1 / 20

LHC Collimation

LHC Collimation. Haroon Rafique. Project B. CERN & LHC What is collimation? Why do we need it (in the LHC)? Hardware Software. CERN. The European Organisation for Nuclear Research Commonly referred to as The European Laboratory for Particle Physics Established 1954

laken
Download Presentation

LHC Collimation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. LHC Collimation Haroon Rafique

  2. Project B • CERN & LHC • What is collimation? • Why do we need it (in the LHC)? • Hardware • Software

  3. CERN The European Organisation for Nuclear Research Commonly referred to as The European Laboratory for Particle Physics Established 1954 Notable accomplishments: • 1973: neutral currents discovered in Gargamelle bubble chamber

  4. CERN The European Organisation for Nuclear Research Commonly referred to as The European Laboratory for Particle Physics Established 1954 Notable accomplishments: • 1973: neutral currents discovered in Gargamelle bubble chamber • 1983: W & Z discovered in UA1 & UA2

  5. CERN The European Organisation for Nuclear Research Commonly referred to as The European Laboratory for Particle Physics Established 1954 Notable accomplishments: • 1973: neutral currents discovered in Gargamelle bubble chamber • 1983: W & Z discovered in UA1 & UA2 • 2012: Boson consistent with Higgs @ ~125 GeV Others: neutrino families, antihydrogen production, direct CP violation…

  6. The Large Hadron Collider • Circumference = 26.659 km • Nominal beam E = 7 TeV • Nominal collision CoM E = 14 TeV • Ultra High Vacuum < 1E-9 mbar • Superconducting NbTi magnets - up to 8.33 T • Cooled via 700k litres of superfluid He @ 1.9K • Largest cryogenic centre in the world • 1232 main dipoles (bending magnets) • ~850 quadrupoles (focussing magnets) • ~6200 higher order correcting magnets

  7. LHC Collimation: The Large Hadron Collider

  8. LHC Injection from SPS at 450 GeV per beam Beam accelerated using 400.8 MHz RF cavities Dipole magnets operate up to 8.33 T Quadrupoles and higher order magnets focus / correct beam optics 2009 E = 3.5 TeV 2012 E = 4 TeV 2014 E = 7 TeV (per beam) 1 GeV = 1x109eV ~ rest mass of a proton (via E = mc2) 1 TeV = 1x1012eV ~ kinetic energy of a flying mosquito

  9. LHC Beam • ‘Beam’ consists of many ‘bunches’ of particles (usually protons) • The bunch distribution is approximately gaussian • Beam halo refers to the gaussian tails i.e. particles with amplitude larger than given aperture size y x

  10. Beam Halo & Blow Up The beam halo is populated due to various phenomena: • Intra beam scattering • Touschek scattering • Beam – gas • Beam – beam • Synchrotron Radiation (3.9 kW power radiation per beam @ 7 TeV, 66 mW @ 450 GeV) – radiation damping

  11. RF acceleration • Particles exist outside longitudinal aperture (outside RF bucket) • Also occurs by Touschek scattering

  12. Collimation – what is it? Collimator: A device for producing a parallel beam of rays or radiation In this case collimation refers to the removal, or ‘cleaning’ of unwanted particles from the accelerator Each LHC ‘beam’ consists of 1374 ‘bunches’ of protons

  13. Collimation – why? • Clean particles with large amplitude to protect the superconducting magnets – avoid quenches • Remove ‘stray’ particles from the beam • Act as an emergency beam dump - TCDQ • Protect valuable ‘triplet’ magnets used at interaction points (IPs)

  14. Crossing in IP1 (ATLAS)

  15. LHC Collimator Hardware Required efficiency > 99.9% • Usually Cu coated W or Graphite ‘jaws’ • Jaws divide or close as required

  16. LHC Collimator Software - MERLIN • C++ class library • Particle tracking • Scattering routines • Lattice Constructor • Losses • Aperture models

  17. Collimator Interactions • Multiple Coulomb Scattering • Ionisation • Rutherford scattering • Elastic pp (proton-proton) pn (proton-neutron) • Inelastic pppn (single diffractive) • pN (proton nuclear)

  18. Cross sections & proton losses Cross-sections for pN interactions and Rutherford scattering for several materials Specified minimum beam lifetimes, loss durations, maximum proton loss rates and power deposition in the LHC collimators in case of normal losses

  19. Collimation System Development Target = 5 x 1034 cm2 s-1 • 2013 shutdown – Increase in Energy • 2020 HighLumi – increased luminosity • New hardware? e.g. Crystal collimators

  20. Acknowledgements Prof. Roger Barlow Huddersfield Dr. Stefano Redaelli Dr.RoderikBruce Dr.ValentinaPrevitali Elena Quarenta CERN BE-ABP James Molson Manchester NGACDT EPSRC Thank You Proton – Lead ion collision, ALICE 13.09.12

More Related