The author of this post claims this is new, which is interesting if true. If you look at the LANL release it appears Rick has just submitted a POPS paper to Physics of Plasmas, but it seems to be undated so I'm not sure.
7.R.A. Nebel et al., “Theoretical and experimental studies of kinetic equilibrium and stability in the virtual cathode of the intense neutron source (INS-e) device,” submitted to Physics of Plasmas.
At first "virtual cathode" sounds like PW but apparently this is something different. I wonder if they're trying any POPS stuff with WB-7? Not sure how feasible that is.
Conclusion
The IEC Team in our Plasma Physics Group (P-24) and T-15 is working on developing practical fusion devices based on an IEC scheme. The recent experimental confirmation of the POPS oscillation and successful plasma compression in a particle simulation has provided solid scientific foundation for further exploration of this promising fusion device concept. This exploration will include direct experimental measurement of plasma compression and fully two-dimensional particle simulations of POPS dynamics. Successful plasma compression of at least 50 will be followed by a demonstration of nuclear fusion reactions using POPS.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...
I see no reason why POPS would not be applicable to a Polywell, providing you got one working long enough to establish the oscillation. The Nebel/Parks expertise in this area would have put them on the short list of candidates to take on the project.
The paper sounds well worth exploring. If there is some indication of run lengths we might learn something.
Well, WB-7 is presumably still sitting around over at EMC2, which makes me wonder if they aren't already trying some POPS stuff with under funding separate from the Navy contract.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...
The paper is old, I have had a PDF for several years. And it is dated from the late 1990's. Supposedly, they were going to expand, upgrade the experiments, but not a peep sense then. Was it abandoned, is it languishing, was it judged to be interesting but not enough of a gain to make 'fusors' net productive, and it was not needed for neutron sources? IE: only useful if something can cover most of the distance to breakeven on it's own? If so, it might be very important for Polywells. Something similar (?) may be in use in Tri-Alpha's approach to FRC.
Looking at the LANL link, I won't rule out it was done in a WB machine, but if so it was not being driven very hard. Well depths were evidently on the order of 150 V, not 10 kV and more.
Increase in confinement time was on the order of 3 mS. That's longer than the WB6 fusion bursts by a factor of about 12, but I'm not sure how much it means. If they did run this in a WB machine, I would expect it could run steady state at drive potentials < 1 kV with no problem.
The frequency at resonance will have a lot to do with machine dimensions. The resonance in this case was apparently a modest 350 kHz, below the AM broadcast band. It might be fun to look at their basic assumptions and attempt to back-calculate the machine dimensions.
The numbers do suggest possible enhancement of the performance of a WB machine, if the POPS can be synchronized. Assuming a WB6 fusion burst of about 0.25 milliseconds, I get 87 POPS oscillations in that period.
Hopefully the later WBs can sustain a deep potential well far longer.
They appear to state it was a non-PW machine. I was just thinking maybe they were also doing some PW POPS work that they hadn't written up (at least in this paper). Sorry, I should have stated that more clearly.
Dan, do you have a link? The author claims the harmonic oscillation data is new, but I'm not sure I believe him.
Hmm, maybe the "newly submitted" paper is online somewhere...
Tom Ligon wrote:Looking at the LANL link, I won't rule out it was done in a WB machine, but if so it was not being driven very hard. Well depths were evidently on the order of 150 V, not 10 kV and more.
Increase in confinement time was on the order of 3 mS. That's longer than the WB6 fusion bursts by a factor of about 12, but I'm not sure how much it means. If they did run this in a WB machine, I would expect it could run steady state at drive potentials < 1 kV with no problem.
The frequency at resonance will have a lot to do with machine dimensions. The resonance in this case was apparently a modest 350 kHz, below the AM broadcast band. It might be fun to look at their basic assumptions and attempt to back-calculate the machine dimensions.
The numbers do suggest possible enhancement of the performance of a WB machine, if the POPS can be synchronized. Assuming a WB6 fusion burst of about 0.25 milliseconds, I get 87 POPS oscillations in that period.
Hopefully the later WBs can sustain a deep potential well far longer.
I did that a while back and got numbers ranging from about 100 KHz to 30 MHz depending on assumptions and the size of the machine. The larger machines required considerable drive power - something on the order of 3.5 KV RMS @ 40 AMPS - about 100 KW - ball park. But at lower frequencies. It can be class C or E - class E being esp good at the lower frequencies. Efficiencies can run to 95% or better. Class C about 70%.
Engineering is the art of making what you want from what you can get at a profit.
Is a LANL 2004 document that makes reference to the same “Theoretical
and experimental studies of kinetic equilibrium and stability in the virtual cathode of the intense neutron source (INS-e) device,” except with the status of "accepted for publication" to Plasma Physics
That would pretty much rule out PW and mean that this was done with a fusor.
Starting on ~ page10, Bussard talks about some possible aspects of IXL (gridded fusors) machines that might allow greater than predicted performance. Some descriptions of standing waves and core enhancement sounds like they could be something similar to primitive POPS effects. He points out that such effects might conceivably allow large gains and would be useful in IXL systems, but are not needed in EXL (Polywell) systems. That does not mean that Polywell would not benefit from such effects.