1. SLHC Tracker Layout The UTOPIAn Perspective Charles Young (SLAC)

2. UTOPIA Page 2 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 25 or 50 nsec –Detector integration time One BC (at 25 nsec separation)

3. UTOPIA Page 3 Four SLHC Scenarios Frank Zimmermann: four scenarios during February 2009 ATLAS Upgrade Week. –http://indico.cern.ch/conferenceDisplay.py?confI d=45460#2009-02-27http://indico.cern.ch/conferenceDisplay.py?confI d=45460#2009-02-27 Early Separation (ES) Full Crab Crossing (FCC) Large Piwinski Angle (LPA) Low Emittance (LE)  Large Emittance (LE)

4. UTOPIA Page 4 Luminosity Evolution average luminosity From FZ’s talk

5. UTOPIA Page 5 # Events per Crossing From FZ’s talk Max = 400

6. UTOPIA Page 6 With Luminosity Leveling Min = 75

7. UTOPIA Page 7 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)

8. UTOPIA Page 8 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 10 35 cm -2 s -1 the same performance as the present detector is expected to have at 10 34 cm -2 s -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.

9. UTOPIA Page 9 UTOPIA Meetings Meeting every 3 weeks –Six meetings so far –http://indico.cern.ch/categoryDisplay.py?categId =1389http://indico.cern.ch/categoryDisplay.py?categId =1389 Some agenda items –Encourage comparison/validation of tools –Suggest layout with material estimates –Power estimate  cooling –Other considerations and wild ideas

10. UTOPIA Page 10 Current “A Basic Layout” See presentation by Nigel Hessey (http://indico.cern.ch/conferenceDisplay.py?c onfId=61990)http://indico.cern.ch/conferenceDisplay.py?c onfId=61990 4 pixel layers, 3 short strip layers and 2 long strip layers “Fixed length” barrel

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13. UTOPIA Page 13 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)http://indico.cern.ch/conferenceDisplay.py?confId =59516http://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)

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18. UTOPIA Page 18 Primary Vertex Density Nominal LHC ESFCCLELPA Peak Luminosity10 34 cm -2 sec -1 1.015.5 16.310.7  (luminous)cm4.53.7 1.65.3 N event 1975 150  / N event mm2368493 213353 Density ratio=1.04.8 116.7 N event 19294 309403  / N event mm2368126 52132 Density ratio=1.019 4618 ~20 times higher Numbers from FZ’s talk SLHC/Upgrade ~ 100  m luminosity leveling Without leveling LHC/ATLAS

19. UTOPIA Page 19 z Resolution Modified longitudinal impact parameter, z o x sin(  ), resolution as a function of  for pions. ATLAS detector paper Figure 10.10 100  m

20. UTOPIA Page 20 Desired Resolution LHC/ATLAS: FOM ~ 2368 / 100 ~ 24. SLHC/Upgrade: FOM ~ 100 / z-res. Similar FOM implies z-res ~ 5  m. –Probably impossible. FOM ~ 3 or z-res ~ 30  m can be useful and not obviously impossible. Careful studies needed to confirm (or refute) this hand waving!

21. UTOPIA Page 21 Level-1 Track Trigger See presentation by Nikos Konstantinidis (http://indico.cern.ch/co nferenceDisplay.py?confId=59516)http://indico.cern.ch/co nferenceDisplay.py?confId=59516 Doublet(s) – direct impact on layout Regional readout – no direct impact

22. UTOPIA Page 22 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)?

23. UTOPIA Page 23 Summary from UTOPIA Come up with a basic layout by October Targeted for Letter of Intent Upgrade Simulation group doing the hard work!