Focus Fusion is back in business

[belbear]

I invite you to take a new look at http://focusfusion.org/"

After a long search for funding, Eric Lerner and his team from LPP are really on the move now, constructing a new, most powerful DPF (Dense Plasma Focus) machine, exclusively devoted to fusion research, that should deliver a proof-of-concept for nothing less than break-even P-B¹¹ fusion within as little as two years.

Very little neutrons, no liquid helium, no radioactive or "unobtainium" fuels, no steam, no turbines. Just direct conversion of fusion energy to electricity and relatively little waste heat.
Just making watts instead of rads and holding the promise of power plants in the tens-of-megawatts range that are small and safe enough to be operated in industrial and urbanized areas, where electricity is needed most. Furthermore, ships and even trains could benefit from such a fusion drive.

Eric claims to have a solution for the problem that p-B¹¹ fusion should emit more energy as X-ray bremsstrahlung than the reaction can ever produce, by applying a quantum physics principle that cools electrons significantly in the presence of a superstrong magnetic field (in the gigagauss range).
This field, fortunately, generates itself in the course of a tiny plasmoid shrinking down and heating up towards fusion temperatures. As a result, the electrons in his plasma should remain much cooler than the ions, making the whole process energy-positive.

 

[Astronuc]

Eric claims to have a solution for the problem that p-B¹¹ fusion should emit more energy as X-ray bremsstrahlung than the reaction can ever produce, by applying a quantum physics principle that cools electrons significantly in the presence of a superstrong magnetic field (in the gigagauss range).

This field, fortunately, generates itself in the course of a tiny plasmoid shrinking down and heating up towards fusion temperatures. As a result, the electrons in his plasma should remain much cooler than the ions, making the whole process energy-positive.

Aneutronic fusion means that the fusion reaction produces no neutrons, which is the attraction to p-B¹¹.

The brehmsstrahlung has to be converted to electrical energy, and any such conversion process is inherently inefficient, so there will be waste heat.

As for the quoted claim, that seems mostly preposterous. I recommend doing a calculation on the hydrodynamic pressure associated with a field of 1 Ggauss. The pressure is proportional to B², and find a material that can withstand such stress at temperature.

One should be careful about making sensational claims without the physics and supporting analysis.

 

[belbear]

The brehmsstrahlung has to be converted to electrical energy, and any such conversion process is inherently inefficient, so there will be waste heat.

Yes there will be, but not as inefficient as a thermal steam cycle. Even if less than half of the X-ray energy can be converted to electricity, the machine can output net power. Raising the efficiency can be a subject of later research.

And X-rays are not the only way the DPF outputs energy. The other way is a neatly focused ion beam, which carries away the contents of the plasmoid. (which, in the case of p-B¹¹fusion, will be alpha particles and any leftover nonfused fuel). The beam shoots straight out of the electrode set and can be converted to electricity with great efficiency. There is an electron beam shooting the opposite way.
This beam is the result of the superstrong magnetic field, comparable to the beams seen in cosmic sources like neutron stars. The ion beam's energy (about 6 MeV after fusion) will be the main source of power for recharging the capacitor to fire the next cycle. And it conveniently carries the helium waste product out of the reactor core.

This beam is not theory, but experimentally proven in various DPF experiments. Although a magnetic field on "only" 0.4 gigaGauss has ever been measured in such experiments, this is only one order of magnitude short of the goal for fusion.

As for the quoted claim, that seems mostly preposterous. I recommend doing a calculation on the hydrodynamic pressure associated with a field of 1 Ggauss. The pressure is proportional to B², and find a material that can withstand such stress at temperature.

One should be careful about making sensational claims without the physics and supporting analysis.

Is such a material needed? The collapsing plasmoid exists only for a few nanoseconds and does not come in contact with anything at anytime. The gigagauss field is extremely small, in the micrometer or even nanometer range. You should know that magnetic field strength decreases as 1/z³ (z being the distance far outside the field loop)
So, at the nearest solid-matter point (probably the tip of the hollow-tube shaped anode, the plasmoid originates in its center) the magnetic field will already be much lower, at manageable levels for ordinary materials.
This is nothing like magnetic fields generated with coils. These don't go above the hundreds of kilogauss range. Actually, the heat-load from X-ray bremsstrahlung will be much more of a problem. That's why X-ray transparent beryllium electrodes are being considered.

And plasmoids DO exist. They have been created and observed many times. Dr Philo Farnsworth produced his first "poissors", as he called plasmoids, in the 1950's. Actually, plasmoids are a constant nuisance for anyone who wants to contain a stable plasma, like the Tokamak folks want to do.

The DPF is, and always will be, a pulsed machine because its operation is based on plasma instability, not fighting it. In contrast to Z-pinch experiments, the DPF electrodes do not self-destruct, so the cycle can be repeated as often as possible within limits of operation. (like electrode and vessel wall cooling) There will be engineering challenges, but that's nothing compared to the challenges posed to the ones building the ITER.

A pulsed machine has one big advantage over continuous operated machines like tokamaks: It can be "throttled" from practically zero to its max rated output by simply varying its pulse rate. And, by lacking a thermal cycle, the power output will change almost immediately.
A varying power output with quick response time is a necessity for naval and other propulsion, as well as for a small local power grid that is isolated from the "big" electricity grid.

 

[Astronuc]

I would like to see the equations (i.e., the physics) to support the assertions in the preceding post. So far, I read lofty claims without substantiation. That's not how we do things at PF or in the scientific community.

At least provide the momentum equation for that shows how high compression is generated in the plasmoid.

 

[belbear]

I'm not a physicist myself (leave alone a plasma physicist) so I can't dream those equations up for you. :shy:
I will however keep looking into this and try to get equations regarding plasmoids from people who can know them (and are willing to share them)

Anyway, Astronuc, I wish to thank you for answering to the posts from a science-enthousiastic layman like me.
Although a fair degree fo skepticism is always a good thing, I am convinced that the experiment needs to be done, even if the physics behind it are not yet well understood. If they were, shouldn't we have commercial fusion plants operating already?

And it's not MY money that's being spent in this DPF experiment, so even if they fail, I lose no more than all the rest of humanity. But if they win, I will have known it before the big news hits the media.

With my post, I just wanted to stir new interest for a kind of experiment that was seemingly abandoned a few years ago.

After all, should Edison have abandoned his idea for a lightbulb because he did not know the equations behind the conversion of electricity into photons in a glowing filament?

 

[mheslep]

...

The brehmsstrahlung has to be converted to electrical energy, and any such conversion process is inherently inefficient, so there will be waste heat...

Losses from Brehmsstrahlung remain the unsolvable problem, as it does with all these very high temperature ( > ~30kev) fusion schemes. Lerner/Focus Fusion proposes to use a high magnetic field to push the electron gyro radius down to a point where the electrons are unable to transfer energy because they are unable to transition between quantum states, or something along those lines. I'm not aware of any published successes in that area.

 

[Brian H]

The patent contains many of the equations you may be looking for:
http://tinyurl.com/FocusFusionPatent

 

[mheslep]

The patent contains many of the equations you may be looking for:
http://tinyurl.com/FocusFusionPatent

As mentioned above what I'm looking for is anyone to have actually demonstrated the effect:

... Lerner/Focus Fusion proposes to use a high magnetic field to push the electron gyro radius down to a point where the electrons are unable to transfer energy because they are unable to transition between quantum states, or something along those lines. I'm not aware of any published successes in that area.

A quick scan of the patent admits as much.

 

[Brian H]

As mentioned above what I'm looking for is anyone to have actually demonstrated the effect:
A quick scan of the patent admits as much.

Fair enough. There's a first time for everything. So far, however, so good:
"Lerner: The achievement of a pinch, and on the second shot, means that we have accomplished one of the eight technical goals of the current experimental program. The machine is doing what we designed it to do, which is to transfer energy into a tiny plasmoid. It is quite unusual for a DPF to pinch right way. Normally fine-tuning of the electrodes and insulator and “conditioning” of the electrodes by several shots is required. That this was not needed is confirmation that our electrode and insulator dimensions, derived from LPP’s quantitative theory of DPF functioning, are accurate."

 

[mheslep]

Fair enough. There's a first time for everything...

True, but not helpful. Without a solution to the xray losses problem such schemes amount to construction of expensive xray machines.

Also, pinches have been around 40 years. What's been published here that's new?
http://www.plasma-universe.com/index.php/Pinch
See in particular Chapter 12 of Tom Dolan's nuclear fusion opus (ca 1970) referenced in footnote 26 in the link above.

 

[belbear]

http://www.plasma-universe.com/index.php/Pinch
See in particular Chapter 12 of Tom Dolan's nuclear fusion opus (ca 1970) referenced in footnote 26 in the link above.

This reference to the Tom Dolan work is a dead link.
I found another source:
http://www.woodruffscientific.com/fusion_textbook