion 5'
    • 17:40 - 17:50 Break
    • 17:50 - 18:50 Executive session (closed)
      Location: 13-2-005
    • 20:00 - 22:00 Review Dinner
  • Wednesday, 15 June 2011
    • 09:00 - 10:30 Discussion of review committee with ATS and project management (closed)
      Location: 13-2-005
      Material: slides powerpoint file pdf file
    • 10:30 - 12:30 Review committee followup and discussions
      Location: 13-2-005
      Material: slides pdf file
    • 12:30 - 14:00 Lunch
    • 14:00 - 17:00 Review committee followup and discussions
      Location: 13-2-005
    • 17:00 - 18:30 Summary and conclusion (with ATS management)
      Location: 13-2-005
      Material: slides powerpoint file pdf file