NCSX Day 1 ECC (Extra Cheap Cryostat) Cryostat Configuration Status Report – September 30, 2006

The Cryostat is A Simple Hexagonal Shaped Foam Board Structure

First Plasma Cryostat Configuration 6 A-A Vertical ports accessible 3 Mid-Plane Ports accessible: –(3) A-A (NB) ports with circular extensions extend through the cryostat (6) Port 4’s (A-B ports) installed but inside cryostat (3) C-C ports do not extend through the cryostat (18) 6” ID VERTICAL DOWNWARD circular penetrations. For bus runs, cryo lines and TCs. (3) penetrations for stellarator support legs. Two cryostat access ports for possible removal of solenoid and making attachments at the bottom. –No plans for man entry – this port would be used for visual inspection, camera viewing to diagnose motions, etc. IF NEEDED. (6) 8” diameter penetrations for circulating (fan) probes. No ports for vacuum pumping (pumped from one of the NB ports listed above as A-A).

Issues Scaffolding requirements? NB compatibility? (ie, can isolation valves fit with cryostat walls as configured?) Upgradability –accessing angled ports require significant modifications. Maintenance access

Estimated Cost is ~50% of Current Budget

There Are Other Options Possibly less costly design– Top & Bottom rigidity foam board discs, but outside “walls” would be fabric “quilt drapes”. –Fabric double walled quilt with poured-in “aerogel” or other cryogenic insulation. –Tentmaker fabrication with cross-ties or internal sleeves to limit “ballooning”. Fireproof fabric required –Major advantages: easy core access; no problem with port motions! –Zip or lace together “quilt panels” with Velcro gas seals. –Support Rings around machine to support drapes in position. “Long-Term” design – Molded panels of GFT PerForma-H. –We’re awaiting costing data, but will clearly be much more expensive (higher material cost & all penetrations would have to be addressed at once). –HOWEVER, it would be the “final” solution.