Groups & Studies about Fusion via Colliding Beams

[AndyUrquijo]

Hi everyone,

I am studying the feasibility of using the collision of two beams to obtain nuclear fusion energy. I would like you to recommend me some serious and intersting articles about this. Is there any experiment that does fusion by beam collitions already?

Im open to hear about any theoretical and techonological issues you can think of. So far the principal problems seem to be the low event rate and the particle loss due to coulumbian scattering.

I don't think I understand the real problem with the event rates. With other parameters such as energy (or temperature) fixed, the event rate is heavily dependent on density, n² for temperature based systems. So what is the diference between a Beam Collider (BC) and other devices? A physical one? Is the dependence on density different for this sytem? Or is there a techonological barrier in achievieng high beam densities?

I clearly understand the problem with scattered particles though. You lose more than 1000 particles per successful fusion*. This sucks, so you need to either reduce this loss or recover some of the scattered particles.

The only method I can think of to the first alternative is using muons. The problem is getting them of course. But supose you could obtain them somehow. Then in a D-T reaction aplying a muon beam to the deuterium or tritium beam (or both) would greatly reduce coulumbian interacions.

To "recover" some scattered particles, you could apply a magnetic field that rectified the path and the velocity. Most of the scattered particles would have small deviation angles and the velocities would only be affected by the small energy loss of brehmsstrahlung. So I would think without doing any calculation, that it is possible to recover a good amount of the lost particles. The recovered particles could then be used in the next collision cycle. And of course cyclic colliders are needed. this idea can't be aplied in linacs.

Resuming:
- Could you help me with material on the subject?
- Do BC for fusion exist already?
- Can you think of critical issues for this method?
- What do you think of my ideas? (Stupid? Awesome?)

*I read this here somewhere, but can't find it again to cite/link it.

 

[Drakkith]

As you said, the main problem is that you only get about 1 in 1000 fusions per collision and have almost no way of increasing that rate other than to increase the amount of collisions each nuclei have before they are lost. As far as I understand it's simply more feasible to use other methods to achieve this, such as magnetic confinement.

 

[capanni]

Hi everyone,
To "recover" some scattered particles, you could apply a magnetic field that rectified the path and the velocity. Most of the scattered particles would have small deviation angles and the velocities would only be affected by the small energy loss of brehmsstrahlung. So I would think without doing any calculation, that it is possible to recover a good amount of the lost particles. The recovered particles could then be used in the next collision cycle. And of course cyclic colliders are needed. this idea can't be aplied in linacs.

I am not sure what you mean by recover the particles.
It may take more energy to do this than to let them hit a thermal blanket and get some heat recovery, and then accelerate new particles.

 

[AndyUrquijo]

I am not sure what you mean by recover the particles.
It may take more energy to do this than to let them hit a thermal blanket and get some heat recovery, and then accelerate new particles.

I mean putting some type of focusing device on the collition site to pull the scattered particles back to the beam. It could be better to recover just the ones that have small deflection angles. This should be cheaper (energywise) than the cost of accelerating a new particle from the beginning.

Im not sure you would get a good enough amount of energy with a thermal blanket to afford losing the scattered particles. Besides, on of the main issues is having high intensity beams, so this is also a method to maintain density as well.

 

[Drakkith]

I mean putting some type of focusing device on the collition site to pull the scattered particles back to the beam. It could be better to recover just the ones that have small deflection angles. This should be cheaper (energywise) than the cost of accelerating a new particle from the beginning.

Im not sure you would get a good enough amount of energy with a thermal blanket to afford losing the scattered particles. Besides, on of the main issues is having high intensity beams, so this is also a method to maintain density as well.

Look up the Polywell on wikipedia. It also uses inertial confinement to confine the ions to the center of the device. (Which is kinda what you want in your beam-beam fusion)
One of the problems that the Polywell device had trouble with was electrons getting lost from the device. They eventually figured out a way to have the electrons circulate back inside if they happen to exit the grid of the device. I say this because a polywell is similar to colliding beams of ions, except that in a polywell the "beams" are coming from every direction at once. The consctruction of the device let's the ions oscillate back and forth through the center of the device enough times for them to fuse. Now, it is still in the prototype and research phase, but hopefully they can get one to perform well enough to breakeven.

 

[capanni]

Your problem with recovering the particles is that they are past the collision site and heading away from it. This means you would have to slow them down then accelerate them back the way they came.