what is the largest problem with the fusor?

[jaaz95]

i've be doing a lot of research on fusion and very much want to build a full sized fusor. But from the reading i've done i've noticed there are a few major design flaws that haven't really been addressed. for one, the inner grid melting. yes this has been "fixed" with a virtual electrode but it hasn't been really fixed. there are others but im still new to fusion so im not very familiar with them. so in your experience what is keeping the fusor from going break even?

[Chris Bradley]

If you have done 'a lot of research on fusion' and what you have found is not enough to satisfy you, then anything more is going to be opinions.

My opinion is that the two top biggies are;

1st: Electron conductance - thermionic electron emission from the grid, and current flowing though it, seems more likely to me to be the reason it gets hot, rather than being bombarded by ions as is often suggested. (I don't buy the *the grid gets in the way of the ions, and removing it will 'fix' everything* hypothesis.)
My proposed fix; add a magnetic field {viewtopic.php?f=6&t=2854#p12364 }

2nd: Collision losses - most nuclear collisions do not end up in fusion but simply thermalise the energy of the nucleii. (There are only a very small fraction of nucleii at high energy in a fusor.)
My proposed fix; something complicated { viewtopic.php?f=14&t=6798#p42481 }

[PS, best to use a proper name here, if you're doing proper work.]

[jaaz95]

would the magnetic field effect the speed of the particles? and how come the magnetic field always is created in the form of a polywell device?

i had an idea one day when reading up on fusion and it was to instead of using the polywell device, to instead use a more oblong shaped electro-magnet behind each section of the inner grid and tune it to form an airplane wing effect that would just barley guide the plasma and particles around the grid and prevent grid collisions.
it's just an idea and wish to test to see if it would work but i'd need to construct a working reactor first.

[Chris Bradley]

justin a wrote:
> would the magnetic field effect the speed of the particles?
No. To change the speed of a particle, work needs to be done on it. Static magnetic fields cannot do work.


justin a wrote:
>and how come the magnetic field always is created in the form of a polywell device?
I don't understand the question, and if you want to talk about that device then there is a dedicated forum for it.


justin a wrote:
> i had an idea one day when reading up on fusion and it was to instead of using the polywell device, to instead use a more oblong shaped electro-magnet behind each section of the inner grid and tune it to form an airplane wing effect that would just barley guide the plasma and particles around the grid and prevent grid collisions. it's just an idea and wish to test to see if it would work but i'd need to construct a working reactor first.
Yes you do. No one will build it for you here. Best you build the basics, as has been well documented here for you to reproduce a working example, and then modify.

[Steven Sesselmann]

Justin,

What is your definition of a lot of research?

A week, a month, a year, a decade or several decades?

Most of the guys here, especially those who have built one, know why the fusor does not break even, and you can be pretty sure that it is not the shape, nor the material of the grid that is the problem.

And here is where I can just give you another opinion (like Chris), and that is, I don't think it is fully understood, why nuclei choose to fuse. We can NOT pursuade nuclei to fuse against their will, just as we can NOT make water run up hill.

Sure we can push water up hill, but not without adding energy.

Spend 50% of yout time studying, and 50% of your time thinking, and eventually, it will appear clear to you, why the fusor does not work. (ie..the answer is not on Wiki)

Have fun...

Steven

[jaaz95]

Well i only learnt about fusion about half a year or so but have been enthralled with the idea. and have been doing research since then. i tried this site but at first i didn't realize what it had in it. i'm trying to build one for as little money as possible as they can get very expensive. i think i've hunted down most of the parts for one on ebay and around town but im no expert on the stuff and was going to start a thread on peoples opinions of the parts. so once i get a functioning one then i was going to go on to test any ideas i had.

[Carl Willis]

Justin:

Please comply with the site rules, which you had to read only minutes ago in order to sign up for posting privileges. There are only four of them. Your FULL, REAL NAME is required as your user name to post here. Secondly, your first post MUST be an introduction in the Please Introduce Yourself forum, hopefully explaining your interests in fusion and your background so that other contributors have some idea how to interact with you.

Questions about "break even" should be responded to with the caveat that there is identically zero experience with this concept as it relates to Farnsworth fusors--especially in the hobby fusion community. It is the realm of pure, unhinged conjecture, and this being a public forum, I recommend any comments on the issue be taken with a grain of salt or less. This forum's STRENGTH is in the decade-long compendium of practical detail, experimental application, and individual innovations on small-scale, laboratory fusion devices that you can actually put together.

-Carl

[jaaz95]

well first off, i did introduce myself. and i did make a thread in the please introduce your self section. i am aware there is zero experience with break even fusion. this is the theory part of the forum, so i was discussing a theoretical subject. however it is getting annoying that no matter where i go if break even fusion is mentioned, i get shunned and discredited, even if i had said something intelligent.
the point of this thread was to adress problems with the Farnsworth fusor, so that possibly in later work with these devices either me or someone else may try and adress them to make a better machine.
within the next 2 months i intend on building a fully functioning, fusor with a 10-15" diameter chamber. this would help allow me to test any and all ideas i have for the device and even ideas of others to help progress the abilities of these devices. And I know what the rules are of the forum but i am still a little uncomfortable giving my full real name, but so no one can get angry, the A stands for Atkin.

i have read through alot of these forums and am constantly working my way through them to learn everything i can about fusion.

[Carl Willis]

Hi Justin,

Sorry I missed your intro post. My error.

"Theory" on this site, or on any public forum, seldom has rigor or a reliable grounding in observation. The further you go from peoples' concrete experience, the less credence you can give the information. Just a fair warning.

-Carl

[Chris Bradley]

Justin,

Do not be disheartened. There are plenty of ideas here that are not merely conjecture - because they are in the process of being tested out.

Of course, it would be true to say that no-one has experience of 'fixing' what they think are the limitations of the fusor and achieving something towards net-energy outputs. You'd have likely heard about that if it were so!

But some do have first-hand experience of 'fixing' what they think are the limitations of the fusor! It may or may not have gone exactly to plan, or expectation, but the first-hand experience is in turning the idea into a reality and seeing what happens.

I have used magnetic fields in an 'electrostatic' acceleration device, and the currents drawn are around 10 to 100 uA, significantly lower than a normal gas discharge, as per my proposed 'fix' above. This work has been reported on this forum.

Steven, as above, has tried a number of his own configurations to achieve some degree of self-organisation that create the right environment for ions to 'find' each other, with a design of his own, to 'fix' issues he feels he can see. This work has been reported on this forum.

John Hendron has worked with Steven to design a new type of ion gun, with which he is attempting timed sequential beams. [I suggested calling it “the Small Hendron Collider”!]. This work has been reported on this forum.

Frank Sanns has been trying a plasma electrode to 'fix' some issues he feels the fusor has. This work has been reported on this forum.

Doug Coulter has been trying transient operations at much lower pressures to 'fix' some of the issues he sees with the fusor. This work has been reported on this forum.

I don't think it is any coincidence that the folks above have all backed up their commitment to their projects by filing them for patents (excepting Doug, who I think has a personal distaste for patents, but has nonetheless shown equal commitment in his devotion by his superlative hardware).

So although your opinions on improving the fusor may be conjecture, if you built your kit to test your ideas, that idea is no longer merely a conjecture. It may not do what you expect or want (!), but it would then be a practical experimental matter that, I am quite sure, we would all be interested to see.

A final comment is that you may or may not be able to build a fusor in a few months. Best that you take your time, because if you do move on to attempt to implement your own ideas, as you say you want to, then if your experience is anything like those of the folks I have mentioned here, then you should expect it will take you several years. I think this is mainly because if you don't yet know what will work and what won't then you iterate many times. Building something that no-one has ever seen before takes years, because you don't know what it is meant to look like either!

[David Geer]

Definitely try to be like me and take your time researching parts/components to see what will go together without going "boom" or "fizzle". Nothing worse than spending a decent amount of pocket change on a part only to find out it won't even fit in your device. These folks here lead by example and you should most definitely take their advice and experience to heart so that you aren't bumbling along, making the same mistakes that have been made many times before.

I felt like a small chuckle at the Small Hendron Collider joke.

[ab0032]

If you read the wikipedia page on fusors, you will find a number of links at the bottom, one is to
Todd H. Rider, "A general critique of inertial-electrostatic confinement fusion systems", M.S. thesis at MIT, 1994.
http://dspace.mit.edu/handle/1721.1/29869
There you can read about bremsstrahlung and other things that could enlighten you.