1 / 39

LHC & ATLAS UPGRADES

LHC & ATLAS UPGRADES. Toronto Group Meeting. Physics Case for LHC Upgrade LHC Issues General ATLAS Issues ATLAS Canada R&D. R. S. Orr. Alors, c’est fini! Et maintenant?. ATLAS Detector Systems. Diameter 25 m Barrel toroid length 26 m Endcap end-wall chamber span 46 m

jontae
Download Presentation

LHC & ATLAS UPGRADES

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 & ATLASUPGRADES Toronto Group Meeting • Physics Case for LHC Upgrade • LHC Issues • General ATLAS Issues • ATLAS Canada R&D R. S. Orr

  2. Alors, c’est fini! Et maintenant?

  3. ATLAS Detector Systems Diameter 25 m Barrel toroid length 26 m Endcap end-wall chamber span 46 m Overall weight 7000 Tons

  4. LHC Prospects • Date for 7 TeV beam commissioning: July 2008 • Initial physics run starts “late” 2008  collect ~10 fb-1/exp (2.1033cm-2 s-1) by “end of 2009” • Depending on the evolution of the machine…  collect 200-300 fb-1 /exp (3.4-10.1033cm-2 s-1) in 5-6 years time Already time to think of upgrading the machine Two options initially discussed/studied • Higher luminosity ~1035cm-2 s-1 (SLHC) • Needs changes in machine and particularly in the detectors  Start change to SLHC mode some time 2012-2014  Collect ~3000 fb-1/experiment in 3-4 years data taking. • Higher energy? • LHC can reach s = 15 TeV with present magnets (9T field) • s of 28 (25) TeV needs ~17 (15) T magnets  R&D + MCHf needed • Don’t discuss today

  5. LHC context in 2011 - 2015 SLHC make be only game in town for a LONG time.

  6. Physics Case for the SLHC The use/need for for the SLHC will obviously depend on how EWSB and/or the new physics will manifest itself This will only be answered by LHC itself What will the HEP landscape look like in 2012?? • Rough expectation for the SLHC versus LHC • Improvement of SM/Higgs parameter determination • Improvement of New Physics parameter determinations, if discovered •  Extension of the discovery reach in the high mass region •  Extension of the sensitivity of rare processes

  7. Indicative Physics Reach Ellis, Gianotti, ADR hep-ex/0112004+ updates Units are TeV (except WLWL reach) Ldt correspond to 1 year of running at nominal luminosity for 1 experiment Approximate mass reach machines: s = 14 TeV, L=1034 (LHC) : up to  6.5 TeV s = 14 TeV, L=1035 (SLHC) : up to  8 TeV s = 28 TeV, L=1034 : up to  10 TeV † indirect reach (from precision measurements)

  8. The Higgs at the LHC • First step • Discover a new Higgs-like particle at the LHC, or exclude its existence • Second step • Measure properties of the new particle to prove it is the Higgs • Measure the Higgs mass • Measure the Higgs width • Measure (cross sections x branching ratio)s • Ratios of couplings to particles (~mparticle) • Measure decays with low Branching ratios (e.g H) • Measure CP and spin quantum numbers (scalar particle?) • Measure the Higgs self-coupling (HHH), in order to reconstruct the Higgs potential LHC~1 good year of data SLHC Statistics Needed Make sure it really is Higgs

  9. ~ v mH2 = 2  v2 Higgs Self Coupling Measurements Once the Higgs particle is found, try to reconstruct the Higgs potential Djouadi et al. Too much backgr. SM/2 << 3SM/2 Not possible at the LHC

  10. Higgs Self Couplings LHC :  (pp  HH) < 40 fb mH > 110 GeV + small BR for clean final states  no sensitivity SLHC : HH  W+ W- W+ W-   jj jj studied 6000 fb-1 S S/B S/B mH = 170 GeV 350 8% 5.4 mH = 200 GeV 220 7% 3.8 --HH production may be observed first at SLHC: ~150 <MH<200 GeV --  may be measured with statistical error ~ 20-25% LC : precision up to 20-25% but for MH < 150 GeV (s  500-800 GeV, 1000 fb-1)

  11. SM Brane G G Bulk Beyond the Standard Model • New physics expected around the TeV scale  • Stabilize Higgs mass, Hierarchy problem, • Unification of gauge couplings, Cold Dark Matter,… Extra dimensions Supersymmetry +… + a lot of other ideas… Split SUSY, Little Higgs models, new gauge bosons, technicolor, compositness,..

  12. Discovery reach for squarks/gluinos Time mass reach 1 month at 1033 ~ 1.3 TeV 1 year at 1033 ~ 1.8 TeV 1 year at 1034 ~ 2.5 TeV SUSY : Discovery Reach ATLAS 5 discovery curves 5  discovery reach LHC  2.5 TeV SLHC  3 TeV

  13. SUSY Higgses h,H,A,H Heavy Higgs observable region increased by ~100 GeV at the SLHC. • Green region only SM-like h observable with 300 fb-1/exp • Red line: extension with 3000 fb-1/exp • Blue line: 95% excl. with 3000 fb-1/exp

  14. Time Scale of an LHC upgrade Jim Strait, 2003 radiation damage limit ~700fb-1 time to halve error integrated L L at end of year ultimate luminosity design luminosity • Life expectancy of LHC IR quadrupole magnets is estimated to be <10 years due to high radiation doses • Statistical error halving time exceeds 5 years by 2011-2012 → it is reasonable to plan a machine luminosity upgrade based on new low-b IR magnets around ~2014-2015

  15. Machine Upgrade in Stages • Push LHC performance without new hardware • luminosity →2.3x1034 cm-2s-1, Eb=7→7.54 TeV • LHC IR upgrade • replace low-b quadrupoles after ~7 years • peak luminosity →4.6x1034 cm-2s-1 • low-b quadrupoles plus dipoles, plus crab cavities…. • peak luminosity →15.5 x 1034 cm-2s-1 • LHC injector upgrade • peak luminosity →9.2x1034 cm-2s-1 • LHC energy upgrade • Eb→13 – 21 TeV (15 → 24 T dipole magnets)

  16. Beam-Beam Limit Luminosity Equation injector upgrade LHC+ injector changes LHC + injector changes IR upgrade

  17. Nominal Crossing Angle “at the edge” Piwinski angle luminosity reduction factor nominalLHC

  18. Summary of Luminosity Upgrade Scenarios for with acceptable heat load and events/crossing 25-ns: push to limit • Slim magnets inside detector? • Crab Cavities • High Gradient, Large Aperture Quads 50-ns: Fewer bunches, higher charge • Realizable with • Beam-Beam tune shift due to large Piwinski angle? • Luminosity leveling via bunch length and tuning

  19. stronger triplet magnets optional Q0 quad’s D0 dipole small-angle crab cavity ultimate bunches + near head-on collision Early Separation (ES) • ultimate LHC beam (1.7x1011 protons/bunch, 25 spacing) • squeeze b* to ~10 cm in ATLAS & CMS • add early-separation dipoles in detectors starting at ~ 3 m from IP • possibly also add quadrupole-doublet inside detector at ~13 m from IP • and add crab cavities (fPiwinski~ 0) → new hardware inside ATLAS & CMS detectors, first hadron crab cavities

  20. ES Scenario • merits: • most long-range collisions negligible, • no geometric luminosity loss, • no increase in beam current beyond ultimate, • could be adapted to crab waist collisions (LNF/FP7) • challenges: • D0 dipole deep inside detector (~3 m from IP), • optional Q0 doublet inside detector (~13 m from IP), • strong large-aperture quadrupoles (Nb3Sn) • crab cavity for hadron beams (emittance growth), or shorter bunches (requires much more RF) • 4 parasitic collisions at 4-5 separation, • low beam and luminosity lifetime ~*

  21. Large Piwinski Angle (LPA) • double bunch spacing to 50 ns, longer & more intense bunches with • fPiwinski~ 2 • b*~25 cm, do not add any elements inside detectors • long-range beam-beam wire compensation → novel operating regime for hadron colliders larger-aperture triplet magnets wire compensator fewer, long & intense bunches + nonzero crossing angle + wire compensation

  22. LPA Scenario • merits: • no elements in detector, no crab cavities, • lower chromaticity, • less demand on IR quadrupoles • (NbTi expected to be possible), • could be adapted to crab waist collisions (LNF/FP7) • challenges: • operation with large Piwinski parameter unproven for • hadron beams (except for CERN ISR), • high bunch charge, • beam production and acceleration through SPS, • larger beam current, • wire compensation (almost established),

  23. D0 D0 D0 D0 Principle of Early Separation Stronger focusing with cancellation of the geometrical luminosity loss Full Early Separation (50 ns only if D0 not in inner detector) First encounter First encounter PartialEarly Separation (25 or 50 ns) 25ns preferred by ATLAS D0 is just in front of FCal We need a residual crossing angle

  24. Possible locations in ATLAS A B C D • Stay out of A • B,C possible location of D0, but need more calculations to avoid to damage the muon system • D possible location of Q0 or D0, probably the least problematic one

  25. LHC SLHC s 14 TeV 14 TeV L 1034 1035 Bunch spacing t 25 ns 25/50 ns pp (inelastic) ~ 80 mb ~ 80 mb N. interactions/x-ing ~ 20 ~ 300/400 (N=L pp t) dNch/d per x-ing ~ 150 ~ 2000/2500 <ET> charg. particles ~ 450 MeV ~ 450 MeV Tracker occupancy 1 10/20 Pile-up noise in calo 1 ~9 Dose central region 1 10 Detectors: General Considerations Normalised to LHC values. 104 Gy/year R=25 cm In a cone of radius = 0.5 there is ET ~ 200GeV. This will make low Et jet triggering and reconstruction difficult.

  26. Detector Upgrade • ATLAS has begun studying what needs to be upgraded for 1035cm-2s-1 instantaneous luminosity • ~10 harsher pileup, radiation environment • Also constrained by existing detector: what can be moved/stored where/when • Major ID overhaul foreseen • TRT replaced by Si Strips • Pixels move to larger radius • New technology for innermost layers • Calorimeters • New FE electronics for HEC • New cold or warm FCAL • Opening endcap cryostat implies a long installation schedule (~2-3 years) • Schedule to fit 2016 timescale • Aim for upgrade TDR in 2010 to allow adequate procurement/construction • Also Trigger, FE in general, etc.. etc.. etc…

  27. LAr Calorimeters at sLHC - Overview • Critical issues • ion build up and heat load • The HiLum ATLAS Endcap Project • Radiation hardness: • R&D for HEC cold electronics;

  28. FCal - Heatload EMEC HEC FCal Neutron Shielding Mini-FCal Pump 300mm V Strickland • Simulation of LAr FCAL beam heating • Maximum temperature 93.8K • – recently conclude unlikely that will LAr boil • Improve FCAL cooling (open endcap cryostat)? • ~2-3 year round-trip – big timing challenge • New “warm” FCAL plug? • Main FCAL issue is Voltage drop on protection resistors

  29. +ve Ion Buildup – Distorts Electric Field • EMEC and HEC OK • FCAL: may go above 1 close to inner wall • Turn off inner part of FCAL • Instal mini warm FCAL in front – reduce energy deposited in FCAL1 limit r=1 @LHC limit r=0.1 @sLHC sLHC

  30. HiLum ATLAS Endcap Project • Goal: establish limitations on the operation of the endcap calorimeters (FCAL, EMEC, HEC) at highest LHC luminosities. • R&D: 'mini modules‘ of FCAL, EMEC and HEC type, each in one separate cryostat; • IHEP Protvino: beam line # 23: from 107 up to 1012 p/spill; E= 60/70 GeV; • Arizona, Dresden, JINR Dubna, Kosice, Mainz, LPI Moscow, MPI Munich, BINP Novosibirsk, IHEP Protvino, TRIUMF, Wuppertal.

  31. HiLum Test Modules FCAL module • 4 'standard' HEC gaps (HEC1) • 4 read-out channels • 4 HV lines (one per subgap)

  32. Inner Detector Replacement • Order of magnitude increase in Data rates, Occupancy, Irradiation • No TRT – Si strips • Pixels moved to larger radius • New technology for inner layers • R&D required on sensors, readout, and mechanical engineering

  33. silicon TRT P Nevski Tracks • Preserve (improve?) tracking performance in SLHC environment • Need to replace TRT: all-silicon ID • Minimize material

  34. Strawman Layout of Tracker b layer + 3 pixel layers Semi-projective gaps moderator |η|<2.5 3 short-strip layers (2.5cm) + stereo 2 long-strip layers (9cm) + stereo

  35. Si pixel sensor BiCMOS analogue CMOS digital Cathode (drift) plane Cluster1 Cluster2 1mm, 100V Cluster3 Integrated Grid (InGrid) 50um, 400V Slimmed Silicon Readout chip Input pixel 50um Pixel-layer Technologies • Harshest radiation environment (R~4cm) • – investigate new technologies • 3D Si • Highest signal - fabrication? • Thin silicon + 3D interconnects • Conservative – high voltage • Gas over thin pixel (GOSSIP) • Low material – sparks? • Diamond pixels • Rad hard, low noise, low current • – cost, signal, uniformity? • May test in pre-SLHC b-layer replacement (~2012)

  36. Schedule

  37. Tracker Upgrade work in Canada • Diamond Sensors – Toronto, Carleton, Montréal, Victoria +….. • Prove radiation tolerance of pCVD diamond pixel prototypes • Industrialize bump-bonding • FE electronics • Mechanical structure • Test beam program 2008-2009 • Electronics – Carleton, UBC, York, TRIUMF +….. • FE ASICS – Si FE module controller • Initially FPGA, Move to ASIC • Contribute to system design – develop expertise • Backend (eg RODs) later in upgrade path • TRIUMF Technical manpower

  38. LHC Energy Doubler 14*14 TeV Dipoles: Bnom=16.8T, Bdesign=19T • Superconductor • 16T demonstrated at 4K • 10 years for R&D, 10 years production • 3G$ LHC Energy Tripler 21*21 TeV Dipoles: Bnom=25T, Bdesign=29T • Superconductor HTS-BSCCO or • Well above demonstrated • 20++ years for R&D, ? years production • ?G$

More Related