Cheating nature out of Fusion

S

schwarzchildradius

Guest
Can we consruct a centrifuge to accelerate ions and coerce them to fuse into heavier elements? It would have to be a sweeping electric field, because any moving parts would disintegrate from the great velocity they'd invariably have to have. Think fusion could be achieved this way?
 
Intriguing idea. It would be one hell of an engineering challenge and it would be interesting to see if it took us a lot more energy to just get that electric field in the first place than to run the fusion reaction.
 
Could be difficult. I suspect the energy required to do it that way would be huge. Nice idea though.
 

maximus

....
474
4
spooky interesting...
 

Integral

Staff Emeritus
Science Advisor
Gold Member
7,161
54
Isn't this essentially a partical accelerator as currently exists as places lile CERN and Fermi Labs? Ions are routinly accelerated to sigificant fractions of c and collided with similar beams rotatinging the opposite direction to create hi energy collisions between fundamental particals.

Great Idea, but hardly original. :wink:
 
S

schwarzchildradius

Guest
Yes, except that I want to force the ions into the same place on the ring, instead of spread out evenly along the ring, the idea being that one could build up a significant number of ions together.
 
J

jammieg

Guest
I don't think great velocity need be primary so much as very precise velocity, I mean it may not be so much the speed of the collision as the exact trajectory like trying to land squarely on the top of a pyramid that is repulsive to anything moving toward it, unless it follows a perfectly straight flight path it will bounce off and slide down the side or in less it is moving at tremendous speeds in which the repulsive factor hasn't enough time to deflect the path, but if it lands exactly fusion might result. That's my crackpot analogy anyway, but doens't fusion always take energy and fission create it?
 

drag

Spectral Anomaly
Science Advisor
1,046
0
Greetings !

There are many ideas that deal with accelerating
hydrogen/its isotopes and squezing them together
(a Tokomak essentially) and also ideas of smashing
them together. But they are not suffciently effective.
The distance required for fusing hydrogen is
about 10^-15 m and that's very difficult to acvhieve.

Live long and prosper.
 
J

jammieg

Guest
Sheesh, an atom is small enough that's about 100k times smaller.
Maybe I should have said like trying to launch from space and land your skateboard on the tip of a repulsive pyramid.
 
Last edited by a moderator:
S

schwarzchildradius

Guest
all right then, I have a question for ya drag: why can't we accumulate enough ions in one place in a Tokamak to start sustainable reaction (or can we) ? The idea though is that instead of heating the fuel, you just accelerate it enough that the force from circular motion, (by default acceleration,) is greater than the coulomb repulive force etc.
 

drag

Spectral Anomaly
Science Advisor
1,046
0
Greetings !
Originally posted by schwarzchildradius
all right then, I have a question for ya drag: why can't
we accumulate enough ions in one place in a Tokamak to
start sustainable reaction (or can we) ? The idea though
is that instead of heating the fuel, you just accelerate
it enough that the force from circular motion, (by default acceleration,) is greater than the coulomb repulive force etc.
Pure numbers. I think your mathematical skills
by far exceed mine schwarz so I'm sure you
can easily do this and see the problem.
(Basicly, if we need to overcome say a few KeV
than we're talking about velocities equivalent
to about 10^6 m/sec which is pretty high for
protons and hydrogen isotopes.)

Circuilar accelerators are used because you can
accelerate the particles and then maintain the
velocity with relativly little more energy input
over a fairly long time period, thus increasing
the likeliness of the reaction and the total
energy output to input ratio.

There are basicly 3 ways (as you may know) to
contain a sustained fusion reaction:
1. Gravitational.
2. Electromagnetic.
3. Enertial.

Of course, in this case we are not talking about
a direct self-sustaining reaction. However, the
same methods are also required to enitiate it.

BTW, an intresting thing that Warren(chroot), I
believe, said in a different thread - quantum
tunneling plays a significant part in a star's
fusion proccess. Thus, had there been no quantum
tunnelling the star would have to be more massive
to enitiate and contain the reaction. (I have not
confirmed this personally and he did not answer
my question back then so I can't say how much
is "significant".)

So, theoreticly, if we could increase the chances
of the relevant particles to tunnel and fuse
we could increase the output this way too. But,
if I'm not mistaken there is currently no way to
do this and QM does not allow this.

Live long and prosper.
 
S

schwarzchildradius

Guest
cool. that's interesting.
 
I think it's cheaper just heating up the gas with lasers. The ol'fashion way :)
 

drag

Spectral Anomaly
Science Advisor
1,046
0
Originally posted by AndersHermansson
I think it's cheaper just heating up the gas with lasers. The ol'fashion way :)
Either way you need the very strong EM fields to
maintain the plasma and thus sustain the reaction.

Live long and prosper.
 
N

neutroncount

Guest
Don't forget that in a circular accelerator, synchrotron radiation tends lessen the energy of a particle beam. That's why circular accelerators (like the tevatron) have such a wide diameter. But maybe you could use this radiation to exite incoming ions in a centrifuge chamber? Kind of like pre-heating if that's possible. In either case drag is right; it's pure numbers. More energy in than out I assume.
 

drag

Spectral Anomaly
Science Advisor
1,046
0
I think AH meant heating without the use
of an accelerator but by simply containing the
plasma and using laser beams. Synchrotron or
Bremstahlung radiation energy losses are probably
not very significant in such a case.

Live long and prosper.
 
N

neutroncount

Guest
Looks like a misunderstanding. I wasn't replying to AH's post although it does look that way. And you're right. I noticed that synchrotron raditation output in Watts as pretty small. My bad.
 

The Physics Forums Way

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
Top