Focus Fusion On Slashdot

MSimon · Post by **MSimon** » Mon Oct 19, 2009 10:40 am

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http://science.slashdot.org/story/09/10 ... n?from=rss

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kurt9 · Post by **kurt9** » Mon Oct 19, 2009 3:47 pm

You know, compared to polywell, Tri-Alpha, John Slough's FRC, and even General Fusion; I simply cannot overcome my skepticism of Eric Lerner's focus fusion approach. Maybe its the hypy nature of his website, or the fact he got kicked off of the Wiki as a result of an argument with Art Carlson.

The part of their approach that stretches credibility with me is how the plasmoid their system creates is supposed to self-assemble into the complex, self-confining structure that, in turn, is supposed to cause the fusion reactions. I find it difficult to believe this.

I wish the focus fusion people a lot of luck. I really do. But I guess I'm not going to be convinced of their approach until they can successfully demonstrate viable levels of fusion with their process.

MSimon · Post by **MSimon** » Mon Oct 19, 2009 3:52 pm

I'll give them self assembling, plasmoids, etc.

I want to know how they handle electrode erosion from the pulses?

chrismb · Post by **chrismb** » Mon Oct 19, 2009 4:08 pm

kurt9 wrote:You know, compared to polywell, Tri-Alpha, John Slough's FRC, and even General Fusion; I simply cannot overcome my skepticism of Eric Lerner's focus fusion approach.

Don't forget that DPF devices are well known and produce plentiful fusions and emissions of neutrons/x-rays. It is merely a question of efficiency, confinement times and, as MSimon says, basic technology. It is already known to be 'a go-er', Lerner is doing 'tuning' work to try to make it 'viable' (which has defeated other researchers in the area, but there it is...)

The projects you mention have yet to turn out their first provable fast-fast neutrons.

Tom Ligon · Post by **Tom Ligon** » Mon Oct 19, 2009 6:24 pm

I'm intrigued by the plasmoid generator. If it does what I think it does, the plasmoids should not be tokamak-like toroids, they should drop to the form of spheromaks (distort the toroid to nearly spherical). These may very well self-contain.

I've heard negative opinions here about Paul Koloc, but Dr. Bussard thought he might be on to something with his notion that plasmoids of this sort might be the basis for ball lightning, and also might be capable of fusion. I don't recall Dr. Koloc saying anything about using p-B11, though.

I think FF must be at a disadvantage to the Polywell at burning p-B11, since it is supposed to be a purely thermal device, not electrodynamic. It can probably use excess hydrogen to lower Zeff, but the electrons should be "hot", and in thermal equilibrium with the fuel, if it really is a heat-driven machine.

Even if it does not produce commercially useful fusion, the generation of plasmoids alone could lead to understanding or applications worth the effort.

MSimon · Post by **MSimon** » Mon Oct 19, 2009 7:57 pm

Having had personal experience with ball lightning, I'd like to see more work done on it.

I was in the same room with a ball between 1/2 and 1 m in dia and which glowed copper green. It was scary but faded over a period of about 10 seconds as I slowly backed away.

Art Carlson · Post by **Art Carlson** » Mon Oct 19, 2009 8:01 pm

Tom Ligon wrote:I'm intrigued by the plasmoid generator. If it does what I think it does, the plasmoids should not be tokamak-like toroids, they should drop to the form of spheromaks (distort the toroid to nearly spherical). These may very well self-contain.

There are (massive) forces on the outer legs of the toroidal field coils in a tokamak pushing them outward. Similarly the conducting shell around a spheromak is pushed outward. The proof that there will be expansion forces in any plasmoid is the virial theorem. Why would you want to say "These may very well self-contain"?

Tom Ligon wrote:I think FF must be at a disadvantage to the Polywell at burning p-B11, since it is supposed to be a purely thermal device, not electrodynamic. It can probably use excess hydrogen to lower Zeff, but the electrons should be "hot", and in thermal equilibrium with the fuel, if it really is a heat-driven machine.

Nobody has ever been able to explain to me why the polywell should be able to get around Rider's recirculating power argument. Lerner at least had a creative idea that the bremsstrahlung could be suppressed in mega-Tesla fields, while the cyclotron radiation would be re-absorbed at sufficiently high density. I fought him a while on this, but finally had to agree it had enough plausiblity that it should be mentioned in http://en.wikipedia.org/wiki/Aneutronic ... er_balance.

chrismb · Post by **chrismb** » Mon Oct 19, 2009 8:09 pm

Art Carlson wrote: Lerner at least had a creative idea that the bremsstrahlung could be suppressed in mega-Tesla fields, while the cyclotron radiation would be re-absorbed at sufficiently high density.

I believe (as far as I understand it) that this is one of the key items of interest from other pratical experimentation (i.e. is an experimental outcome, unconnected with DPFs) from which Lerner has made the theoretical step that x-rays are screened within magnetic plasmas of sufficient strength.

TallDave · Post by **TallDave** » Mon Oct 19, 2009 8:21 pm

Nobody has ever been able to explain to me why the polywell should be able to get around Rider's recirculating power argument.

WB confinement?

MSimon wrote:Rider's chief criticism is related to the recirculating power required in a colliding beam machine: "In virtually all cases, this minimum recirculating power is substantially larger than the fusion power, so barring the discovery of methods of recirculating the power at exceedingly high efficiencies, reactors employing plasmas not in thermodynamic equilibrium will not be able to produce net power". This is a very valid criticism and is acknowledged by Robert Bussard. However, Bussard claims that the discovery of what he terms the Wiffle Ball effect and by circulating electrons escaping from the Wiffle ball at high efficiencies he can get the total electron circulation efficiency into the 99.999% to 99.9999% range, making machines of his proposed design viable for power production.

Tom Ligon · Post by **Tom Ligon** » Mon Oct 19, 2009 9:06 pm

A little web searching shows me Dr. Koloc does indeed think his concept could burn boron. Better to use his words than mine, as all I have to go on is one day's visit to the lab, with me as spectator.

http://prometheus2.net/spacepow.pdf

If Koloc's insights are correct, and I'm right that the FF plasmoids work on circulating plasma current producing a surrounding magnetic field, they ought to distort to the spherical approximation of Koloc's Plasmak. The difference seems to be that Koloc envisions a fairly large plasmoid achieving a "burn", whereas Focus Fusion expects a fairly small one that collapses to a pinch.

My opinion does not count in any case. Let the experiment proceed. It should make entertaining fireworks in any case.

Art Carlson · Post by **Art Carlson** » Mon Oct 19, 2009 9:09 pm

TallDave wrote:
Nobody has ever been able to explain to me why the polywell should be able to get around Rider's recirculating power argument.
WB confinement?

MSimon wrote:Rider's chief criticism is related to the recirculating power required in a colliding beam machine: "In virtually all cases, this minimum recirculating power is substantially larger than the fusion power, so barring the discovery of methods of recirculating the power at exceedingly high efficiencies, reactors employing plasmas not in thermodynamic equilibrium will not be able to produce net power". This is a very valid criticism and is acknowledged by Robert Bussard. However, Bussard claims that the discovery of what he terms the Wiffle Ball effect and by circulating electrons escaping from the Wiffle ball at high efficiencies he can get the total electron circulation efficiency into the 99.999% to 99.9999% range, making machines of his proposed design viable for power production.

Have you ever seen a power balance calculation? What he expects the EEDF to be? What the loss rate for various electron energies is? How this energy is captured and recirculated?

Nada.

Torulf2 · Post by **Torulf2** » Mon Oct 19, 2009 10:25 pm

Regarding the plasmoids in DPF and ball lightings.

In the pinch region in DPF there is a hotspot. This have been photographed from its own x-rays. In the theory by Bostick this consist of swirled plasma philaments. It’s not a simple thoroid.

This movie have I made from how Lerner think its work.
http://www.youtube.com/watch?v=vQ9bXbnLI6U

Its may have contact with the pinch current and if so it’s not a really plasmoid.
But if not, it’s not necessary a problem. Complex topology and hal-efect is not count in the viral theorem. For Paul Kolocs thoroidal plasmoid there are an essential atmospheric pressure not count in the viral theorem.

I have also seen something I think was ball lighting. It was high up in the air after and ordinary lighting. A bright radiant spot lasted in maybe 5 seconds. I think it was a ball lighting but if there not exist such a things it can have been a “star” from a rocket. Someone may send up a firework rocket a stormy night in Gothenburg and the rocket trace was conduct the lighting.

MSimon · Post by **MSimon** » Mon Oct 19, 2009 10:26 pm

Art Carlson wrote:
TallDave wrote:
Nobody has ever been able to explain to me why the polywell should be able to get around Rider's recirculating power argument.
WB confinement?

MSimon wrote:Rider's chief criticism is related to the recirculating power required in a colliding beam machine: "In virtually all cases, this minimum recirculating power is substantially larger than the fusion power, so barring the discovery of methods of recirculating the power at exceedingly high efficiencies, reactors employing plasmas not in thermodynamic equilibrium will not be able to produce net power". This is a very valid criticism and is acknowledged by Robert Bussard. However, Bussard claims that the discovery of what he terms the Wiffle Ball effect and by circulating electrons escaping from the Wiffle ball at high efficiencies he can get the total electron circulation efficiency into the 99.999% to 99.9999% range, making machines of his proposed design viable for power production.
Have you ever seen a power balance calculation? What he expects the EEDF to be? What the loss rate for various electron energies is? How this energy is captured and recirculated?

Nada.

Have we seen the appropriate calculations for any number of fusion proposals now in the works or under serious consideration?

TallDave · Post by **TallDave** » Tue Oct 20, 2009 4:53 pm

Have you ever seen a power balance calculation?

I've done a couple really rough and ugly ones. I believe Rick gave us a number for electron losses at one point. Anyways, you asked for an explanation, not a calculation.

What he expects the EEDF to be? What the loss rate for various electron energies is?

The Electron Energy Distribution Function? I imagine he has some numbers in mind. If you ask him by private email, he might share them, subject to NDA etc.

How this energy is captured and recirculated?

AFAIK electrons just recirculate by bouncing off of the B fields. I'm not sure what you're looking for beyond the WB effect.

KitemanSA · Post by **KitemanSA** » Tue Oct 20, 2009 7:53 pm

TallDave wrote:
How this energy is captured and recirculated?
AFAIK electrons just recirculate by bouncing off of the B fields. I'm not sure what you're looking for beyond the WB effect.

Plus those that escape the cusps (the holes in the wiffleball) are supposed to be returned by the positive charge of the MaGrid, saving that energy. And the electrons that actually make it back to the chamber walls have lost all the energy they gained by falling in from the walls in the first place!