Muons

Discuss the technical details of an "open source" community-driven design of a polywell reactor.

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GWW57
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Muons

Post by GWW57 »

Just a wild idea from a non-physicist...

What about injecting muons along with the electrons?

I know they decay quickly (~2 ms ?), but they may have a synergistic effect on the reaction rate.

(Yes, I am aware of some of the history of muon-catalysed fusion)

Making the muons may soak up all the spare power, and then some - I have no idea how difficult they are to make.

blaisepascal
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Re: Muons

Post by blaisepascal »

GWW57 wrote:Just a wild idea from a non-physicist...

What about injecting muons along with the electrons?

I know they decay quickly (~2 ms ?), but they may have a synergistic effect on the reaction rate.

(Yes, I am aware of some of the history of muon-catalysed fusion)

Making the muons may soak up all the spare power, and then some - I have no idea how difficult they are to make.
A reply from another non-physicist...

Muon-catalyzed fusion works because the heavier mass of the muon allows the atoms of hydrogen to be much smaller, bringing the nuclei closer together in molecules, thus reducing the Coulomb barrier to fusion.

In the polywell, we are dealing with a plasma: no molecules and bare nuclei. In this environment, muons look just like heavy, unstable electrons. When they decay, they spit out a fast electron and a pair of neutrinos. None of this sounds like it'll help significantly, but I could be wrong.

drmike
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Post by drmike »

Muon mass is 105MeV ~ 10^-11 J. It's lifetime is ~2.2 msec. So you need ~5 x 10^-7 W per muon. Normal electron density is 10^19 m^-3 so to replace that would take 1000 GW. Even 6 orders of magnitude less would be hard to justify.

It'd be a fun experiment though!

rnebel
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Post by rnebel »

Muon fusion was tried experimentally at Los Alamos in the 1980s. The targets weren't plasmas, but rather were cryogenic. The problem was that a muon couldn't induce enough fusions to make up for the energy required to make the muon (Q<1). I believe the person who ran the experiments was Steve Jones, who later crossed swords with Pons et.al. over cold fusion.

EricF
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Post by EricF »

I was reading up on muons a couple of weeks ago while reading about the Strong force, as I understand it the only player involved in the Strong Force between particles is muon exchange.

Does the muon exchange involve the muons flowing back and forth within and between/among particles much like electrons flow back and forth in a covalent bond?

blaisepascal
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Post by blaisepascal »

EricF wrote:I was reading up on muons a couple of weeks ago while reading about the Strong force, as I understand it the only player involved in the Strong Force between particles is muon exchange.

Does the muon exchange involve the muons flowing back and forth within and between/among particles much like electrons flow back and forth in a covalent bond?
Muons don't interact with the strong force at all. Perhaps you are thinking of gluons?

EricF
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Post by EricF »

blaisepascal wrote:
EricF wrote:I was reading up on muons a couple of weeks ago while reading about the Strong force, as I understand it the only player involved in the Strong Force between particles is muon exchange.

Does the muon exchange involve the muons flowing back and forth within and between/among particles much like electrons flow back and forth in a covalent bond?
Muons don't interact with the strong force at all. Perhaps you are thinking of gluons?
Now I'm not sure, I do remember reading it in an article online (my memory is usually really good so its possible the article was simply wrong). I'll just finish up these Richard Feynman lecture books before I start asking more stupid questions :oops:

blaisepascal
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Post by blaisepascal »

EricF wrote: Now I'm not sure, I do remember reading it in an article online (my memory is usually really good so its possible the article was simply wrong). I'll just finish up these Richard Feynman lecture books before I start asking more stupid questions :oops:
The Feynman Lectures are good generally, but are a bit weak in the quantum physics realm. At the time he gave the lectures (1964ish) Quantum ChromoDynamics (the strong-force analogue of QED) was still a decade away from being formulated. I'm not certain that at the time the books were written there was a clear understanding of what a muon was (although it was known to be a particle with electric charge -1 and a mass much greater than an electron, and that it readily decayed into an electron).

If you want to get a rough introductory handle on the Standard Model (which describes all the fundamental particles and the fundamental forced between them (excepting gravity)), you might want to check out The Particle Adventure, an award-winning website from folks who really know the Standard Model.

MSimon
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Post by MSimon »

blaisepascal wrote:
EricF wrote: Now I'm not sure, I do remember reading it in an article online (my memory is usually really good so its possible the article was simply wrong). I'll just finish up these Richard Feynman lecture books before I start asking more stupid questions :oops:
The Feynman Lectures are good generally, but are a bit weak in the quantum physics realm. At the time he gave the lectures (1964ish) Quantum ChromoDynamics (the strong-force analogue of QED) was still a decade away from being formulated. I'm not certain that at the time the books were written there was a clear understanding of what a muon was (although it was known to be a particle with electric charge -1 and a mass much greater than an electron, and that it readily decayed into an electron).

If you want to get a rough introductory handle on the Standard Model (which describes all the fundamental particles and the fundamental forced between them (excepting gravity)), you might want to check out The Particle Adventure, an award-winning website from folks who really know the Standard Model.
An excellent introduction to QED by Feynman:

http://vega.org.uk/video/subseries/8

This was my first definitive exposure to the subject and it has changed my life. It was given in 1979.
Engineering is the art of making what you want from what you can get at a profit.

EricF
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Post by EricF »

Yeah I saw that on your blog, I'm about halfway through the 3rd video now. So far its mostly about probability :lol:

EricF
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Post by EricF »

I've just skipped over a lot in the first Feynman book concerning the math so far and tried to absorbs the concepts, there are a lot of expressions I am just unfamiliar with that I haven't come across in any of my math or science classes yet. Also, something thats been irking me from the Tuva series, he talks at length about gravity being the inverse of the square of the distance, is that written as

(G=newtons? is a newton a metric measurement?) (D= meters?)
G = 1/D^2 ??

Someone really needs to come out with a physicists Almanac or something lol

MSimon
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Post by MSimon »

EricF wrote:I've just skipped over a lot in the first Feynman book concerning the math so far and tried to absorbs the concepts, there are a lot of expressions I am just unfamiliar with that I haven't come across in any of my math or science classes yet. Also, something thats been irking me from the Tuva series, he talks at length about gravity being the inverse of the square of the distance, is that written as

(G=newtons? is a newton a metric measurement?) (D= meters?)
G = 1/D^2 ??

Someone really needs to come out with a physicists Almanac or something lol
F = G (m1 * m2)/r^2. I think D=distance equivalent to r, I think.
Engineering is the art of making what you want from what you can get at a profit.

Aero
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Post by Aero »

G is a fundamental physical constant, the Newtonian constant of gravitation.
It is experimentally determined to equal 6.674 28(67) x 10-11 m3 kg-1 s-2

See
http://physics.nist.gov/cgi-bin/cuu/Val ... l+constant

I hope this link works. For some reason the standard method of entering a URL is not working for me today. You may need to copy and paste ...
Aero

krenshala
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Post by krenshala »

I've always found it humorous that the "constant" G appears to have a non-constant value, based on all of the experimental results that have been achieved attempting to measure its value. Some of the differences were above the margin of error, while others were small enough to have been no more than error.

(I was trying to find the article I had read that listed the results of 30+ experiments to find the value for G to ever greater precision, however, all I found was this interesting article, instead.)

EricF
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Post by EricF »

Aero wrote:G is a fundamental physical constant, the Newtonian constant of gravitation.
It is experimentally determined to equal 6.674 28(67) x 10-11 m3 kg-1 s-2

See
http://physics.nist.gov/cgi-bin/cuu/Val ... l+constant

I hope this link works. For some reason the standard method of entering a URL is not working for me today. You may need to copy and paste ...
I copied and pasted it, thanks :D The statement they give looks like jibberish, there are expressions they could simply solve and simplify and I don't understand why it hasnt lol

Why is there a space between 6.674 and 28(67) with no operator, and why does it say
28(67) instead of just multiplying it out to 1876?

then for X 10^-11 m^3 kg^-1 s^-2 I suppose you multiply all those together? I'm guessing m is meters, kg is kilograms obviously, I have no idea what s is though.

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