Pros and Cons of Fusion Power Generation

[RogerFox]

Let's not forget Rostoker and Bussard were also each partially funded by the Office of Naval Research,...
this is just my opinion.

Right, both got ONR $$, I thought that was the point I was making...
AS far as the rest of your observations about Rider, very well said.
It is, at the very least a very strange story.

cuddihy, did you catch my bit on vacuum tubes circa 1933, and inelastic particles upthread? Since we are dealing with an ion accelerator.. are the ions going fast enough to become inelastic? If they are, they don't bounce...no?

if there is bounce we are talking about imparting spin... or exciting.. electrons changing orbits... no ?

I'm asking, because I'm not sure I have it right.

 

[mheslep]

BTW how you coming on the vacuum tube book (Chafee)?

What happened to your posted link to that copyrighted book?

 

[RogerFox]

Yep, but one can always suppose that Ridder said that in tongue-in-cheek mode. I don't think a jest like that should be used to destroy the credibility of a scientist.

Nevertheless, Rider got a fellowship. If there was some gamesmanship, it was thru Rider's & the ONR's action and not mine. Rider took the money & ran away to work another field... no?

Forget the hyperbole, that I have introduced, forget it. Look at Riders actions.

 

[mheslep]

With the due respect, Why?

The argument is hard for me to parse. The part on angular momentum is just wrong about a basic conservation law.

So as ions approach the center, their angular velocity components become non-maxwellian, such that at the center they are all exactly the same: 0.

If a particle has somehow acquired some angular momentum (via a collision say) on the edge its not going become zero as falls down a radial potential gradient. The non zero angular mo means the particle will form some kind of orbit about the center, it will be defocused compared to a radially traveling particle, and in fact will never go through the center until/unless some other force other than the external qE force acts on it (another collision say). Its Phy mechanics 101.
And so on.

See Nevins for a good, mathematically modeled treatment:
"http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PHPAEN000002000010003804000001&idtype=cvips&gifs=yes" ", W.M Nevins Physics of Plasmas 2, 3804, 1995.

 

[sunday]

The argument is hard for me to parse. The part on angular momentum is just wrong about a basic conservation law.


If a particle has somehow acquired some angular momentum (via a collision say) on the edge its not going become zero as falls down a radial potential gradient. The non zero angular mo means the particle will form some kind of orbit about the center, it will be defocused compared to a radially traveling particle, and in fact will never go through the center until/unless some other force other than the external qE force acts on it (another collision say). Its Phy mechanics 101.
And so on.

See Nevins for a good, mathematically modeled treatment:
"http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PHPAEN000002000010003804000001&idtype=cvips&gifs=yes" ", W.M Nevins Physics of Plasmas 2, 3804, 1995.

Yes, about radial velocities, I agree. But I find the part about radial velocities acceptable.

I have no access to the full text of the cited paper...

 

[RogerFox]

Sunday:

http://www.osti.gov/bridge/servlets/purl/41400-kmR97s/webviewable/41400.pdf

 

[M. Simon]

What happened to your posted link to that copyrighted book?

The copyright has expired.

It is public domain. These things happen.

Despite that fact it appears that the link has been removed.

Pity. A lot to learn there.

Well if you look around you can find it.

 

[M. Simon]

I've found that most of the technical books published before about 1964 never had their copyrights renewed, so now are in the public domain. So I am endeavoring to digitize and post some selected books relating to the "vacuum tube age" of electronics here.

I have checked to the best of my ability to confirm that these works have expired copyrights and are now in the public domain. If you have information to the contrary, please contact me at:

For information about copyrights and copyright renewals, look here. Here's a nice, easy copyright renewal search tool.

Want to help? If you have any pre-1964 books relating to vacuum tube technology, radio, or electronics that you'd like to sacrifice, let me know. And when I say "sacrifice", I really do mean sacrifice - the way I do this is to cut the book loose from it's cover, then slice the pages away from the binding. This way I can send it through an automatic document feeder. I can scan a 400 page book in about one hour. I'll have to verify that the copyright is expired and has not been reviewed - I can do that before you send anything.

From:

http://www.pmillett.com/tecnical_books_online.htm

Which has lots more books on tubes.

I recommend it.

 

[RogerFox]

John F. Santarius
University of Wisconsin

Injected electrons form a cloud throughout the interior of the sphere, resulting in a negative electrostatic potential well, as shown in Fig. 3. Ions are injected at low energy or created by neutral gas ionization at the outer edge of the electron cloud. These ions fall down the potential hill and converge on the origin of the sphere, giving a small, spherical core of high density (see Fig. 2). For a sufficiently deep potential well, steady-state fusion power can be generated in this core. Preliminary investigations of the Polywelltm concept have led to the conclusion that it can be a viable fusion reactor [2, 12-14],

2. R.W. Bussard, "Some Physics Considerations of Magnetic Inertial-Electrostatic Confinement: A New Concept for Spherical Converging-flow Fusion," Fusion Technology 19, 273 (1991).

12. N.A. Krall, "The Polywell: A Sperically Convergent Ion Focus Concept," Fusion Technology 22, 42 (1992).

13. M. Rosenberg and N.A. Krall, "The effect of collisions in maintaining a non-Maxwellian plasma distribution in a spherically convergent ion focus," Phys. Fluids B 4, 1788 (1992).14. S.K. Wong and N.A. Krall, "Potential well formation by injection of electrons with various energy distributions into a sphere or a slab," Physics of Fluids B 4, 4140 (1992).

although several questions remain [15, 16].

15. W.M. Nevins, "Can Inertial Electrostatic Confinement Work Beyond the Ion-Ion Collisional Time Scale?," Physics of Plasmas 2, 3804 (1995).

16. T.H. Rider, "A general critique of inertial-electrostatic confinement fusion systems," Physics of Plasmas 2, 1853 (1995).

http://fti.neep.wisc.edu/iec/inertial_electrostatic_confineme.htm

Santarius cites article pro & con, offering both sides for your consideration. From one of 2 (IIRC) University IEC programs in the US, (Urbana is the second, U of Wis has a working IEC reactor).

Dr. Kulcinski with IEC device

http://fti.neep.wisc.edu/iec/potential_uses.htm

Grahic: Likelihood of fusion
http://fti.neep.wisc.edu/iec/operat1.gif

Peer reviewed work from U of Wis. #10 looks good.

http://fti.neep.wisc.edu/iec/peer_reviewed.htm

 

[RogerFox]

Which has lots more books on tubes.

IIRC it was Bussard who said that a polywell device such as WB6 is more akin to a vacuum tube than a Tokamak, so would WB6 be a diode? Thats what I infered from the intro in Chaffee's book. WB6 is a Vacume tube diode. ..?

 

[M. Simon]

IIRC it was Bussard who said that a polywell device such as WB6 is more akin to a vacuum tube than a Tokamak, so would WB6 be a diode? Thats what I infered from the intro in Chaffee's book. WB6 is a Vacume tube diode. ..?

Due to the electron beams in some ways it is like a beam power tube. Well formation is a beam power tube type phenomenon - a virtual suppressor grid. . The magnetic field makes it kind of like a magnetron diode. Add in grids on your electron guns an you really have a very strange tube.

Electron dominance is the key. Just as it is in most types of vacuum tubes.

 

[RogerFox]

Due to the electron beams in some ways it is like a beam power tube. Well formation is a beam power tube type phenomenon - a virtual suppressor grid. . The magnetic field makes it kind of like a magnetron diode. Add in grids on your electron guns an you really have a very strange tube.

Electron dominance is the key. Just as it is in most types of vacuum tubes.

Then why do so many get hung up by talking the language of Tokamaks?
Rhetorical, I know, sorry.

 

[M. Simon]

Then why do so many get hung up by talking the language of Tokamaks?
Rhetorical, I know, sorry.

Obsolete technology. People haven't studied it for decades. I haven't thought about it much for 20 years or so myself. Now I know more than I ever did.

 

[TallDave]

Hopefully this will help shed some light

This might elucidate a bit.

http://www.sciencemag.org/cgi/content/full/281/5375/307a

http://www.sciencemag.org/cgi/content/full/281/5375/307a" . Rostoker had the last word, which doesn't, of course, mean he was right.

Rostoker's argument seems to hinge on this (click link for equations, haven't been able to paste them):

Carlson employs a classical generic formula for the power density required to overcome the friction between proton and boron beams. This formula is inadequate for the Colliding Beam Fusion Reactor. The magnetic field is important, and it is distinguished by its absence in this formula. The complete formula can be derived by taking the appropriate moment of the Vlasov/Fokker-Planck equation.

Is there an error in his reasoning here?

mheslep, I believe this is what you referred to in #30.

They've just been given $40M to try to make a demo machine that will shock and amaze the world. Not sure what their timeline is, but based on what I remember reading, if we don't hear from them within a couple years then things probably aren't working out. Anyone have a better guesstimate?

 

[M. Simon]

Rostoker says: We have previously considered long, thin cylindrical shell models because they simplify many calculations.

Which says that their reactor model may be based on ease of calculation vs optimum design.

Rostoker says that his machine will require 3.6 Mev of power into get 8.68 Mev (per reaction) of power out at 580 Kev in the center of mass frame.

For Dr. Bussard's machine under similar conditions the drive energy is 1.2 Mev.

 

[RogerFox]

if we don't hear from them within a couple years then things probably aren't working out. Anyone have a better guesstimate?

Tri Alpha is not building a large device at first? Right? I mean they got 5 mill up front, right... so they are not talking about a ITER sized cathedral.

Yeah 2, 3 years tops. I'll bet Tri Alphs gets "Q" @ .65 or under for a buck, anyone else ?

 

[TallDave]

My recollection is that they are first building a smaller device, which is supposed be a good enough neutron source that it can be used for nuclear waste disposal.

Tri Alpha is not building a large device at first? Right? I mean they got 5 mill up front, right... so they are not talking about a ITER sized cathedral.

Yeah 2, 3 years tops. I'll bet Tri Alphs gets "Q" @ .65 or under for a buck, anyone else ?

 

[mheslep]

Carlson employs a classical generic formula for the power density required to overcome the friction between proton and boron beams. This formula is inadequate for the Colliding Beam Fusion Reactor. The magnetic field is important, and it is distinguished by its absence in this formula. The complete formula can be derived by taking the appropriate moment of the Vlasov/Fokker-Planck equation.

Is there an error in his reasoning here?

mheslep, I believe this is what you referred to in #30.

Yes I think when he says with respect to thermalization "the magnetic field is important" he must be wrong, it is not important as I showed inhttps://www.physicsforums.com/showpost.php?p=1370035&postcount=52"

 

[TallDave]

Yes I think when he says with respect thermalization "the magnetic field is important" he must be wrong, it is not important as I showed inhttps://www.physicsforums.com/showpost.php?p=1370035&postcount=52"

Hmm, yes. I was hoping there was a specific flaw in Rostoker's derivation someone could point to. If the magnetic field can't reduce the entropy, it seems to me there ought to be some flaw we could point to in how they introduced it when they took the moment of the Vlasov/Fokker-Planck equation.

Obviously one of the two arguments must be using an inapplicable equation for the thermalization effects in an IEC device of the type described by Rostoker -- and similarly for Bussard's Polywell, to which Rider's thesis should apply as well (I asked Bussard if they might be publishing a detailed paper anytime soon, and he said probably not before the end of the year). It's hard to find much reference that would support either interpretation, but if it were easy we wouldn't be discussing it. Maybe we'll just have to wait and see if either IEC design actually works as the inventors claim.

I give them a 1 in 3 chance of being correct, and only that high because Bussard claims to have those n-counts and seems fairly credible (i.e. unlikely to have fabricated or misinterpreted them).

 

[mheslep]

This might elucidate a bit.

http://www.sciencemag.org/cgi/content/full/281/5375/307a

http://www.sciencemag.org/cgi/content/full/281/5375/307a" .

Well it was between Rostoker and Nevins/Carlson. Nevins w/ LLNL and Carlson at Max Planck. Rider is only cited. Nevins authored the "Can IEC work beyond..." paper in '95 so its to be expected he would publicly reply to the Rostoker-Monkhorst paper in Science 3 years later that basically ignored his well crafted objections to mono-energetic plasmas.

 

[TallDave]

Well it was between Rostoker and Nevins/Carlson. Nevins w/ LLNL and Carlson at Max Planck. Rider is only cited. Nevins authored the "Can IEC work beyond..." paper in '95 so its to be expected he would publicly reply to the Rostoker-Monkhorst paper in Science 3 years later that basically ignored his well crafted objections to mono-energetic plasmas.

Yes, silly of me. I get so used to seeing Rider's name in these discussions, I forgot it was Nevins who made the argument.

 

[TallDave]

Funded by CA?

If this article is accurate, we'll get to find out for sure who's right.

http://www.nextenergynews.com/news1/nextnews7.24b.html

 

[mheslep]

No 'Ca spokesman said', no sources at all, zip. I call BS.

 

[TallDave]

No 'Ca spokesman said', no sources at all, zip. I call BS.

Well, of course there are no sources. It's a leak, not a press release.

It might well be BS, or more likely, have some kernel of truth but not be entirely accurate (e.g., there is discussion of funding Polywell, but no decision yet).

Or it could be a total fabrication, for reasons unknown. Time will tell.

 

[sanman]

I don't know if this has been posted here yet, but here is an interesting approach called the Periodically Oscillating Plasma Sphere:

http://www.lanl.gov/p/rh_pp_park.shtml

So basically it's inertial electrostatic confinement, but in the form of oscillating spheres akin to the sonofusion idea, only using electrostatics instead of sound.

http://fusor.net/board/download_thread.php?site=fusor&bn=fusor_theory&thread=1184299189

 

[RogerFox]

If this article is accurate, we'll get to find out for sure who's right.

http://www.nextenergynews.com/news1/nextnews7.24b.html

false alarm.

 

[sanman]

Does Dr Bussard's IEC fusion device have any reasonable chance of working? (ie. providing net energy output)

What about that POPS thing? I read something that said space charge neutralization in an oscillating plasma puts limits on the amount of compression of the plasma, whereas a steady state plasma has no such limits. So does that mean the POPS idea is a dead end?

 

[TallDave]

false alarm.

We don't know for sure yet.

 

[sanman]

Does Dr Bussard's IEC fusion device have any reasonable chance of working? (ie. providing net energy output)

What about that POPS thing? I read something that said space charge neutralization in an oscillating plasma puts limits on the amount of compression of the plasma, whereas a steady state plasma has no such limits. So does that mean the POPS idea is a dead end?

http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PHPAEN000014000004042701000001&idtype=cvips&gifs=yes

A major issue for electron injected inertial electrostatic confinement (IEC) devices is space charge neutralization. A new formalism is developed that will allow this neutralization to occur for both oscillating and steady-state IEC plasmas. Results indicate that there are limits on the amount of compression that can be achieved by oscillating plasmas while simultaneously maintaining space charge neutralization and parabolic background potential. For steady-state plasmas, there are no such limits and space charge neutralization can be achieved even when the plasma becomes quasineutral.

To me, that sounds like POPS can't be made to work. It's nice that steady state plasmas have no charge neutralization problems, but they're not trying to achieve compression.

 

[sanman]

http://www.ofes.fusion.doe.gov/more_html/2007BPM/BPM2007-Master-Wurden-final.pdf

Look at page 40 on that PDF