Stave Development Project

1. Stave Development Project US ATLAS SLHC Tracking Meeting

2. Occupancy • At 30 cm an SCT module covers 0.25% of the barrel surface area. • For present SCT region, modules will have to be modified to meet old occupancy and merged cluster targets • Increased segmentation • Finer pitch (increases channel count per module) • Shorter strips (increases number of modules) • Re-visit binary vs multi-bit front ends for cluster merging? • For TRT region need guidelines for width x length, extrapolate from SCT, scale to 1035 US ATLAS SLHC Tracking Meeting

3. Occupancy • Even at large radius will need considerably shorter strip lengths to meet low occupancy specifications • Need to optimize module width vs length with concerns for • Material • Signal/power distribution, reliability • Cooling • Typical “Outer (TRT) Region” module size could be 4 cm (wide) by 6 cm (long) • Single module design model still valid at all radii? US ATLAS SLHC Tracking Meeting

4. Elements of an SLHC Tracker • < 20 cm: inner, dose:1016 /cm2 • new technology • 20 < r < 50 cm: intermediate, dose: 1014-1015 /cm2 • pixels, short strips, strip-pixels • modularity, mass, reliability, system issues • 60 m2, 4K “SCT modules” • > 50 cm: outer 1012-1013 /cm2 • strips • modularity, mass, construction logistics • 140 m2, 16K “SCT modules” US ATLAS SLHC Tracking Meeting

5. 1070 500 300 US ATLAS SLHC Tracking Meeting

6. Development of Tracking Structures • Address here the SCT region and the replacement of the TRT with silicon strip modules. • The modularity required or adopted will be effected by a number of factors • Experience from present SCT effort • Radius, occupancy, simulations • Material • Assembly logistics, cost, and schedule • Starting concept is a stave (multi-module) structure as was studied for Run2b • Effort funded so-far with 1-time DoE allocation US ATLAS SLHC Tracking Meeting

7. Stave Conceptual View • 2 sensors + hybrid = 1 module (ladder) • 3 modules per side • Modules linked by embedded bus cable and • readout token passing scheme • 2 sided – axial/stereo or axial/axial • 1 Mini-Port Card /stave • Total length 66 cm • 3072 channels /stave Bus cable is Cu/Kapton laminate with 100 um lines and spaces, Al shield layer. Distribute signals, data, power, HV Hybrid fabricated on BeO For low mass and thermal Performance. Use advanced fine pitch design US ATLAS SLHC Tracking Meeting

8. Fraction of Total RL: • Hybrids 13% • Sensors 39% • Bus Cable 17% • CF/Coolant 29% • Material/stave: • 1.8% RL • (compare 2.5% ATLAS) • 124 grams Stave End View Silicon Sensors 4mm separation Peek Cooling channels 2.9 x 5.6 mm Hybrid electronics Carbon Fiber Skin Foam Core US ATLAS SLHC Tracking Meeting

9. US ATLAS SLHC Tracking Meeting

10. Phase 1 Stave (Outer Region) US ATLAS SLHC Tracking Meeting

11. Phase 1 • The purpose of Phase 1 is to gain experience with ATLAS style electronics on a multi-module structure • This design is not far from a conservative SLHC stave for the TRT region • Expect a real design would re-optimize strip length and axial-stereo aspect. US ATLAS SLHC Tracking Meeting

12. Hybrid and Interconnections Key initial task is the design of a hybrid and bus cable for the ABCD chips US ATLAS SLHC Tracking Meeting

13. US ATLAS SLHC Tracking Meeting

14. Phase 1 Milestones (completion dates given) full electrical specification and schematic for Phase 1 stave 10/04 done establishment of test stands at LBNL, BNL, and Hampton 11/04 done validation of test stand operation on test parts 12/04 LBL design and layout of Phase 1 hybrid 12/04 1/05 fabrication of hybrid 03/05 4/05 assembly and test of hybrid 04/05 5/05 re-commission and tests with existing fixtures 03/05 assembly of ATLAS staves 06/05 * initial test of ATLAS staves at LBNL07/05 transfer to and test of staves at BNL/Hampton 08/05 irradiation studies of staves 10/05 transfer of assembly methods to BN 07/05 US ATLAS SLHC Tracking Meeting

15. Status • Check prints for hybrid in-hand • ~30 days for revisions and review • Order substrates • Fabrication order requires additional funding\ • Begin bus cable layout US ATLAS SLHC Tracking Meeting

16. Stave Assembly • For Phase-1 use inherited fixtures from FNAL • Procure dummy wafers and hybrids for tests (in progress) • Start to consider new fixture set for Phase-3 • Look towards automated process using motion control and vision • Try to understand work-flow and load to determine scale, requirements, and cost of a production process US ATLAS SLHC Tracking Meeting

17. Stave Assembly Fixtures from FNAL Stave assembly fixture Stave bonding fixture Module holders Test boxes Transfer plates Hybrid,fanout attach fixture Glue transfer plates Module assembly Fixture (sans stages) US ATLAS SLHC Tracking Meeting

18. Assembly and Test Process • Hybrids • Printed substrates inspected and probed • Component attach, wirebond • Inspection and test • Staves • Glue hybrid and fanout to detector (= module) • Wirebond • Test • Glue 6+6 modules to stave, wirebond • Test US ATLAS SLHC Tracking Meeting

19. US ATLAS SLHC Tracking Meeting

20. US ATLAS SLHC Tracking Meeting

21. Phase 3 • This is an out-year effort FY06 • Configuration, region, radii to be determined from earlier phase work and simulations • Considerable component and fixture development will be required. US ATLAS SLHC Tracking Meeting

22. Strip-pixel staves (Phase 3) US ATLAS SLHC Tracking Meeting

23. For strip-pixel layer two sides Independent, therefore thicker stave is more appropriate US ATLAS SLHC Tracking Meeting

24. Comments on Strip-Pixel Staves • As detector becomes short hybrid covers much of the surface area • BeO-gold thick film technology while robust is probably too massive • These issues are currently of concern to the strip layer development for PHENIX at RHIC, that effort should be monitored • Their present approach is probably unrealistic! US ATLAS SLHC Tracking Meeting

25. Sensor elements: Pixels: 80 µm 1 mm, projective readout via double metal XU/V “strips” of ~3 cm length. PHENIX Strip Detectors Developed at BNL Two strip-pixel arrays on a single-sided wafer of 250 (400) µm thickness, with 384  384 channels on 3 x 3 cm2 area. Initial design: “longitudinal” readout. Made by SINTEF Strip Read-Out card (ROC) new design: “lateral” SVX4 readout. Made by HPK Strip ladder: 5 (layer 3) or 6 (layer 4) sensor+ROC 12 SVX4 per sensor R&D at ORNL US ATLAS SLHC Tracking Meeting

26. Issues • CDF BeO hybrid – 1.11 %Xo realized • PHENIX assumes thin Al layers for power and signals and no substrate – 0.411 %Xo • Issue of voltage drops along stave • With no substrate have assembly and reliability issues • Need a shield layer between hybrid and strips • With no substrate hybrid on strips will significantly increase source capacitance of input! US ATLAS SLHC Tracking Meeting