Joe Gayo's lab tour

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Richard Hull
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Joe Gayo's lab tour

Post by Richard Hull » Sun May 26, 2019 8:07 pm

I just tuned into Joe's lab tour. A fabulous effort that shows a continuing interest in IEC fusion. A real fine example of researching this effort.

I have placed this in the construction forum due to his detailed construction account. He is either very well off or very talented across the board as his recent work is with multiple machined 6061 aluminum cubes. This is far beyond the high schooler "I wanna' do fusion" efforts so common here. It is all about thoughtful application of talents and wise use of resources.

Joe doesn't believe in the best of everything and is is more interested in getting the job done. He is capable of assembling multiple NIM modules, vacuum pumps, etc to get the job done regardless of brand name. It is obvious to the meanest intelligence that he is multi-faceted, multi-talented and if he doesn't know something, he soon will via reading and by the "doing" plus, pouring on the coals needed to press on. A rare breed, indeed.

I could see this in just his past postings, but the lab tour just confirmed and boosted my respect for his efforts here.

He has more than verified that small volume fusors, (his small cubes), allow for high pressures for deuterium fuel which in the standard Lawson criteria increases fusion. (Fuel density) This has been an ongoing talking point here for about two years. At the amateur end this makes the needed high voltage tough to get into these small chambers without arcing for the novice HV amateur.

The aluminum, as he notes, is a low emitter of electrons. This is something new to consider for those with machining skills or plenty of money and the verve needed to take this into their own lab.

As an amateur machinist, the cube is an easy item to machine in a four jaw chuck on a suitable lathe or even easier on a milling machine equipped with a rotary table in the hands of a tolerably good machinist. Aluminum, in a free cutting alloy is a dream to machine. Tool speeds are not hyper critical as with SS, though still important. Tool wear it virtually zero and only tool clogging at terribly wrong speeds on softer alloys needs attention.

The whole fusor biz gets a good bit easier if you have a lathe and the milling machine and know enough to use them, not necessarily with high precision, but with a good ability to know where to whack metal off an item. Precision comes with time and experience. Interestingly, I was forced to learn some machining skill in the 70's and 80's in amateur astronomy. It was mostly whacking metal into shape, but I was forced to learn how to thread, internally and externally as many oddball, useful, pre-threaded items came my way which needed coupling to telescopes and mounts.

I know a great machinist who I respect mightily, but he avoids any threading outside of tap and die work. Threading is typically the last cutting on most larger pieces. This means they are finished items and a mistake in threading could kill all the preceding work. As my friend is hyper precise and does beautiful satin finished items, I guess he fears ruining good work.

Joe either hires good machinists or is a competent one himself.

In the electronic erector set world of NIM, Joe is either very capable from the get go or he is a quick learner.

Regardless he has mastered many skills never even attempted by the vast majority of folks who land here. Admittedly many are teenagers and have a lot of life yet to live and learn many things that will hopefully propel them forward. They are not to be faulted for their youth or its inexperienced exuberance.

It is more often the bit older Joes, the Jons and the Carls who have the verve, knowledge and ability to do that tends to inspire us, and often make it look all too easy.


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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Re: Joe Gayo's lab tour

Post by Joe Gayo » Sun Jun 02, 2019 10:47 pm

Thank you, Richard, for the kind words. I've been fortunate to have studied power electronics and physics which gives a solid foundation to build, modify, and repair NIMs, power supplies, and controllers. I performed all the mechanical design but used a local machinist who is a friend and was willing to be compensated with traded services.

I have some exciting news from my lab, Kineutro, the latest electrode geometry was able to further increase the operating pressure and combined with a custom 70kV power supply I was able to sustain 7.5M+ n/sec TIER! https://youtu.be/MGOdzLYGoks & https://youtu.be/LtMH4XQClgc
IMG_0644_sm.jpg
Custom Power Supply
DXM70N Transformer and Multiplier with Custom Driver/Control
IMG_0645_sm.jpg
Setup

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Re: Joe Gayo's lab tour

Post by Joe Gayo » Mon Jun 03, 2019 6:12 am

944224C4-741E-4941-9568-E9C97C68D09E.jpeg
Calculations
This may be the highest Q for an amateur device.

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Re: Joe Gayo's lab tour

Post by Dennis P Brown » Mon Jun 03, 2019 8:26 am

Very nice setup and excellent work.

Relative to your claim for your overall Q, while Richard is the final authority, I'd suggest that in order to better support the Q value obtained (and aid others in their work here), that you should show, in detail, how you arrived at the various values in your display. I would especially suggest you provide a detailed discussion of your calculations and what they are based upon. Your bubble detector, is course, the gold standard for the neutron flux. So include a photo of its results (with both the 300 bubbles and its mfg. rating.)

For us here, those are black box values so it would be informative to see the details. For instance, a back calculation from your value of 30 mrem to a neutron flux would be useful for many here trying to understand that issue for a amateur fusion device. Also, you didn't include the system pressure that you used - that would be an important addition to the display.

Again, impressive work.

Aside: I would like to clarify one data display: For your mrem value, that would be 30 mrem for 3600 seconds as derived from the bubble detector (300 bubbles)?

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Re: Joe Gayo's lab tour

Post by Richard Hull » Mon Jun 03, 2019 9:24 am

I looked at and studied Joe's work and it looks very well done and tied up with a bow on it.

Dennis is correct though, a photo of a bubble detector chocked full o' bubbles would be nice.

I would say that in the past almost all bubble detectors that were exposed and photographed might have had 10-50 bubbles for a total of ten minutes of a single hard run.

3600 seconds, (one hour), naturally, if run full bore over that period, with the 300 bubble result, would lessen any need for statistics due to the number of bubbles over the finish line and the long period of exposure.

A great report. I would love to have seen the x-ray dose using a dosimeter at the same range of the 3He detector. Most 3He detectors of the P3 and P4 types claim they may be immersed in a 5 roentgen x-ray field before detection might be compromised. I doubt if you had more than a 1R field at that range. The field might be back figured from a 200 mrem pen dosimeter after a 5 or 10 minute run at near 70kv. It would be fearsome for sure....Of course, the Aluminum bodied, block fusor would not produce x-rays at the level of an SS chamber operated at the same potential.

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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Re: Joe Gayo's lab tour

Post by Joe Gayo » Mon Jun 03, 2019 3:49 pm

I have three neutron detection systems:

1. A BF3 tube / LDPE moderator placed 40 cm from the cathode
2. A BF3 tube / LDPE moderator placed 160 cm from the cathode - calibrated with 54 bub/mrem dosimeter (Feb - April)
3. Ludlum 12-4-7 (x10 scale, slow 22 sec) placed 50.8cm from the cathode - calibrated by an outside lab

Detectors 2 (custom controller monitoring SCA pulses) and 3 (with camera) were continuously monitored.

The way I used the calculator from Bee Research is as follows:
- The sustained dose rate indicated by the Ludlum 12-4-7 was 300 uSv/hour (entered in bubbles/counts)
- 10 uSv/hour = 1 mrem/hour (entered in detector calibration since the detector was calibrated to read uSv correctly)
- Entered detector distance (50.8 cm)
- Exposure time was set to 1 hour (3600 sec) to convert rate to dose (rate meter isn't showing cumulative, but instantaneous rate averaged over 22 seconds)

This calculation is very similar to viewtopic.php?f=6&t=2899#p12409

The rate calculated from the Ludlum 12-4-7 was within 10% of detector 2. (Detector 1 was not monitored)

The full parameters of operation are as follows: 72kV and 6.9mA @ 18mTorr

(I'll follow-up in a future post with x-ray dosimeter readings at the detectors ... currently, the dosimeter is at the operator's computer)

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Re: Joe Gayo's lab tour

Post by Dennis P Brown » Mon Jun 03, 2019 5:06 pm

So if I follow, is the device right next to your fusor a bubble detector in its count housing? Is its response the 10 bubbles/mrem shown as the value in the display? And the value of 300 was obtained for the 3600 second run? Or are these values derived from the other detector via a previous calibration run?

What is the point of the other detectors (@ 40 cm and 160 cm) if they are not being used? If you have data from these can you include their values, detector areas and calibrated values?

I am assuming that you are using a spread sheet to calculate the various displays. So what formulas are you using in the spread sheet to convert the mrem, uSv into neutron flux? Can provided the area of the detector used at 50.8 cm (Ludlum 12-4-7)?

Again, a photo of the bubble detector is needed since all your data is based on that device either by calibration or direct detection.

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Re: Joe Gayo's lab tour

Post by Joe Gayo » Mon Jun 03, 2019 5:16 pm

A second detector was used (@160 cm), it read 7.8M n/sec based on it's previous calibration. The detector @40cm wasn't monitored because it's un-calibrated.

The bubble detector I have is now expired. The bubble detector was used previously from runs between February and April (viewtopic.php?f=18&t=12623&p=82120) to calibrate the electronic detection.

Also, I have all these detectors because I have 2 devices that I compare and contrast, which allowed me to optimize the cathode geometry.

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Re: Joe Gayo's lab tour

Post by Dennis P Brown » Mon Jun 03, 2019 8:40 pm

Thanks for that information. That helps clarify what you did.

So I can properly calculate your results, what is the collection area of your detector?

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Re: Joe Gayo's lab tour

Post by Joe Gayo » Mon Jun 03, 2019 8:53 pm

The is Ludlum sphere has a surface area of 1195 cm^2 and cross section of 299 cm^2

Maybe I'm missing something, but the Ludlum is calibrated to show uSv/h with a inverse RPG curve (that's pretty accurate at 2.45MeV) so the detector area is already considered in the measurement. Isn't the calibrated dose rate at a distance all that is necessary for a neutron rate?

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