Talk-Polywell.org

https://www.youtube.com/watch?v=u8n7j5k ... e=youtu.be

http://www.crossfirefusion.com/nuclear- ... actor.html

I am a bit surprised to see you posting this. I have seen some of their earlier posting on their idea, while it seems intriguing I do not have the knowledge base to poke holes in it even though my gut tells me something is wrong with it.

I don't have the necessary skill set to analyze it either. I was hoping to learn from the guys here.

I'm generally very quiet when it comes to the fusion topics. There are lots of others who understand far better than I do.

GIThruster wrote:I don't have the necessary skill set to analyze it either. I was hoping to learn from the guys here.

I'm generally very quiet when it comes to the fusion topics. There are lots of others who understand far better than I do.

This think has been around for a while and I think it even has been discussed on this board in the past. I cant really remember, but I think it was not all that positive.

I don't see how the design handles recirculation. That makes it a non-starter.

To expand on what MSimon said, if I'm not mistaken this is a two beam colliding scheme. If the ions fuse in the high density center, fine, but if not, they will scatter. The coulomb scattering rate at the ideal temperature still exceeds the fusion rate by a factor of ~ 10 for D-T fuel and ~ 1000 times for D-D fuel. With a cylindrical geometry, lateral scattering will quickly drive the ions to the walls. Even if the B field is strong enough to stop the primarily scattered ion, the high enesity in the area and the small distances would allow for rampant ExB dffusi0on through the B field. Even if there was a potential well with a central core of excess electrons, the ions would have little time to decelerate. And with these small lateral dimensions even the electron ExB losses would be considerable. The spherical geometry of the polywell is different as at the ideal central convergence (intersect of however many beams you want to invoke) the concentration is 3-D, not just 2 D. As such any scattering of ions near this center is always back towards (one of) the beam origin, there is no (little) lateral scattering. All directions from the center of a sphere is radial. This allows for recirculation of ions that are scattered and not fused back up their potential well for another chance on the next pass. The particles and the energy of the particles are conserved. Lateral scattering can occur away from the center, but with convergence, the density decreases and the collision rates decrease exponentially so that the radial nature of the ion trajectories are mostly preserved. At the ion low energy edge the Coulomb collision cross section becomes so great it dominates over any other consideration like density or vector, and the ions thermalize about a small KE value. This thermalized distribution is tiny in magnitude relative to the KE the ions have once they fall back down their potential well. This is 'Annealing'. It is possible in a spherical geometry with a centrally directed potential well so long as several considerations are met. It is not possible in a non spherical geometry. The ions cannot be maintained in a non thermalized high energy state, they cannot be isolated from ExB effects, and they cannot achieve near energy neutral lifetimes in the 10s to 1000s or more of passes necessary. At least they cannot with these natural mechanisms. Some active intervention has to be used and this always resists the natural tendencies of the plasma.

Could the scheme be made to work? I don't know. But, compared to the spherical approach*, problems and challenges are greater, perhaps much greater.

*Not to mention the potential well effects of electrostatically confining the ions and isolating them from the ExB limitations that cannot be avoided if the ions were magnetically contained. Of course the electrons in the spherical potential well scheme do undergo ExB diffusion, but at rates ~ 60 times less less than would any ions that were magnetically contained.

Dan Tibbets

GIThruster wrote:https://www.youtube.com/watch?v=u8n7j5k ... e=youtu.be

http://www.crossfirefusion.com/nuclear- ... actor.html

Looks a lot like my magnofusor idea. Too bad it won't work.