Basic starting point New tracker layers on the timescale of the first 5 years of running are a sensible first step Contained in the volume from pixel layer 0 to 4 Need to use/reuse service space for pixels Questions for R&D Single layers or a complete replacement? New sensor geometry and/or technology? Small strips? What features in the electronics to make first steps towards using these layers in L1? Seeding vs correlation Be on the road maps at the right levels and at timescales To assist, already agreed CMS peer-review scheme Main lines identified so far Tracker & Trigger Microelectronics and Power Optoelectronics & data architectures Merge at early stage into system(s) SLHC Meeting - Frascati 24 Nov 2005 Fabrizio Palla INFN Pisa

Cost & Power estimate for new Tracker Pix Sys #1 : 3 layers 330 mW/cm2 High f pix 400 SFr/cm2 Pix Sys #2 : 2 layers 130 mW/cm2 Large pix 100 SFr/cm2 Pix Sys #3 : 3 layers 45 mW/cm2 Macro pix 40 SFr/cm2 Eta =1.4  Area = 18.3 m2 Mechanics etc. not in costs! Strip detector ~25 mW/cm2 SLHC Meeting - Frascati 24 Nov 2005 Fabrizio Palla INFN Pisa

Longer term R&D Power requires major effort & new ideas Chip voltages reduce with technology evolution, currents may (??), but number of channels will not Need to bring increased total currents through volumes which can’t expand Material budget should not increase R&D and qualification time is underestimated Reduce the number of module types Increase automation of assembly Large systems are hard to build Qualification must be taken seriously True industrial production is likely to be required Sensors are one of many issues Any new material technology must be large-scale commercial within ~5 years Electronic technology evolution will bring benefits and also more complexity and much difficult work SLHC Meeting - Frascati 24 Nov 2005 Fabrizio Palla INFN Pisa

Strategy Is the right strategy R&D followed by request for complete new tracker? Alternative could be upgrade… ..by installation of modest protoype system at tp = to + 5y Less cost and lower risk Less substantial case for support needed More chance of resources, on short time scale Allows trial of components or devices, which may still evolve Technology investigations less popular with funding agencies than physics experiments Human time-scale Might be possible to react to LHC conditions, either machine, experiment or even discoveries or to convince reviewers & funders… May be complete pixel system replacement ??? SLHC Meeting - Frascati 24 Nov 2005 Fabrizio Palla INFN Pisa