ESLI new proposal Questions generated after their new proposal –radial fintubes –Dog-leg –Manifold –Development and production cost –CM’s design

ESLI ppt file Long discussion last Thursday and again on Friday A lot of the discussion was on CM’s design Did talk about manifold, radial fintubes, SOW, plan/schedule but not cost Dog-leg dropped for this year Review of design options added to proposal – including fabrication of small sample CM will be working with Tim on the design options

Radial fintubing Heat transfer depends on contact of chips, conductivity through the core, interface to tubes. Excessive impedance with vertical fibers because many fibers missed the tubes Problem known but only solved recently Ideal arrangement: tube diameter and separation the same; possible with new technique

Manifold Weakest part in the old substrate Use epoxy and Al manifold New proposal uses POCO graphite tube which has submicron holes Coat with pyrocarbon CVD to seal holes Put in oven and carbonized the whole piece (integrated piece) – technique used by General Atomics for Nuclear fuel pellets He leak test in each step Easy to attach Swagelock snap-on piece

Reinforcement Options Existing article has Carbon fabric wrap around Proposed to wrap around manifold if needed Start from carbon-fabric; remove most of the fibers until only few in-plane fibers left; transfer to the article

CM’s proposal Use rectangular carbon tubes to improve thermal performance Use closely packed tubes to form a rigid plate Then stick this plate into the velvet structure Pros- simpler to fabricate, maybe lighter Cons- stiffness, needs stiffening features or make the velvet higher;too much material because of coolant On Friday, Tim was more enthusiastic. He had some other ideas such as ribs, H-beams on the edge etc. Plan: review design options with CM; what’s the best solution: wall thickness, size of tubes etc

New proposal v2 Over the weekend, Tim worked more and sent me two revised ppt files He called me up this morning; briefly discussed pg 8-9 Dog-leg not included in the quote –now $115K; dog-leg estimated to cost 15K more What should we do next?