The Focus Fusion Society › Forums › Dense Plasma Focus (DPF) Science and Applications › CNO cycle energy generation with the plasmoid.
http://en.wikipedia.org/wiki/CNO_cycle#CNO-I
All elements there are very stable, for the purpose of the process. The ones with the shorter life times may be produced alongside the process. The really stable ones are extremely common and the atomic numbers and masses are not very different from the Boron.
What do you think?
The CNO cycle relies on sufficient confinement time for some of the intermediates products to undergo beta type decay, before fusing with another proton to move to the next link in the chain.
O-15 has a half-life of 122s and N-13’s half-life is 9.9 minutes
in a bound atom these decays are normally via electron capture, but in a plasma this decay time will be different (possibly even longer).
So although the temperature required is in the realm of what a DPF can handle the confinement time needed is impossible for anything other than a gravitationally bound system where the confinement time is essentially infinite (ie a star).
jamesr wrote: The CNO cycle relies on sufficient confinement time for some of the intermediates products to undergo beta type decay, before fusing with another proton to move to the next link in the chain.
Yes, but why not just waiting? The point here is just using the minimum amount of external fuel. So, the input of usual hydrogen would just be the step needed.
What’s a “plamoid”?
Plasmoid :S typo. Sorry.
Rezwan wrote: What’s a “plamoid”?
Interestingly, the other usual typo is “plasmid” which is a relatively small circular DNA molecule.
jamesr wrote: The CNO cycle relies on sufficient confinement time for some of the intermediates products to undergo beta type decay, before fusing with another proton to move to the next link in the chain.
O-15 has a half-life of 122s and N-13’s half-life is 9.9 minutes
in a bound atom these decays are normally via electron capture, but in a plasma this decay time will be different (possibly even longer).
So although the temperature required is in the realm of what a DPF can handle the confinement time needed is impossible for anything other than a gravitationally bound system where the confinement time is essentially infinite (ie a star).
here is a missing element on the cycle, right? which decays in 9.5 minutes among others. So, just like in an ethanol car, where a small tank of octanol is kept for turning up the engine keep the short half life product available just before starting the engine the rest will be produced inside the engine as a by product
How will you fill your “octanol” tank with these short-lived missing ingredients to begin with?
DerekShannon wrote: How will you fill your “octanol” tank with these short-lived missing ingredients to begin with?
Making them in another lossy focus fusion and feeding it right away.
Why would you ever want to do that, and how would you capture all the energy released by the gamma rays?
Is there a reason that pB11 wouldn’t be the preferred fuel? Who cares if CNO requires little external fuel — it’s not like boron is rare or expensive.
DerekShannon wrote: Why would you ever want to do that, and how would you capture all the energy released by the gamma rays?
You mean, from the big one? The big one is just to make the gas. It would run until it has a quantity. Send it to the smaller and efficient ones, and start them.
The purpose is to rely only in the atmosphere and does not require refuel. The possibility of using an airplane to go to orbit, for example.
I don’t see how the way you are proposing CNO would be advantageous here is compatible with how a dense plasma focus works. The mass FUSED will remain trivial relative to the overall reaction mass required for high-thrust applications, so boron would not be at a disadvantage.
I convinced myself now that this won’t work because O15 and N13 rely on spontaneous fission, so it would require high concentrations and great quantity of both elements.
http://en.wikipedia.org/wiki/File:CNO_Cycle.svg
Now, I understand jamesr comment.
The other problem is that the sun burns 1/4 of its fuel in 10 billions years while we expect to burn 80% in 10 ns. The difference is about 25 orders of magnitude in the reaction rate (lucky for us, or the sun would not be around that long!)