Breakthrough Billion Degree Confinement – LPP Press Release Jan 4 2011

[Tulse]

Quick question about a statement in the press release:

The fusion energy yields achieved in these experiments are still far less than the energy used to run the machines. However, LPP hopes to make rapid progress in the coming year when the machine will be running with hydrogen–boron fuel for the first time.

I’m a bit confused about the connection between the two sentences, as it seems to imply that using pB11 will make theoretical breakeven easier than D-D. I thought that D-D produces more energy per reaction than pB11 (even though most of that is uncharged neutrons, and thus hard to capture), and under easier conditions. Am I reading an implication that isn’t actually there in the paragraph, or am I misunderstanding something fundamental?

[Lerner]

No at high energies pB11 bunrs easier than DD. It is DT that is the easiest. We also expect more progress with DD.

[Ivy Matt]

I’m guessing that’s a reference to this, from Advances towards pB11 Fusion with the Dense Plasma Focus (Lerner & Terry):

To see what the consequences of the magnetic field effect are for DPF functioning, we
first use a theoretical model of DPF functioning that can predict conditions in the plasmoid,
given initial conditions of the device. As described by Lerner [12], and Lerner and Peratt
[13], the DPF process can be described quantitatively using only a few basic assumptions.
Using the formulae derived there, Lerner [1] showed that the particle density increases with μ
and z as well as with I, and decreases with increasing r. Physically this is a direct result of the
greater compression ratio that occurs with heavier gases, as is clear from the above relations.
Thus the crucial plasma parameter nτ improves with heavier gases.

I have a question about the best shot. According to the recent update, it was on September 29. However, according to fig. 1 in the same update, it’s shot 9301002. Both give the average ion energy as between 160 and 220 keV. Now, in the update of October 6, 2010, the best shot was shot 93002, which achieved an average ion energy of 143 keV. I presume they are the same shot, so what changed?

[Tulse]

Lerner wrote: No at high energies pB11 bunrs easier than DD.

Thanks, Dr. Lerner, but I’m still a bit confused — does this mean that the pB11 reaction gets relatively more efficient at higher energies, compared to DD? And more efficient enough to overcome the disadvantage of having to use more input energy for the pB11 reaction? I had thought that the main attraction of the pB11 reaction was that it was aneutronic, and not that it had a higher total energy of fusion products at any level of input energy (relative to DD or DT). In other words, I thought that under all conditions one would get more energy out of DD and DT than pB11.

[mchargue]

I want to thank you for the update. It’s good news, no doubt, and I’ll be waiting for more.

Pat

[Aeronaut]

Tulse wrote:

No at high energies pB11 bunrs easier than DD.

Thanks, Dr. Lerner, but I’m still a bit confused — does this mean that the pB11 reaction gets relatively more efficient at higher energies, compared to DD? And more efficient enough to overcome the disadvantage of having to use more input energy for the pB11 reaction? I had thought that the main attraction of the pB11 reaction was that it was aneutronic, and not that it had a higher total energy of fusion products at any level of input energy (relative to DD or DT). In other words, I thought that under all conditions one would get more energy out of DD and DT than pB11.

The main attraction as I understand it is that pB-11 fusion produces almost (as a percentage) no neutrons, and their energy is too low to make anything else radioactive. Until somebody can convert a neutron into useful energy (could it carbonate beverages?), neutrons are wasted energy in my opinion. FoFu’s attraction using pB-11 fuel should be that all of the fusion products can be converted directly into electric energy. Plus it makes a lot of thermal energy available in the process.

The higher percentage of fusion products that can be used productively leads to the greater efficiency.

[Tulse]

Aeronaut wrote: The higher percentage of fusion products that can be used productively leads to the greater efficiency.

So this gets us back to the appropriate use of the term “breakeven”. I was presuming that when the press release said “The fusion energy yields achieved in these experiments are still far less than the energy used to run the machines”, it meant that the total amount of energy produced, whether theoretically capturable or not, was still below input energy (especially since we don’t yet know how much energy a FoFu machine will recover in practice). Perhaps Dr. Lerner can clarify.

[Augustine]

Silly question but are you seeing results that are in agreement with your theoretical model?

[Matt M]

Another silly question. I know that Farnsworth’s fuzor actually fused hydrogen.
But, has anybody ever successfully fuzed Boron before? Did it throw off the
electrons just like it should in theory?

[Ivy Matt]

I had been under the impression that nobody had achieved hydrogen-boron fusion before, but I was wrong about that, as clearly shown in Observation of neutronless fusion reactions in picosecond laser plasmas (2005). I haven’t been able to find much on the history of hydrogen-boron fusion, but from what little I have been able to find, it appears that the seminal paper on the subject was Fusion cross sections and reactivities (1974), of which George H. Miley was one of three authors. It is not available for free, but can be ordered from the National Technical Information Service for $40 on microfiche or $60 print-on-demand. However, without spending that much money, the Office of Science and Technology’s Energy Citation Database helpfully gives “BORON 11 TARGET” as one of the subjects of the paper. So, presumably the information on the p-B11 fusion reaction was obtained by bombarding a boron-11 target with accelerated protons, and this was done back in the early ’70s.

I’m not quite sure I understand your second question. Fusion occurs between unbound atomic nuclei (i.e. ions), not electrons. The products of the p-B11 fusion reaction are three helium-4 nuclei/ions, also known as alpha particles. If you’re referring to the electron beam produced by the plasmoid in a DPF, I’m not aware of any plasma focus device that has used hydrogen and boron in its fill gas so far, and I presume FF-1 would be the first.

[Matt M]

The theory is boron fusion would be: p + 11B→34He + 8.7 MeV.

My question was whether the 8.7 MeV result has ever been documented?

[vansig]

Matt M wrote: The theory is boron fusion would be: p + 11B→34He + 8.7 MeV.
My question was whether the 8.7 MeV result has ever been documented?

Yes!
Take the discrepancy in mass between the reactants and products, and run it through E=mc²:

H-1=1.007825u;
He-4=4.002602u;
B-11=11.0093054u;

1.007825u + 11.0093054u – 3x 4.002602u = 0.009324u;

0.009324u x 1.660 538 782×10^−27 kg x ( 299,792,458 m/s )² = 1.3915×10^-12 joule
= 8.685 MeV

[Matt M]

Well, more specifically, has anyone fused Boron and actually measured the charge released? Until
someone does, it’s all just an educated hypothesis.

In theory there is no difference between theory and practice.
But in practice there is.

Matt

[Tulse]

Matt M wrote: Well, more specifically, has anyone fused Boron and actually measured the charge released? Until
someone does, it’s all just an educated hypothesis.

It’s an hypothesis informed by E=MC^2 and basic particle physics. If the reaction doesn’t behave like that, there’s a lot more wrong than just the focus fusion approach.

[Lerner]

It actually is easy and fun to look up the answers to these questions on the web—reaction rates and all are easy to find. I hope people on this forum will do that.
Researchers have been fusing pB11 for decades. The way we know what reaction rates are is by experiment, based on reactions measured when particles are shot from accelerators at targets. These reaction rates are highly dependent on ion energy and how they vary depends on the fuel involved.
At 10 keV, pB11’s reaction rate if 1600 time LESS than for DD and 300,000 times LESS than for DT
At 100 keV, pB11’s reaction rate if 1.6 times MORE than for DD and 20 times LESS than for DT
At 160 keV, pB11’s reaction rate if 3.2 times MORE than for DD and 5 times LESS than for DT
At 600 keV, pB11’s reaction rate if 2.7 times MORE than for DD and only 10% LESS than for DT

[Author]

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