NEW Fusor V build under way.

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Cai Arcos
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Real name: Cai Arcos
Location: Barcelona, Spain.

Re: NEW Fusor V build under way.

Post by Cai Arcos »

I do tend to dislike travel. Home is called home for a reason! Your comment about never visiting 35 states made an European like me realize how huge and vast the USA really is. You could in fact visit almost all climates without changing country.

The calculation of flux in a non uniform scenario seems to me, unless you assumed all neutron flow was thermalized and just diffused into the detector aftet, would require some notable mathematical/geometrical skills. I found the FAQs about simulation to be a lot more instantaneous. If I recall correctly, Experimental Nuclear Physics by Mukhin, had some detailed explanations. Will check when I got time and if so, post them here.

EDIT: Here are 9 pages, the more "practical" ones I could find of a notable section that talks about moderation. I'm sorry these are photos and not scans, but I'm fearful of damaging the spine of the book (bough it "new" at a scientific library which only has original and reprints of MIR editions, and I've made every effort to keep them intact). It is a really great book that I would recommed to anyone here. Also note his remark about light moderators (only a very rough estimation can be given, and the exact value should be determined experimentally) after spending several pages discussing possible models! Finally, it is also important to me that (at least for what I've gathered), the only "easy" way to estimate the flux of neutrons in a semi quantitave manner is through diffusion.
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Richard Hull
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Re: NEW Fusor V build under way.

Post by Richard Hull »

We come back to the old saw. Exact neutron numbers based on all the mathematical gyrations is, in effect only a close approximation, assuming the moderators covered in the 9 pages. HDPE is another medium altogether! Geometry in this case is also critical. Theoretical machinations are great under precise, controlled and unchanging input parameters There are no neutron beams from a fusor. Detectors are macroscopic with considerable extent.

Most of the more recent postings here are a crude attempt to get a feel for the TIER for fusor V and avoid the necessity of spending $300 plus for a 6 month life span bubble detector that is carefully binned to a precise number of bubbles per mrem of fast neutrons.

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 Fusor V build under way.

Post by Bob Reite »

Hopefully my REM ball will let you know to within 20% of what Fusor V is actually putting out. If someone else is bringing a calibrated neutron detector, the more the merrier!
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 Fusor V build under way.

Post by Richard Hull »

Sad news... I am once again going to make up a new fusor V as fusor V "C". the saga of fusor V "A" was short and not sweet.
Fusor V "B", the current model, was going great as witnessed during HEAS during October. The real work appeared in the neutron forum with the silver activation reports and calibrations. Unfortunately, over the last three runs the old insulator arced externally. I think I know why. I have started to run the fan over the fusor to increase the output via external cooling and it has done marvelously as my recent reports on activation show. Note: All of the relevant information between the last post by Bob Reite and this one is to be found in the large number of posts in the URL below.

viewtopic.php?f=13&t=13568

The URL above really speaks to the best work done by Fusor V "B"! I consider this my best work with fusor V thus far.

The reason for yet another or third iteration of fusor V

I had an external arc condition 6 days ago. It carbonized, (blackened the silicone HV putty). I picked out the little area of putty and replaced it with fresh putty. The next day another run reached 41 kv and the external arc re-occurred. This shook me considerably. What changed? The fusor has worked flawlessly from July onward! I suddenly realized it was the fan! It seemed the fan blowing over the tilted fusor, carried the stream of hot air over the insulator. Hot air in a moving stream will reduce the breakdown in air. My old days in Tesla coiling taught me that lesson well.

I repaired the fusor putty once again and again it broke down at 42kv. That was yet another straw to break the camel's back and my patience!! Over the last three days I have pondered deeply and have decided a fusor V "C' is in order. All here will remember the A,B, episodes and now will suffer a C episode. I will, once again upon completion of fusor V "C", in future, refer to it as simply fusor V. Hopefully, a long term fusor V will some improvements!

I have just secured and purchased a 6 way 6" conflat cross. I want more interior room than the old "A" cross. I am sure the 4" open area In "C" will be more kind than the 1.5" area in "A"

So, I am signing off and will be closing out this post's thread to start yet another new fusor posting around the new fusor embodiment in the near future. The one saving grace is that in spite of the three external arcs, unlike Fusor V "A" 7 internal arcings, the Turbo and controller survived the EMP and RFI bursts. Whew.... 2020 has just been a year for the history books in many ways.

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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