The ATLAS S emiConductor Tracker commissioning at SR1

1. The ATLAS SemiConductor Tracker commissioning at SR1 Ryuichi Takashima（Kyoto Univ. of Education） For the Atlas SCT collaboration APS and JPS joint conference October 30, 2006 SR1

2. AToroidal LHC ApparatuS (ATLAS) Muon Spectrometer(<2.7) MDT/CSC, RPC/TGC air-core toroidal magnet Bdl = 2~6Tm (4~8Tm) Inner Tracking (<2.5) Pixel, Silicon Strip, TRT 2T solenoid magnet good e/g id, t/b-tag Calorimeter (<4.9) Liq.Ar EM/HAD/FCAL, Tile HAD good e/ id, energy, ETmiss

3. SCT Barrel 4 layers, 2112 modules Binary read out via opt fiber, work independently 1492mm SCT Endcap A,C 9 disks, 1976 modules

4. The SCT Barrel module Strip pitch:80mm Stereo Angle:40mrad • Survive through direct • irradiation by primary proton beam • Operational until 4X1014protons/cm2 . • deep submicron technology gives • the radhard feature to the ABCD3T chip. • remarkable precision < 5 mm • by exquisite construction • procedure. • Channel by channel adjustment of threshold to give uniform response to signal. • Two readout links can bypass through a dead chip. • Chips generates ~6W. • Elaborate thermal • property design needed. • Carbon has good • thermal conductivity.

5. Goals of SR1 Commissioning • Detector Operation & Commissioning of System: • Gain experience with detector operation • Test combined detector supply systems • Development of standalone & combined monitoring tools • Commission and test combined readout and trigger • Commission offline SW chain with real data • The detector performance aspects: • TRT performance with SCT inserted and powered • Test 4 SCT barrels together and operation with TRT • Checks of grounding for SCT and TRT • Test synchronous operation and check for X-talk and noise • Collect cosmics for efficiency, alignment & tracking studies

6. Assembly at Oxford

7. Barrel 3 insertion into Barrel 4,5,6 and thermal enclosure

8. Barrel SCT insertion into barrel TRT

9. Individual test at SR1 for barrel 3 through 5 expected electron number for 285mm Si ~20000=3.2fC defective channels 0.3%

10. Detector Tests • Detector performance checks • Standalone calibration tests on SCT and TRT after insertion • Noise studies on SCT and TRT before installation in the pit • Physics-mode running with common readout and trigger for SCT and TRT • Synchronous readout of 4 SCT barrels and SCT+TRT • Noise on SCT from TRT + Noise on TRT from SCT • Test with heater system • Feedback of readout cycle to FE noise • Studies with cosmics currently ongoing • Track Reconstruction • First look at efficiencies in SCT and TRT • Residuals • Detector alignment and test/tuning of different alignment methods • Analysis of data is on-going, so please consider the following slides as preliminary results

11. Cosmics • First cosmics very helpful in commissioning the online and offline SW chain • Combined DAQ, DCS and LTP trigger + TOF of Scintillator • Configuration, data handling, mapping, BS converter, monitoring and event display • Software frame work is different. Offline uses Athena. Online uses Scram. • Data base shifted to COOL which interfaces to Oracle, MySQL and sqlite. • Preliminary results from the cosmic data taking and analysis ….(talk by Y. Nagai) • Run at nominal thresholds (1fC SCT) • Collected 0.5M cosmic triggers • ~70% with good tracks

12. Barrel Configuration in SR1 Test View from outside towards Side A • SCT: • 468 of 2112 modules ~ 1/4 of SCT barrel • Keep detector dry using dry air to thermal enclosure • Readout using 12 ROD +1 TIM+1LTP • TRT • 2x ~6600 Channels ~ 1/8 of TRT barrel • Readout in 9 ROD • Note: usually no electronics on bottom -Z sector • 3 scintillators for trigger

13. Alignment using Cosmic tracks Residual without alignment red dots: space poits, orange dots: cluster hits

14. Robust pattern recognition even in tripled noise condition. Noise counts tripled in expand mode on the ROD and hit mode on the chip. Very few fake space points V pattern of SPs in pseudo-f-h plane gives track params. Minimize the sum of residulals on the surface of wafers.

15. Noise Occupancy at SR1 compatible with production Noise Occupancy at 1fC threshold 1fC Noise run at SR1(Offline Monitor) <NO> = 4.5 x 10-5 x 10-5 Module production (NO specs: < 5 x 10-4) Chip NO. No trigger rate dependence run3065,black,500Hz run3066,red,5kHz run3067,blue,50kHz

16. Noise runs changing threshold • Equivalent Noise Charge • is very sensitive to • the threshold setting. • ENC can be derived • fitting a plot of occupancy vs • threshold using error function. • Offline value matched with • production. Number of chips • ~ 1600 e- ENC at 30C • hybrid temperature • reduces at final operation • temperature by ~ 5e-/C * 30C ENC = 1605 electrons

17. Quiet, Stable, Respond properly Noise run of 1.0 fC threshold Typical Cosmic-ray run Cut Nhit < 200 Perfect Gaussian! Nhit (Number of hits /event) Nhit (Number of hits /event) Longest 30kHz noise run of 10M event observed no spike

18. Summary • SCT and TRT barrel tested for 3 months in SR1 with 1/4 of SCT and 1/8 of TRT connected • Gained a lot of experience on detector operation • Noise studies • Have not observed any cross talk between SCT and TRT • Noise on SCT well below specs • No evidence of significant noise increase in SCT with all 4 barrels together and inside TRT during tests • Cosmic runs • Tracked cosmics through both barrels! • First efficiency and noise-hit studies confirm expected detector performance • Alignment work is going on. • Threshold can be checked by noise. But no experience of extra noise. • Cosmic trigger at the PIT expected to be ~0.03Hz. So SR1 cosmic data are very important. • 2 chips out of 5832 was not functional. • Learned much SCT jargon.