1. Material calculation of petal core variants Sergio Díez Cornell with input from many people CERN AUW, 3 rd Nov 2014

2. Petal core material  This is an updated calculation of the total petal core material based on the current petal model  Bus tapes, locking points, E breaks included  NOT included: silicon, SE4445, hybrids, ASICs, WBs, EoP, etc.  Disclaimer:  Most of the values come from volumetric estimations provided by the CAD software. No mass measurements were made (we don’t have petals yet)  Due to this, adhesive estimations are the ones with biggest uncertainties Assumed 100% coverage and constant glue thicknesses in all glue interfaces The most obvious error is on honeycomb-facings glue: honeycomb structure is simplified as a full block with very low density; this is ok for the honeycomb estimation, but most likely overestimates greatly the amount of glue  A more accurate calculation should be expected once petal cores are produced (and weighed)  Expect also some minor “systematic uncertainties” on X0s (check backup slides) i.e., used X0 of Korex for N636 HC  The “baseline” is just the default version I have considered for this study 3 Nov 2014Petal core material, AUW Nov 2014 2

3. Current petal core model 3 Nov 2014Petal core material, AUW Nov 2014 3 Locking points are PEEK This pipe section and connectors are not included (top bus tape and facing not shown here) Lateral C-channels are CF Top and bottom closeouts are PEEK

4. Baseline petal core X0 3 Nov 2014Petal core material, AUW Nov 2014 4 ItemMaterial Total mass (g) Density (g/cm3) Volume (cm3) Normalized thickness X0/ρ (cm)%X0 Facings K13C2U/EX1515 (45 gsm, 43% RC) 56.7591.617.7370.0450729.240.154% Bus tapes Cu/Polyiamide/adhesive 51.373 various16.92 0.04300 various0.227% C-Channels K13C2U/EX1515 (45 gsm, 43% RC) 8.5141.6 5.3210.00676 29.240.022% Closeouts + Locking points PEEK 16.643 1.32 11.1220.01602 31.9 0.050% Allcomp K9 Allcomp (0.23g/cc) 15.9990.2334.7800.08837185.60.048% Honeycomb YSH50A-75 +EX-1515 (1/4) 27.7090.048577.2810.7333810060.073% Adhesives Hysol9396/BN (30%) 18.979 1.49 12.7140.01602 25.4 0.064% Pipe + E breaks Ti /Al2O3 7.216 4.54/3.97 1.4390.00205 3.58/7.04 0.054% TOTAL:203.192 g0.692% Spreadsheet with detailed calculations: https://twiki.cern.ch/twiki/pub/Atlas/StripsUpgradeLocalSupport/Diez_petalcore_material_31_10_2014_v2.xlsx

5. Bus tape variants  Different bus tapes considered:  “Baseline”: bus tape covers full area “C” is part of the bus tape:  3 Kapton layers (25+50+12.5 µm)  3 adhesive layers (25 µm each) “A” and “B” are part of the bus tape (barrel approach)  Parylene isolation: bus tape only covers “A” and “B” “C” is a thin (40 µm) parylene layer, no HV power traces  20 µm should be enough for HV isolation, but surface may not be perfectly flat (difference between 20 and 40 µm is 0.013 %X0) “B” is a bridge on top of the R5 sensors 3 Nov 2014Petal core material, AUW Nov 2014 5 “A”: sides “B”: bridge “C”: HV contact and isolation

6. Material calcualtion for bus tapes 3 Nov 2014Petal core material, AUW Nov 2014 6 ItemNumberMaterialTotal Mass(g)Density(g/cm3)Volume (cm3)Total thick (cm)X0 (cm)%X0 TOPKAPTON (kapton cover layer), 12.5um 2Polyiamide4.1741.421.4700.0037328.60.01306% Adhesive, 25 um 2Adhesive6.7011.142.9390.00747350.02134% BOTTOM (Cu shield layer), 12 um 2Cu5.38580.3370.000861.430.05980% INNERKAPTON (adhesiveless Kapton), 25 um 2Polyiamide8.3471.422.9390.0074728.60.02611% Adhesive, 25 um 2Adhesive6.7011.142.9390.00747350.02134% TOP (Cu traces), 18 um 2Cu2.81380.1760.000451.430.03124% Adhesive, 25 um 2Adhesive0.5571.140.2440.00062350.00177% BOTTOMKAPTON (Kapton) 50 um 2Polyiamide16.6951.425.8780.0149428.60.05222% 51.3730.043000.22687% ItemNumberMaterialTotal Mass(g)Density(g/cm3)Volume (cm3)Total thick (cm)X0 (cm)%X0 TOPKAPTON (kapton cover layer), 12.5um 2Polyiamide1.3311.420.4690.0011928.60.00416% Adhesive, 25 um 2Adhesive2.1381.140.9380.00238350.00681% BOTTOM (Cu shield layer), 12 um 2Cu5.38580.3370.000861.430.05980% INNERKAPTON (adhesiveless Kapton), 25 um 2Polyiamide2.6871.420.9460.0024028.60.00841% Adhesive, 25 um 2Adhesive2.1571.140.9460.00240350.00687% TOP (Cu traces), 18 um 2Cu2.81380.1760.000451.430.03124% Adhesive, 25 um 2Adhesive0.5571.140.2440.00062350.00177% BOTTOMKAPTON (Kapton) 50 um 2Polyiamide5.3741.421.8920.0048128.60.01681% HV insulation (Parylene) 40 um 2Parylene7.0151.13.188840.0081039.40.02056% 29.4580.023210.15643% “Baseline”: Bus tape covering full area “Parylene”: Bus tape on the sides, parylene on the center

7. X0 of petal variants 3 Nov 2014Petal core material, AUW Nov 2014 7 Petal variants Item“Baseline” Parylene isolation PEEK closeouts N636 HC“light core” Facings0.154% Bus tapes0.227%0.156%0.227% 0.156% Closeouts + Locking points0.073% 0.072%0.073%0.072% Allcomp0.048% Honeycomb0.073% 0.056% Adhesives0.064% Pipe + E breaks0.054% TOTAL0.6923%0.6219%0.6909%0.6758%0.604%

8. Material comparison (I) 3 Nov 2014Petal core material, AUW Nov 2014 8 “Baseline” 0.6923 %X0 Total mass: 203.192 g Parylene isolation 0.6219 %X0 Total mass: 181.277 g

9. Material comparison (II) 3 Nov 2014Petal core material, AUW Nov 2014 9 “Baseline” 0.6923 %X0 Total mass: 203.192 g N636 honeycomb 0.67585 %X0 Total mass: 193.96 g

10. Material comparison (III) 3 Nov 2014Petal core material, AUW Nov 2014 10 “Baseline” 0.6923 %X0 Total mass: 203.192 g All PEEK closeouts 0.6909 %X0 Total mass: 202.089 g

11. Material comparison (IV) 3 Nov 2014Petal core material, AUW Nov 2014 11 “Baseline” 0.6923 %X0 Total mass: 203.192 g “Light core”: Parylene, N636, all PEEK closeouts 0.6040 %X0 Total mass: 170.94 g

12. What does it really mean?  The %X0 of the barrel modules+adhesive between Si and core (not including power components) is equal to 1.20 %X0  One should expect a similar number for the petal modules  Detailed calculation will come first design of all hybrid flavors is available  Using the barrel estimate for the modules: 3 Nov 2014Petal core material, AUW Nov 2014 12 Core optionCore (%X0)Core + electronics (%X0)Core contribution Percentage of material saving wrt baseline Baseline0.692%1.892%36.59%0.00% Parylene + bus tape0.622%1.822%34.13%3.72% All PEEK closeouts0.691%1.891%36.54%0.08% N636 honeycomb0.676%1.876%36.03%0.87% "Light core" option0.604%1.804%33.48%4.67%

13. In summary  Material saving is one of the main arguments in favor of parylene coating (the other one is thermal performance)  Parylene gives you around 3.5% less material (although probably less)  However, this may lead to other challenges as opposed to using a well known option from the barrel effort  How do you connect your HV?  A bridge (+WBs, connectors?) that goes on top of the R5 sensors is still needed, or a bus tape folding on the top region (L&F-like)  How flat and uniform is your coating going to be?  My opinion: material savings are not big enough to justify the extra effort, but of course others may disagree... →A comparison of the thermal performance needs to be performed as well (maybe this has been done already?) 3 Nov 2014Petal core material, AUW Nov 2014 13

14. Other savings  N636 honeycomb instead of CF gives you < 1% material saving  But material is not the main argument here! Although it goes in your favor also  Going for PEEK closeouts does not give you any material savings  However it may help to simplify build (and G&S) procedure 3 Nov 2014Petal core material, AUW Nov 2014 14

15. Backup 3 Nov 2014Petal core material, AUW Nov 2014 15

16. Comments about X0 numbers MaterialX0/rho (cm)Comments Facings and C-channles K13C2U/EX1515 (45 gsm, 43% RC) 29.24X0 scaled from K13D2U/RS3 facings, 80 gsm, using differences in density CF honeycomb YSH50A-75 +EX-1515 (1/4) 1006 X0 scaled from YSH50/RS3 HC using differences in density (provided by manufacturer) Allcomp foam K9 (0.23g/cc) 185.6X0 scaled from Allcomp 0.3 g/cc, new 0.23 g/cc provided by manufacturer PEEK31.9X0 from SCT calc Ti3.58X0 from PDG Hysol9396/BN (30%)25.4 Assumes full block of HC with very low density, X0 from barrel calculations, assumes 100% glue coverage and a fixed thickness Bus tape adhesive layers 35X0 from barrel, coming from pixel calculations Polyamide 28.6 X0 from PDG Parylene39.4X0 from LHCB calc N636 honeycomb N636 PK2-3/16-2.0 1300Used X0 of Korex 3 Nov 2014Petal core material, AUW Nov 2014 16