Hello Keegan,
Good to be around here again. Work has been a bit crazy the past 2 months. The dog doesn't know me anymore.
Great to see Richard Nebel posting. That's like Christmas coming. Really glad he can give us the occasional heads-up.
Also good to see Simon and the regular crew are keeping the Talk-Polywell fire burning.
Regards,
Tony Barry
Ion injection into a Polywell
I wish I had some reading material for this wakefield oscillation stuff, I must confess my mind has not yet begun to come to grips with how this would effect a polywell. (I wish I had that private email from Joel you refer to, does he post any of his stuff on blogs or somewhere in the internet where I might read it?) I read Tom McGuires thesis but I gathered the oscillations (synchronisation) had nothing to do will any external driving mechanism but were rather a spontaneous plasma instability that actually helped the confinement for once.
No. Joel does not post online. However, I take his work as a confirmation of McGuire's efforts.jmc wrote:I wish I had some reading material for this wakefield oscillation stuff, I must confess my mind has not yet begun to come to grips with how this would effect a polywell. (I wish I had that private email from Joel you refer to, does he post any of his stuff on blogs or somewhere in the internet where I might read it?) I read Tom McGuires thesis but I gathered the oscillations (synchronisation) had nothing to do will any external driving mechanism but were rather a spontaneous plasma instability that actually helped the confinement for once.
Re: synchronization - yep. The plasma naturally oscillates. No drive. Tom Ligon said in another thread that many of the problems with plasmas are naturally overcome with the Polywell design. Think of it as a natural POPS oscillation.
The beam oscillations should tend to sweep up (anneal) particles whose energies have caused them to get out of sync with the machine. i.e if they are near beam velocity/direction as the beam passes the beam will sweep them up. The fast will be slowed, the slow will be sped up.
When I first read Drs. Nebel's/Park's papers on POPS I though it might be applicable to Polywell. McGuire's paper confirmed that for me.
I did a preliminary engineering study of how that might be accomplished:
http://iecfusiontech.blogspot.com/2008/02/lc-pops.html
Once the phenomenon is well understood it may be possible to enhance it sufficiently with just a tuned circuit.
Engineering is the art of making what you want from what you can get at a profit.
This is not exactly the same thing, but close enough: Plasma wakefieldjmc wrote:I wish I had some reading material for this wakefield oscillation stuff, I must confess my mind has not yet begun to come to grips with how this would effect a polywell. (I wish I had that private email from Joel you refer to, does he post any of his stuff on blogs or somewhere in the internet where I might read it?) I read Tom McGuires thesis but I gathered the oscillations (synchronisation) had nothing to do will any external driving mechanism but were rather a spontaneous plasma instability that actually helped the confinement for once.
I think the idea behind all these things is similar enough that it's really a question of which one makes the most economic sense. I would bet that an "afterburner" will make sense.
In the case of the Polywell it appears that the waves are self generating.
If the purpose of the waves is just annealing particle energies no external separating force like a laser need be applied to the machine.
What I think we want is more akin to klystron bunching than high energy particle acceleration. Don't forget if the particles gain too much energy too quickly they leave the system.
If the purpose of the waves is just annealing particle energies no external separating force like a laser need be applied to the machine.
What I think we want is more akin to klystron bunching than high energy particle acceleration. Don't forget if the particles gain too much energy too quickly they leave the system.
Engineering is the art of making what you want from what you can get at a profit.
Self generated waves which are stable will also decay. I think a little bit of external help will be useful - but I have yet to prove it. Creating a spherical TM wave front will accelerate particles radially, so the trick will be to make the electrons always see the parallel E pointing towards the center. The ions should follow the E field into the center and be accelerated along the way. If all the self generated waves damp out, the overall system will be stable and you'll have a CW power reactor.
Plasmas don't usually work that way though, so it'll be interesting to see how it works out.
Plasmas don't usually work that way though, so it'll be interesting to see how it works out.