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SLHC Tracker Layout. The UTOPIAn Perspective. Charles Young (SLAC). SLHC Parameters. Peak luminosity ~ 10 35 cm -2 sec -1 Average luminosity 4 x 10 34 cm -2 sec -1 Instantaneous rate important for detector layout and design purposes: Number of events per bunch crossing Bunch spacing
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SLHC Tracker Layout The UTOPIAn Perspective Charles Young (SLAC)
SLHC Parameters • Peak luminosity ~ 1035 cm-2 sec-1 • Average luminosity 4 x 1034 cm-2 sec-1 • Instantaneous rate important for detector layout and design purposes: • Number of events per bunch crossing • Bunch spacing • 25 or 50 nsec • Detector integration time • One BC (at 25 nsec separation) UTOPIA Page 2
Four SLHC Scenarios • Frank Zimmermann: four scenarios during February 2009 ATLAS Upgrade Week. • http://indico.cern.ch/conferenceDisplay.py?confId=45460#2009-02-27 • Early Separation (ES) • Full Crab Crossing (FCC) • Large Piwinski Angle (LPA) • Low Emittance (LE) a Large Emittance (LE) UTOPIA Page 3
Luminosity Evolution From FZ’s talk average luminosity UTOPIA Page 4
# Events per Crossing Max = 400 From FZ’s talk UTOPIA Page 5
With Luminosity Leveling Min = 75 UTOPIA Page 6
What is UTOPIA? • A very bad acronym for Upgrade Taskforce On Possible Innerdetector Layout • Members • Leonardo Rossi (Genova - chair) • Andrea Catinaccio (CERN) • Allan Clark (Geneva) • Nigel Hessey (NIKHEF) • Nikos Konstantinidis (UC London) • Andi Salzburger (CERN- DESY) • Teddy Todorov (Annecy) • Jeff Tseng (Oxford) • Norbert Wermes (Bonn) • Charlie Young (SLAC) UTOPIA Page 7
Mandate • The mandate is to define a baseline layout for the central tracker in view of the Letter of Intent ATLAS will write for the SLHC. • As the physics focus of SLHC is not defined yet, we require that the new layout has at 1035cm-2s-1 the same performance as the present detector is expected to have at 1034cm-2s-1. • We should also take into proper consideration the need to build & commission such a detector in a relatively short time (~ 5 years). • The new layout should be optimized for the inner tracker, including pixel, short strip and long strip, and barrel plus endcap simultaneously. • The Task Force is expected to reach a result by October and then hand over the information to the LoI editors. UTOPIA Page 8
UTOPIA Meetings • Meeting every 3 weeks • Six meetings so far • http://indico.cern.ch/categoryDisplay.py?categId=1389 • Some agenda items • Encourage comparison/validation of tools • Suggest layout with material estimates • Power estimate a cooling • Other considerations and wild ideas UTOPIA Page 9
Current “A Basic Layout” • See presentation by Nigel Hessey (http://indico.cern.ch/conferenceDisplay.py?confId=61990) • 4 pixel layers, 3 short strip layers and 2 long strip layers • “Fixed length” barrel UTOPIA Page 10
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Power Estimates • See presentations by Norbert Wermes (http://indico.cern.ch/conferenceDisplay.py?confId=59516) and Alan Clark (http://indico.cern.ch/conferenceDisplay.py?confId=61990) • Consider contributions from: • Front end power dissipation (digital + analog) • Losses in local cabling • Leakage current x depletion voltage (depends on radiation dose) UTOPIA Page 13
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Primary Vertex Density Numbers from FZ’s talk luminosity leveling LHC/ATLAS Without leveling SLHC/Upgrade ~ 100 mm ~20 times higher UTOPIA Page 18
z Resolution • Modified longitudinal impact parameter, zo x sin(q), resolution as a function of h for pions. ATLAS detector paper Figure 10.10 100 mm UTOPIA Page 19
Desired Resolution • LHC/ATLAS:FOM ~ 2368 / 100 ~ 24. • SLHC/Upgrade:FOM ~ 100 / z-res. • Similar FOM implies z-res ~ 5 mm. • Probably impossible. • FOM ~ 3 or z-res ~ 30 mm can be useful and not obviously impossible. Careful studies needed to confirm (or refute) this hand waving! UTOPIA Page 20
Level-1 Track Trigger • See presentation by Nikos Konstantinidis (http://indico.cern.ch/conferenceDisplay.py?confId=59516) • Doublet(s) – direct impact on layout • Regional readout – no direct impact UTOPIA Page 21
Computing Impact • Pattern recognition and reconstruction time driven by combinatorics. • Can a layout make a (large) impact? • Possibilities: • Layer doublets • More pixel layers • What are the costs (in $ as well as physics performance)? UTOPIA Page 22
Summary from UTOPIA • Come up with a basic layout by October • Targeted for Letter of Intent • Upgrade Simulation group doing the hard work! UTOPIA Page 23