(An open-ended discussion with random slides attached…) OUTLINE: Layouts Common Issues / Distinguishing Issues U-Shape L-Shape (Si and Si+Diamond) How to Proceed

SU VELO Meeting, 27 Jan 2010R. Mountain, Syracuse University2 Work Package I – Finalize ‘Strawman’ layout Contribute ideas (by 25 th January) Study selected layouts with parametric simulation Study selected layouts with full simulation Contribute engineering cartoons Thermal simulations Foil R&D assessment Impact on electronics design Plus CAD drawings, cooling options, RF shield studies, physics impact of design variations (SU) Addition of hybrid geometry option (SU) Work Package II – CO2 vs LN2 cooling choice Specify baseline CO2 solution Specify baseline LN2 solution Risk Assessment (…From Paula’s survey)

SU VELO Meeting, 27 Jan 20103R. Mountain, Syracuse University VELO L-Shape Layouts and Others – Marco Gersabeck -velo.upg cartoon

SU VELO Meeting, 27 Jan 20104R. Mountain, Syracuse University VELO L-Shape Layouts and Others – Marco Gersabeck -velo.upg

5R. Mountain, Syracuse UniversitySU VELO Meeting, 27 Jan 2010 U-Shape Sensor Periphery: Active area close to R7.0 only in H direction – limited by ASIC size RF Foil: Design close to current – so AlMg3 possible Can pursue composite, but we have a fallback Cooling: Has 10 chips Sensor Periphery: Can get active area closer to R7.0 in both H,V – principal physics reason for L-shape RF Foil: Must be a new design Must be new material – can’t be AlMg3 This is a strategic gamble Cooling: Has 12 chips L-Shape Many of these differences erased by using Diamond

Physics: Simulation of efficiency, resolution, coverage, etc. A given, not detailed here but the questions are well known Also, material effects, number and spacing of stations vis-à-vis U vs L, etc. ASIC: What is the ultimate size of the ASIC? How much modification is needed How many submissions can be made, given time constraints Sensor Periphery: Silicon limited by rad damage to R7.0 at closest, but guard ring of ~0.5 mm moves active region back to R7.5 Guard ring of 0.5 mm – feasible? Some questions were raised Edgeless silicon – R&D stage, what is max size sensor made edgeless? Note that Diamond will allow recovery to R7.0 Sensor Size: Split silicon into two – if sensor/ASIC registration gives low yield How many ASICs can be accurately bonded to a single sensor? If split, will introduce either overlaps or gaps in coverage (maybe both) SU VELO Meeting, 27 Jan 20106R. Mountain, Syracuse University In order of importance (?)

Overlap: Is an overlap (~0.1 mm, 1-2 pixels) necessary? Can gaps be tolerated? Does a staggered layout help? How bad is the effect of the additional material? Inner Aperture: Square geometry at inner radius gives no coverage in corners – significant? RF Foil: Reduced RL reduces MCS for both cases Cooling: Placement of cooling pipes – effect in fiducial volume? Diamond eases the cooling requirements ASIC Readout: Issue of column direction readout rate and multiplicity? – How serious? Motion Control: Have to adjust the position in V direction? – raised previously Other … SU VELO Meeting, 27 Jan 20107R. Mountain, Syracuse University

SU VELO Meeting, 27 Jan 20108R. Mountain, Syracuse University

SU VELO Meeting, 27 Jan 20109R. Mountain, Syracuse University

SU VELO Meeting, 27 Jan R. Mountain, Syracuse University

What can we determine in the next “two” months? RF Foil: Determine if there are any first-order show stoppers, by Evaluating a realistic L-shape design with CMA Determining basic material parameters, vacuum-tightness, shielding Diamond: Work out U-shaped diamond layout (problem?) Critical, but can’t prove it in short term… Simulations: Continue current work, aim at some killer issue, like… Thermal: Continue simulations (kill CO2?), plus … Plus: Pin down issues related to sensor periphery, size of ASIC, etc. Seriously evaluate potential of higher-risk technologies, like edgeless silicon, TSVs, etc. And … SU VELO Meeting, 27 Jan R. Mountain, Syracuse University I think we can only kill an idea in a two-month period, but we cannot prove it.