Farnsworth Questions

Reflections on fusion history, current events, and predictions for the 'fusion powered future.
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Nicolas Krause
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Farnsworth Questions

Post by Nicolas Krause » Sun Mar 15, 2020 1:03 am

I think the most interesting aspect of Richard's historical descriptions are when the device does not behave as expected. In the beginning Farnsworth had an idea about how the device operated, it was incorrect, and by reversing the polarity of the power supply, some fusion was obtained. The later descriptions, of transparent ion beams and overexposed radiation badges are also deeply intriguing. I'd like to begin by asking about the hole burned through the vacuum chamber. Is there a plausible mechanism for operator error that could have caused such a problem? For example if the ion beams were set too high could they have burnt a hole through the chamber? I presume if there was some failure of the main power supply, it simply would have melted the whole device, not burnt a hole in a spot.

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Re: Farnsworth Questions

Post by Richard Hull » Sun Mar 15, 2020 5:08 am

Today's fusors are rather thick walled .0625 and are deep dish hydro formed. The Farnsworth systems were spun from thinner metal for the most part. If the guns were set to high power, especially at a deep vacuum, ...And, they pumped deep as witnessed with the ion pumps. It is easy for the mean free path to be long enough so that full energy ions would impact and heat the thin metal walls so that at some point, the vacuum would drag a hole into the fusor.

Both Gene Meeks and George Bain told me that punctures did occur and a close look on some photos, show a little weldment or patch to fix these holes. With the guns in some models finely aligned, Gene noted that they would burn an off center hole in the extractor plate of an opposite gun.

They drove the guns hard and a typical run pressure as noted in some of the runs seen in the attached graphs, (of which there are many I did not post images of), were on the order of just a few microns at 100keV applied. To warrant significant ion-ion beam interaction in the center they maintained a significant mean free path by running at low pressure and high gun currents.

Asking questions like this related to my histories is good as I can expound on specific issues and some nuances that are not dealt with as fully as the questioning minds here might thoughtfully wonder about, as Nicolas has. I hope I have dealt with his question well here.

I would have to check my notes but I was told of at least 4 catastrophic punctures, which really caused internal arcing, oil diff pump flash boilings and general system wide mayhem before power to the device could be removed. At some point Gene installed a "Crash all power Kill" mushroom button on both the Pit and Cave control systems.

Richard
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
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Frank Sanns
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Re: Farnsworth Questions

Post by Frank Sanns » Mon Mar 16, 2020 10:39 am

Early on with work here on fusor.net, there was discussion about these runaway events. So much so that I did a calculation to see what would happen if all of the deuterium in my chamber actually all fused at once. The physical force would have been about like an M-80 firecracker. The neutron flux would have been on the level of the Slotton incident with the Demon Core. Serious stuff for sure. My first experiments with the fusor were thus with air and not deuterium. Only after some experience and more info on the run a ways from Farnsworth days did I crank up the power and start to push deuterium and higher powers. Still to this day though, I always wear a dosimeter when I am running my fusor or visiting a person running theirs. Just in case some anomaly does occur.

It was concluded that the run a way reactions were really not fusion run a ways but rather power supply run aways. The power supplies were quite beefy and once a fusor got to really rolling, things started to get hot and sometimes very hot. Thermionic emissions would escalate, reduce the series resistance, and create an ever and quickly increasing path for the current to flow. The large power supplies were not current limited so they could deliver a great deal of power to the innards of a fusor that had to terminate somewhere. It is my belief that the large input power spikes were responsible for the chamber melt throughs. Couple this with the lack of activation of the metals that everything around the fusor and lab were made of never because "hot" to their Geiger counter. A neutron excursion sufficiently large to generate that level of heat, would have been sufficiently large to significantly activate metals in the chamber and power supplies as well as supports.

This past January, I had the opportunity to partially disassemble and exam the cave fusor with Jonathan (Farnsworth) Moulton. I was aware of the reports of visible beams coming from the ion guns during my examination so I kept that in mind as I looked at each component and chamber geometry. The very first thing that I noticed about the chamber was that MANY of the insulators for the ion guns had loose insulators. The insulators were floating between metal end cups. This seemed very strange to me and while some were physically broken by handling over the decades, others were just not integral to the metal as a vacuum feedthrough would be.

The ion gun feed throughs were very small compared to the HV voltage insulator on that fusor or on most of our fusers. This surprised me a bit considering the current that they had to carry for the beefy filaments within the ion guns. The wire that was coaxial within the insulators was also not very thick. It was maybe 10 gauge (rod) wire perhaps. I should have measured it precisely but there was much else to discuss and look out so those multiple days just slipped by with other relevant items of interest.

The point is that high voltage needs large insulators for hold off voltage and small diameter wires within the insulator as currents are low for any given power. Power = Volts x Amps. High voltage means not many amps needed. On the ion guns though, that is reversed. For a given power input, the volts are low and the currents are high. The conductors within the insulators need to be robust to carry those currents. In an thermally insulated environment like inside of a ceramic insulator, heat dissipation is not going to be the greatest. Running high power 40 amps+ through a 12 gauge rod is going to heat the conductor and perhaps quite significantly. It is my believe that on the high power fusor runs, that the inner conductor of the ion gun insulators may have been starting to become thermally incandescent. That dull red glow would diffuse though the ceramic insulator and be externally visible. More evidence of this was the fact that multiple beams were seen emanating from the ion guns. There are multiple insulators on each of the guns so believe this a plausible explanation.

None of us were actually there for these events but circumstantial evidence like robust power supplies that were not current limited, or lack of evidence (like no neutron activation) suggest that no new physics was occurring there. There will, of course be those that think something supernatural occurred with some of these events and they in fact may be right. Like I said, none of us were there and the level of instrumentation to properly account for the events was not in place at the time.

Please continue the discussions on this matter here. We should all add our thoughts to see what else might be plausible explanations.

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Re: Farnsworth Questions

Post by Nicolas Krause » Mon Mar 16, 2020 2:59 pm

Hi Frank,

If I understand your descriptions correctly, it would seem the simplest way to think about the Fusor would be as a resistor in series with a power supply. When damage to the chamber occurred it was due to some sort of thermal runaway event, basically like putting a 0.5 W resistor in to a circuit with 1W of power and being surprised when it goes up in smoke.

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Re: Farnsworth Questions

Post by Frank Sanns » Mon Mar 16, 2020 4:38 pm

The short answer is yes.

The more in depth answer is that the fusor is complex. It acts as a series of resistors that change with vacuum level, voltage, and current. They are all intertwined and dependent upon each other.

Where there is a thermionic run away, the increasing flow of electrons effectively reduce the resistance of the path. It would be like having a variable resistor set to 100,000 ohms then cranking it down to 20 ohms. The current would just build and build as the resistance falls.

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Re: Farnsworth Questions

Post by Nicolas Krause » Wed Mar 25, 2020 3:32 pm

Thank you for the clarifications and responses! Are there any records of the direction the research intended to go had funding been maintained at ITT or if Farnsworth had been able to make his company a going concern? I've read the paper Robert Hirsch authored about the fusor research, but beyond that, if he'd been able to pursue further developments did he have any ideas about modifications to the fusor he would have liked to investigate? Did Gene Meeks mention anything similar? From Richard's descriptions of Farnsworth he seems to have had a million ideas, have any of his ideas for future iterations survived?

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Re: Farnsworth Questions

Post by Richard Hull » Wed Mar 25, 2020 10:18 pm

All great questions, but rather contestable from many quarters. Ultra Farnsworth dream boosters might say that they were on the cusp of a breakthrough, but were cutoff at the knees. The naysayers, like myself, genuinely believe that they (ITT and the Farnsworth team) had wrung this thing out about as far as it would go, at that time.

Now to your specific questions. I got no real feeling from Hirsch or Meeks that they had the rug pulled out from under them at a critical moment. Hirsch did note that when he became head of the AEC thermonuclear effort, he tried his best to get a small program going on the electrostatic confinement fusion. Unfortunately, he had already "killed" 3 sacred programs left over from Sherwood. 2 mirror programs and the stellarators! He made a lot of high-end fusion enemies. He admitted that this had many in the AEC, poo-poo any attempt to start a small version of the old ITT effort at two universities. Both universties were willing to take it up if federally funded. It did not happen, of course. Hirsch admitted that he still held out that all aspects of the work had not been investigated. This is not my impression, these were from Bob's own mouth.

Who knows where Phil's brain was at PTFA. I am unaware of a group of notebooks or a filing cabinet full of Phil's ideas on fusion from which we might try to glean some insight into his thoughts. Many of his modern day supporters believe that his ideas were never investigated in their purest form. The best among them, who are qualified to question whether the purity of his work was ever really tested, are currently more focused on recovering lost energy that exists within the fusor. Unfortunately, such efforts are purely speculative and not one hand has been lifted to do the work among the hopefuls.

There are so many supposed "forgotten geniuses" that promised much and who were just secretive enough to leave long lingering questions with their passing. Farnsworth is but one. Tesla is another, T.T. Brown and many others of this venue have adoring followers and virtual cults formed around the more bizarre claims that never saw any development by their object of adoration.

We are where we are in IECF and the fusor work. What might be considered more advanced work in the field, in the interim, might best be summed up as being that of the University of Illinois and the University of Wisconsin. None have seen a significant advance, being pretty much long running student research efforts. Admittedly, they have really pushed the envelope with a number of innovations, but none have moved forward to any significance so far as fusion energy is concerned.

In Summary: I have no idea related to Phil's thoughts, before, during, or after the ITT program. I have no reason, based on extended discussions with Meeks and Hirsch, that they felt they were on a directed path towards great improvements in 1968 at the end of the project. Hirsch, as of 1999, still loved the idea of more research on IECF. For me, IECF is more or less a dead duck for power-ready, controlled fusion. It is the easiest and least costly way to actually do fusion, of this, there is little doubt. This is why I continue to pursue it.

Richard Hull
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Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Re: Farnsworth Questions

Post by Frank Sanns » Thu Mar 26, 2020 12:36 am

Having been on the team that had the opportunity to examine the Farnsworth archive this past January, I have to say that there was much more there than what has yet been reported. Most of it was other technologies that include heavy metal removals, water purification, lasers, and other items. These materials will be released once it is all compiled and put into a form that digestible by those that that view it.

Related to fusion, there were some interesting drawings and configurations that for whatever reason, never came to fruition. Some of them were technically interesting. Yes, energy recovery and recirculation were some of them but the actual focusing of the beams to locations at will is a very interesting concept. It is also interesting that it was taking inside of a large volume space that was essential a spherical drift chamber.

At the time, the ion guns were archaic compared to developments over the last 50 years so they fought with them to get them balanced. Today, those kinds of experiments and the instrumentation would make studies far easier.

Do I think there is more work there to be done? Yes, absolutely. Do I think it will have a Q much greater than 1, maybe, but I doubt it. From the devices and drawings that I saw, I think, if nothing more, some good studies could shed light on some of the phenomenon that we see in our fusors.

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Re: Farnsworth Questions

Post by Richard Hull » Thu Mar 26, 2020 3:57 am

Pem, in her book touches on some these lofty Eco-friendly efforts that Phil dreamed of to be encompassed by PTFA. Unfortunately zero traction was gained by any of them to bring in the much needed cash to keep the store open. Lofty and laudable goals with no money behind them never feeds the bulldog to keep him at bay. I have seen a number of the letters of some desperation fired back and forth between PTFA and various entities. In them, PTFA is looking for contracts, opportunities and funding. These PTFA letters are typically answered with great delicacy, but ultimately refusing either interest or funding. Some returns do express great interest, especially the Air Force, but fain no funding exists "at this time".

The world moved on without PTFA and usable nuclear fusion energy.

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
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Nicolas Krause
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Re: Farnsworth Questions

Post by Nicolas Krause » Thu Mar 26, 2020 3:55 pm

Hi Frank,

What exactly is a spherical drift chamber? I haven't come across that term before.

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