Skin Effect in Wires.

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#402
Speedskater said:
In his day job at a major research lab, jneutron is co-author of at least 9 scientific/engineering/research papers.
I believe that he was responsible for installing 250,000 kilometers (or maybe miles) of wires and cables near super-conductor systems.
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Actually, a tad over 250 papers. But who cares..I do not..
And yes, miles. It was fun talking to the vendors though...10kfeet minimum...with an NRE?? Really??? Pay close attention...1000 power supplies, 1000 magnets, 800 meter circumference,that is only the ring, about 1/5th of the need of the project. Over 20 meg dollars(copper pricing went nuts a decade ago).

I must admit, I like what I do, may never retire...
However, I am pushing the younguns to write papers, they are early in their careers but need to publish.
Jn
Ps. I truly lament the projects of the future...we work on stuff I will not be alive to see complete...sigh
 
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#412
scottjoplin said:
What's so impressive about writing loads of research papers? 🙂
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As I said, I do not worry about the numbers. Some I actually wrote, but mainly as a record of what I did. Nobody cares about a 66mm diameter diode going into thermal runaway in liquid helium at 7000 amps because of TCE differences between silicon and molybdenum..and how I fixed it.. I can barely write that without falling asleep...

Most of them I am included because I built some magnet or diode or motion control system that somebody used to do something that advances science or physics or biology. I work in a support role making some widget that never existed before, and usually add some blurb about what's novel in how the widget was made.
What is cool is, I get to learn about their science. That is interesting.
I am totally amazed at the x ray crystallography, and how those guys can convert a dot pattern into covid spike protein 3D models.
Also, the supercomputers being used to model existing drugs against covid or cancer, then use crystallography to test results...awesome.
Jn
 
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#414
N101N said:
Surface charge accumulation (in common parlance: skin effect) is a consequence of the ionisation mechanism, that is, the spatial expansion associated with the excited atomic state where the ion core and electron are widely separated and distributed over a large orbital, allowing high polarizability, interactions over great distances and the development of large magnetic dipole moments. Surface charge density increases with the applied voltage. Surface potential varies with the concentration of the ions.
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You have NO CLUE about what ionization is, and assuming it happens inside solid copper is preposterous.

That said, there are conductors where ionization exists, specially water based saline solutions.

Crediting you with one "win", here we see such an example.

Maybe you use a similar conductor to wire your speakers?

To boot, it should alson "prove" skin effect ... at least this particular conductor is wrapped in skin. Human skin I might add:

Navy First Class Electrician: Nitro from Down Periscoope.
Nitro from "Down Periscope" - YouTube

Yes, it may tickle a little.
Small price paid for improved "Skin Effect" 😀
 
#415
I was thinking along these lines, a paper on plasma physics (hence my reference to ITER).

snip..""that the skin effect can be a major factor of plasma uniformity in a high-density plasma, even if the discharge regime is in a small electrode area and under moderate excitation frequency. When a radio frequency (RF) bias power was applied to an inductively coupled plasma (ICP),""...

Gonna watch that movie while riding my exerbike… never heard of it..

jn
 
#416
I can't find that freaky video of JET running from the outside with all the hollywood style light show.


I went to school near JET and had a lecture from one of the bods there. The flywheels for helping power up the plasma kinda scared me. The cooling system for their bearings requires its own UPS as you wouldn't want a power cut to cause a bearing seizure. They had calculated where it would land if it all went wrong and suspected it would skip like a stone on water for some miles.


Edit: But here are pretty pictures of the Z-machine in operation and using a LOT of power https://www.physicscentral.com/explore/pictures/meet-the-z-machine.cfm
 
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#417
JN,

Just for fun, my standard loudspeaker cable is a 10 gauge pair for the low frequency drivers, which the NEC under some readings may permit to still be considered class 2 wiring. However for the high frequency drivers I go to 14 gauge (Nominal .0641" diameter actual around .058") as my target is flat power delivery to 8,000 hertz. (Skin depth around .030" in copper wire) Actual power loss to the high frequency drivers is rarely an important consideration!

There is a second important consideration in these cables which is also improved by using different gauge twisted wire pairs, I suspect you know what it is. I am curious as to if anyone else can guess what the consideration is?

Hint I get my cables in 5,000' put ups.
 
#419
418 posts discussing "something".

I switch on my stereo and sitting in an armchair, I enjoy a cold beer.

Skin effect or not, capacitor brand x or y, who cares?
The music gives me a good feeling.
That's al that matters.
What else on earth do you want?
Really...
 
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