higher pressure environments for ff

[meems]

So Eric thinks focus fusion is happening in the Sun right? I agree. So that means focus fusion can happen under high pressure conditions. But Eric chose to study focus fusion under low pressure conditions. Why? Most likely cos it was cheapest & easiest. But does focus fusion happen naturally at low pressure? Where? Also is there any research into focus fusion in medium pressure environments? Like in water? If ff occurs naturally mostly in higher pressure environments, arguably ff should be easier to obtain as pressure increases. Seems like there’s a huge amount of research to do here finding mediums and pressures that are more suitable to ff than low pressure gas.
Meanwhile Eric’s committed to all this engineering work on low pressure environments. Well it’s good, but it seems almost inevitable that of all the different environments that are available to us, there will be some that are better than low pressure gas. Am I the only one here that wonders that some group soon will find a much better ff medium than low pressure gas. Such a discovery might even be prompted by the ultimate success of lawrenceville in 5 years time.

Looking at the engineering problems of low pressure gas ff, purity is always going to be a major problem. Tiny percentages of contaminants stop the ff from being useful. Perhaps Lawrenceville will succeed in removing all the chamber impurities soon. But will it be practical to keep low pressure gas extremely pure in ff power generators for weeks or months?

Surely this has been discussed a few hundred times over the last 50 years… can some of the seniors share the fruits of those discussions?

[Francisl]

The neutral gas in a ff device is at low pressure. When the electrical discharge occurs in the chamber the neutral gas is changed to a plasma that is a good conductor. A powerful electrical current creates a very strong magnetic field in the plasma and squeezes the plasma to a very dense state. The effort now is to increase the current enough so that the plasma is squeezed to a solid state. At that point the temperature, density and time should be sufficient to create good fusion yields.
Look at this description: https://lppfusion.com/fusion-power/dpf-device/

[meems]

Hi Francisl,
You referred to the start conditions of low pressure gas getting transformed to high pressure inside a micro plasmoid.
This avoids the point I made. I’m talking about higher pressure start conditions. Not the conditions late in the process inside micro plasmoids.
Can plasmoids form in higher pressure start conditions, such as in liquid or solid?

[Francisl]

Hi meems,
There are practical problems that arise with higher pressures. Shock waves can damage equipment as LPPFusion found out in these early experiments: https://lppfusion.com/breaking-records-and-window/.
I haven’t looked up the link yet but I remember reading an article that the plan is to increase pressures to reduce the percentage of impurities from the electrodes. This will also increase the fusion yields. That requires higher currents to maintain high temperatures in the larger mass of fuel. The power delivery system will be reconfigured to provide those higher currents.

I don’t know if plasmoids can form in starting conditions using liquids or solids. I suppose it is possible to engineer a system that could do that. A dpf is a type of particle accelerator that concentrates the beam into a tiny volume and compresses it with a strong magnetic field.
It is possible to pass a very large current through a liquid or a solid, convert that to a plasma and compress it with a strong current and magnetic field.
That would be close to what a Z machine does if it had a liquid or solid target. http://www.sandia.gov/z-machine/about_z/how-z-works.html It does not have the particle accelerator function that a dpf has and relies on heating and compression from a very large current.

[sanman]

Hi, I’d posed some related questions in another read – I’d asked if lithium metal or lithium hydride could be used for the electrodes instead of beryllium. It’s cheaper than beryllium, and is a well-known electrode material.

Lithium metal has a low melt point of 185C, but lithium hydride has a higher melt point of 692C – the issue is that lithium hydride can lose some of its hydrogen in a vacuum, by undergoing outgassing. But higher pressures, as you were discussing, might mitigate that. Besides, hydrogen is the least problematic impurity possible.

And even if lithium metal has a low melt point, the most that LPP’s machine has ever generated was 0.1 J in a single shot.

Since Focus Fusion is all about a grassroots R&D effort, I think that any would-be imitators out there should try coming up with ways to use Lithium electrodes – either Lithium metal or Lithium Hydride – in a higher pressure environment.

[Author]

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