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Posted

Hey,

I'm looking for high critical temperature superconductors (110-130K range) for a project I'm working on. Does anyone know where I can get these?

Thanks

Posted

from what i've seen there are some that aren't terribly expensive. I found one that has a Tc around 110K for a couple hundred dollars but it was part of a kit and I wasn't interested in all the other stuff. I'm looking for ones in 1/2-2" diameter range.

Posted

Here is a Thomas Register listing of MFRs which may be of help to you in purchasing Type-II Superconductors which exhibit the 'flux pinning' effect:

(note: C = coatings or film, M = materials or components, W = wire)

 

Advanced Ceramics Inc., NJ, M, 609-397-2900, 609-397-2708

Alfa Aesar Johnson Matthes, MA, M, 800-343-0660, 508-521-6350

All-Chemie LTD, SC, M, 803-884-4400, 803-884-0560

Alloys International Inc., NY, W, 516-342-0043, 516-342-0051

Angstrom Sciences, PA, M, 412-462-2777, 412-462-2780

California Fine Wire Co., CA, W, 805-489-5144, 805-489-5352

Commercial Crystal Labs Inc., FL, M, 914-643-5959, 914-643-6058

ESDI Inc., NY, C, 516-563-8278, 516-563-8231

G & J Steel & Tubing Inc., NJ, W, 800-322-8823, 908-526-9487

G&S Titanium, OH, W, 800-860-0564, 330-262-1550

GE Co., CT, M, 800-626-2004

Grove Grundilling Inc., ME, W, 207-743-7051, 207-743-7083

Hitachi Cable America, NY, M, 800-394-0234, 914-993-0990

HITC Superconductors Inc., NJ, M, 609-397-2700, 609-397-2708

Hypres Inc., NY, M, 914-592-1190, 914-347-2239

IGC Advanced Superconductors Inc., CT, W, 203-753-5215, 203-753-2096

Innovare Inc., PA, M, 610-837-8830

Intermagnetics General Corp., NY, M, 518-786-1122

InterWire Group, NY, W, 800-799-4978, 914-273-6510

MolecuWire Corp., NJ, W, 908-938-9473, 908-938-3189

Omega Engiuneering Inc., CT, W, 800-826-6342, 203-359-7700

Oxford Superconducting Technology, NJ, W, 908-541-1300, 908-541-7769

Rea Engineeered Wire Products Inc., IN, W, 219-422-4252, 219-422-4246

SAES Getters USA Inc., CO, M, 719-576-3200, 719-576-5025

Satcon Technology Corp., MA, M, 800-663-4916, 617-661-3373

SonoTec Corp., NY, C, 917-795-2020, 914-795-2720

Superconductive Componenets, OH, M, 800-346-6567, 800-292-8654

Superconductor Tech Inc., CA, M, 805-683-8527, 805-683-8527

Superconix Inc., MN, M, 612-222-0046, 612-222-0049

Vacuumschmelze (Siemens), NJ, M, 908-494-3530, 908-603-5994

Watteredge Uniflex Inc., OH, W, 216-871-9215, 216-933-8248

 

May I ask, what is your field of study? or academic institution?, potential application? or nature of experimentation; e.g. antigravity craft?, or transportation levitation?, teleportation?, particle acceleration?

 

Have you considered Room-Temp Semiconductors and/or diamagnetics as an alternate means of creating the 'flux pinning' effect?

Posted

Thanks for the info. It's a project for Cornell University, and its goal is to have two spacecraft essentially connected without touching each other. One would have a system of magnets and the other superconductors. The flux pinning would hold them together without letting them touch. Would room-temp semiconductors do what I want them to do, how could I find out more about them. I believe the team already looked into diamagnetics (I'm new) and decided against them, I don't know there reasons.

Thanks

Posted
Have you considered Room-Temp Semiconductors and/or diamagnetics as an alternate means of creating the 'flux pinning' effect?
Could you please elaborate ?
Posted

Hi cessna7686,

 

Cornell, excellent academic program. Are you a team member of the (N C M R S ) Non-Contacting Modular Reconfigurable Spacecraft Project?

 

If so, then you are actively involved in the actual design of the HTS device itself -- to further exploit the flux pinning effect, or at least are having it made to your exact specification to do so. That being the case, then I do not want to mis-guide your efforts in suggesting the sole use of non-SC diamagnetic devices, or even room temp SC (RTS) devices for your application, as I'm not sure if the alternate would provide a beneficial increase in the flux pinning effect.

 

Your project sounds intriguing. If possible, I'd like to hear some more about the potential 'applicational uses' of N C M R S. :)

Posted

Remember Faradays experiment with a spinning copper disc and a permanent magnet? I want to recreate faraday's experiment but instead of using a spinning copper disc, I want to use a spinning superconducting disc. What would happen?

Posted

rotatingcoppermagnet0an.th.png

 

I am trying to recreate faraday's disc experiment but I am using a rotating hollow copper ring about 6 cm, diameter. I am trying to measure the electromagnetic drag. Is the setup feasible? The copper sphere should be a hollow copper ring.

Posted

Hi Labview1958,

 

I am not a skeptic, nor a critic but an alternative energy advocate, research engineer and scientist seeking answers to these most difficult questions. I hope to find like minded individuals, perhaps together we may find the soultions.

 

In regards to your posting #10, to re-create Faraday's homopolar disk generator using HTS SC's instead of a copper disk: replacing the copper disk with a HTS SC is not a novel idea, this has been suggested and explored before. But, there are many complications with this idea, such as:

 

First, Faraday's copper disk produces its current output as a result of an external magnetic field causing eddy currents within the copper disk which is rotating in fixed orientation such that the magnetic field is perpendicular to the radius of the disk. Current flows from center axial pivot point (termination contact 'A'), through the copper disk to its outer edge along its circumfrance (termination contact 'B').

 

This differs from using a HTS SC disk: since it does NOT rely on eddy currents, but instead current flow increases with decrease in temperature thus producing the Meisner effect (which requires an LN2 catalyst to invoke). As a result of achieving the meisner effect, the HTS SC provides many useful benefits; e.g. magnetic levitation, low resitivity and high current capability. Difficulty arises from cost, size, quality of material composition, and ease of use (LN2 is tricky to handle), etc.

 

Secondly, if given a "perfect" machanically built apparatus, the HTS SC would most surely out perform the copper disk. Unfortunately, creating such a perfect device is easier said than done! Perfection is not always obtainable, and even when possible it is very costly (e.g. Hubble Telescope).

 

Inherent to the functionality of the homopolar generator (copper disk, or otherwise) is the ability to tap the current from the high-speed rotating disk. The two most widely used methods for the copper disk are: (a) solid carbon contact, which suffers from wear and surface contact irregularities, and (b) liquid mercury bath contact, which is difficult to contain not to mention the difficulty to maintain liquid level and surface contact.

 

Third, if either of the two termination/contact methods mentioned above are to be used, would not their excessive contact resistance and wasted frictional heat defeat the sole purpose and benefit of using the 'low resistive' HTS SC?

 

So, copper -vs- SC disk? I'd say, go for the SC disk. The end result of increased current flow appears to be the same, but for entirely different reasons, methods and practices. Aside from the difficulties in building a functional HTS SC aparatus, the homopolar generator ulitimately suffers from one key design difficulty: "termination contact".

 

That said, what do you suggest would be more appropriate in providing an alternative termination contact material and/or method for the suggested HTS SC disk?

 

Lastly, how do you maintain constant LN2 contact and temperature to maintain a steady current flow? This is the most difficult question.

Posted

Hi Labview1958,

 

Regarding your #12 posting, Faraday disk generator using hollow copper ring ...

 

Q. Is there a metal ball inside the copper ring which is allowed to move upon rotation?

 

Q. Is the rotatig hollow copper ring's radius parallel (preferred) or perpendicular to the external magnet? From the diagram, it appears to be perpendicular.

 

Q. Where are your two termination contact points located?

 

Q. What is your reasoning behind using a 'hollow' copper ring? How do you believe this will improve the eddy current effect, as ooposed to using Faradys flat copper disk?

 

Q. Are you familiar with electric-magnetic breaks?

 

Q. In what way do you believe the hollow copper ring will show drag?

 

This is an interesting design.

Posted

Q. Is there a metal ball inside the copper ring which is allowed to move upon rotation?

The copper ring surrounds a plastic disc.The center of the plastic disc is attached to a spindle of a high speed rotating drill.

 

Q. Is the rotatig hollow copper ring's radius parallel (preferred) or perpendicular to the external magnet? From the diagram, it appears to be perpendicular.

It is perpendicular.

 

Q. Where are your two termination contact points located?

There are no termination contact points.

 

Q. What is your reasoning behind using a 'hollow' copper ring? How do you believe this will improve the eddy current effect, as ooposed to using Faradys flat copper disk?

The "hollow" copper ring is easier to spin then a disc. The eddy current penetration levels off about 1cm thickness. Thus a copper ring with thickness of more then 1cm is not necessarry.

 

Q. Are you familiar with electric-magnetic breaks?

Yes.

 

Q. In what way do you believe the hollow copper ring will show drag?

As the copper ring moves downwards, the magnet will relatively move upwards with respective to the copper. Thus if the magnet moves "upwards" then the electromagnetic drag is "downwards". Thus registering a reading on the balance.

Posted

My "thought" experiment is to explore or study the eddy current generated in the copper disc and the meisnner effect in superconductors. I want to show that both are two sides of a coin.

Posted

You might want to look at the alternate formulation of Electromagnetic theory for the possibility of exploiting small side-effects:

 

Weber's Electromagnetic theory. It was recognized and approved by Maxwell, but rejected by him in his formulation of Electromagnetics for other reasons (see his explanation). Secondly, the Maxwell equations as we take them now (not the 12 messy ones, but Heaviside's 4 tidy ones) have a probable error in the 'signing' of the formulas, which may mislead experimentors.

To investigate this problem, try reading some work found here:

 

http://www.andrijar.com

 

I found his derivation of the Maxwell equations interesting.

For Weber, look for the treatments by Andre K.T. Assis.

  • 6 years later...

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