OUTLINE: 1.Current Design 2.Hybrids, Staves 3.Radiation Length 4.Cooling, etc.

CURRENT DESIGN (ALMOST) R. Mountain, Syracuse University UT Tracker Discussion, 16 July Support Structure column geometry stiff, stable no twisting (wb) no therm motion no vibr modes Superstructure massive frame outer box Hybrid mounting front & back Permanent wirebonds Cabling readout flex service flex (only shown for central columns) Beampipe Interface clearance BP movement (bumpers?) heaters insulation sealing Sensors gapless coverage overlap optimization Hybrids stiff, stable wirebond support Balcony (Electronics & Services) evaporative CO 2 Cooling

HYBRID R. Mountain, Syracuse University UT Tracker Discussion, 16 July Simone & Mauro, 8 Jul 2013 Shown with stave section not to scale Currently, “hybrid” consists of… –Silicon Sensor –ASICs (4,8,16 per hybrid) –Kapton substrate a.k.a. flex circuit, or “jeff-flex” NOT kapton tape for signals, NOT kapton tape for power, NOR the combination –Epoxy layers (thermal) Silicon sensor to flex circuit ASICs to flex circuit Flex circuit to stave (may not be continuous) –Possible additional carbon fiber support The necessity of this will be determined by the mechanics, i.e. what is necessary to support and handle flex circuit Adds another epoxy layer: carbon fiber to flex circuit Caution: there is some disagreement as to whether this is formally part of the “hybrid” Originally the flex circuit plus carbon fiber was called “substrate” Remember: Hybrid is not yet designed !

HYBRIDS in PLANE Location of different types of hybrids –4 = 16-ASIC hybrid –2 = 8-ASIC hybrid –1 = 4-ASIC hybrid There are four different types of columns in this scheme This scheme gives an upper limit on the number of ASICS in order to provide a conservative estimate of power dissipation. This is not the canonical numbering. R. Mountain, Syracuse University UT Tracker Discussion, 16 July Column Type: A B C D D D D D (symmetric)

LIGHT-WEIGHT SUPPORT LBL-type Stave (ATLAS) –CFRP facings + CF foam (sandwich structure) –Embedded Ti cooling tubes –Closed structure, allows for stiffness of support, compactness, and low mass –Column as a unit, in construction and testing Modifications under test: –Reduced amount of foam –Cutouts in facings –Judicious path for cooling tubes Various constructions in progress –Quarter-length, Full-length R. Mountain, Syracuse University UT Tracker Discussion, 16 July Cooling Tubes CF Foam / Honeycomb CFRP Facing ATLAS STAVE

The SNAKE –Single tube –Flow is top-to-bottom –Probably only metal tubes feasible, to keep bends under control –Contact heat xfer from ASICs, but rely on substrate to provide heat xfer path from Si If INTERIOR COOLING –Encase cooling tubes in carbon foam –Takes ~30% of full carbon fill (tuneable) –Hybrid would be “lighter” If EXTERIOR COOLING –Not do-able, can’t snake on both sides (wrapping around sides interferes w neighboring column) VARIATIONS –Diagonal path, Sawtooth, X, etc. COOLING CARTOONS (2) R. Mountain, Syracuse University UT Tracker Discussion, 16 July mm -6- Element%RL Tubes (single) 0.048% Fluid (water+glycol 60:40) 0.037% POCOfoam0.119% Total=0.331% with faces, epoxy, etc. [manifolds] AA’ SECTION AA’ facing tube INTERIOR Old slide from RM, 12 Apr 2013

Quarter-Length STAVE w Cutouts R. Mountain, Syracuse University UT Tracker Discussion, 16 July Variations under consideration, constructed and tested … All have ribs only in “Box” configuration (these yield relative measurements only) One more design will test X with ribs in full “X” configuration RatiosKX+KBoxXOSolid(Ribs) facing/facing 0% (28%)47% (76%)31%46%75%100%— stave/stave 18% (38%)63% (83%)42%71%85%100%— stiff enough? NYNY?YY— * Numbers in parentheses refer to those cases in which the kapton is included

Radiation Length in UT Region R. Mountain, Syracuse University UT Tracker Discussion, 16 July UT Configuration in DDDB RL = 4.83% X O Four layers: XUVX RL between Z= mm, including 0.14% X O from air, and 0.34% from UT box. Overall RL between 2 <  < 4.9 is 4.30%. RL per UT plane ≈ 0.95%. …from JC Current TT Beampipe (current) Beampipe jacket now significantly thinned Sensor active region extends to R35 Radiation Length for UT Designs Outer frame, balconies (now no cooling plates)

UT Materials 9 PartsMaterial Thickness (  m) RL (%X o ) (2<  <4.9) Hybrid Sensor Si Al10 ASICSi+ Al Hybrid Flex Circuit (jeff-flex) Kapton Ground Al11 Traces, wirebonds6 Thermal epoxy100 Signal/Power Flex (tape) Kapton Ground, traces, epoxy x 11/ Stave (module, column) POCO foam3000 (½) 3460 (1757) CFRP face2x130 (½) Epoxy4 x 50 (½) Titanium 2x  =2.2, t=0.12 mm Cooling fluid- UTaX TOTAL0.95 Outer BoxGraphite,epoxy,Kevlar2 x Air430 mm0.14 UT TOTAL4.30 R. Mountain, Syracuse University UT Tracker Discussion, 16 July 2013 …from JC

Other Mechanical Issues Thermal simulation & measurements –Thermo-mechanical Simulation underway (Milano) –ASICs are heat islands with thermal barriers to movement of heat –Measurements of cooling power with thermal mockup (SU) Hybrid flex circuit & Kapton tapes –Will need to have thermal paths through the plane of the kaptons –Design of tapes underway (Milano) Epoxies –Adhesives from ATLAS/CMS (tested before and after irradiation) –Epoxies loaded with BN, etc. UT Mechanical Requirements document –To be found on twiki R. Mountain, Syracuse University UT Tracker Discussion, 16 July Simone & Mauro, 8 Jul 2013

CO2 Blow-Thru SU R. Mountain, Syracuse University UT Tracker Discussion, 16 July (MASS) FLOW METER NEEDLE VALVE BACK -PRESSURE REGULATOR HEATER (+50°C) VENT TO AIR EVAPORATION VOLUME (Stave in Insulating Box, w dry N2 flush) XX DRY-OUT INTERLOCK (last hybrid) HEAT EXCHANGER (siphon draws from liquid at bottom) VCR / SWGLK FITTINGS SAFETY RELIEF VALVE (110 atm) VENT TO AIR PRESSURE GAUGE P1 * follows from discussions with Bart Verlaat inlet manifold return manifold P = 15 atm T = –25°C P = 1 atm T = +20°C P = 57 atm T = +20°C P = 57 atm T = +20°C P = 15 atm T = –15°C * P = 15 atm T = +20°C P = 15 atm T = –25°C CO 2 O2-DEFICIENCY INTERLOCK SOLENOID VALVE PRESSURE GAUGE P2 PRESSURE GAUGE P3 P = 57 atm T = +10°C *

CO2 State Diagrams R. Mountain, Syracuse University UT Tracker Discussion, 16 July orig. Bart Verlaat, Forum Trk.Det.Mech 2013 ← Critical Point (31°C, 73 atm) ← Triple Point (–57°C, 5 atm) 40 atm = 580 psi = 4 MPa – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – 30 atm = 435 psi = 3 MPa – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – 20 atm = 290 psi = 2 MPa – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – 60 atm = 870 psi = 6 MPa – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – 10 atm = 145 psi = 1 MPa – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – REF: - Pvap = 57 20°C - lobe above TP shown Mollier PH diagram