Have ANY projects got a future?

Reflections on fusion history, current events, and predictions for the 'fusion powered future.
Dan Tibbets
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Re: Have ANY projects got a future?

Post by Dan Tibbets »

Well, thanks for calling me a fool, liar, and generally evil person. So, to spare you my views that are contrary to yours, this is my last past on this subject. First let me preface it by stating that I answered the original poster about one POSSIBLE project with a future. Any subsequent posts was in response to CB's criticisms and what I beleive are misconceptions on his part.

The Polywell is intended to be a steady state machine. The short runs were due to reasons that I have already stated. That copper wire heats up when a large current is passed through it and that a vacuum is a good thermal insulater are simple physical properties and has nothing to do with the fusion processes beyond the engeenering concerns. By your argument the Large Hydron collider is silly because it has to cool it's magnets. And the JET Tokamak reacter was a pulsed device because it only operated within it's design goals for a few seconds. So long as the test runs are long enough to cover a reasoned period of time the physics can be extrapolated to predict behavior over the long term, provided you can resolve the engeenering issues to make it actually work in the real world. Again, my impression is that the electron transit/ orbit time is on the order of ~ 1 microsecond, so if you can run the machine near 'steady state' conditions for ~1 millisecond, that is near a thousand cycles- ie steady state as far as the physics is concerned. The measured neutron output had a confidence interval of +/- 1 neutron based on hearsay.

And, that Dr Bussard has a fondness for space propulsion is irrelivant to the claimed facts. He has admitted that he got into physics due to his love of space flight and hopes to go to Mars. Thus his development of the Bussard Ram scoop concept and his work on nuclear rockets in the 1960's. In several venues he has stated that he could not talk about his work while under the Navy embargo. But he could talk about possible applications- such as space flight.


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Chris Bradley
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Re: Have ANY projects got a future?

Post by Chris Bradley »

Dan DT wrote:
> Well, thanks for calling me a fool, liar, and generally evil person.
Not sure I said that. You've got a valuable and inventive interest, demonstrated many times. My critque is aimed squarely at the material you've read on Polywell, not directly on your faith of it. But faith only has a limited place in such scientific endeavours and at some stage the goods need to turn up by the barrel load and as yet some of us are [more than] disappointed with the waiting, though that is actually mainly due to the accompanying hyperbole.


> By your argument the Large Hydron collider is silly because it has to cool it's magnets.
super-cooled bending magnets come up with the goods by the barrel load. Proven 100s of times (1600 times in fact in the LHC - very silly indeed! but great fun!)


> And the JET Tokamak reacter was a pulsed device because it only operated within it's design goals for a few seconds.
Absolutely. This is true. ITER will be a pulsed device aswell, I think, though some will hope and dream otherwise.


> The measured neutron output had a confidence interval of +/- 1 neutron based on hearsay.
I'd love to hear more about objective, statistically significant Polywell successes, less about the hopes and dreams.

best regards,

Chris MB.
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Richard Hull
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Re: Have ANY projects got a future?

Post by Richard Hull »

Bottom line...........

1. No fusion system made by the hands of man has ever run continuously within even 6 to 8 orders of magnitude below break-even as long as the Earth-Sun System has existed.

2. Real energy must flow 24-7-365 as that is what we expect from a wall outlet.

3. We need energy now!

Forget green....we just need energy.....or several billions less people to consume it.

I realize that there are many, many, things in the works with many promises, adherents and hard workers.

I realize hope springs eternal. Hope, however, don't feed the bulldog.

I also realize that waiting for the lucky donkey may take a while.

In the end.......... we wait. We wait for innovation, evolution and or revolution. Whether a step by step logical process based on first principles or a paradigm shift.....We wait.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Chris Bradley
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Re: Have ANY projects got a future?

Post by Chris Bradley »

Hopefully we're not all *just* waiting! Some must act.

That's what I like about this forum. It objects to blithering on about star-ship propulsion and instead is full of folks actually *doing* stuff with lumps of electronics and vacuums in their garages with grubby bits of 2nd hand ebay kit, or stuff they've honed out of left-overs with their own tools. (Lest I play down particular efforts, also exquisitely sculpted and crafted own-designs!)

We may only be gently grazing the surface of fusion science, but if nothing actually comes out of work done today then I believe it can still inspire those of tomorrow in a way that neither chit-chat nor 'big-science' can.
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Re: Have ANY projects got a future?

Post by DaveC »

Joining this discussion, late.

A lot of topics have been discussed peripherally in this discussion, and I may have missed the points I want to make.. so if I am repeating what has already been said, I offer my apologies in advance.

It seems to me, that if we set aside all considerations of HOW you do it, the D-D fusion process, "theoretically" is sound as a net energy source. "Exothermic" would be an energy related description.

That conclusion is easily reached. Energy in: Two D's at 2AMU which when fused release two 2.45 MEV 1AMU particles, plus some other energy.

So, at any energy or temperature equivalent, less than about 1.25 MEV per Deuterium atom (or ion), you get a net energy yield.

So, if this simplistic picture is physically correct, then the "process" at its limiting effiency is a winner. But this is not to say the process is either practical or possible.

Carnot efficiency in terms of temperatures is also deceptively simple being the ratio of the difference in temperatures (where heat is extracted and heat is rejected) in the system, scaled to the highest heat extraction temperature of the process. At zero degrees K heat rejection.. any temperature above zero results in 100% thermal efficiency.

However, any real system struggles to get a significant fraction of that "theoretical efficiency".

As this discussion thread (and a host of others before it) has been exploring, the fusion processes we know anything about, are far away from the efficiency indicated by simple theoretical numbers.

With thermal efficiencies as a comparison, fusion is a number of orders of magnitude below the lowest efficiencies of engines and other mechanical gadgets.

I think we are all talking about WHY this is so.

The actual answer is again remarkably simple to state. Fusion efficiencies are low because it doesn't happen very often, out of all the times we throw particles at each other. Well.... Duhhh.

But this is true. We sling coulombs worth of Deuterons at each other..and get a million or so to fuse. That's a ratio of 1 million, out of a million, million, million. (American millions here.. = 1E6) So the actuall efficiency of the basic process is simply 1 out of a million million.. or 10^-12.

Nothing new here... we all know this. But this IS where the answer to "What to do" lies.

See the guy in the baggy sweater over there in the lab corner? He's from the basic physics crowd..."Psssst...Shouldn't you raise the yield?" He's not DOE, DOD, or Gummint anything.. He represents the simple minded questioner...who sees what we're trying to do.. and is not wound up in politics, or vested interests. Just objective science.

We are discussing what's wrong, when our batting average about 0.00000000001%.
If you were coach...what would YOU recommend for this "hitter" or YOUR team?

A couple options leap into mind:

1. Trade him!! Well okay that IS an option.. But who do you have in mind to replace him? Another 0.0000000000001% hitter? OR

2. Teach him how to hit!! Hey with an average like that....there's only ONE way he could go.... UP.

In fusion parlance, increasing the batting average...means not... MORE TIMES at BAT, but MORE HITS per TIME at BAT. You can give your awful hitter more opportunities at the plate, (at practices) but if that doesn't improve his hitting probability, then you need a new strategy.

The various containment schemes polythisorthat, electrostatics and etc. are all the same... scheme... really. They throw lots of baseballs thinking the "hitter" is bound to hit something... which is actually TRUE. But energy efficiency is not improved by this technque. And that's what we have to do if fusion is to become a practical source.

So where to go? Keeping building ever more ingenious fusors? Nothing wrong with the education this provides. Wonderfully simple way to get into understanding, plasma, vacuum, high voltage, instrumentation, machine tools, welding..and so on...This for our increasingly sedentary society is a great therapy. But it's only the first stage, not the end of the energy discovery process ,and it's a terrible waste of tax dollars, since the folk employed in these behemoths are supposedly already knowledgeable and triained. One must ask "WHY ARE THEY DOING THIS, STILL?"

We need to find a way to get a much higher percentage of fusion "at bats" producing fusion "hits". The batting average needs to go up orders of magnitude.

How to do that is not perfectly clear to me... But I am reasonably certain that new ionizers and electrode configurations are too gross to address the basic problem.

And there may more than one problem.

First off, in the fusors, we the pitcher are throwing bazillions of baseballs in the general direction of homeplate. The batter is somewhere in there swinging and mostly missing. A first level improvement might happen if the pitcher could actually find home plate. (Clearly this is not a real ball game since the batter and pitcher would be on different teams.) There are several folks in our midst working in that stadium.

So, step one... get the ball over the plate.

Step two, then follows. If the batter is not now under a huge hail of baseballs coming from everywhere, perhaps he can learn how to hit. All the metaphors apply here.

There is one caveat to be noted. We do not actually know what the fusing probability (batting average) is for perfectly thrown atoms. We've talked about "cross section" and there are numbers in the literature. How is this data obtained?

By throwing things at each other.. and recording the scattered pieces. The question to ask here is this: Does this approach have anything at all to do with what we need to do? Maybe, maybe not

What we need to know, is this: If we place two atoms "close enough" together how long do we have to wait for them to fuse, and how often will do other things, first?

If two atoms placed side by side with their exterior cores "touching" (some portion of their nuclear wavefunctions adjacent, intermingled, whatever)....how long must they remain there for fusion to occur? Is fusion inevitable? Is it within a small or large number of wavefunction oscillations...(whatever that might mean)...Does it actually require more than two nucleii before it can happen at all?? Maybe it takes N nucleii all together to get one pair to fuse...??? This clearly affects yield energies.

I don't know any of the answers or how to do this last experiment. I doubt if it has ever been done by anyone, yet... But we DO have people at various labs... National and otherwise.. who have atomic scale manipulators and can build structures atom by atom. Perhaps the approach to answer this question lies here in atomic scale manipulation, not high power ion slinging. Furthermore piezomanipulators are out and about. and prices are coming down, and you can make your own. Think... stereo, and microphones... and the base material suppliers.

End of discussion... for now... Just ideas to chew on...

Dave Cooper
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Steven Sesselmann
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Re: Have ANY projects got a future?

Post by Steven Sesselmann »

Chris,

We should get together a list of ideas that "Should" be tried.

And then we can cross off those items that have been tried and that did not work.

This would save some of the repetitive work that is being done.

Steven
http://www.gammaspectacular.com - Gamma Spectrometry Systems
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Re: Have ANY projects got a future?

Post by Steven Sesselmann »

Reply to: viewtopic.php?f=16&t=7428#p53943

Dave,

This was well written, and does indeed see through some of the smoke.

I would like to make one more point...

With the Fusor, we are creating a potential energy well (PEW), using electrostatic fields, and to maintain this well, we need to input a continuous amount of energy, and this is why we clock up such high losses.

In theory, at least, there is no reason why it should require any energy to hold a potential energy well open. Energy is required to open the PEW in the first place, but not to hold it open.

The losses that are being measured are leaks!

A second factor that would be an essential factor to successful energy gain is, that in the bottom of a PEW, fusing atoms suddenly move towards eachother, small distances, but huge velocity. This coalescing has the effect of further lowering the potential in the center. Create enough fusions in the centre of a potential energy well, and your batting average will be vastly improved.

The dueterium atoms will fuse, like water down the bath drain!

Steven

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Re: Have ANY projects got a future?

Post by 001userid »

One idea that I have been looking at for several months, involves superconducting ions. It is another out on a limb idea, but it makes alot of sense.

If superconducting electron paths can be made at room temperature, why not superconducting ion paths?

The path of a pitch is defined in solid state. No vacuum is required to maintain a mean free path, as this is also defined in the solid state.

I see two options in the configuration, either crossing paths or various paths converging on the same point. There is very little information on the subject of ion conductivity. Where to start?

Joe Sal
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Re: Have ANY projects got a future?

Post by Dan Tibbets »

I had abandoned this thread earlier, but after rereading the post below and thinking about it I cannot resist giving some counter arguments to the ' polywell is BUSTED ' arguments.

----------------------------------------------------------------------------------------------
From Frank S.-
"Please explain to me that if all the deuterium or any other fuel that you choose is FULLY ionized and traveling at 100 kv and there are no electrons for any loss, how can even this be anywhere near break even no matter what the size?

I also just did a quick calculation on the maximum theoretical energy output from a 3 meter diameter polywell device. There are 14,000 liters which is 3.8 E 26 atoms at 10 mtorr. Assuming ~3 MeV per fusion or 1.5 MeV per atom, that gives 390 MW. The theoretical calculation you reported was 100 MW. This is frightfully close to the theoretical physical law breaking reality of the universe. That is tough to accept. This also assumes a 100% full and complete turn over of all of the spent fuel and 100% new fuel every second without fail. On top of that, how can this scale to the power of 7??? It is already nearly at the theoretical maxium for the energy contained in an atom.

Hell, in an atomic or hydrogen bomb the efficiency of mass conversion is only fractions of a percent of the starting materials and you think polywell will surpass this too by orders of magnitude as you have reported?

Call me pig headed but I am not seeing it. Way too much pie in the sky and outrageous and unsubstantiable numbers are being thrown around. There is no way in this universe that any of this can even be close to the truth. Look at the facts guys, I say the polywell myth is BUSTED! "

Frank Sanns
--------------------------------------------------------------------------------------------------------------------------------------------------------------------

Concerning the energy yield per fusion:
A more accurate and complete assessment of the possible energy yield per D-D fusion is described in this quote from page 7 of this pdf

http://www.askmar.com/Fusion_files/EMC2 ... plants.pdf

"The result of these observations was that the average
energy of one net DD reaction could be made to vary
from the low value of 3.65 MeV arising from the basic
DD fusions alone, to 10.24 MeV for burn of the 3He
directly produced "DD 1/2 cat, to 14.63 MeV for additional
burn of the 3He resulting from decay of the tritium produced.
Capture of the neutrons from the neutron branch of the
associated DD reactions could also add energy to the plant
system, through their use to cause fission in a 10B loaded
blanket,,,"

You only considered the energy contribution from the neutron produced. You also have to include the kinetic energy from the proton, helium 3 and/or tritium that are produced. And, as described above, recycling the appropriate fusion products can yield even higher yields from the 2 parent deuterium atoms.


Concerning the density of the ions, given as 10-5 torr (10 microns), is uncertain I think. Certainly the vacuum outside the magnets is low, I'm uncertain what the average density inside the coils is, but it is presumably more. The ions are injected into the interior via an 'ion gun'. There have been estimates that the density at the focused core approaches 1 atmosphere as the ions converge and pass through the center region. Also, the volume you gave is true for a sphere, but the actual volume would be slightly to moderately more depending upon how many magnets end up being used. WB6 and 7 were truncated cubes. In any case the ions are confined to a smaller volume within the magnets (Magrids), so I'm uncertain what the actual effective volume would be. 14,000 liters is probably a good ballpark figure. At one atmosphere (STP) there are 6.02 E 23 gas molecules in 22.4 liters, so in 14,000 liters there would be 3.7 E 26 molecules ( or in this case ions) . Assuming 10 micron pressure (~1/100,000th of an atmosphere) there would be 3.7 E 21 ions present (round up to 4 E 21).

The comment that the D-D reactions only converts <1% of the mass into energy is given. I'm uncertain about your energy yield for the complete (100%) conversion of matter though. Complete conversion of two deuterium ions would yield ~ 4,000 MeV. I based this on the rest mass of the electron, which is 511,000 eV, and since protons and neutrons are ~ 2,000 times heavier...
Converting electron volts to Joules taken from this site-

http://www.unitconversion.org/energy/el ... rsion.html

gives ~ 2 E -19 Joules = 1 eV. So 4,000 MeV would give ~ 6 E -10 Joules, which over one second would give the same number of Watts. Adjusting your estimate for the numbers of atoms in the 3 meter Polywell to 4 E 21 (see above) atoms/ions in the machine at any given time, divided by two (pair of deuterium atoms per reaction) gives a total of ~ 2 E 21 reactions possible.
2 E 21 reactions X 6 E-10 Joules per reaction gives 1.2 E 12 Joules, and over one second that would be 1.2 E 12 Watts, or 1,200 Gigawatts. One of us is off in his calculations. Using the fusion yield instead (~ 4 MeV per reaction) gives a result of ~640 Megawatts.
As a check, plugging numbers into this calculator to get 2 E 21 fusions per second yields ~ 1.8 Gigawatts.-

http://www.beejewel.com.au/research/fus ... ulator.htm

Mm... this is ~3 times higher than my calculation. I'll assume its's more accurate, so ~ 1/20th of the ions present would have to fuse per second to give ~ 100 Megawatt output.

Is this rate reasonable? The lifetime of an electron in the WB6 has been reported as ~ 0.1 microsecond, in which time it makes ~ 100,000 transits. Assuming the ions have a similar lifetime, and makes a thousand or more transits in that time, and using the often claimed need for 10,000 transits for a reasonable chance for a fusion reaction to occur, then things would balance out well. Guessing that the density is higher and that the number of transits made by an ion is greater would relax the conditions further. Keep in mind that the electron and ion losses are replaced so the numbers involved would be steady state.



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Re: Have ANY projects got a future?

Post by Frank Sanns »

The atoms do not anhailate, the just fuse and the energy that I quoted is correct. All of the other energy that you talk about was waste input energy or at least non fusion productive energy so it should not be counted twice.

Secondary nuclear ash will burn but its build up rate is really slow and it will not be a significant part of the equation.

I will not be so bold as to say busted but I do not see any significant changes to think it would be anything other than pie in the sky.

Frank Sanns
Achiever's madness; when enough is still not enough. ---FS
We have to stop looking at the world through our physical eyes. The universe is NOT what we see. It is the quantum world that is real. The rest is just an electron illusion. ---FS
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Re: Have ANY projects got a future?

Post by Dan Tibbets »

No, annihilation energies are not relevant, but you included them in your post so I included both, with hopefully accurate yields, for comparison. Your claim that annihilation only produced a few 100's of MeV for the number of aviable atoms is way off based on my included calculations. So argument from that standpoint is negated (assuming my calculation is more accurate).
Actual energy yield for the two dominate DD reactions yields an average of 3.65 MeV per fusion, so by rounding down to 3 your calculated results for the aviable fuel fusion calculation was low by a factor of 1.2. And, it was significantly below both my calculation, and the source I referenced.
The nuclear ash recycling is just that. The high speed fusion products quickly leave the reaction space with minimal chance of reacting with a deuterium on the way, and fly to the walls, where they give up there energy as heat, etc. The He 3 and tritium would be recovered in the vacuum pump exhaust gasses , processed and reintroduced as new fuel.
This might or not be economically viable if the system works at all, but it does allow you to recover more energy if the base DD reaction is only providing marginal gains (or losses) and the radioactive tritium would need to be isolated and used or stored in any case.


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Chris Bradley
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Re: Have ANY projects got a future?

Post by Chris Bradley »

I think there are things that could be said about either calculation, your respective two taking on 'opposing' ends. In reality, no, I don't think it is reasonable to presume you're going to consume 1/20th of the reactor fuel per second. This is a couple of orders of magnitude better than tokamaks yet we're talking about a device that hasn't yet *proved* a single fast-fast neutron according to the 'advertised' details.

Also, you realise you are saying that you are going to be able to fully populate the volume of the reaction vessel by material injected by ion guns alone, in 20 seconds! That full mass of material passes through the ion guns to displace what is already in there? 20 seconds....hmmm...4E21 ions/20s = min. 32 Amp ion guns. Has that ever been achieved before?

Sure, you can go thru the calcs and if you believe that Polywell really can generate a continuous multi billion kelvin central ball of reaction volume at 1 atmosphere without any neutrals or other contaminants therein, then you *could generate* the numbers being talked about here. But that's a heck of an *if* without some real, substantial, repeatable, traceable, verifiable diagnostics and results, plus real evidence of the confinement time of the ions (that is, total energy confined/power loss, not this figure for electrons).

The other part which needs to really get some evidence behind it is how well you're ever going to make use of the T and 3He. JT-60 has run DD up to a point that, theoretically, it could've exceeded net if it had been running DT (it's not set up to do so). Yet even when it was running DD so well, it still didn't 'self-generate' enough T to actually make *much* of a difference to the overall neutron output.

So, Dan is probably right if you believe in atmospheric-pressure billion-K reaction volumes devoid of any contamination and driven by multi-amp ion guns, but Frank provides the reality check.

Frank S. wrote:
> I will not be so bold as to say busted

Stop backtracking, Frank! You've already stated a view, stick to your guns! It's for someone to prove you're wrong, not the other way around. Let's see the colour of those Polywell neutrons, then those of us who couldn't foresee Polywell's greatness will all happily backtrack and shall confess "mea maxima culpa".
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