1. CDC Scrutineer Talk Elliott Wolin GlueX Collaboration Meeting Jefferson Lab 9-Sep-2004

2. Scrutineer? scrutineer n. a scrutinizer; specifically, an examiner of votes, as at an election. scrutinizer n : a careful examiner; someone who inspects with great care

3. Strategy Assume role of a skeptical reviewer Assume role of a skeptical reviewer Present list of questions/concerns not covered in Design Report and in DocDB Present list of questions/concerns not covered in Design Report and in DocDB Please add to my list! Please add to my list!

4. But first… I find the project in good shape I find the project in good shape Confidence in CMU to solve remaining problems Confidence in CMU to solve remaining problems Only concern is effectiveness of dE/dx in magnetic field, with real preamps, etc. Only concern is effectiveness of dE/dx in magnetic field, with real preamps, etc.

5. Skeptical Reviewer’s Concerns Conceptual Conceptual Performance Performance Mechanical Mechanical Services (gas,electrical,hv,etc.) Services (gas,electrical,hv,etc.) Onboard electronics Onboard electronics Reconstruction and Analysis Reconstruction and Analysis

6. Conceptual No VTX implies need for re-optimization of STC/CDC/FDC geometry No VTX implies need for re-optimization of STC/CDC/FDC geometry New Cerenkov implies reevaluation of dE/dx requirements New Cerenkov implies reevaluation of dE/dx requirements Is prototype plan adequate…need more? In B field? Is prototype plan adequate…need more? In B field? Why not resistive wires? Why not resistive wires? If dE/dx not needed skip ADCs? Or drift? If dE/dx not needed skip ADCs? Or drift?

7. Performance Look at other gases? CO2 - long pulse, pile-up? Look at other gases? CO2 - long pulse, pile-up? Understand aging better Understand aging better Understand Lorentz angle effects better Understand Lorentz angle effects better Effect of breakdown, broken wire? Effect of breakdown, broken wire? Verify dE/dx works in B field Verify dE/dx works in B field Gain variations vs V, wire sag, gas purity, etc. Gain variations vs V, wire sag, gas purity, etc. Cross talk – straws, preamps, via HV, etc. Cross talk – straws, preamps, via HV, etc. Rate effects – V sag, preamps, x-talk, heat, signal pile-up, etc. Rate effects – V sag, preamps, x-talk, heat, signal pile-up, etc.

8. Mechanical Verification of matl’s, glue, techniques Verification of matl’s, glue, techniques Glue lifetime – radiation damage, etc. Glue lifetime – radiation damage, etc. Failure mode analysis Failure mode analysis How to repair? Time? Replace wire? How to repair? Time? Replace wire? Survey, align requirements? Plan? Survey, align requirements? Plan? Supports, stability, deflections, vibration? Supports, stability, deflections, vibration? QC (clean,glue,crimp,tension) – students? QC (clean,glue,crimp,tension) – students? Al vs Cu vs Au? mylar vs kapton? Al vs Cu vs Au? mylar vs kapton? Metal coating thickness, skin depth? Metal coating thickness, skin depth? Are compound angle problems under control? Are compound angle problems under control? Interfaces, keep out zones, installation plan? Interfaces, keep out zones, installation plan?

9. Services Gas distrib, uniform flow, purity, cleaning? Gas distrib, uniform flow, purity, cleaning? Room for cables, services? Mass? Room for cables, services? Mass? HV dist, granularity, currents, cable type? HV dist, granularity, currents, cable type? Discharges - HV cap, resistor size calc? Discharges - HV cap, resistor size calc? Power, heat, noise, shielding, grounding? Power, heat, noise, shielding, grounding? Is temperature rise a problem? Gas flow rate? Is temperature rise a problem? Gas flow rate?

10. Onboard Electronics Preamp design? Preamp design? Preamp mounting, power, heat, x-talk? Preamp mounting, power, heat, x-talk? Cable type, quality, thickness, max length? Cable type, quality, thickness, max length? Signal shape variations? Shaping? Signal shape variations? Shaping?

11. Reconstruction and Analysis Calib plan – special runs? Survey reqs? Calib plan – special runs? Survey reqs? Pat rec – spiraling tracks, bad straws, showers, event pileup, x-talk, ambiguities, Pat rec – spiraling tracks, bad straws, showers, event pileup, x-talk, ambiguities, Track fitting – mult. scatt, dE/dx, Kalman filter? Track fitting – mult. scatt, dE/dx, Kalman filter? What if no tagger info? What if no tagger info?

12. Conclusions CDC project in good shape CDC project in good shape Some open questions Some open questions Some tests still needed Some tests still needed CMU headed in the right direction CMU headed in the right direction Seem to have enough time, people, $$? Seem to have enough time, people, $$? “Reviewer’s” questions should be satisfied by adequate documentation of past work, and planned future work “Reviewer’s” questions should be satisfied by adequate documentation of past work, and planned future work