1. 2S Module Workshop, 30 Jan 2012 Module positioning and cooling contacts 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN  The objectives  Module positioning  Module cooling contacts

2. ΔT: 5-7 ºC Module positioning: –Sufficiently precise initial geometry (< 1mm overall) to ensure module overlaps. –High stability (<< 0.1 mm) to minimize calibration needs during operation. Cooling contacts between module and cooling pipe: –Silicon T max: -20 ºC, or preferably -25 ºC. –ΔT (silicon sensor – coolant) must be ≤ 10 ºC To avoid need for very cold coolant. Though, we face a major problem here as the current pipe insulation is designed for -25 ºC and tested to -20 ºC. But, the coolant would need to be -30ºC or lower ! –The available ΔT of 10 ºC splits roughly into ΔT (within module) < 7 ºC ΔT (module cooling contact – module support piece – pipe wall) < 2 ºC. ΔT (pipe wall – fluid) < 1 ºC, which seems achievable with 2-phase CO 2. Develop and qualify tracker-wide common solutions, keeping in mind different module types (2S, PS, Stereo, Vertical 3D) + Barrel and End-cap geometries. The objectives 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN

3. Module positioning In the present TK there is no common module positioning method –So, we have now a wider experience... 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN

4. Module positioning: TIB 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN Inputs from A. Basti / INFN Pisa Precision insert Slot insert Inserts with clearance

5. Module positioning: TEC 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN Inputs from M. Wlochal / Aachen

6. Module positioning: TOB 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN

7. And the net result with TK precision? 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN Already after first cosmic runs the residuals with Track Based Alignment are at ~50um rms, and improve within 2008 to ~30um. Much better than what the mechanics can (reasonably) do!

8. Module positioning Sufficient precision can be reached with the TIB & TEC methods –Smaller and lighter than the TOB method Maybe a sufficient precision can be reached even without positioning pins?! –Precision screw + hole / slot ? –Counter sunk screw + 2 holes or 1 hole and 1 slot ? –Use module edge as guide reference ? –Are inserts needed on the module? Captive screws (permanently with module) could be excellent to have. –Not fully obvious, due small dimensions  Tasks for 2012-2013: –Analyse the present TK results and set precision requirements for the upgrade TK. Impacts the mechanics design from modules up to complete TK, as well as what needs to be done in terms of pre-alignment and measurements. –Produce test assemblies and measure their mechanical quality (precision, strength,...). Need sample materials/components for these tests ! 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN

9. Module cooling contacts Different variants of module cooling contacts were applied in the present TK –So, we have now a wider experience... 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN

10. Module cooling: Present TK 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN Support

11. Module cooling Uncertainties in calculation inputs (composites, glues, joints)  measurements are necessary, though not fully obvious either (e.g. inputting of power load, availability of correct materials/components) For the present tracker calculations and tests done mostly in 2000-2002 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN

12. Coolant temperature: 5 - 6 º C. Module power loads: –FE-power ~ 0.45 W / APV –Silicon self-heating ~ 0.014W / module @ 5 fb -1, 0.4W / module expected @ 500 fb -1 (10y LHC) Silicon mean temp: 13 – 14 º C ΔT (silicon - coolant) = 7 – 9 º C –Will grow to ~ 10 ºC due self-heating increase Module cooling currently (TOB) 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN Plots by Christian Barth DS modules P = 3.6W SS6 modules P = 2.7 W SS4 modules P = 1.8 W Cooling segment #44 TOB 1.3.1 (132 modules) off

13. Module cooling contacts Estimated power load in a 2S module: ~3.5 W (TOB: 1.8 – 4.4 W) Following calculations (A. Mussgiller) and present TK experience ΔT (silicon – coolant) of 10 ºC seems reachable, but is not automatic! –10 ºC easily ‘lost’ already within the module. Good quality dry cooling contact can be sufficient –No need for thermal pastes. Avoid them, they are ‘dirty’ –But requires good planarity of the module and support contacts (no gaps, minimal stresses) –Even a small contact area is enough with these low powers, if the contact is good.  Tasks for 2012-2013: –Study the support/cooling contacts in the modules Is aluminium the choice? Any other candidates? –Study the module support/cooling blocks. Is aluminium the choice? Any other candidates? Geometry and dimensions. Connection to cooling pipe. –Qualification of assembly glues and methods, for all mechanical/thermal contacts –Produce test assemblies and measure their thermo-mechanical performance. Need sample materials/components for these tests ! 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN

14. Thank you for your attention. 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN

15. Spare slides 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN

16. 2S module, Jan 2012 version 2S Module Workshop, 30 Jan 2012 Antti Onnela, CERN 3D models by A. Conde Garcia / CERN