Wiffleball size

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Indrek
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Wiffleball size

Post by Indrek »

Something I threw up for fun, following from the previous electron count estimates in the "significance of electron recirculation revisited" thread.

http://www.mare.ee/indrek/ephi/wbsize.pdf

rcain
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Post by rcain »

thats useful, thanks Indrek. just re-reading over your http://www.mare.ee/indrek/ephi/images.pdf also.

as I asked MSimon, on separate thread, shouldnt we be trying to derive this using gyro-radius?

MSimon
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Re: Wiffleball size

Post by MSimon »

Indrek wrote:Something I threw up for fun, following from the previous electron count estimates in the "significance of electron recirculation revisited" thread.

http://www.mare.ee/indrek/ephi/wbsize.pdf
That comes amazingly close to my BOE calculation for a .5 m radius coil 10T coil.
Engineering is the art of making what you want from what you can get at a profit.

MSimon
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Post by MSimon »

rcain wrote:thats useful, thanks Indrek. just re-reading over your http://www.mare.ee/indrek/ephi/images.pdf also.

as I asked MSimon, on separate thread, shouldnt we be trying to derive this using gyro-radius?
It may help but it is not obvious to me how to do it.

I just took the simplistic approach that the currents have to be equal.

Of course that is only a sanity check approach.
Engineering is the art of making what you want from what you can get at a profit.

TallDave
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Post by TallDave »

Very interesting and easy to follow, thanks for sharing Indrek!
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...

BenTC
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Post by BenTC »

That link http://en.wikipedia.org/wiki/Inversive_geometry in the PDF doesn't work, the colon has been included.
In theory there is no difference between theory and practice, but in practice there is.

icarus
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Post by icarus »

More specifically it is a

http://en.wikipedia.org/wiki/Kelvin_transform

for the magnetic field of the coils. The transform produces the spherical inclusion (ideal wiffle ball) containing the interior potential field solutions that are merely the exterior potential field solutions mirrored (internally) under a spherical inversion.

rcain
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Post by rcain »

... still trying to understand the formation/physics of the Wiffleball ... have come up with a bit of background-and-around reading some might find of interest.

http://www.tkk.fi/Units/AES/courses/crs ... _Jamsa.pdf - nice little intro pp.

http://arxiv.org/PS_cache/physics/pdf/0 ... 0139v2.pdf - 'Is PLasma Diamagnetic?' - very interesting read - '...It seems that the Lorentz force is a test-particle approximation which is not suitable to describe the interaction of moving particles in agreement with the conservation of energy....'

http://media.iupac.org/publications/pac ... 3x0389.pdf - 'Electromagnetic Induction in Plasma' - ancient paper, but consise.

http://people.physics.anu.edu.au/~jnh11 ... chap06.pdf - diamagnetics in MHD. good general read.

http://books.google.co.uk/books?id=ToAt ... ma&f=false - good background even without the missing pages.

http://www2.warwick.ac.uk/fac/sci/physi ... cture4.pdf - quick pp on mag pinches and stability.

Giorgio
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Post by Giorgio »

rcain wrote: http://arxiv.org/PS_cache/physics/pdf/0 ... 0139v2.pdf - 'Is PLasma Diamagnetic?' - very interesting read - '...It seems that the Lorentz force is a test-particle approximation which is not suitable to describe the interaction of moving particles in agreement with the conservation of energy....'
If you liked that you will love also his 2006 and 2008 papers:

http://arxiv.org/PS_cache/physics/pdf/0 ... 4037v1.pdf
http://arxiv.org/PS_cache/arxiv/pdf/080 ... 1243v1.pdf

The Discussion and Conclusion sections are even more interesting than the 2005 paper you mentioned.

rcain
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Post by rcain »

Thanks Giorgio, certainly is.

i found another paper by W. Engelhardt here http://redshift.vif.com/JournalFiles/V1 ... 1N2ENG.pdf - 'On the Relativistic Transformation of Electromagnetic Fields'. - 2004.

he is a dude.

tearing great holes in 'accepted'physics without breaking into a sweat.

i hadn't realised that this subject would be so littered with gaps and paradoxes at such a fundamental level.

MSimon
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Post by MSimon »

i hadn't realised that this subject would be so littered with gaps and paradoxes at such a fundamental level.
Feynman has two routes to "mass/inertia is at least 1/2 electrodynamic."

1. Maxwell
2. Quantum Electrodynamics

He may be passe' by now though.
Engineering is the art of making what you want from what you can get at a profit.

Art Carlson
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Post by Art Carlson »

rcain wrote:Thanks Giorgio, certainly is.

i found another paper by W. Engelhardt here http://redshift.vif.com/JournalFiles/V1 ... 1N2ENG.pdf - 'On the Relativistic Transformation of Electromagnetic Fields'. - 2004.

he is a dude.

tearing great holes in 'accepted' physics without breaking into a sweat.

i hadn't realised that this subject would be so littered with gaps and paradoxes at such a fundamental level.
I never expected to run across Wolfgang Engelhardt again. I spent untold hours at IPP arguing with him and finding flaws in his mathematics, so much so that it probably hurt my career. Nobody else cared much, but I was fascinated by the man. He had a good reputation as a spectroscopist, and I still remember being impressed by the talk where he argued for making the first wall of tokamaks out of tungsten. (At the time, all the machines in the world (with one exception) had a first wall of graphite. Now, everyone agrees that at least part of the first wall of ITER and any reactor will have to be tungsten.) In my naivety I thought it must be possible to eventually come to a rational meeting of minds with such an intelligent and well-read physicist. But every time I pointed out a flaw in his logic or mathematics, instead of admitting he was wrong, [h]e constructed a different gedanken experiment o[r] mathematical proof, and the whole story would start over again. I don't know if these papers (none of which are peer reviewed, I point out) have the old errors I know or new ones, but I don't intend to find out. Do enjoy yourselves.
(edited [typos])
Last edited by Art Carlson on Sat Apr 10, 2010 6:44 pm, edited 1 time in total.

Giorgio
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Post by Giorgio »

Art Carlson wrote:But every time I pointed out a flaw in his logic or mathematics, instead of admitting he was wrong, we constructed a different gedanken experiment of mathematical proof, and the whole story would start over again. I don't know if these papers (none of which are peer reviewed, I point out) have the old errors I know or new ones, but I don't intend to find out. Do enjoy yourselves.
The beauty of mathematical proofs without experimental supports (especially at this level of complexity) is that you can prove and disprove almost anything simply by adding or changing an hypothesis here and there.
And as there are no experimental data to support an hypothesis or the other, you can most of the time hypothise what you like more.

Is Engelhardt right or wrong? We won't know until some eperiments wil be done to check his ideas, but is mathematic does not look too weak to me.

Let's remember that also Einstein General Relativity Theory was controversial and proved wrong in 2 different observations until finally proved right at the third observation.
And Einstein himself was not perfect, he also made lot of mathematical mistake in works, but his best idea was proved correct in the end.
There is really nothing new under the sun.

Giorgio
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Post by Giorgio »

rcain wrote:i hadn't realised that this subject would be so littered with gaps and paradoxes at such a fundamental level.
That's becouse there are too many scientists spending their time on the desk instead that in the lab :twisted:

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