Why does it cost so much ?

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KitemanSA
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Location: OlyPen WA

Post by KitemanSA »

Forget the lead. What is the conductivity of copper at 8K? A copper tube properly wound might allow fields in the multi-Tesla range very cheaply.

Don't give up this thought!

MSimon
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Post by MSimon »

In fact Cu at 8K might work out rather well. Just keeping it a little below LN2 temps (77K) gives a significant boost.

Google Book

See page 237.

Cryogenic Hyperconductors

http://adsabs.harvard.edu/abs/1990acem...36..695C
For high magnetic field operation at cryogenic temperatures near 20 K, the best lightweight conductor presently available is high-purity aluminum, sometimes referred to as a hyperconductor. However, because of its high purity, the material is mechanically weak, and because of its high conductivity the conductor must be fabricated as fine twisted strands to reduce ac eddy current losses. Thus a construction whereby fine filaments are embedded in a high-strength, high-resistivity matrix has been suggested. The ac loss in such a conductor is computed and shown to be similar to that of a multifilamentary superconductor.
Engineering is the art of making what you want from what you can get at a profit.

icarus
Posts: 819
Joined: Mon Jul 07, 2008 12:48 am

Post by icarus »

Carbon nanotubes eventually? Lots of unknowns but lots more design knobs to twist also.

http://physicsworld.com/cws/article/news/24222

"Physicists in Japan have shown that "entirely end-bonded" multi-walled carbon nanotubes can superconduct at temperatures as high as 12 K, which is 30 times greater than for single-walled carbon nanotubes. The discovery has been made by a team led by Junji Haruyama of Aoyama Gakuin University in Kanagawa."

MSimon
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Joined: Mon Jul 16, 2007 7:37 pm
Location: Rockford, Illinois
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Post by MSimon »

icarus wrote:Carbon nanotubes eventually? Lots of unknowns but lots more design knobs to twist also.

http://physicsworld.com/cws/article/news/24222

"Physicists in Japan have shown that "entirely end-bonded" multi-walled carbon nanotubes can superconduct at temperatures as high as 12 K, which is 30 times greater than for single-walled carbon nanotubes. The discovery has been made by a team led by Junji Haruyama of Aoyama Gakuin University in Kanagawa."
Love to see the Jc vs B vs T on that stuff.
Engineering is the art of making what you want from what you can get at a profit.

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