Overview of D-D and D-T Fusion Detectors

This area is for discussions involving any fusion related radiation metrology issues. Neutrons are the key signature of fusion, but other radiations are of interest to the amateur fusioneer as well.
Harald_Consul
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Overview of D-D and D-T Fusion Detectors

Post by Harald_Consul » Tue Oct 23, 2018 10:25 am

Hello!

I am new in the forum and do not know much about, how to detect (and proof) a fusion process, yet.

Could "any"one more experienced give me an overview of the methods/ types of detectors, that are frequently used to detect a nuclear fusion, respectively one of its (side) products?

I am interested in detecting deuterium-deuterium fusion and deuterium-tritium fusion.

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Dennis P Brown
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Re: Overview of D-D and D-T Fusion Detectors

Post by Dennis P Brown » Tue Oct 23, 2018 10:38 am

This forum has FAQ's that have this exact information; however, search using neutron detectors. You should focus on He-3 based detectors. Please check the FAQ's before asking such elementary questions.

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Re: Overview of D-D and D-T Fusion Detectors

Post by Harald_Consul » Tue Oct 23, 2018 2:48 pm

First of all I did recognize, that there are a lot detectors mentioned in this subforum. However, I do not know, which one to choose and why.

The choose of the right detector seems to be so complicated, because following German wikipedia not 1 but 4 nuclear fusion reaction can occur at the same time

(1) 2D + 3T → 4He ( 3,5 MeV ) + n0 ( 14,1 MeV )
(2) 2D + 2D
(2a) → 3T ( 1,01 MeV ) + p+ ( 3,02 MeV ) (50 %)
(2b) → 3He ( 0,82 MeV ) + n0 ( 2,45 MeV ) (50 %)
(3) 2D + 3He → 4He ( 3,6 MeV ) + p+ ( 14,7 MeV )
(4) 3T + 3T → 4He + 2 n0 + 11,3 MeV
Source: https://de.wikipedia.org/wiki/Kernfusio ... reaktionen

Following theses reaction equations it seems to be problematic to use a 3He Detector, as 3He can take part in another secondary nuclear reaction with deuterium [Reaction formula (3)], thus might disappear. Am I wrong?

Maybe I would not have asked this "basic" question, if the FAQ- The herald of real fusion - good measurement would provide more instructive guidance, how to do "good fusion measurement", exactly.

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Dennis P Brown
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Re: Overview of D-D and D-T Fusion Detectors

Post by Dennis P Brown » Tue Oct 23, 2018 3:57 pm

First off, no one except government grade labs can use tritium - that is a radioactive gas. As such, it is tightly controlled and very dangerous to have around people (breathing it.) So, please stop discussing that reaction. As for He fusion - this occurs very, very rarely even for the big machines. In a fusor? Not an issue at all - have you read any FAQ's on this site?

You really do need to read on neutron detectors in general (maybe an hour at most to get a few elementary principles/concepts clear so please do that before asking more such questions.) I only now realize your knowledge base since you think I am referring to detection of the He-3 reaction in my previous post!

Neutron detectors are made using a number of materials - one of the best detector's is the one that uses He-3 gas as the detector substance. Hence my main point in my post. Until you bother to read the FAQ's and learn a little about fusor's, I will not continue to answer such questions - you need to learn on your own the simple stuff. Best of luck.

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Re: Overview of D-D and D-T Fusion Detectors

Post by Richard Hull » Tue Oct 23, 2018 6:14 pm

Reaction #2 is the only one we can do, (D-D).
2a you can't detect T or P....They never make it out of the chamber. Nothing to detect here.
2b you can't detect 3He, it will never make it out of the chamber. This leaves only the neutron which doesn't even see the chamber walls. The neutron whistles right through the steel chamber's shell.

This escaping neutron is the only way to detect and prove D-D fusion is actually taking place within a fusioneer's budget. period...

As everyone says all the time to all newcomers... read the FAQs........They never do and thus continue to ask ridiculous questions easily answered in a FAQ written 10 years ago. These are written to avoid re-writing what I just listed above.

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: Overview of D-D and D-T Fusion Detectors

Post by Harald_Consul » Wed Oct 24, 2018 10:04 am

Dennis P Brown wrote:
Tue Oct 23, 2018 3:57 pm
First off, no one except government grade labs can use tritium - that is a radioactive gas.
Richard Hull wrote:
Tue Oct 23, 2018 6:14 pm
Reaction #2 is the only one we can do, (D-D).
You are right, as far no lithium is fissioned in the process, which would produce tritium.

However, I have got a "Beam on Target Fusion Design", which would theoretically provide the option to include lithium into the palladium-deuterid target (by manufacturing a palladium-lithium alloy, for instance).

What's wrong with simply answering a question straightforward instead of giving people indirect lections how to best create a fusion process through the backdoor of your answer? :sad:

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Re: Overview of D-D and D-T Fusion Detectors

Post by Cai Arcos » Wed Oct 24, 2018 10:30 am

Tritium itself is extremely expensive, aside from being radioactive, as others here have mentioned. Any type of metallurgy with this material is WAY beyond amateur experience; doing any type of "alloy" with Paladium and Tritium can be regarded only as a dream. Furthermore, there is a reason why literally all fusor presented here (including those built and operated by people far more knowledgeable and experienced than both of us) use D-D reactions: aside from all the handling hazards mentioned above, the energy required and operating skill is simply too high.

"What's wrong with simply answering a question straightforward instead of giving people indirect lections how to best create a fusion process through the backdoor of your answer? :sad:" This forum has an enourmous amount of data and information "hidden" in the FAQs. Creating new useless posts for topics explained several times several different times only creates confusion, more server use and clutter. For instance, the very exactquestion you are asking can be found in 3 minutes of searching:

viewtopic.php?f=31&t=10077

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Re: Overview of D-D and D-T Fusion Detectors

Post by Harald_Consul » Wed Oct 24, 2018 7:18 pm

As you guys seem to think over fusors in very predefined railway lines, I have worked out a deuterium-tritium fusion process now, that uses lithium fission as a tritium source.

Can I use any neutron detector mentioned above for proving a deuterium-tritium fusion process, although tritium has a radioactive beta-decay ?

Many thanks in advance for your patience.

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Re: Overview of D-D and D-T Fusion Detectors

Post by Robert Dwyer » Wed Oct 24, 2018 8:33 pm

One of my jobs is working in fusion neutron detection for pulsed power. I cannot name one of the neutron detection methods that are in the hands of the amaeture that have not been mention here. If you want to try and detect D+T fusion reactions you can try, good luck. The same detection methods for D+D will work for D+T, neutron moderators are a wonderful thing for activation detectors.

IF you mean measuring the ratio of your D+D to D+T yield then you use scintillators. Good luck with the electronics setup and analysis that goes into pulling those spectrums out. If you want activation materials may I suggest looking at many of the archives found online of neutron cross sections. Good luck trying to get any measurable DT neutron measurements with beam-target device using the design you talk about (if it will even do fusion at all).

As a side note, I don't think that lithium reaction works the way you think it will, and that's all I will say about it,for good reason. I have seen multiple postings of people talking about ideas using lithium as some sort of fusion miracle worker, yet none of them have ever translated to actual experiment. Here we say D+D is the only thing we can use, because it is the only thing that has been used. Prove to us there are measurable DT, D-He3, or other types of reactions in your design, and we will eat our words. Until there are results we will be skeptical.
If we throw more money at it, it will have to work... right?

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Richard Hull
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Re: Overview of D-D and D-T Fusion Detectors

Post by Richard Hull » Thu Oct 25, 2018 3:53 am

Robert put it right. Let the experiment be done and report back to us on the result. This may be the 100th time I have written the last sentence in response to some wonderful new armchair idea. So far, no one has taken my suggestion and performed the experiment and absolutely no one reported back on their ground breaking idea.

The idea is so much wind over the decks until it is assembled in hardware and tested. If it fails, no one dare report abject failure of their brainstorm.

Give it a whirl and get back to us on what you find. Just how enthusiastic are you about you idea? All it takes is a good bit of money, multiple skill sets, and time plus the inevitable mistakes along the way.

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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