1. Pre-Baseline Pixel R&D Simon Kwan BTeV Electronics & Software Mtg., May 24,2001 And BTeV Coll. Mtg., May 25, 2001

2. WBS Level 3 Activities Sensor and Pixel Detector Hybridization Readout Electronics Mechanical support, cooling and vacuum systems System integration Project Management

3. Sensor and Hybridization Sensor –FNAL and Syracuse –Good progress on measurements at FNAL I-V, C-V, voltage distribution on guard-rings measured on wafers and single dies of various structures (diodes and pixels) using different p- stop designs and 3 different guard-ring designs from different sources Normal and oxygenated wafers Will also measure interpixel capacitance and interpixel resistance Effect of temperature(cold-chuck), humidity, dicing, cleaning Will extend to different resistivity, p-spray technologies from different vendors Irradiation studies Laser test stand setup to study effect of magnetic field (before and after irradiation) Will have most of the results we want for the baseline review

4. Examples of Guard Ring Design

5. SINTEF Sensor Wafer Breakdown Voltage

6. Sensor (cont’d) Syracuse University –3D Simulation program –Probe station and accessories –Lack of NSF money hampers the effort –Need support to get a laser test stand –Start assembly of FPIX0 detectors (extended finger to bias the p-stop)

7. Detector Hybridization Rec’d 11 detectors and 2 modules made using both Indium(4+1) and Pb/Sn bumps (7+1) Long term test, thermal cycle + irradiation tests on dummies now under way Remaining issue : 8” wafer and thinning Existing contract with MCNC to do assembly from 8” dummies provided by CERN. AIT claimed that they have 8” capability Thinning – program of studies; working together with MCNC (issues: flatness, stress, probing, dicing after thinning, bump protection) Yield and quality assurance – work in progress with vendor

8. Readout Electronics preFPIX2 Pixel Readout Chip –preFPIX2Tb – SEU tests last month; more test early June, also total dosage effects –Detectors using preFPIX2Tb – expected delivery in the summer; irradiation tests planned for September –preFPIX2Ti : may get 1 or more detectors from UCD; still negotiating with CERN to get 1 complete wafer Development path to FPIX2 and production chip –Needs a consensus (dynamic range, threshold dispersion, number of serial lines, serialization scheme,pads, iterations) –Features (e.g. Pattern to check bump bonding) –Specification document (summer) –Schedule Complete engineering run Dec 01? Small chip with complete readout via MOSIS (MPW) Split submission with SVX4: submission in Oct 01 with another submission in 2002

9. High Density Flex Cable Expected delivery of flex- circuits from CERN next week PCB being procured to test the circuit and bare FPIX1 chips before moving to detector module Plan to address assembly issue Embark on a comprehensive program of studies on adhesives

10. Module Prototype X-section Module

11. EMI studies Test FPIX1 chips and then detectors in beam simulator PCB now being tested EMI test will start in July to evaluate necessary RF shielding for pixel planes

13. Data Combiner board Study number of serial lines, maximum clock frequency as function of chip size and number of interactions per BCO Working on input protocol from the pixel module to the board Plan to have a pixel module simulator and Data Combiner Board simulator tested in the summer

14. Feed -Through Use PCB with connectors as vacuum feedthrough First test of a std bare in vacuum is OK Large number of cables/connectors Large PCB (17x22”), 6 layers now being designed Plan to test this PCB with connectors in a vacuum system

15. Misc. PCI test stand ( working) Test beam preparation (needs help from university groups and maybe software professional) HV and LV power supply, connectors (HV workshop; compact, high density HV connector, simple RGS125 cable; Document being prepared summarizing all the requirements and the choices provided by the vendors)

16. Pixel Vacuum Vessel

17. Rf shielding Same membrane hopefully serve three purposes: –RF shielding of the pixel detector –Vacuum barrier –Image current Plan is to proceed with the mechanical design and then expert from BD will calculate impact on the beam and whether it’s enough to carry the image current

18. Vacuum System

19. Motor Drive Assembly Prototyping phase Use pneumatic actuators All parts are in except the precision screws Working on a test plan Needs to fit the overall vacuum vessel and pixel station support structure design

20. Fuzzy Carbon Substrate Light-weight Good thermal performance and CTE match to Si Problems: fragile, heavy manifold and brittle joint between tube and manifold, difficult to fabricate, sole source, small company

21. Cooling Test Results on fuzzy carbon substrate Used water/glycol mix (70/30 by wt) Neslab chiller to set temp Small pump to get the flow rate Flow-meter calibration to the mixture Hydrometer to check density of mix Filter, insulator, glove box(dry N2) SMT resistors as heaters RTDs to readout temperature (5 points; water inlet and outlet line, fuzzy carbon surface-entry,notch, exit) Also monitor pressure drop, absolute pressure of inlet Haven’t used laser to monitor vibration

22. Problems Sensitive to ambient temperature (do it in vacuum vessel) Two of the RTDs’ need to be re-calibrated (temporary fix; need more RTDs) Lack of pumping power, flow rate just above 1.4 L/min (new pump) Inside glove box – hard to manoeuvre and fix things (new plexi-glass box) Fuzzy carbon very fragile – so far only populate 1 side (starting to populate the other side) Measure temperature only outside the coupling piece on the inlet and outlet of coolant line Non-uniform heat load (under investigation)

23. Prototype Vacuum Vessel Test substrate in vacuum Monitor vibration Can put in real pixel plane and test Can also be used to test prototype vacuum barrier Empty vessel: vacuum is good to 10 -10 torr

24. Highlights Too good to be true! I had a hard time to believe the results because the differences in the RTD readings between HEAT OFF and ON are so small. HEAT ON- 10.2W (RTD 1-5 ) ; no coolant 21.66 | 34.78 35.07 34.89 | 21.83 HEAT ON; coolant ON and chiller at 0C 7.52 | 9.78 10.06 9.87 | 7.94 HEAT OFF; coolant ON and chiller at 0C 7.56 | 7.58 7.68 7.87 | 7.91 Thermal performance probably OK. Mechanical strength and handling is the big issue

25. FY01 Development Plan Objectives –Increase thermal conductance between chip and coolant –Increase toughness of carbon tube ends at manifolds Phase 1 – Coupon scale demonstrations –Radial high-k fiber architecture on ovalized tubing –Toughened tube/manifold joining (preferably all carbon) Phase 2 – Full scale fabrication of two support planes –Incorporate latest design modifications by FNAL –Incorporate Phase 1 results on process modification by ESLI

26. Ovalized Tubing Array Ovalized carbon tubing precursor fuses together for greater stiffness Monolayer of carbon fiber applied to ovalized tube array

27. Manifolded CC Tubing Array Initial coupon fabrication All carbon heat exchanger –Glassy carbon manifold tubing –Glassy carbon lines –Carbon joint toughening paste reinforced with carbon nanotubes

28. Next Steps Add in-plane Carbon fibers Fabricate coupon with several tubes to measure through-thickness thermal conductance –Compare with FY00 coupon to validate performance improvement Phase 1 completion ~ June 15 Deliverables – coupons to demonstrate all the key components that we can evaluate; tests to show the rigidity of the joint Phase 2 : now being designed

29. Be option Fallback solution Prototype done with Al; will also do SS version Material budget Machining and joining thin pieces of Be Contacted 6 vendors Average thickness of 2.3mm Be (incl. 0.5mm cooling channel) is do- able (0.33% X 0 per plane) Issues: rigidity, method of joining, manifold

30. WBS and WBS dictionary WBS –Reasonably good shape except the Mechanical and System Integration section –Plan to address these two parts –Will prepare a document summarizing the assumptions that will into the WBS WBS Dictionary –Just started on this –Cut and paste from what we did last year

31. Summary Good progress has been made in almost all areas Need more effort still on RF shielding, support structure and vacuum vessel This will be a very busy summer; expect a lot of tests and results We are on track to produce all the material we want for the design and TDR Manpower – would prefer more people working on EMI tests and/or module. Some outside help? Also needs university group to help in preparing for test beam next year