Pyroelectric fusion (the other "cold" fusion)

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CharlesKramer
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Pyroelectric fusion (the other "cold" fusion)

Postby CharlesKramer » Sat Feb 06, 2010 9:55 pm

One of the possibilities raised by the Navy's recent revelations about cold fusion (or, if you prefer, LENR) is:

- the Pons/Fleishman type experiments that *do* generate heat sometimes maybe are nuclear (neutron generating, element transmuting)

- maybe such reactions are no big deal -- occurring in nature with such low levels of energy output and neutron emission that no one notices.

I recently read about a kind of fusion that maybe has been kicked around here (I didn't search) but it seems not to be discussed anywhere very often: Pyroelectric fusion

If I understand it, UNLIKE LENR

--- Pyroelectric fusion is a proven thing -- reliably reproducible

--- Pyroelectric fusion it is proven to be nuclear (measurable neutrons)

--- so far no one is talking about Pyroelectric fusion as an energy source. A source neutrons, maybe, in a small way

Like LENR of the Pons/Fleishman type, Pyroelectric fusion is low energy, countertop small science. Strictly speaking in requires heat, but it's still a "cold" reaction compared to ITER, NiF, or Polywell for that matter.

Pyroelectric fusion seems to have been proven since at least 2005, but work didn't stop then.

[1] http://en.wikipedia.org/wiki/Pyroelectric_fusion

[2] Nanotoday June 2009
Enhanced pyroelectric crystal D–D nuclear fusion using tungsten nanorods
SUMMARY: Thin films of vertically aligned tungsten nanorods were used to enhance field ionization in pyroelectric crystal D–D fusion experiments resulting in increased neutron production. The tungsten nanorods were deposited on a single LiTaO3 crystal using sputter deposition at glancing angles. The combination of a single tungsten tip with a thin film of nanorods on the face of the crystal yielded about four times the number of neutrons than did either a single tip or nanorods alone.

[3] http://www.scienceblog.com/cms/ny_team_ ... 10017.html

NY team confirms UCLA tabletop fusion 13 Feb 2006

chrismb
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Re: Pyroelectric fusion (the other "cold" fusion)

Postby chrismb » Sat Feb 06, 2010 10:39 pm

CharlesKramer wrote:I recently read about a kind of fusion that maybe has been kicked around here (I didn't search) but it seems not to be discussed anywhere very often: Pyroelectric fusion

If you want a small compact and low flux neutron source, sure, that seems to work out. But no chance for 'over-unity' - too many electrons spoiling the party.

CharlesKramer
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Re: Pyroelectric fusion (the other "cold" fusion)

Postby CharlesKramer » Sat Feb 06, 2010 11:12 pm

chrismb wrote:If you want a small compact and low flux neutron source, sure, that seems to work out. But no chance for 'over-unity' - too many electrons spoiling the party.

I believe even those pursuing pyroelectric fusion agree with you.

What I find curious is pyroelectric fusion appears to be the first proven (reproduced and now even improved) Low Energy Nuclear Reaction -- or, put another way, the first proven cold fusion. It just happens to be totally unrelated to the Pons/Fleischmann/SPAWAR messing about with paladium & heavy water.

Doesn't that make pyroelectric important? Doesn't it make more credible that the Pons/Fleischmann effect might also be nuclear? And also more likely that Pons/Fleischmann even if nuclear will never be more than a curiousity (unlike pryoelectric, not even a meaningful neutron source)?

Hey, I got an "A" in physics in 10th grade! Many decades ago, and no physics classes since. But I'm curious if any of the many people here who do have physics chops agree that pyroelectric fusion is under-appreciated, and maybe Pons/Fleischmann is over appreciated.

Or is there some fundamental reason why the energy output of pyroelectric fusion is likely always to be fundamentally trivial or negative, but Pons/Fleischmann energy output could someday be useful (not just as a curious puzzle)?

C

MSimon
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Re: Pyroelectric fusion (the other "cold" fusion)

Postby MSimon » Sat Feb 06, 2010 11:18 pm

CharlesKramer wrote:
chrismb wrote:If you want a small compact and low flux neutron source, sure, that seems to work out. But no chance for 'over-unity' - too many electrons spoiling the party.

I believe even those pursuing pyroelectric fusion agree with you.

What I find curious is pyroelectric fusion appears to be the first proven (reproduced and now even improved) Low Energy Nuclear Reaction -- or, put another way, the first proven cold fusion. It just happens to be totally unrelated to the Pons/Fleischmann/SPAWAR messing about with paladium & heavy water.

Doesn't that make pyroelectric important? Doesn't it make more credible that the Pons/Fleischmann effect might also be nuclear? And also more likely that Pons/Fleischmann even if nuclear will never be more than a curiousity (unlike pryoelectric, not even a meaningful neutron source)?

Hey, I got an "A" in physics in 10th grade! Many decades ago, and no physics classes since. But I'm curious if any of the many people here who do have physics chops agree that pyroelectric fusion is under-appreciated, and maybe Pons/Fleischmann is over appreciated.

Or is there some fundamental reason why the energy output of pyroelectric fusion is likely always to be fundamentally trivial or negative, but Pons/Fleischmann energy output could someday be useful (not just as a curious puzzle)?

C


It is no more low energy than poping a few neutrons into U235 is low energy.

In fact it is higher energy than shooting thermal neutrons into U235. Coulomb forces need to be overcome.
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CharlesKramer
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Re: Pyroelectric fusion (the other "cold" fusion)

Postby CharlesKramer » Sat Feb 06, 2010 11:44 pm

MSimon wrote:Coulomb forces need to be overcome.

If achieving fusion necessarily means overcoming Coulomb forces, then pyroelectric fusion *does* that -- since it achieves fusion, and at very low temperatures (heating a crystal from −30°C to +45°C over a period of a few minutes).

The Pons/Fleischmann reaction, in comparison, may not overcome Coulomb forces (since whether that reaction is ever nuclear is unknown).

One funny result is cold fusion *has* been proven -- it just happens to be pyroelectric, and unrelated to Pons/Fleischmann/SPAWAR.

Btw, is a 2.45 MeV neutron (what pyroelectric fusion generates) a "heat" neutron, or high energy neutron? I assumed it was a heat neutron.

Excerpt from Wikipedia below

CBK

http://en.wikipedia.org/wiki/Pyroelectric_fusion

The novel idea with the pyroelectric approach to fusion is in its application of the pyroelectric effect to generate the accelerating fields. This is done by heating the crystal from −30°C to +45°C over a period of a few minutes.

A UCLA team, headed by Brian Naranjo, conducted an experiment demonstrating the use of a pyroelectric power source for producing fusion on a laboratory bench top device in April 2005. The device used a lithium tantalate (LiTaO3) pyroelectric crystal to ionize deuterium atoms and accelerate the ions towards a stationary erbium dideuteride (ErD2) target. Around 1000 fusion reactions per second took place, each resulting in the production of an 820 keV helium-3 nucleus and a 2.45 MeV neutron. The team anticipated applications of the device as a neutron generator, or in microthrusters for space propulsion.

A team at Rensselaer Polytechnic Institute, led by Dr. Danon and his graduate student Jeffrey Geuther, has confirmed and improved upon these experiments using a device using two pyroelectric crystals and capable of operating at non-cryogenic temperatures.

MSimon
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Postby MSimon » Sat Feb 06, 2010 11:51 pm

If achieving fusion necessarily means overcoming Coulomb forces, then pyroelectric fusion *does* that -- since it achieves fusion, and at very low temperatures (heating a crystal from −30°C to +45°C over a period of a few minutes).


You are confusing low energy input with low energy of reaction.

The heat is used to generate high voltages. High voltages = hot fusion.

For instance suppose I use a thermoelectric generator and step up the voltage to 50KV (essentially what is happening) is it really a low energy reaction?
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CharlesKramer
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Postby CharlesKramer » Sun Feb 07, 2010 4:36 am

MSimon wrote:You are confusing low energy input with low energy of reaction. The heat is used to generate high voltages. High voltages = hot fusion.

I see your point that at the spot where fusion occurs there may be high energies ("an electric field of about 25 gigavolts per meter to ionize and accelerate deuterium nuclei into an erbium deuteride target. Though the energy of the deuterium ions generated by the crystal has not been directly measured, the authors used 100 keV (a temperature of about 109 K) as an estimate in their modeling").

But it would seem to be "cold" in the sense it's a desktop event -- no containment, no tremendous pressure. I don't know if there is any shielding to block neutrons.

Maybe Fleishman/Pons, and pyroelectric fusion should be called desktop fusion.

For what it's worth, I am not the first or only person to characterize pyroelectric fusion as "cold" fusion. Example below. Muon catalyzed fusion is also sometimes characterized as "cold."

CBK

http://en.allexperts.com/e/c/co/cold_fusion.htm

The popular press sometimes use the term "cold fusion" to describe "globally cold, locally hot" plasma fusion that occurs in table-top apparatus such as pyroelectric fusion."Coming in out of the cold: Cold fusion, for real", CS Monitor, June 06, 2005

Another form of cold fusion is muon-catalyzed fusion; unfortunately, the muons it uses require too much energy to create and have too short of a half-life to make the process practical for energy generation. Neither pyroelectric fusion nor muon-catalyzed fusion are presented further in this article.

chrismb
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Postby chrismb » Sun Feb 07, 2010 10:49 am

What you are describing is the ignorance of the media, not a legitimate scientific description of pyroelectric fusion as 'cold fusion'... I mean, look at the words.. 'electricy' and 'fire'!

'Electric fusion', a phrase I am beginning to adopt, I think more appropriately reflects the nature of these techniques because an electric field can accelerate an individual fusible ion to fusible energies, but an ion cannot have a temperature because temperature is a bulk property.

An ion on its own, can be neither hot nor cold. Yet electric fusion is about the individual behaviours of individual ions so isn't really hot or cold.

So, to have called this 'cold fusion' is a media invention of phrase.

Muon catalysed fusion certainly is 'cold'. In a very real sense because it is best done at liquid deuterium/trituim densities, thus at cryogenic temperatures, let alone room temperature. 'Cold fusion' in an electrolysis cell is, literally, 'very hot' by comparison and is well above D boiling point!

Stoney3K
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Postby Stoney3K » Tue Feb 09, 2010 11:59 am

chrismb wrote:So, to have called this 'cold fusion' is a media invention of phrase.


From the media's POV, any fusion that's not 'promised' to work (in practice: anything except toks) is called "cold fusion", possibly to emphasise the negative urban-myth load it has.

Sadly enough, experiments that actually have real physics behind them fall in this category as well, as far as the reporters and TV stations are concerned. Maybe that's one of the reasons we need to push Polywell to the media with this enormous amount of effort.
Because we can.

ohiovr
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Re: Pyroelectric fusion (the other "cold" fusion)

Postby ohiovr » Mon Mar 06, 2017 2:31 pm

Yeah, it is hot fusion, and it doesn't make a heck of a lot of fusion events. But I wonder if you accelerated H ions instead of deuterium, and you used a lead target, could you get some decent spallation neutrons from such a setup?


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