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LHC – Upgrade: Schedule and Options Physics Motivation Detector Upgrades Machine Upgrade Options

D. Lissauer Brookhaven National Laboratory Presentation to: HEPAP Future Facilities Subcommittee. U.S. Participation in LHC Upgrade. LHC – Upgrade: Schedule and Options Physics Motivation Detector Upgrades Machine Upgrade Options Conclusions Questions/Answers.

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LHC – Upgrade: Schedule and Options Physics Motivation Detector Upgrades Machine Upgrade Options

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  1. D. Lissauer Brookhaven National Laboratory Presentation to: HEPAP Future Facilities Subcommittee U.S. Participation in LHC Upgrade • LHC – Upgrade: Schedule and Options • Physics Motivation • Detector Upgrades • Machine Upgrade Options • Conclusions • Questions/Answers

  2. LHC Schedule & Upgrade Options • LHC Schedule • First Beams April 2007 • Physics Run July 2007 • LHC Upgrade Options • Luminosity upgrade – SLHC : L = 1035 cm-2 s-1 • --extends LHC mass reach by ~ 20-30% • --modest changes to machine • --very challenging for experiment • --time scale ~ 2014 • Energy Doubled LHC - EDLHC: s ~ 25 TeV L = 1034-1035 cm-2 s-1 • --extends LHC mass reach by ~ 1.5-2 for L=1034-1035 • --requires new machine (e.g. 15 T magnets …) • --very expensive option • --time scale > 2020

  3. Physics Potential of SLHC • integrated luminosities : * Detector Performance at SLHC • LHC 100 fb-1/year L  2 x 1034 needs to be similar to LHC. • SLHC 1000 fb-1/year L = 1035 • Higgs physics • rare decay modes • Higgs self-couplings • Higgs couplings to fermions and bosons • Supersymmetry • Heavy Higgs bosons of the MSSM • Mass reach up to 3 TeV • New Gauge Bosons • Strongly-coupled vector boson system • WLZL g WLZL WLWL g WLWL , ZLZL • Extra Dimensions • Quark substructure • Electroweak Physics • production of multiple gauge bosons (nV .ge. 3) • triple and quartic gauge boson couplings

  4. q q VL VL VL Fake fwd jet tag (|| > 2) probability from pile-up (preliminary ...) q VL q ATLAS full simulation Strongly Coupled Vector Boson System If no Higgs, expect strong VLVL scattering (resonant or non-resonant) at • Difficult at LHC • At SLHC • degradation of fwd jet tag and central jet veto due to pile-up • BUT : factor ~ 10 in statistics  5-8 excess in W+L W+L scattering •  other low-rate channels accessible

  5. Indicative Physics Reach Units are TeV (except WLWL reach) Integrated luminosities correspond to 1 year of running at nominal luminosity for 1 experiment PROCESS LHCSLHC EDLHC 14 TeV14 TeV 28 TeV 100 fb-11000 fb-1 100 fb-1 Squarks 2.534 WLWL24 4.5 Z’ 568 Extra-dim (=2) 91215 q* 6.57.5 9.5  compositeness 3040 40

  6. LHC SLHC s 14 TeV 14 TeV L 1034 1035 Bunch spacing t 25 ns 12.5 ns pp (inelastic) ~ 80 mb ~ 80 mb N. interactions/x-ing ~ 20 ~ 100 (N=L pp t) dNch/d per x-ing ~ 150 ~ 750 <ET> charge particles ~ 450 MeV ~ 450 MeV Track density 1 10 Pile-up noise in cal 1 ~3 Dose central region 1 10 Detectors: General Considerations

  7. ATLAS

  8. CMS

  9. Inner Tracking • The inner tracker will need to be re-built using higher granularity detectors in a harder radiation environment in order to preserve the current pattern recognition, momentum resolution, b-tagging capability. • aRadiation increase by ~ 10. • a To keep Occupancy constant granularity has to increase by a factor 10. • Small Radius Region: Vertex detector (r < ~20cm) • aim for a pixels size factor ~ 5-8 smaller than today • (50x400 mm2g ~ 50 x ~ 50 mm2) gbenefit b-tagging, t-tagging • R&D: • Pixels Sensor Technologies • Super rad-hard electronics to achieve small pixel sizes.

  10. Inner Tracking • Intermediate Radius: ~20<r<~60 cm • Aim for cell sizes 10 times smaller than conventional Si strip • detectors. • benefit: momentum-resolution and pattern recognition • R&D: • Lower cost/channel compared to present Si strip detectors • Si macro-pixels of an area ~1mm2 : pads or shorter strips ? • Single sided two dimensional readout (new concepts) • Large Radius: ~60<r • Large area Si detectors. • Could use present day ‘radiation resistant’ strip technology, • or new single sided technology • R&D: • Similar to intermediate radius – less demanding except for cost.

  11. Inner Tracking Engineering/Integration: Aim at a factor of ~10 more channels but with less material. This means that the System aspects have to be integrated and understood from the start. R&D: new light weight materials for stable structures, Power Multiplexing of readout cooling, alignment installation and maintenance aspects Activation: 250 mSv/h – implications for access and maintenance Timescale : Need ~ 8-10 years from launch of R&D ~ 4-6 years of R&D and prototyping , ~4 years to build,

  12. Calorimeter Increased Luminosity will increase the contribution of the pile up to the noise by a factor of ~ 3. Increased radiation will imply moderate changes to the detectors mostly in the forward direction. R&D: Endcap: find an alternative to plastic scintillator (CMS) Long term irradiation effects on crystals. (CMS) Readout electronics – some will need to be upgraded for increased radiation level. E.g: ATLAS Front end board should be redesigned either by making components more radiation resistant,and/or use analog optical links to bring the signals out.

  13. Muon System • Current ATLAS/CMS Muon systems have a safety factor of 3-5 with respect to background estimations. • Background has strong geometric dependence – • Detectors that now function at high-h at LHC will function at low-h in SLHC • Radio-activation at high h, of shielding, supports and nearby detectors • may limit maintenance access • Strategy: • Balance robust detectors vs. shielding and reduced high-h acceptance • R&D: • Study limits of current detectors – possible use of CSCs at lower h. • At high-h - higher rates – higher granularity CSCs, GEMs?

  14. Level-1 Trigger/DAQ • Increased LHC Luminosity up to SLHC means trigger and DAQ needs to evolve in time. • Reduced Bunch crossing to 12.5 n-sec will have an impact on the Level –1 trigger architecture. • R&D: • Study Required modifications to LVL1 trigger and detector front end • electronics. • Data transfer for processing at 80 MHz sampling. • Synchronization (TTC, etc) becomes an issue for short bunch crossing • period. • How to handle bandwidth (rate  size); is an issue both for readout and • for event building.

  15. LHC Upgrade Options • SLHC Luminosity upgrade to 1035: • -- increase bunch intensity to beam–beam limit  L ~ 2.5 x 1034 • -- halve bunch spacing to 12.5 ns (electron cloud limitation?) • --Reduce * to 0.25 m (from 0.5 m) • --Increase crossing angle. • --Reduce bunch length. (new RF) • --Super Bunch option being investigated. moderate hardware changes time scale  2014 • EDLHC  s upgrade to 25 TeV : • -- ultimate LHC dipole field : B= 9 T  s = 15 TeV •  any energy upgrade requires new machine & Injector • -- present magnet technology up to B ~ 10.5 T • small prototype at LBL with B= 14.5 T • -- magnets with B~17 T may be reasonable target for operation • in >2020 provided intense R& D • on new superconductors (e.g. Nb3Sn) major hardware changes time scale  2020

  16. U.S. Role in Machine R&D • LHC R&D by the U.S. Labs will focus on increasing the luminosity. • Understand the limitations of the current machine configuration, particularly the IRs, and develop proposed modifications. • Low b* insertion sections: (separation dipoles, triplet quads) • Develop high-field Nb3Sn magnets for new low b* insertion … b* ~15-20 cm seems possible. • Next Generation Machine Instrumentation and feedback systems. • Other luminosity upgrade R&D to be addressed by CERN, e.g. • r.f. upgrades – for halving bunch length or handling superbunches • collaborate with U.S. labs on R&D on luminosity upgrade magnets • R&D for EDLHC adequately covered by U.S. base program. • High-field Nb3Sn dipole R&D and BNL, FNAL and LBNL addresses either EDLHC or VLHC.

  17. Conclusions • Physics reach of LHC can be extended significantly by increasing the Luminosity by a factor of 10 or by doubling the energy of the machine. • Luminosity upgrade can be achieved by ~ 2014 • Detectors must preserve (the expected LHC) performance to realize the physics potential. • R&D for both machine and detectors upgrades needs to start soon. (Note that many present ATLAS/CMS detectors started R&D in ’87) Assuming sufficient funds, this is covered by the LHC Research Program. • US Machine R&D projects are well suited to the capabilities at • the three national labs. (FNAL, BNL & LBNL)

  18. Conclusions • Tracking system upgrade is the most challenging. The system • will need to be almost completely rebuilt. Significant R&D is • needed covering the full spectra from generic new materials • to system integration. • Calorimeters and Muon systems should be able to perform well with moderate upgrades.This will involve mostly increasing the radiation hardness of the readout electronics. • Trigger,DAQ will be upgraded – benefiting from commercial developments. • Strong US involvements in the SLHC will ensure significant U.S. presence at the physics frontier for the coming decades.

  19. What is the estimated cost of the tracking upgrade, given the greatly increased channel count associated with the Luminosity upgrade? 2. Can you give more information on the scope and cost of the Nb3Sn magnet R&D for the luminosity upgrade? More generally , what would be the scope of the U.S. part of the accelerator upgrade? 3. What is the scope and cost of the U.S. part of the detector upgrades? Questions from the Committee

  20. The estimate is very preliminary and is based on the following assumptions: The active components of the tracker are all Si. The inner radius has upgraded Si Pixel detectors, followed by Si Strip detectors, in the outer radius we use single sided 2-D Si detectors. The estimate was done by scaling the cost of the ATLAS Si detector as well as information from CMS, and the CDF/D0 upgrade cost. In scaling the costs we had to make assumptions on how the main cost drivers will scale with the number of channels, the area and the expected time evolution. The R&D and final design will have to be driven by optimizing the cost to performance of the overall system. Tracking Cost estimate

  21. Mechanics:The mechanics does not scale with the number of channels. One has to keep the services and the total weight to a minimum. The cost estimate assumes there is added complexity due to light weight: Si Detectors:Scale with the detector area and only marginally with the granularity. The optimization of the number of layers and exact location has not been finalized. The total amount of Si will be factor of ~ 5-10 greater than the present ATLAS detector. Possible cost reduction: Si detectors: Cost is driven to a large extent by the size of the wafers and industry is moving toward larger wafers. Minimize the the amount of Si: by using advances in detector technology. For example single sided 2D readout can be used in the medium and larger radii where the segmentation needs are dominated by tracking accuracy rather than occupancy. Tracking Cost estimate

  22. On detector read out electronics: The readout electronics cost is driven by the number of channels. Take advantage of the reduction in the feature size of the electronics. (ATLAS design used ATMEL/DMILL rad hard technology that has a conservative feature size of 1.2 Micron in the Strips. CMS and ATLAS pixels are using sub micron technology of 0.25 micron) Present industry standard is 0.18 moving toward 0.13 microns. We expect that by the time we go into production the standard feature size will be as low as 0.08 microns. Allowing for a substantial reduction in the power and space needed for the electronics and allowing for finer granularity without an increase in power and space needed. The reduction in power has important implication also on the cooling and services that will be needed. Tracking Cost estimate

  23. Module integration: Module integration costs include costs of Hybrids and the components assembly. In the case of the Pixel detectors the cost of bump bonding Si is a significant part of the module integration. Significant cost reductions are possible assuming one of the integrated developments matures in time. They integrate the readout and the active detector on the same wafer eliminating the need for individual bonds. Cables & Data Links: Assumed a higher level of multiplexing compared to the present solutions. In particular the amount of power cables that need to be reduced for physics (reduced mass), space and cost reasons. Power Supplies: Power supplies will need to be optimized and serve a larger number of modules. This has implication on coherent noise and very detailed system integration will be needed to achieve this. Tracking Cost estimate

  24. Cooling: (Additional)The needed cooling capacity will scale with the number of channels, but we have taken advantage of the lower power requirements of the lower feature size electronics. A large part of the external cooling can be reused. Off detector electronics: (Read out Drivers)We have to take advantage of advances and reduction in the cost of electronics. We assume that a factor of 10 more data 10 years from now will cost factor of ~ 1.5 more than present cost. The Tracker cost for one detector thus estimated to be between 150-180 M$. (assuming the full detector is built in the US) These numbers are only given as a rough estimate. We are not ready for an engineering estimate, which will have to be done after R&D has progressed and better optimization done. Tracking Cost estimate

  25. See note from Jim Strait U.S. Machine R&D

  26. Scope: The U.S. has ~ 20% of the Physicists on both experiments and contributes close to 20% toward the construction of ATLAS & CMS. In the R&D phase of the LHC program the U.S. contributions have been more significant. The U.S. participation in electronics development and production is significantly higher than 20% . We expect this to hold true also in the SLHC era. We note that the Upgrade will take place while the LHC will be fully operational and a large maintenance and operations effort will be in place. The maintenance and operation will be concentrated at CERN. In principle this responsibility will be shared equally between all collaborators. The division of responsibility for the upgrade has not been finalized. We assume the U.S. Share will be the same as during the construction of the experiments. (~20%). There is a good possibility that the U.S. will trade off some of the M&O responsibility for additional responsibility in the Upgrade. . Scope and cost of U.S. involvement.

  27. Cost: The total cost estimate of the upgrade is hard to predict. We expect the main cost to be in the tracking upgrade. The exact scope of the upgrade for the different systems is not clear and will be somewhat different in the two experiments. The split between the different systems and what upgrade will be done will have to be a result of optimization – based on actual LHC experience. One can only make a “straw man” upgrade model for the detector upgrade. This cost does not include R&D that we expect to be covered from the ongoing LHC Research Program. We expect that the experiments share will be more than 2/3 and the rest for the accelerator. U.S. cost for SLHC experiments.

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