Hadron Collider Jos Engelen CERN Physics at the Terascale The LHC brief overview and status The LHC experiments brief overview and status Standard Model and Beyond 2 x8 gauge ID: 1043632
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1. 1Highlights from the Large Hadron ColliderJos EngelenCERNPhysics at the TerascaleThe LHC: brief overview and statusThe LHC experiments: brief overview and status
2. Standard Model and Beyond(?)2x8gaugeThe Supersymmetric world? One supersymmetric partner for each ‘standard’ particle –the Higgs sector becomes slightly more complicated: 5 supersymmetricHiggs bosonsHThe Higgs sector – ‘the unknown’
3. 3The ‘Standard Model’is a wonderful model for describing the fundamentalparticles and fields and their interactions, it provides aquantitative description of all experimental results so far, but:the model invokes a mechanism for dealing with mass: it is an empirical fact that certain field particles (W, Z bosons) carry mass, incorporating this in the theory is highly non-trivial – it requires the introduction of a new field (Higgs field) and corresponding particle (‘the Higgs’): this particle has never been found by an experiment it will be at the LHCthe model would ‘go wrong’ at high energy without the Higgs particle (or other ‘new physics’)‘unification of forces’ at very high energy could be revealed by a new trend setting in at LHC energy: ‘supersymmetry’
4. 4‘The Terascale’Based on ‘extrapolations’ from our presentunderstanding and on quite general theoreticalinsights we expect the ‘new physics’ to manifestitself at an energy around or below 1 Tera-electronVolt = 1012 electronVolt, i.e.at the Terascale accessible at the LHC for the first time(and only at the LHC for years to come!)
5. Quark Gluon PlasmaThe LHC will also provide Pb Pb collisions at574 + 574 TeVallowing unique contributions to the studyof a quark gluon plasma
6. Accelerator and ExperimentsUndergroundcircular tunnel27 km circum-ference; 100 munderground4 caverns forexperiments ()xxxxRFBDATLASCMSLHCbALICE*6
7. AcceleratorCollisions of 7,000 GeV on 7,000 GeV protons(for reference: proton mass = 1 GeV)Luminosity 1034 cm-2s-1(collision rate normalized to cross section)Innovations: ‘2 in 1’ superconducting 8.3 T dipoles (operating temperature 1.9K) focusing s.c. quadrupolesChallenges: collimation (350 MJ stored energy per beam, can melt 800 kg of copper) and furthermore the mere size of the system, e.g. more than 33,000 tonnes of ‘cold mass’, 27 km of cryogenic distribution line, etc.
8. Accelerator complex(1959)Biggest ring = 27 km circumference
9. R&Dpre-productionindustrialproduction1232plusspares
10. Van streng tot kabel10NiTi filamenten, 7(geproduceerd viaextrusie)
11. In the tunnelMagnetinter-connectQuality controlandQuality assurance
12. 6 superconducting bus bars 13 kA for B, QD, QF quadrupole20 superconducting bus bars 600 A for corrector magnets (minimise dipole field harmonics)42 sc bus bars 600 A for corrector magnets (chromaticity, tune, etc….) + 12 sc bus bars for 6 kA (special quadrupoles)13 kA Protection diodeTo be connected: Beam tubes Pipes for helium Cryostat Thermal shields Vacuum vessel Superconducting cables Magnet Interconnect
13. In the tunnelJumper connectingcryogenicdistributionline and magnets(once every~100 m)(early photo,tunnel practicallyempty)
14. In the tunnelBeam deliverytowardsinteractionpointCurrent distributionusingHigh TemperatureSupercondutorcurrent leads
15. LHC StatusInstallation completecryogenic distribution lineinjection linessc dipoles and quadrupoles; interconnectinner triplets preparing beams for collisionRF stations (sc) for acceleration 450 GeV 7000 GeVbeam dumpscollimationbeam instrumentationHardware commissioningcool-down completepressure tests powering testsCommissioning with beamcirculating beamsColliding beamsRestart Spring 2009
16. 16The Large Hadron Collider project saw a wonderfulstart of operations on September 10, 2008:LINAC, Booster, PS, SPS were accelerating beam to 450 GeV for injection into the LHCThe injection lines (TI8, TI2) transported the beam to the LHCThe injection kickers sent the beam(s) into the LHCCirculating beams, in both apertures, were established for the first time, with the whole world looking over our shoulders, in a matter of hoursThe LHC experiments were ready and operational as planned and recorded beam related (timing!) data immediatelyThe Worldwide LHC Computing Grid was up and runningStart of Operations
17. 17Start of OperationsDuring the days following September 10 someunreliable (‘old’) elements of the electricalinfrastructure (transformers) had to be repaired/replaced,but the preparations for collisions continued, one othervery important milestone was passed easily, not becauseit was easy but because of excellent preparations:the RF system captured the beamthe road to first beam-beam collisions was now fully open
18. 18Final Hardware CommissioningThe magnets in Sector (‘Octant’) 34 had not beencommissioned yet to full current for operationat 5 TeV (i.e. commissioning to 5.5 TeV)The 7 other octants of the LHC had been commissionedto 5 TeV (and well above) without problemsOn September 19 (around 11:18) an incident occurred,leading to a large Helium leak in sector 34 – cold Heliumescaped into the tunnel, the insulation vacuum was broken(up to vacuum barriers), the beam vacuum was broken(up to sector valves)
19. 19Recovery Sector 34It is now clear that recovery of Sector 34 will takeuntil (‘into’) the planned (and obligatory) Wintershutdown – LHC operations will restart Spring 2009.A precise planning is being worked out. The nature of the incident has been understood– it is due to an electricalfault (resistive splice in interconnect)The loss of the insulation vacuum lead to some collateraldamage – the logistics of the repair program are beingworked out. Very importantly: diagnostic tools are being designed toavoid such problems in the future
20. 20Schedule of ExperimentsThe experiments will now go into ‘long shutdown’ mode,to be ready again in early Spring 2009: a more precisedate will be agreed with them as soon as this is possibleMost experiments have identified a useful and/or necessaryprogram of work of 4 – 5 months: repairs, refurbishments,improvements, additional installation workEverybody involved in the LHC project is as motivated asever (or more motivated than ever) to overcome thistemporary setback! Everybody has reacted professionallyand with determination.
21. 21The successful start-upThe behaviorof the beams was excellent and understood
22. Cross-section of LHC cryodipole
23. Cooldown Status
24. Cooldown Status
25. RF cavities
26. The RF cavities and transverse dampersCourtesy Edmond CiapalaPreparation for BeamRF synchronization in place – clocks and timing now going from SR4 to all users. Recent successful dry run tests with all users and OP group, including basic software.Procedures for beam commissioning well defined.Longitudinal diagnostics in good shape to study and commission first beams….Fibre-optics signal distribution from RF in SR4 to Experiments, BT & BI equipment and to CCC.40 MHz bunch clocks, revolution frequencies,40 MHz 7TeV reference. Injection & dump kicker pulses
27. SynchronisationCourtesy Roger Bailey
28. Injection Region
29. 08 08 08Friday 15:20Beam on to TI2 TEDMSI etc pulsingCycle LHC Sector 23OPBeam down TI2 first shot Friday 19:00TI2 TED out, beam to TDI, kickers offGive Alice 20 minute warning before taking TED outINJBeam on TDI after correction end TI2Friday 21:00Kickers on, time in, position checksResolve timing issuesINJInteresting collaboration between timing and RFFriday 21:40TDI out - threading - momentum matching - beam to IR3 Jorg & teamBeam to IR3 first shot. Tweak SPS. Courtesy Roger Bailey
30. First Trajectory
31. Kick response compared with theoretical optics
32. Dispersion 2-3 The trajectory of the off-momentum (1 per mil) beam. On the far left is the end of TI2 where there are no measurements. It goes through LSS2 and Alice with practically zero dispersion. In the arc there is a slight mismatch which is of no consequence and LSS3 it perfectly maps the large dispersion bump from positive to negative that is designed to stop uncaptured particles (which will be lost as the field rises since they are not accelerated) on the collimators.The vertical dispersion (bottom) is zero as it should be.
33. 33
34. Beam on turns 1 and 234Courtesy R. Bailey
35. Few 100 turns35Courtesy R. Bailey
36. Dump dilution sweep36
37. No RF, debunching in ~ 25*10 turns, i.e. roughly 25 mS37Courtesy E. Ciapala
38. Capture with optimum injection phasing, correct reference38Courtesy E. Ciapala
39. The LHC experiments haveseen first ‘man made’ beam
40. ALICE DetectorTPCPHOSMuon armTOFTRDHMPIDPMDITSACCORDE
41. Injection testsSPD/SSD, Sunday, 15.6Dump on TEDSPD hits versus bunch intensity(beam through ALICE)FMD hits versus SPD hits(beam through ALICE)FMD event display(1 bunch through ALICE, > 100 000 hits)
42. Single turnDouble turn, beam 1 back at point 2 !Luminosity monitor (V0)
43. Trigger timing (before alignment) versus bunch numbersingle shotfor SPD, V0, beam-pickup BPTX, T0 triggersAuto-correlation for SPD trigger, with multi-turn correlations (3564 bunch crossings)Beam pick-upT0SPDV0
44. First interactions 12th SeptemberITS tracks on 12.9.2008 Circulating beam 2stray particle causing an interaction in the ITS
45. 24/10/2007 23rd RRB J. SchukraftTPCParticleIdentificationMomentum ResolutionKrypton Gain Calibration
46. 46LHCb SpectrometerVELORICH1TTMagnetOTRICH2Calo. SystemMuon System
47. LHCb sees tracks from the LHC injection testsSilicon trackerMuon chambersVELO(Run 30933, Event 14)SPD (provided trigger)TED events
48. Beam1 induced OT tracks originating close to the beam pipe
49. 49ATLAS45 m24 mATLAS superimposed tothe 5 floors of building 40LHCC, 24-Sep-2008, PJStatus of ATLAS7000 Tons
50. 50Very first beam-splash event seen in ATLAS (as seen online in the ATLAS Control Room) on 10-Sep-2008 at 10:19
51. 51A busy beam-halo event with tracks bent inthe Toroids from the start-up day (offline)
52. 52Barrel-tracksTRT in the run 22-25 August (a cosmic shower)Shower
53. The CMS Detector
54. Calorimeters: Collimators ClosedEnergy in ECAL (EE-, EB, EE+)ECAL: Splash events provided a source for overall internal synchronization.Crystals were time aligned to within 1ns !
55. WLCGSince CCRC08 in May the experiments have continued to run work at very high levels on the grid infrastructure and continued to keep data transfers running at a level consistent with that expected in data taking. WLCG has seen cosmic data and also the first “events” from LHCb during the second injection test, and data sets from all 4 experiments on Wednesday 9/10. The transfer rates all summer have been in excess of 1 GB/s more or less continuously with higher peaks (the data taking rate is 650 MB/s, twice that for safety). This, and the continuous high rate of job submission has been driven by experiment functional testing, and more and more detector-driven stress tests.
56. ConclusionsThe LHC experiments have followedthe remarkable performance of theLHC machine with an equally remarkableperformance:the detectors work with real beam!
57. 57ConclusionsRecovery of Sector 34 has the highest priorityStart-up in Spring 2009 is now the targetAnd then: a two phased approach to SLHC