1. SLHC Pixel Layout Studies S. Dardin, M. Garcia-Sciveres, M. Gilchriese, N. Hartman LBNL November 4, 2008

2. Background and Goals Studies shown here are simple, almost “lines on paper” Have included some realism in lengths of staves and radial extent of disks based on module dimensions but don’t believe dimensions to the mm-level Previous reports are worth looking at to understand evolution – see for example talks here here 2

3. Assumptions Minimum of four pixel hits Cover |  | ≤ 2.5 for tracks |z| ≤ 10 cm (nominally 2  although needs to be confirmed as design of SLHC evolves) Define “pixel-only volume” bounded by (short) strip detectors (R ≤ about 35 cm but final boundary TBD) and beam pipe at inner radius Two pixel hits permanent Two hits insertable from end/replaceable 3

4. June 2008 Layout 1 Radius(cm ) Z(cm) Insertable section Single-sided staves here Fixed section “End-of-stave card” Arbitrary guess Insertion tube Boundary of silicon strip tracker Drawn width represents tilt Modules both sides assumed here Angle  Common support shell “End-of-disk card” Not shown

5. June 2008 Layout 2 “Bent” stave to reduce material Measurement mostly at larger R Gap in  coverage and bend?

6. Input to Project Office Models

7. Many Options Explored These and more are described more here.here 7

8. Monolithic insertable pixel options BOX Section Beam, single cooling circuit. I Section Beam, single cooling circuit. Buttable modules to avoid large gaps

9. Pixel Barrel Overall - Example LayerNumber StavesModules per StaveTotal ModulesModule Type 01532480Single Chip 115284204Chip Active Edge 232 10244Chip Normal 3403212804Chip Normal

10. Disk Examples Hermetic by design (see local supports talk for how implemented) Overlaps in R and  10 Both sidesOne side

11. Push Outer Envelope What is outer envelope? Maintain space for support structure and services at outer radius. This is tight if outer envelope is about 34cm, based on current experience 11 End-of-disk “cards” Same arbitrary area/module as for staves

12. More Outside Room 12 Reduce radius of outer layers by 2 cm Reduce disk size May allow exterior support structure and services routing or support from insertion tube and routing along it.

13. More Forward Hits Possible to add more forward hits Could keep all disks same and do this(not shown here but easy to imagine) Of course could add disk also…. 13

14. My Comments Staves are long(material?) and disks are big. Need reality check from design and prototypes before expending too much effort on detailed layouts. Nearing end of utility of simple layout studies (at least for engineering) Obvious information needs – What is outer envelope of pixels? – What are the dimensions of end-of-stave and end-of-disk cards? – Insertion tube (only) or insertion+support outer layers? Stiffness and other requirements (it’s not so large in diameter) – Thermal requirements for this tube – Feedback from services and support envelopes => change layout Time for some more detailed modeling with real engineering design input. 14