1. Ageing … Eric Kajfasz (CPPMarseille) D0 Workshop, Beaune, June 17, 2003 DØSMT

2. D0 Workshop 06/17/03E. Kajfasz2 D0SMT ageing... ‘’HDI’’ failures: Limited access => ‘’HDI’’ means [Low Mass Cable + HDI + chips] Excess Noise: Usual noise between 1.5 and 3 ADC counts Excess noise seem to affect only Micron F-Wedges Irradiation Detector was built to sustain 2 fb -1 F11-1-2 Example of a worst case

3. D0 Workshop 06/17/03E. Kajfasz3 SMT Design 6 Barrels 12 F-Disks 4 H-Disks South 1/2-cylinder North 1/2-cylinder F-Disks sensor vendors: # 3,5,8 and 10: Eurysis 8 others: Micron

4. D0 Workshop 06/17/03E. Kajfasz4 HDI Low Mass Cables Pigtail Ladder South Half Cylinder 3 (F-Disk+Barrel) modules 3 forward F-Disks SVXII R/O chips

5. D0 Workshop 06/17/03E. Kajfasz5 Conclusions... 80/3M+CLK cables Adapter card Low-mass+CLK cables ½-cylinder

6. D0 Workshop 06/17/03E. Kajfasz6 ~19’-30’ High Mass Cable (3M/80 conductor) Serial Command Link Cathedral Interface Board Crates (8x18) 8’ Low Mass Cables 3/6/8/9 Chip HDI Sensor CLKs Horse Shoe 3/6/8/9 Chip HDI Sensor Adaptor card 25’ High Mass Cable (3M/50 conductor) CLKs IBIB MCH2 VRBCVRBC SBCSBC VRBVRB Pwr PC Monitoring SDAQ PDAQ (L3) VRB Crates (12x10) Platform SEQSEQ SEQ Controller Optical Link 1Gb/s Sequencer Crates (6x20) VTM Around Iteraction Region CLKs MCH3 Pwr PC 15531553 PowerPCs and Single Board Computers are accessed thru Ethernet MCH2 Pwr PC HVmodHVmod HV Crates (8x6+2x4) Cathedral Fuse Panel Bulk LV Power Supplies HV fanout 1=>4 HV breakout box VME Crates (4x3) 25 twisted pair cables 17 twisted pair cables HV LV I,V,T Monitoring

7. D0 Workshop 06/17/03E. Kajfasz7 HDI failures Would not bet my shirt on an extrapolation of these …

8. D0 Workshop 06/17/03E. Kajfasz8 HDI failures

9. D0 Workshop 06/17/03E. Kajfasz9 Effects on physics … Take with a grain of salt … these are run IIb studies

10. D0 Workshop 06/17/03E. Kajfasz10 Noise in North Barrels… Usual noise between 1.5 and 3 ADC counts Look at the fraction of channels with a noise above 4 or 10 ADC counts OK 10/01/2001 05/15/2003

11. D0 Workshop 06/17/03E. Kajfasz11 Noise in South Barrels… OK 10/01/2001 05/15/2003

12. D0 Workshop 06/17/03E. Kajfasz12 Noise in F-disks … NOT OK For Micron wedges 10/01/200105/15/2003

13. D0 Workshop 06/17/03E. Kajfasz13 Noise in F-disks … NOT OK For Micron wedges 10/01/200105/15/2003

14. D0 Workshop 06/17/03E. Kajfasz14 Noise H-disks … ~ OK But keep an eye on them … 10/01/2001 05/15/2003

15. D0 Workshop 06/17/03E. Kajfasz15 Irradiation … Main effects of irradiation: (see R. Lipton, D0note-4077 for details): Increase of leakage current Increase in shot noise Not the show stopper. Increase in trapped and surface charges in insulating layers lowered threshold for junction breakdown (micro-discharges) Expect to limit the lifetime of Micron detectors Change in effective impurity concentration: Remove donors and form acceptors in bulk silicon n-type inverts to p-type after about 300 KRads Depletion voltage decreases until inversion, then increases with dose. This in turn induces: coupling capacitor breakdown micro-discharges SVX polysilicon resistors +HV - HV n-side p-side coupling capacitors AVDD AVDD2 DVDD HDI sensor DATA

16. D0 Workshop 06/17/03E. Kajfasz16 Irradiation … Vdep (V) Dose (Mrads) Noise (ADC) Dose (Mrads) Voltage (V) # broken capacitors Bias Voltage (V) Coupling Capacitors Breakdown @ 2.1 MRads 2fb -1 @ layer 1

17. D0 Workshop 06/17/03E. Kajfasz17 Conclusion: Diamonds (not Silicon) Are Forever! HDI failures: Difficult to conclude on a real trend: Anywhere between 13 and 100% disabled channels by 2009 Following months will help us understand a bit more how it goes Increasing Excess Noise: With present trend: Seem to affect Micron F-wedges only Some (large?) fraction of these wedges will become useless in the next few years Irradiation (R. Lipton, D0note-4077) Significant loss of channels in layers 1&2 above 3.6 fb -1 (Vd=150V) All channels in layers 1&2 dead above 4.9 fb -1 (Vd=200V) Wise thoughts of the day: Need Run IIa MC studies to better understand effect on physics Because of all of the above, it is very risky to count on SMT to behave sufficiently well by 2009, not to impede our physics program Build the upgrade, if we have the funding to do so