Focus Fusion news story

Joseph Chikva · Post by **Joseph Chikva** » Sat Apr 28, 2012 4:15 am

mvanwink5 wrote:Hanleyp,
This was also obvious to me, I am confused what JC is thinking.
Best regards

Obvious? In theory it is very easy to set up a plate with potential (voltage) of several millions volts. But you can try to do that with only several thousands Volts.
I am afraid that result would not be pleasant for you.

So you are talking about electrostatic direct energy converters?
Ok:

Electrostatic Direct Energy Conversion
As illustrated in Figure 1, five processes2 are involved in
the electrostatic direct conversion of the plasma energy
that leaks out of a mirror fusion reactor &#56256;&#56322;It may be possi&#56256;&#56321;
ble to convert the plasma energy directly, leaving a toroidal
reactor via a diverter; however, a detailed technique has no&#56256;&#56325;
yet been worked out.&#56256;&#56323;:
1. Selective Leakage: By means of magnetic and
electrostatic, the ions and electron are made to
leak selectively through limited regions of the
plasma boundary.
2. Expansion: The plasma stream is guided and
expanded in volume by a decreasing magnetic
field that reduces the power density and con&#56256;&#56322;
verts rotational energy to directional energy.
3. Electron Separation: The electrons are sepa&#56256;&#56322;
rated from the plasma steam and collected on
an electron collector grid, an electrode that
forms the negative terminal of the power source
of the direct energy converter.
4. Deceleration: The ions are decelerated by
retarding electric fields; kinetic energy is
thereby converted to potential energy.
5. Collection: The decelerated ions are collected
on high&#56256;&#56322;voltage electrodes that form the posi&#56256;&#56322;
tive terminal of thepower source of the direct
energy converter.

-Collection,
-electron separation,
-deceleration.
But first of all: Expancion The plasma stream is guided and expanded in volume by a decreasing magnetic field that reduces the power density and converts rotational energy to directional energy.
Now please explain how you can do all of these in short distnce.
Thnks.

mvanwink5 · Post by **mvanwink5** » Sat Apr 28, 2012 5:03 am

Take it easy Joseph, we're not your adversaries here.
Best regards

Joseph Chikva · Post by **Joseph Chikva** » Sat Apr 28, 2012 5:09 am

mvanwink5 wrote:Take it easy Joseph, we're not your adversaries here.
Best regards

I am not your adversary too. But someone here considers my doubts (well stated) in Polywell's viability as personal insult. Thanks,

mvanwink5 · Post by **mvanwink5** » Sat Apr 28, 2012 5:23 am

Thanks Joseph, I also realize you are not an adversary, and I appreciate your sharing your concerns that are based on your background and understandings.
Best regards

Joseph Chikva · Post by **Joseph Chikva** » Sat Apr 28, 2012 6:45 am

mvanwink5 wrote:Thanks Joseph, I also realize you are not an adversary, and I appreciate your sharing your concerns that are based on your background and understandings.
Best regards

Thank you too.

ladajo · Post by **ladajo** » Sat Apr 28, 2012 12:28 pm

Joseph,
Maybe part of the problem is that you are basing many of your judgements on older texts? Is it possible?

For direct conversion using collector plates/venetian blind, you should look around some more. There has been some thought put in for this type of approach. Also, please note that you are cherry picking your reference, and has been pointed out before, context is just as important as the single word or sentance.

In your case above, I would take that to read: This has not been done in detail for toroidal designs. Which would include the diverter, etc. And we all know that power level Toroidal designs still have many challenges to beat before they think about power taps.

My issue Joeseph with your methods are that you remain naroow minded in focus, and religeously fundamental in approach. Your certainty is to be admired, but also challenged. It is dangerous for a mind to limit its willingness to be wrong. That would seem to be the case with you.

I also am not your adversary Joseph. I am however, frustrated on occassion with your unwillingness to explore alternate ideas, nor back up sufficiently the ones you claim. This creates the impression of you being a yapping mouth spewing empty words.

Do you consider POPS a beam approach? I do not. I consider it a convergence approach, as I do Polywell, in the macro. In the micro, I do think there can be applied a simplification of beam principles (as I have said before), to analyse detailed interaction, but the larger construct, is not viable for beam machine analysis. It is more complex, and does not function in a beam mode.
I am concerned that you continue to take Dr. Nebel's words out of context, and then leap forward to an unbased conclusion. He did not say they have done 2 stream analysis of the machine, he siad that the machine is not susceptable to it due to its contruct. That is a big difference from what you are arguing based on your interpretation of what he said.

Please show Nebel's words again, in context, and show me I am wrong. I would be happy to be wrong, as it furthers real understanding.

tomclarke · Post by **tomclarke** » Sat Apr 28, 2012 1:26 pm

Joseph Chikva wrote:
mvanwink5 wrote:Hanleyp,
This was also obvious to me, I am confused what JC is thinking.
Best regards
Obvious? In theory it is very easy to set up a plate with potential (voltage) of several millions volts. But you can try to do that with only several thousands Volts.
I am afraid that result would not be pleasant for you.

So you are talking about electrostatic direct energy converters?
Ok:
Electrostatic Direct Energy Conversion
As illustrated in Figure 1, five processes2 are involved in
the electrostatic direct conversion of the plasma energy
that leaks out of a mirror fusion reactor ��It may be possi��
ble to convert the plasma energy directly, leaving a toroidal
reactor via a diverter; however, a detailed technique has no��
yet been worked out.��:
1. Selective Leakage: By means of magnetic and
electrostatic, the ions and electron are made to
leak selectively through limited regions of the
plasma boundary.
2. Expansion: The plasma stream is guided and
expanded in volume by a decreasing magnetic
field that reduces the power density and con��
verts rotational energy to directional energy.
3. Electron Separation: The electrons are sepa��
rated from the plasma steam and collected on
an electron collector grid, an electrode that
forms the negative terminal of the power source
of the direct energy converter.
4. Deceleration: The ions are decelerated by
retarding electric fields; kinetic energy is
thereby converted to potential energy.
5. Collection: The decelerated ions are collected
on high��voltage electrodes that form the posi��
tive terminal of thepower source of the direct
energy converter.
-Collection,
-electron separation,
-deceleration.
But first of all: Expancion The plasma stream is guided and expanded in volume by a decreasing magnetic field that reduces the power density and converts rotational energy to directional energy.
Now please explain how you can do all of these in short distnce.
Thnks.

Joseph,

Forgive me if I am missing something, but I believe the "Polywell is smal"l thesis is based on the assumption of p-B11 fusion where much of the the fusion product energy goes into charged particle KE. The direct conversion is of high energy monopolar charged particle beams. This is not the same problem as plasma leakage.

Having said that I have not looked it detail at what will be the variability in KE of these beams, or what other stuff might leak out with them. I expect others have. Anyway, it does not seem to be the case discussed in your reference.

Joseph Chikva · Post by **Joseph Chikva** » Sat Apr 28, 2012 4:06 pm

ladajo wrote:Do you consider POPS a beam approach? I do not. I consider it a convergence approach, as I do Polywell, in the macro. In the micro, I do think there can be applied a simplification of beam principles (as I have said before), to analyse detailed interaction, but the larger construct, is not viable for beam machine analysis. It is more complex, and does not function in a beam mode.
I am concerned that you continue to take Dr. Nebel's words out of context, and then leap forward to an unbased conclusion. He did not say they have done 2 stream analysis of the machine, he siad that the machine is not susceptable to it due to its contruct. That is a big difference from what you are arguing based on your interpretation of what he said.

Please show Nebel's words again, in context, and show me I am wrong. I would be happy to be wrong, as it furthers real understanding.

I do not consider POPS as beams. But electron beams are injected into plasma sphere and they interact each other. "Beam injected into background plasma" is a standard condition when 2-stream is an issue. And electron beams are more vulnerable than ions'.

Somewhere in this thread is the link and further discussion of Dr. Nebel article regarding to 2-stream in Polywell. And as I remember Kiteman opposed me actively that time.
I've found:
http://pop.aip.org/resource/1/phpaen/v1 ... horized=no

Theoretical and experimental studies of kinetic equilibrium and stability of the virtual cathode in an electron injected inertial electrostatic confinement device
R. A. Nebel, S. Stange, J. Park, J. M. Taccetti, S. K. Murali, and C. E. Garcia
Theoretical Division, Los Alamos National Laboratory, MS K717, Los Alamos, New Mexico 87545
This paper explores the electron-electron two-stream stability limit of a virtual cathode in spherical geometry.

Joseph Chikva · Post by **Joseph Chikva** » Sat Apr 28, 2012 4:24 pm

tomclarke wrote:The direct conversion is of high energy monopolar charged particle beams. This is not the same problem as plasma leakage.

I am not saying here that the problem is in plasma leakage. But I am saying that Direct Energy Converter will be rather roomy not allowing to place on to any warship. As I see big expectations of some high rank US Navy officers.

ladajo · Post by **ladajo** » Sat Apr 28, 2012 5:45 pm

Joseph Chikva wrote:
ladajo wrote:Do you consider POPS a beam approach? I do not. I consider it a convergence approach, as I do Polywell, in the macro. In the micro, I do think there can be applied a simplification of beam principles (as I have said before), to analyse detailed interaction, but the larger construct, is not viable for beam machine analysis. It is more complex, and does not function in a beam mode.
I am concerned that you continue to take Dr. Nebel's words out of context, and then leap forward to an unbased conclusion. He did not say they have done 2 stream analysis of the machine, he siad that the machine is not susceptable to it due to its contruct. That is a big difference from what you are arguing based on your interpretation of what he said.

Please show Nebel's words again, in context, and show me I am wrong. I would be happy to be wrong, as it furthers real understanding.
I do not consider POPS as beams. But electron beams are injected into plasma sphere and they interact each other. "Beam injected into background plasma" is a standard condition when 2-stream is an issue. And electron beams are more vulnerable than ions'.

Somewhere in this thread is the link and further discussion of Dr. Nebel article regarding to 2-stream in Polywell. And as I remember Kiteman opposed me actively that time.
I've found:
http://pop.aip.org/resource/1/phpaen/v1 ... horized=no
Theoretical and experimental studies of kinetic equilibrium and stability of the virtual cathode in an electron injected inertial electrostatic confinement device
R. A. Nebel, S. Stange, J. Park, J. M. Taccetti, S. K. Murali, and C. E. Garcia
Theoretical Division, Los Alamos National Laboratory, MS K717, Los Alamos, New Mexico 87545
This paper explores the electron-electron two-stream stability limit of a virtual cathode in spherical geometry.

This paper explores the electron-electron two-stream stability limit of a virtual cathode in spherical geometry. Previous work using a constant density slab model [ R. A. Nebel and J. M. Finn, Phys. Plasmas 8, 1505 (2001) ] suggested that the electron-electron two-stream would become unstable when the well depth of the virtual cathode was 14% of the applied voltage. However, experimental tests on INS-e have achieved virtual cathode fractional well depths ∼ 60% with no sign of instability. Here, studies with a spherical gridless particle code indicate that fractional well depths greater than 90% can be achieved without two-stream instabilities. Two factors have a major impact on the plasma stability: whether the particles are reflected and the presence of angular momentum. If the particles are reflected then they are guaranteed to be in resonance with the electron plasma frequency at some radius. This can lead to the two stream instabilities if the angular momentum is small. If the angular momentum is large enough it stabilizes the instability much the same way as finite temperature stabilizes the two-stream instability in a slab.

So we are both right and wrong.
See what happens when you actually look at references...

Two stream studies in code show it is not a problem. Nebel also stated elsewhere it is not a problem for Polywell. So it would seem between the theorectical and practical it is not an issue.

Joseph Chikva · Post by **Joseph Chikva** » Sat Apr 28, 2012 6:24 pm

ladajo wrote:Two stream studies in code show it is not a problem.

Sorry, but I do not see where I am wrong.
Not "two stream" but "electron-electron two stream". It is a big difference. As Nebel states that damping of electron-electron two-stream goes thanks to the large angular momentums of background electrons. This is so called "Landau damping". This also causes some questions but let's admit that Dr. Nebel is right.

As now I am tolking that initially ions in Polywell will not have angular momentums. WB6 ran at 0.1T with corresponding number density. Later generations should run at e.g. 2T - 20 times higher field. And if you would have 100 times denser plasma (not 400 times denser as my some my optimistic friends expect) electron-ion two-stream instability can become critical. At least that will not allow to run at high beta.

D Tibbets · Post by **D Tibbets** » Sun Apr 29, 2012 1:34 am

Direct conversion is an extremely widely used and successful process. I am referring of course to ion rocket engines, Cathode ray tubes, etc, etc.
An ion gains kinetic energy from a set of electrodes or space charge. The reverse, the gaining of potential energy by decelerating ions (or electrons) is the exact same process, only in reverse You cannot have one without the other. I don't think anyone will claim that classic TV didn't work. Also, I suspect similar processes are used in many vacuum tubes. This was one of Bussard's complaints. Many modern physicists suffer from a training blind spot. They have little understanding of vacuum tube practical technology. Much of the Polywell principles are founded on established vacuum tube technology.

Changing direction of a charged particles does not generate energy (other than some inefficiencies/ processes like cyclotron radiation or bremmstruhlung radiation). Certain manipulations may be desirable or necessary in certain systems like a tokamak, but again a reminder that the Polywell is a much different machine. The magrid is an already proven direct energy converter, at least if you accept that electron circulation is real. I think the real question with direct conversion is not whether it is possible, but whether it can be done efficiently and pratically. In the Tokamak, the diverter may fall under this consideration. Just diverting edge plasma flow in a tokamak is going to be very difficult as the heating of the diverter structure will be severe. I have one seen one paper that proposed applying direct conversion aspects , not just as a power harvesting effort, but to cool the plasma before it contacts the diverter, thus sparing it from much of the heating problems.

Dan Tibbets

Joseph Chikva · Post by **Joseph Chikva** » Sun Apr 29, 2012 2:08 am

D Tibbets wrote:Direct conversion is an extremely widely used and successful process. I am referring of course to ion rocket engines, Cathode ray tubes, etc, etc.

I agree. Ion rocket motors are extremely widly used.

D Tibbets wrote:I am referring .....................Cathode ray tubes, etc, etc.

So. you think that stream of alphas or particles or plasma should bombard some plate without deceleration?

KitemanSA · Post by **KitemanSA** » Sun Apr 29, 2012 12:52 pm

Seems obvious this is a willful misconstruction of Dan's statement. Mr. Chitva is trolling.

Joseph Chikva · Post by **Joseph Chikva** » Sun Apr 29, 2012 7:52 pm

KitemanSA wrote:Seems obvious this is a willful misconstruction of Dan's statement. Mr. Chitva is trolling.

Seems obvious that you can not imagine how big direct energy converter will be.
Five consecutive steps should be carried out in it:
1. Selective Leakage
2. Expansion
3. Electron Separation
4. Deceleration
5. Collection
Once again:

Expancion The plasma stream is guided and expanded in volume by a decreasing magnetic field that reduces the power density and converts rotational energy to directional energy.

You called me "idiot". Now Mr. Smart please explain me what length will be sufficient for only this piece?
Dan said that all mentioned steps are not needed at all. Only to bombard some plate charging that. Is that possible technically? I am afraid that you are not aware with very basic design principles of such devices.