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Session 1 Summary - LHC and GSI Complex Upgrades. Emmanuel Tsesmelis CERN TS-LEA 1 st CARE-HHH-APD Workshop 11 November 2004. Scientific Objectives for LHC Upgrade (R. Aymar).
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Session 1 Summary -LHC and GSI Complex Upgrades Emmanuel Tsesmelis CERN TS-LEA 1st CARE-HHH-APD Workshop 11 November 2004
Scientific Objectives for LHC Upgrade(R. Aymar) • While keeping as the utmost priority the completion of the LHC Project (machine & experiments) and the start of operations in Summer 2007, the proposed strategic orientations for CERN activities in 2004-2010 include • the development of detailed technical solutions for a future LHC luminosity upgrade to be commissioned in about 2012-2015. • launch in the period 2004-2006 studies in cooperation with other laboratories
Scientific Objectives for LHC Upgrade(R. Aymar) • Studies in the following areas: • Definition of the Linac4 (160 MeV H-), in relation with the European Programme for a High Intensity Pulsed Proton Injector (HIPPI). • Definition of modifications to the magnets in the interaction regions at two crossing points of the LHC beams, linked with the European programme Next European Dipole (NED) aiming at 15 Tesla. • Definition of upgrades to the ATLAS and CMS detectors to withstand a factor 10 higher luminosity.
Scientific Objectives for LHC Upgrade(R. Aymar) • In 2009-2010 review and re-define the strategy for CERN activities in the decade 2011-2020 in light of the first results from the LHC and of progress and results from previous actions. • Possible choices are presently quite open.
Relevance of Possible Upgrades of CERN Accelerator Complex for Fixed Target Physics (J. Engelen) Reasons for considering new multi-GeV high intensity proton accelerators
Physics Motivation – Extend LHC Physics Discovery Reach (D. Denegri) Experiments consider that the total integrated luminosity, acquired in stable running conditions, is of primary importance.
Physics Motivation – Extend LHC Physics Discovery Reach (D. Denegri) • If no (light) Higgs, consider new strong interaction regime in VLVL scattering • These studies require both forward jet tagging and central jet vetoing. LHC: S/B ~ 4 SLHC: S/B ~ 10
Physics Motivation – Extend LHC Physics Discovery Reach (D. Denegri)
Physics Motivation – Improve Precision Measurements (D. Denegri) • Higgs-to-fermion-boson couplings • Triple gauge boson couplings • SUSY mass measurements (for rate limited processes)
Detector Considerations (D. Denegri) • To fully profit from increased luminosity assume similar detector performance as LHC • Discoveries at higher masses could be done with calorimetry and muon systems only • Precision measurements and understanding of new phenomena require: • Identification & precise reconstruction of high pT objects (electrons, photons, tau-leptons, b-jets…) • Good tracking capabilities and background rejection • Forward jet tagging
Detector Considerations (D. Denegri) • Tracker • To be replaced due to increased occupancy • Need improved radiation hardness for sensors & electronics • present Si-strip technology is OK at R > 60 cm • present pixel technology is OK for the region ~ 20 < R < 60 cm • at smaller radii new techniques required (diamond, cryogenic Si) • Calorimeters: ~ OK • Degradation of energy resolution due to pile-up events • Endcap HCAL scintillators in CMS to be changed • Endcap ECAL VPT’s and electronics may not be sufficiently rad-hard • Increased granularity of very forward calorimeters for jet tagging • Muon Spectrometer: ~ OK • Acceptance reduced to || <~ 2.0 to reinforce forward shielding • Occupancy degradation due to additional hits • Trigger(L1) largely to be replaced • L1(trig.elec. and processor) matched to bunch crossing frequency
Bunch Spacing and the Detectors • With 25 ns-based TRIDAS there will be on average 25000 inelastic events in the case of super-bunches • 20 with nominal LHC scheme and 125 with 12.5 ns bunch spacing • Experiments cannot see how increase in luminosity can be exploited in the case of super-bunch • Preference from experiments for • Shorter but finite bunch spacing (e.g. 10, 12.5, 15 ns) • To reduce effect of minimum bias events • Eases pattern recognition for tracking and reduces pile-up in calorimeter
Integration of Machine Elements in Detectors Integrate machine magnet elements with detectors?
Technology Challenges for LHC Upgrade(W. Scandale) • At present only serious candidate to succeed NbTi is the intermetallic compound Nb3Sn • R&D started within framework of CARE-NED • Series of record-breaking dipole magnet models operating in 10-to-15 T field range • However, not yet of accelerator class
US-LARP Contribution (S. Peggs) • BNL, FNAL, LBL, Stanford collaborate with CERN on LARP to: • Help produce more luminosity earlier. • Collaborate in an LHC IR upgrade to increase luminosity later. • To use, develop & preserve unique US resources & capabilities. Complementary to CARE
US-LARP Contribution (S. Peggs) • Improve long-term physics research opportunities of the LHC by providing magnet options for an LHC luminosity upgrade • Large aperture, high gradient quadrupoles (main emphasis) • High-aspect ratio, large aperture separation dipoles • Deliverable is a successful R&D program, leading to accelerator-ready magnet design(s) (production magnets are outside LARP scope)
US-LARP Contribution (S. Peggs) FY04 Quadrupole Development FY04 Dipole Development
FAIR – Facility for Antiproton & Ion Research at GSI (W.F. Henning)
FAIR – Facility for Antiproton Ion Research at GSI (W.F. Henning) Common areas of R&D with LHC Upgrade
Conclusions and Outlook • LHC Upgrade would provide significant extension to the LHC physics reach. • The challenge of increasing LHC luminosity towards 1035 cm-2 s-1 is considerable (for both machine & experiments) • Must consider several ways to achieve it. • Must choose R&D directions carefully. • Must start R&D now. • Resources are limited and convergence among the various options needs to be encouraged.
