Fusion energy from a D-D reaction + A bit of Fusion Physics

If you wonder how/why fusion works, or how/why the Fusor works, look here first.
Post Reply
User avatar
Richard Hull
Moderator
Posts: 12290
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Fusion energy from a D-D reaction + A bit of Fusion Physics

Post by Richard Hull » Mon Feb 24, 2020 11:33 am

Wow! I can't believe I haven't done this before now. All this involves some recent discussions I have had with other people related to recovering fusion energy. A lot of pie in the sky stuff related to "what if we had 1e12 fusions per second such as that claimed by the last iteration of fusion in the ITT Farnsworth era?" "What could we do with the debris in the way of energy reclamation?" "How much total fusion energy would the system put out working at that level if in D-D fusion?"

It turns out that it is a mere 1.8 watts of fusion energy, if done in D-D fusion. This figure is not really collectable as 100% of the fusion energy can't really be collected and converted to useful electricity. That is not much in the grand scheme of things, but the ITT team figured it was about 1e8 neutron flux at 6 feet! That is dangerous and nasty without special shielding, which they had in the "cave" God only knows what the X-ray level was!! They also noted that they could only sustain that for about 3-5 minutes, before the fusor and ion guns heated to the point that the numbers fell off considerably.

The average, highly successful amateur fusor generates only micro-watts of fusion energy with about 500 watts applied from the wall outlet to do this!

I have assembled a paper and will submit it here in this FAQ that explains how to compute the total fusion energy released in D-D fusion, (amateur fusion), based on real isotropic neutron numbers that you can prove you have produced per second. It also lets you extrapolate, instantly, to any isotropic D-D neutron emission from my base case of 1 millions neutrons per second, isotropic using simple math and scientific notation.

Near the end of the paper I give the neutron physics involved, (very basic and condensed for the newbie), in a fashion using analogies that I feel are easy to grasp at a fundamental level. Hopefully, It might inspire the best who read it to delved much deeper into the physics of fusion.

Richard Hull
Attachments
D-D fusion paper.pdf
(402.04 KiB) Downloaded 77 times
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.

User avatar
Frank Sanns
Site Admin
Posts: 1710
Joined: Fri Jun 14, 2002 6:26 pm
Real name: Frank Sanns
Location: Pittsburgh, PA USA

Re: Fusion energy from a D-D reaction + A bit of Fusion Physics

Post by Frank Sanns » Mon Feb 24, 2020 9:19 pm

Really good paper Richard! That sums it up nicely and goes in step with your recent FAQs post about the effects of small changes within a fusion. Anything that is changed in the Fusor can improve or reduce the efficiency of a device that is a net loser by so much that those minor changes are lost in the noise of inefficiency. This is true with ALL of the fusion concepts out there spending billions or trillions of dollars.

User avatar
Richard Hull
Moderator
Posts: 12290
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: Fusion energy from a D-D reaction + A bit of Fusion Physics

Post by Richard Hull » Tue Feb 25, 2020 1:10 am

Thanks for the kind words Frank. The newbies would love this treatment if only they would read it. This goes along with the complaint "why do the same thing over and over." We are not trying to make any power.
Each of us actually working with the fusor have out own goals in mind.

This Faq is to give a decent grounding in the physics for the noob.

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.

User avatar
Erich Gazenko
Posts: 9
Joined: Fri Jul 03, 2020 9:36 am
Real name: Erich Gazenko

Re: Fusion energy from a D-D reaction + A bit of Fusion Physics

Post by Erich Gazenko » Sun Jul 05, 2020 12:00 am

That was a good explanation Richard. The FAQ are very useful. Its too bad fusion is so difficult to get energy from. I guess its just fate for fusion to be efficient for mankind. I am tempted to try to make a small scale fission reactor. I spend 2 years learning about fission and it seems like it will not happen anytime soon by anything other than a large enterprise.

User avatar
Rich Feldman
Posts: 1321
Joined: Mon Dec 21, 2009 11:59 pm
Real name: Rich Feldman
Location: Santa Clara County, CA, USA

Re: Fusion energy from a D-D reaction + A bit of Fusion Physics

Post by Rich Feldman » Sun Jul 05, 2020 1:04 am

Right you are. Technologically easiest path needs tons of natural uranium and even more tons of boron-free graphite, as demonstrated 78 years ago.
If you came to have a bunch of highly enriched uranium, making a controlled fission reactor from it would be harder than making a bomb.
And making a practical bomb would be much harder than piling up enough to get barely critical (lethal radiation dose for you, no windows broken).
All models are wrong; some models are useful. -- George Box

John Futter
Posts: 1625
Joined: Thu Apr 22, 2004 2:29 am
Real name: John Futter
Contact:

Re: Fusion energy from a D-D reaction + A bit of Fusion Physics

Post by John Futter » Sun Jul 05, 2020 2:29 am

Erich
one does not add frivolous replies to faqs
only corrections or missed information posts are wanted

Richard you know what to do!!

User avatar
Richard Hull
Moderator
Posts: 12290
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: Fusion energy from a D-D reaction + A bit of Fusion Physics

Post by Richard Hull » Sun Jul 05, 2020 4:19 am

Thanks John for pointing this out.

I will erase these responses within a day or two.

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.

Post Reply