New fusion idea based on ultra-dense deuterium

[bengt.gustafsson@beamways.com]

Hi there.

Recently there was some fuzz over here in Sweden based on net positive energy fusion experiment using ultra dense deuterium and laser ignition. Unfortunately my physics knowledge is not deep enough to understand much of it.

Here’s an article they got published recently:

http://scitation.aip.org/content/aip/journal/adva/5/8/10.1063/1.4928572

If anyone can understand and write something in simpler terms I would appreciate it, thanks. The very concept of ultra dense deuterium itself is beyond me, is it just a soup of nuclei or what? Under what conditions can that exist?

[Breakable]

I haven’t read the paper (who has time for that), but possibly they are talking about https://en.wikipedia.org/wiki/Bose–Einstein_condensate
in this instance the nuclei are loose most of the space between them and start acting as a single nucleus. You cannot have that freely floaing in a reactor, but you could inject pellets with it.

[rafal]

Hi,

I came here “redirected” from “http://lppfusion.com/fusion-power/dpf-device/” (the dense plasma focus company website). I’m not sure if anybody from there frequent this discussions, but whoever read this: the LPP fusion people colide protons (hydrogen H1) with boron (B11) commpressing the plasma using its instability indused by flow of electical current.

I was wondering, if quantum effects could help them get more dense plasma if they use Deuteron (D2) with spin of 1 instead of proton with spin of 1/2 (and consequently B10 instead of B11)?

[Francisl]

rafal wrote:
I was wondering, if quantum effects could help them get more dense plasma if they use Deuteron (D2) with spin of 1 instead of proton with spin of 1/2 (and consequently B10 instead of B11)?

This leads back to a previous conversation. I haven’t found much information about spin and fusion rates that isn’t behind a pay wall so lets dream a little.
B10 has a spin of 3 and B11 has a spin of 3/2 according to this reference. If spin has any influence then D2 + B10 should have the best reaction rate. Refer to this article.
The Magnetic Field Effect and plasmoid effects probably operate on a quantum level.
One good way to see the influence of spin is to actually try different fuel combinations.

[Lerner]

nuclear reaction depend on lots of things in addition to spin, so the reactions suggested here don’t work. However, reactions do depend somewhat on spin and if the hydrogen and boron nuclei become aligned in the same direction, the reaction rate goes up by 50%. may be possible to try at some point.

[rafal]

Why exactly: ” reactions suggested here don’t work”? References provided by Francisl indicate they’ve been studied.

I must say, that after reading a bit on the DPF devices I’m truely puzzled why “wariations” of the reactor haven’t been studied. Quite recent publications from LPP indicate that they are fighting some minute metal/oxide impurities, thile the overall structure of the device does not change:
1. they don’t exorcise D2+B10 outcome
2. they don’t change the geometry (like bend the cathodes, so the form a cone instead of a cylinder).
3. there is no info in the influence of anode pyrex insulator length.
… just to mention the most prominent variations.

… while on their 2007 google-talks presentation they stated, that their density-time parameters is just 65 times to low …. e.g. less then two orders of magnitude! I’d expect that in such circumstance one tries every possible (or impossible) variation of his/her device to cross-over. And their recent papers suggest, they only look for minute fine-tuning of the process. that’s strange.

BTW: is there a “beginners guide” which explains what exactly happens within the umbrella shaped current sheath? Because “my everyday experience” with plasma (like thunderbolts) suggest, that current goes through plasma along lines, not surfaces (like spokes between cathode electrode surface and anode). Still, the sheath seem to originate from thin “air” between cathodes? how come?

[Francisl]

We are all eager to see great results but we must be patient. This is very complicated and expensive work. LPP has a small staff and limited funds. They are gathering all the important data they can before they make improvements based on that data. Some of these parts take over a year to get.
There is a lot of useful information on this website. Many of these questions have been asked before and you can find some of them by using the Search function at the top of the page.

[rafal]

I’m sure people at LPP do a great job of building up knowledge around physics involved – including tedious plasmoid properties measurements. Obviously that’s valuable, and time consuming.

I only tried to say, that:
1. I’d expect that a sort of perturbence (shake-up of a design) of the DPF device structure/geometry is also exorcised … in the spirit of Edison trying every possible filament for his incandescent light bulb.
2. but mainly I wanted to ask if there is any sort of tutorial/beginners guide on the DPF device parameters: like basic dependencies of output-jet total energy, and its ion energy spectrum v.s basic device design like: anode diameter, anode lip curvature, number/diameter of cathodes; length of pyrex insulator; its thickness, etc.

before we fully understand the physics of the process (and thus can “design for” a successfull cross-over to Q> 1), it’s usually worth (blindly) testing various “engineering options”.

I for one would like to know how the density-time varies with the number of cathode rods – may be one does not need that many (like: what if just three would do?) … or if it pays to have a lot of them (in consequence to have as many as possible plasma spokes crossing the sheath) and thus one needs to change the cathode array geometry towards a circular comb of copper blades. Anyone knows what’s better?

And one “engineering option” I’d personally would surely check very early (but haven’t seen done) is to check the D2-B10 filament. This does not require any changes in hardware, while this close to target density-time constraint should highlight any influence spin has on the reaction.

[Francisl]

This link may lead you to the information you are looking for. It is a little older information but if you follow up on the links to Dr. Sing Lee and Dr. S H Saw you may find the direction for your future searches.

[Francisl]

This Wikipedia link is also a good overview.

[Francisl]

The Plasma Focus- Numerical Experiments Leading Technology paper by S H Saw and S Lee will give you a substantial amount of the information you are looking for.

[rafal]

Oh yes. It’s excellent.

But, as it’s often the case when learning … every answer rises more questions 🙁 So I cannot help myself asking those that occurred to me while reading that Saw+Lee paper:

1. is it not a mistake, that under figure.2 they state: it shows setup results with additional inductance of 33uH … which is gigantic with respect to intrinsic device inductances in the range of 33nH?

2. They say, that for a variety of devices, there is always an “optimal” inductance, where current reaches maximum. And that reducing inductance further does not increase discharge current (and they’ve published that observation earlier). I don’t have an access to that their earlier paper, but …. I was wondering if that effect can also have something to do with sin effects. In particular, one of the LPP devices reportedly had cathode rods fi=10mm, while at the frequencies equivalent to speed of the discharge (e.i. c.a. 20micro-sec), copper effectively conducts only at depths of c.a. 2mm. So having cathodes build from copper bars of 3mm/30mm cross section should do better. shouldn’t it?

3. Saw+Lee describe setups pinching current in pure D2, and measurement of D+D reactions which yield neutrons. Are there papers presenting special/angular distribution of resulting neutron outbursts? As opposed to ion jets from H+B reaction, neutrons could expose something regarding the internal dynamics of plasmoid vortexes. I think.

4. and last and the most important for me question: I cannot find any hints on why exactly the sheath forms at bottom of cathodes along the pyrex insulator, and not at their tops, where electric field between anode and cathode is the strongest. Where should I look for that answer??

So I’d really appreciate any further pointers to published results? (the links three posts above are probably interesting, but as they are mainly raw data, it’ll take me more time to really digest them)

But thenx anyway,

-R

[Francisl]

You are asking questions that I don’t have answers for. I will give you some suggestions.
Question 1. It could be a printing error but I don’t know.
Question 2. Looks like an engineering choice. The designers of the particular machines would have to answer that.
Questions 3 and 4. There is some information available by searching on Google and Wikipedia. You may find that some of the information is behind pay walls. Some university and public libraries have subscriptions to these publications.

The e-mail addresses for Saw and Lee are listed at the top of their paper. You can try sending these questions to them to see what they say.

[Lerner]

There are many studies of neutron distribution. Overall they show that with low current DPF, most neutrons come from collisions of the ion beam with the plasmoid. But in higher current machines, they come from collisions of ions trapped in the plasmoid with each other, which increase faster with increasing current. In FF-1 neutrons are very evenly distributed, showing that the ions are trapped.

The current starts next to the insulator because that minimizes induction and thus the amount of energy in the magnetic field. Currents always minimize the amount of energy they have to expend. Mother Nature is not lazy, just efficient!

[rafal]

Lerner wrote: There are many studies of neutron distribution. Overall they show that with low current DPF, most neutrons come from collisions of the ion beam with the plasmoid. But in higher current machines, they come from collisions of ions trapped in the plasmoid with each other, which increase faster with increasing current. In FF-1 neutrons are very evenly distributed, showing that the ions are trapped.

by any chance; You don’t have any links to experimental results on that?

The current starts next to the insulator because that minimizes induction and thus the amount of energy in the magnetic field. Currents always minimize the amount of energy they have to expend. Mother Nature is not lazy, just efficient!

I see.

Have there been any experiments on how close the tips of the anode and cathode can be to each other, while the “nature preference” to ignite the arc along the insulator remains “in force”? I’m asking, because it looks to me, that the shorter the “final part” of the sheath “bulb”, the more energy of the arc could be trapped within the plasmoid …. have that been tested, yet?

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