New Home for Doug's Fusor

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John Futter
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Re: New Home for Doug's Fusor

Post by John Futter »

Bob go back to those vids I posted recently
the first vid shows a run and at the end the silver is taken out of the oven (guesstimate of 15" or more from the neutron producing plasma) and put on the counter starts at 2000 counts per sec and falls away
there is a break near the end (red trace) [gammas] the trace green is zero (neuts) then the red trace pops up again as the silver decays away
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Bob Reite
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Re: New Home for Doug's Fusor

Post by Bob Reite »

First of all, Doug's fusor is not currently fully configured for "Gonzo Mode". The only piece of it is the inductor in series with the main gird HV feed. I'm just operating it as a standard Farnswroth fusor at this time, albeit with an ion grid, which does help with starting the plasma and being able to use lower gas pressure.

All operation is done by remote control from 100 feet away, yes this takes more time but much safer.

However I am considering the purchase of a fresh bubble detector to recalibrate the REM ball if nothing else.

Background count at my site is on the high side. The Victoreen 493 reports 100-150 CPM both in the office (the control point) and the fusor shed.
The CDV-700 shows a more believable 10 counts per minute. No idea why the Victoreen reads so high. Don't think that I have alpha particles floating around. Disconnecting the probe gives a zero reading, so it's not something arcing in the electronics.
The more reactive the materials, the more spectacular the failures.
The testing isn't over until the prototype is destroyed.
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Mark Rowley
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Re: New Home for Doug's Fusor

Post by Mark Rowley »

Bob, I know you have not switched on the Gonzo Mode electronics, but even in standard fusor mode the cited numbers aren't in alignment with the hints of activation that was spoken of in the last paragraph in the July 13th post.

My reference to Gonzo Mode in the last post was only to highlight the fact you're in possession of a very famous and controversial device. A device which will require undisputable proof (activation) every step of the way as you build up to switching on the Gonzo Mode portion of the electronics.

TBH, I'm not much of a rem-ball fan when it comes to fusors. I had a calibrated Ludlum 12-4 which still seemed susceptible to high voltage related electronic noise and intense xrays.

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Jon Rosenstiel
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Re: New Home for Doug's Fusor

Post by Jon Rosenstiel »

Mark and Bob,

I too initially had EMI issues with my Ludlum rem-ball, found that adding another shield over the rem-ball to rate-meter cable eliminated the interference. Also, grounding the rate-meter with a short, heavy-gauge wire seemed to help a little.

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Bob Reite
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Re: New Home for Doug's Fusor

Post by Bob Reite »

While I will use the REM Ball and the Hornyak button detectors to aid in tuning the fusor, I will not claim success until confirmed by activation of an element, or even better, a bubble dosimeter reading. Because of the six to nine mouth shelf life of the bubble detectors, I probably won't order one until I have activated silver to a substantial degree.
The more reactive the materials, the more spectacular the failures.
The testing isn't over until the prototype is destroyed.
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Mark Rowley
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Re: New Home for Doug's Fusor

Post by Mark Rowley »

Bob, if known, what were the close proximity X-ray levels of Dougs fusor during the famed Gonzo Mode incident? How does that compare to the average research grade fusor operating at 60-80kV?

Since you’re using electronic detection methods to aid in tuning, it may be wise to subject them first to similar extremes so you can subtract the noise when the time calls for it.

Regarding BTI’s, after my pinch tube experiments it was learned that they are highly subject to UV influence. Although a fusor won’t typically cause UV issues, Dougs Gonzo Mode high-frequency conditions may create a similar undesirable effect, especially if they’re radiative in the 2.45ghz or microwave bandwidth. To be absolutely solid on this, it would be worthwhile to test them in close proximity to the exact frequency range and intensity (even if not in the uWave bandwidth) used during gonzo mode conditions.

Since this is all uncharted territory, I’d even recommend exposing the BTI to 100kV 10mA (or more) xrays to rule out said influence.

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Joe Gayo
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Re: New Home for Doug's Fusor

Post by Joe Gayo »

At high voltages (90kV+), electronic noise wasn't the only issue, without lead shielding of the detector tube, electronic detection falters because of x-ray pulse pile-up issues.
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Richard Hull
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Re: New Home for Doug's Fusor

Post by Richard Hull »

At the extreme end of fusor operation, Activation of tough elements would be the real test. Something with a cross section around 1-5 or even less when using extremely high voltages. x-rays would play little part in such activations beyond being death dealing.

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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Bob Reite
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Re: New Home for Doug's Fusor

Post by Bob Reite »

Doug never operated the fusor above 50 KV. The most that make and model of supply will do is 51.something KV. The ion grid is at an even lower voltage. Before Doug switched to remote control, he lead shielded the entire fusor, except for the front viewport which had a sheet of leaded glass, out of a hospital X-ray facility that the X-ray tech would be watching a patent through while giving the X-ray.
The more reactive the materials, the more spectacular the failures.
The testing isn't over until the prototype is destroyed.
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Mark Rowley
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Re: New Home for Doug's Fusor

Post by Mark Rowley »

Richard,
Dougs definition of Gonzo Mode included the ability to activate cobalt based tooling (across the room) to such dangerous levels that necessitated their immediate disposal. Taking into consideration the inverse square law, such a neutron flux from even the best of the best fusors would be a pittance in comparison. This claim is the raw essence of why this device is so famous and that the term Gonzo Mode has such folklore and fanfare.

—Cobalt Activation to Dangerous Levels from Across the Room—

That is the ultimate test for this fusor, otherwise the term Gonzo Mode will never be confirmed as accurate.

Regarding the above X-ray remark, I’m not convinced of a bubble detectors reliability under such extreme conditions. If a fusor is running at over 100kV and activating cobalt to crazy levels, I for one am going to be skeptical of any BTI results. Perhaps if encased in a 30lb brick of lead the results may be acceptable. Maybe.

Mark Rowley
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Mark Rowley
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Re: New Home for Doug's Fusor

Post by Mark Rowley »

50kV?!
I could be mistaken but I don’t think even the best continuous-output commercial BoT could activate Cobalt to “dangerous levels” at such a low voltage. And from across the room no less!

How long was the GM event?

This is getting very interesting.

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Mark Rowley
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Re: New Home for Doug's Fusor

Post by Mark Rowley »

For a definition of what constitutes Gonzo Mode, refer to this thread:

viewtopic.php?t=10401&fbclid=IwAR1KXhkh ... yQOTAFV9Rc

“I had to toss a couple thousand bucks worth of activated machine tools in the trash, and move out of the now-hot shop.”

I’m only reiterating all this so “Gonzo Mode” doesn’t inadvertently get watered down in the not so distant future.

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Joe Gayo
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Re: New Home for Doug's Fusor

Post by Joe Gayo »

It's not a secret, I'm skeptical. However, activation of tools isn't required in my mind to make"gonzo mode" interesting. I understand that was the claim, but we have an opportunity to investigate the unvarnished truth. Any potential advance in Q (or n/sec/mA for a given cathode voltage) should be studied and is a noble pursuit.
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Mark Rowley
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Re: New Home for Doug's Fusor

Post by Mark Rowley »

Totally agree Joe. The attempted recreation of the mode is most important and a worthwhile undertaking.

I’m only pointing out that Gonzo Mode has a distinct definition and that it should not be clouded, watered down, or redefined.

If Dougs system is efficient and produces a lot of neutrons, then good! But if it falls short of a neutron flux capable of activating $10k worth of cobalt, iron, and steel tools, then it’s not Gonzo Mode. After all, that’s why it’s called Gonzo Mode and not Efficiency Mode or High Output Mode.

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Bob Reite
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Re: New Home for Doug's Fusor

Post by Bob Reite »

I finally got silver to activate to a decent degree. Two runs give about 550 counts per minute at shutdown, well above background so I know it's not a fluke.

Here is a graph:
Silver_Activation.png
I know that people will ask how this is obtained, so here goes:

The data aq of this system counts pulses from the Geiger counter every 0.1 seconds and records this in a mySQL database. Until Gonzo Mode is obtained, this is too short of a spacing to give meaningful results, so I wrote a script in php (because it's a programming language I know well and have plenty of code snippets that I can reuse). The script goes through the mySQL table and adds the counts over ten seconds (100 0.1 sec intervals). The output gets exported to a spread sheet, where the raw count is multiplied by six to get the output in counts per minute.

The hotter short lived isotope decay is easily recognized. The longer life isotope is buried under the high background level at my site unfortunately.

However more work to be done as I would expect around 1000 counts per minute operating at 50 KV and 10 mA. I'm still learning the art of driving this machine in "batch mode" and using the ion grid for current control.
The more reactive the materials, the more spectacular the failures.
The testing isn't over until the prototype is destroyed.
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Richard Hull
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Re: New Home for Doug's Fusor

Post by Richard Hull »

Thanks Bob this is real data here and is inline with all that those of us here who have done activation find a perfect fit. This is the real deal!
I am glad you grabbed data more or less as I do. It makes for easy graphing that tells a lot to the knowledgeable observer as well as teaching the un-initiated neophyte should they wish to absorb it.
A plus-ultra fusor like this should be capable of this kind of activation as a minimum! You got it making real fusion again. A very long road ahead to gonzo mode for sure.

Background is very important on short grabs or long ones. I like to do a background 10 minute run before I turn the fusor on to get a graph and average count over the period. surprisingly, mine can vary from 4-6 in 5 sec grabs 48-72 cpm while my peak Rhodium count is in the 82 count per 5 sec or 984 cpm activation count range.

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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Bob Reite
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Re: New Home for Doug's Fusor

Post by Bob Reite »

Time to wake up this thread with a report of progress (or lack thereof) so far.

I could never get the device to self-oscillate to any respectable degree. Bill thinks that the fusor had a different feed through who's arcing contributed to the self oscillation. The arcing was causing other issues so that's when Doug decided to build new feed throughs with boron nitride which would stand up to the ion bombardment inside the chamber.

So I went ahead with getting a broad band amplifier set up that would let me drive the ion grid with any frequency from 400 KHz to 5 MHz, which is the range that Doug's various coils were self resonant.
Here are some views of the amplifier, which is a repurposed homebrew ham radio linear amp.

The amp consists of a 6146 driving a pair of 4-125A tetrodes in parallel. Coupling between stages is with ferrite transformers. The output transformer is the large coil, the secondary of which can be seen connected in series with the feed to the ion grid. The primary has about 1/4 the number of turns wrapped around four ferrite rods taped together and inserted inside the insulating tube. I added another video camera so that I could read the driver plate and final plate current remotely.

The exciter is an old General Radio Bridge Oscillator which is at the remote control point in my office. I ran RG-58 cable from the office to the fusor shed, so that I can adjust frequency and drive remotely and observe the effects of changes.

Now for the bad news. No the amp did not blow up, even though when I pushed it too hard one time, the 2500 volt plate supply (not shown in the photo) tripped out on overload. The nice thing about tubes is that they can take some abuse. However exciting the fusor with frequencies in the range stated above produced no significant increase in neutron output. I also tried driving it with square waves from a function generator with no change in resuls.

There are two possible conclusions:
1: I don't have enough RF voltage still. even though I wound a new secondary with more turns I could not get the fusor to "light off" on just RF alone, I also had to provide a DC bias on the ion grid. Even backing off the bias to where the plasma just extinguished, the RF would bring it back only at a narrow range of frequencies that were in the amplifier's "sweet spot".

2: Gonzo mode was NOT the result of oscillation in the MF to low HF range. I suspect that while Dong had a fundamental oscillation at 455 KHz or 1.8 MHz, the real magic was happening due to a parasitic oscillation, in the range from 20 MHz all the way up to VHF.

So the next thing I'm going to try is to get a higher RF voltage, and if still no go at MF or low HF frequencies, build an amp (or modify this one) to do high HF to VHF frequencies.
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The more reactive the materials, the more spectacular the failures.
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Richard Hull
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Re: New Home for Doug's Fusor

Post by Richard Hull »

Very nice and concerted effort there to try and get to Gonzo mode. You are certainly the man to whip up the RF in this scenario. Good luck in your efforts to get this thing boosted.

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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Dennis P Brown
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Re: New Home for Doug's Fusor

Post by Dennis P Brown »

Trying to repeat Doug's results is an extremely worthy endeavor.. Sorry the current experiment didn't produced the desired results but often occurs when science is done properly . Your efforts, builds and experiment are really an outstanding example of amateur fusion research that reaches a very high aspect. Glad your continuing and best of luck but above all, be safe.
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Bob Reite
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Re: New Home for Doug's Fusor

Post by Bob Reite »

An update:

I had been so busy working that there was no time for fusor work. That changed when I took an at home vacation break from RF that helps pays the bills and I had a house guest with an interest in science and technology that wanted to see the fusor operate, from the safety of the remote control point of course.

The run was typical of a standard fusor with an ion grid. The guest got to hear and see the decay of my silver sample on the geiger counter.

But I found two problems. The intake valve now leaks. The pressure keeps climbing even with the valve closed and I have to keep hitting the exhaust valve button to keep the pressure where I wanted it. The Nitrile "button" on the valve is worn out. A new valve with Viton is only $50, so I ordered one, but it will take a month to get here.

The other more expensive problem is that the bearings on the turbo are wearing out. It's twice as noisy as when I first put the fusor back in service and when I shut it down to work on the intake valve, the "winding down" was very noisy with nasty sounding grating at some speeds. I'm not going to start up the turbo again until it is rebuilt. I got sticker shock over the $2200 quote to rebuild it, plus adding freight both ways will probably drive it up to $2600. So I ordered a rebuild kit for $850. I did ask for rebuild instructions and any special tools, but I may want to pick the brains of others here that have done bearing replacements on Pfeiffer TMU 521 turbo pumps.
The more reactive the materials, the more spectacular the failures.
The testing isn't over until the prototype is destroyed.
Jerry Biehler
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Re: New Home for Doug's Fusor

Post by Jerry Biehler »

I have a 521 that I was rebuilding until I found the upper magnet was shattered. So I have a brand new bearing from Alpine that was installed and never used. Whoops. Pfeiffer does recommend changing the oil cartridge every couple years.

There's not much in there. You will need a pin spanner but that's about it for special tools.
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Richard Hull
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Re: New Home for Doug's Fusor

Post by Richard Hull »

I am only a recent user of a Turbo, 4 years now. I blew up my controller 2 years ago. Being electronic, I repaired it. I vowed that should the mechanical pump go bad, I would rip it out and go back to my old Diff pump that served faithfully from 2003-2018. Fortunately, At the 2020 HEAS conference flea market, I bought for $200 an identical turbo pump, tested it and have it as a spare. Still, I have that old air cooled Diff pump at the ready. No moving parts, no complex electronic controller and no special cabling needed. Tough to beat an air cooled diff pump for a small fusor. Water cooled Diffs of larger pumping capacity work fine with much larger chambers.

Bob, I hope you get the system back up and under vacuum without too much trouble.

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
Peter Schmelcher
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Re: New Home for Doug's Fusor

Post by Peter Schmelcher »

Just a word of caution. Turbo pumps don’t have a proper current path for ion currents impacting on the rotor blades. The ball bearings end up arcing to dissipate any charge which eventually damages the bearings.
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Dennis P Brown
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Re: New Home for Doug's Fusor

Post by Dennis P Brown »

Excellent point. So, another good reason to have a wire inlet cover/shield that is grounded (via the case.)
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Richard Hull
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Re: New Home for Doug's Fusor

Post by Richard Hull »

I use a very twisted path through grounded flex SS pipe of limited conductance to my turbo.
I defy any electron/ion currents to enter my turbo which also has a fine mesh screen over its throat. I attach the current twisted vacuum path to fusor V when first laid out in 2019. Optimum vacuum conductivity? You bet! It ain't exhibited here, but then, who needs it! It pumps well and fast enough for all fusor work I demand of it.

Richard Hull
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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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