Talk-Polywell.org

One of my Google Alerts dropped this in my lap this morning:

http://www.pddnet.com/scripts/ShowPR~RID~25898.asp

Information on Kapton are available here:

http://www2.dupont.com/Kapton/en_US/index.html

Mylar is also good at low temperatures and has one of the highest volts/mil available. 7,500 ultimate.

Which means a half mil should be sufficient. In my LN2 estimates I used mylar. A half mil should be good for about 1,000 volts. I was expecting about 10 to 15 volts per coil in a bitter magnet design. Which means the EMF between turns was about .2 volts or less. So the occasional pin hole likely would not have been a problem.

Kapton of course is also excellent and a favorite of flex circuit designers. Something I have done a couple of times.

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Engineering is the art of making what you want from what you can get at a profit.

What I was thinking about here is the potential improvement in structural strength. The addition of fiberglass and epoxy strikes me as a good thing simply because my big concern is a fracture or spalling in the coil. Unfortunately, adding this stuff for strength brings up worries about cooling. As a structural geek, I like the Bitter plate design better.

I would like to minimize supports inside the tube. They cause two potential problems. One, they provide an avenue for the conduction of heat; two, they increase head pressure in the coolant. They are lot like adding resistors in an electric circuit. You don't want anymore of those than are absolutely necessary.

Life's full of them little tradeoffs.

I think that in a SC design the outer Cu (or sometimes Ag or other metals) sheath provides the electrical insulation. Such a design packs in more turns and serves as a thermal sink for the occasional point loss of SC properties. At least that is the way I read the literature. I may be incorrect on that though.

You might want to check on how this SC motor was wound:

http://powerandcontrol.blogspot.com/200 ... -navy.html

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Engineering is the art of making what you want from what you can get at a profit.

I'm gonna plug along as best I can without details on the magnets. I'll assume worst case. There is no way we'll know for sure until we can talk to some magnet guys.