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This document summarizes the discussions and decisions made during the LSWG meeting led by Richard Nickerson. Topics include mechanical components, cooling systems, power tapes, quality control, assembly equipment, and cost estimation for the LS upgrade project. The proposal for the Phase 2 pixel layout "NEWPIX" is analyzed, comparing Short-barrel, Utopia, and Long-barrel options. The cooling system's issues and the need for a decision on the coolant are highlighted. Additionally, the thermal and mechanical properties of carbon foam and laminate materials are discussed with detailed test results and recommendations. Stave thermal cycling tests and mass reduction programs are also covered. The document provides valuable insights and updates on the ongoing upgrade project.
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Richard Nickerson • LSWG content • All mechanical components • Cooling/connectors • Power tapes • Locking components for GS • Shipping containers • Text fixtures/boxes/equipment/DAQ/cooling plants • Survey equipment • Insertion tooling/Assembly equipment • Assembly of LS, including attaching modules • Quality control of components and materials • Test of assembled local supports • Survey of LS • Shipping of LS • Cost estimation (Richard Nickerson + Andrea Catinaccio) • Atlas Web>Atlas>Upgrade>UpgradeITKLocalSupports • Preliminar agenda: Upgrade week
Tuesday – pm LSWG Weds IWG, Strips Thurs all day – Cooling Assembly: mon/fri
Neal David Hartman • Pixel upgrade layout proposal: Phase 2 pixel layout “NEWPIX” - 2018 • All proposed layouts include a staging option to arrive at the best of both worlds • Assume the utopia medium barrel layout, as it’s the most balanced and buildable option available • Including more disks: infinite variations • Look at services routing and implications in different layouts, material comparison…
Nigel Hessey • Compares Short-barrel, Utopia and Long-barrel options (services not included) • Short barrel: lower cost/work/best pattern recognition • Utopia: is not so different • Long barrel: is worse! • Compares Short-barrel, Utopia and Long-barrel options (services included) • Long-barrel small improvement in the barrel-only region • Long- barrel + pixel produces a wall of services in front of the end-cap strips • Pixel services routing: what if we go directly forwards, not through the strip barrel/end-cap gap? • Compares Utopia, NewPix and layout with variable pixel barrel lengths • NewPix: more services in barrel-endcap gap
George Viehhauser • Cooling; not formal decision about coolant • Issue 1: scale the CO2 cooling system to 200kW? • Issue 2: location? • Re-usability of type II/III (SCT) or type III/IV (TRT) outside services • Current SCT services (calorimeter endplate or PP2) need to be cut and re-connected • Current TRT cables > connect to distribution at PP2 • Strip services • Current SCT or TRT cables> enough Cu for serial and DC/DC (grounding? aging?) • Not enough HV lines to connect every individual sensor (TRT+SCT 5k for 17k sensors) need to consider some kind of multiplexing • New optical fibres • Still need to look into DCS and all pixel services • Positioning requirements • Placement accuracy not important, present system very stable <10um globally with no external perturbation • Track-based alignment can do everything but “weak modes” are hard to compensate by software
W. Miller, R. Bates • Allcomp: Berkeley spin off (Wei Shih and Bill Miller) • Thermal and mechanical test for carbon foam… • Carbon foam strength and thermal properties increase with density (0.22g/cc) • Foam conductivity is weak function of cell size • 130ppi foam processing at 0.2g/cc and above produces higher conductivity than 100ppi foam • Current foam core material for LBNL stave prototypes with embedded cable. • The thermal and mechanical performance is highly determined by components interfaces and assembly/manufacturing processes.
W. Miller, R. Bates • Laminate thermal conductivity • In-plane; micromechanics code “Helius – composites pro” • Transverse; best to measure it! • Recommend new FEA model of co-cured laminate with embedded cable suggested to compare with test results. • Laser diffusivity measurements and comparisons with micromechanics… • Tensile test results influenced by thickness measurement… • Results of predicted and measured conductivities… • Fibre mechanical properties • Sandwich 50x50mm tensile test: face sheet fails – irradiated samples? • K13D2U (0-90-0) + UCF-126-3/8-2.0 + Hysol9396
Tim Jones • Stave thermal cycling • 2m long chamber, Liquid N2 cooling – 50ºC, electrical heater +50ºC; 1 hour cycle time • Overall plan: 50 cycles (visually inspect every 10 cycles) • No sign of delamination after 10 cycles • C channel – face sheet delamination in evidence after 20 cycles • Mass reduction program • Co-cured face sheets sucked onto vacuum jig, although residual curvature difficult to control along the edge • Nearly glueless stavelet (pre-preg to attach face sheet to core components) • Glue film investigations (CNC cuter) • No core stave; CFRP tubes running the full length • Corrugated cores • Radiation length • 2.65% stave • 2.37% supermodule (no bus cable but insertion mechanism included)
William Emmet • Experimental set-up
