Thermo-mechanical petals Volker Prahl, Sergio Díez, on behalf of the petal community CERN AUW, 3 rd Nov 2014

A thermo-mechanical petal  It was agreed at the ITk meeting to build a fully “instrumented” thermo-mechanical petal in the following months  Tooling and building experience  Thermal studies  Mechanical studies  QA  …  That will lead to the manufacture of full length petal cores  DESY Hamburg will be the main site that will produce the cores, with help from the petal community  The cores will follow the current petal model  This talk is mostly a summary of the discussion from Oct 24 th : 3 Nov 2014TM petal, AUW Nov

Current petal model 3 Nov 2014TM petal, AUW Nov locking points, 2 on long side, 1 on EoP area C-channels on lateral (long) sides PEEK closeouts on top and bottom (short) sides, accommodate E breaks

Components: bus tapes  Bus tapes  First version of TM bus tape for each face designed by Pepe Ber nabeu Follows the standard barrel layout (220um thickness)  Bottom Kapton (50 µm)  Cu traces (18 µm)  Inner Kapton (25 µm)  Cu shield (12 µm)  Top Kapton (12.5 µm)  Adhesive layers Includes power rails and data lines Bottom Kapton + Cu traces layers cover the whole petal surface  Vladimir Cindro already submitted it to Elgoline Tapes will be back in 3-5 weeks  Will be co-cured along with the facings 3 Nov 2014TM petal, AUW Nov

Components: facings, honeycomb  CF Facings  K13C2U/EX1515, 45 gsm, CF orientation, 150 um thick + bus tape (same as staves)  Tim Jones (Liverpool) agreed to co-cure them for us for the first prototypes with help from Luise Poley (DESY Zeuthen)  Honeycomb  DESY has in hand both vented CF and N636 honeycomb  First core will be produced with CF, second one with N636  Total thickness = 5.2 mm, will need to be grounded/milled on either case  DESY doesn’t have grinding capabilities as of today First cores will be milled in-house DESY working on obtaining a grinding tool and looking for options in industry (such as it was done for the petalets) 3 Nov 2014TM petal, AUW Nov

Components: graphite foam, pipes, E break  High thermal conductivity foam (Allcomp)  Order of K9 allcomp foam, 0.23 g/cc purchased recently, enough for ~10 petals  Will be in hand next week  DESY has equipment for the cutting of the parts and milling (again, not grinding) of the mm grooves  Also experience with Pocofoam from petalets  Cooling pipes  Ti, mm OD, total length required for a petal is 1205 mm  DESY has 5 pipes, mm OD, 3m long (can produce 2 petals per pipe)  Ti pipe bending experience from petalet  First bending trials with new geometry already started  E break  Need to clarify if parts will be in hand in the near future Will drop them from the TM if real parts not available 3D-printed or PEEK parts most likely not compatible with CO2 3 Nov 2014TM petal, AUW Nov

Components: closeouts and adhesives  Top and bottom closeouts  Will be manufactured in PEEK at DESY workshop  Will accommodate E breaks on the top part (if available)  Lateral closeouts (C-channels)  Can be CF or they can be also segmented and manufactured in PEEK  Not clear we actually need C-channels at all, simple lids may also work  Locking points  Will be manufactured in PEEK (at DESY workshop?, at IFIC?)  Adhesive  % BN-loaded Hysol everywhere in the core (foam to pipe, foam to facing, HC to facing, closeouts, …) BN load enhances T conductivity and allows a good control of glue viscosity 3 Nov 2014TM petal, AUW Nov

Components: electrical  Sensors  Si dummies from 6” wafers, cut to size at IMB-CNM  Very little processing (just guides for cut and marks at hybrid corner locations)  Brass could be used as a backup  Hybrids  130 nm hybrids, a first version of all flavors can be produced in a reasonable timescale (see Kambiz’s talk on Wednesday)  ASICs  Glass dummies with heaters from IMB-CNM, bonded to hybrids  DC-DC converters and EoP boards  Real size dummy FR4 PCBs with resistors acting as heaters  Glue  SE4445, epolite, UV glue (not TRA-DUCT) Need a new order of SE4445 and epolite  No WBs or HCCs 3 Nov 2014TM petal, AUW Nov

Petal core Tooling  The aim should be producing similar tooling as the barrel community (see Stephanie Yang’s talk at Itk week:  Not really feasible for the first round of petal cores  Most of the operations will be performed in a “manual” way or with simplified tools following our expertise with the petalets  T. Jones also produced a preliminary design, that may be a good starting point  Sensor, hybrid, and ASIC positioning either “by hand” or with very simplified tools  Module construction sites will help with this (Freiburg, DESY Zeuthen, IFIC) 3 Nov 2014TM petal, AUW Nov

Flavors  The first TM prototype will follow the “Bear” approach electrically  Will use v1 of 130 nm hybrids 2 barrel-like hybrids on R0  Different cores  “Baseline” for this round of cores: CF honeycomb TM Bus tape covering all surface (as shown before) IFIC locking points and closeouts  Other alternatives that will come after the first core N636 honeycomb Parylene coating for HV isolation and two bus tapes per facing Alternative locking points Will need quite some help from other institutes if we want to try all this  Total number of cores/petals for needs to be worked out, to be discussed later today 3 Nov 2014TM petal, AUW Nov

Tentative schedule for TM core manufacture 3 Nov 2014TM petal, AUW Nov Components/actionsNov 2014Dec 2014Jan 2015Feb 2015Mar 2015 Bus tapes Facings Honeycomb(s) Pipes Allcomp foam E breaks? Closeouts Locking points Core gluing Core milling Dummy sensors Hybrids ASICs DC-DC dummies EoP dummies Manufacture at Elgoline Co-curing (Liverpool) Cut and glue trialsCut to size Cut and glue trials Receiving Cut to size Test Bending and test Manufacture in PEEK Manufacture in CF (Liverpool?) Final designManufacture in PEEK Gluing step 1 Gluing step 2 Milling step Design, manufacture, cut to size (IMB-CNM Barcelona) Design, manufacture (Freiburg) Assembly of dummies (Zeuthen, Freiburg, IFIC) Assembly of dummies (Zeuthen?) Design and manufacture of jigs Assembly of dummies (Zeuthen, Freiburg, IFIC) Start loading first cores with dummies here Assembly of dummies (Zeuthen, Freiburg, IFIC)

Next steps: thermal and mechanical tests  Need to come out with a TM testing strategy as soon as possible  DESY, IFIC, Nikhef?  Thermal simulation effort started recently at DESY (D. Meissner)  First (very preliminary) results with current model already produced, more in the near future Thanks G. Beck for the support and info! 3 Nov 2014TM petal, AUW Nov Glue contact surfaces included. No Honeycomb at the calculation No thermal radiation convection Heat transfer only by the cooling CO2: const Temp and HTC (8000W/m2K, -30C°) over the length of the cooling tube Heat 86Watt