Talk-Polywell.org

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http://www.askmar.com/Fusion_files/EMC2 ... plants.pdf

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I was re-reading the above and came across something I had missed the first time around.

From pdf page 7

Capture of the neutrons from the neutron branch of the associated DD reactions could also add energy to the plant system, through their use to cause fission in a 10B loaded blanket; a non-hazardous application not practically available to DT fusion systems "which must use their neutrons for tritium breeding. DD cycles thus grew in interest and importance as the study progressed, and were concluded to be the most promising of all available fuel combinations for earliest practical use in fusion power systems.

I had noticed this when I was doing shielding calculations and heat load calculations for a D-D MaGrid machine. The output from B10 fission is about 60% to 70% of the neutron impingement grid load (depending on neutron production estimates) i.e. almost a doubling of power out if the whole reactor is used in a neutron producing reaction - although it would have to be recovered in a steam cycle.

You know - once we get proof of reasonable net power there are an awful lot of possible design options that do not require the use of heavy metals for fuel.

And the really neat thing is that because of the high neutron cross section for B10 a layer a few mm thick will last about a year with only a modest increase in non-absorbed neutrons. A 10 mm thick layer would be a multi-year supply. A 1 cm layer would be good for a decade minimum.

Here is the study I did:

http://iecfusiontech.blogspot.com/2008/ ... oling.html

Another perl from that paragraph that I, at least, had not considered is the production of Helium 3. As a reactor fuel with deuterium it is comparable to deterium alone, to moderatly easier ( closer to DT in Barns in a broad range of eV), so it would not only be a possible power booster for it's parent reactor, but could be used in seperate reactors where you want to limit neutron output, like space applicatons. It would presumably be much cheaper than trying to mine Helium 3 on the Moon as it is essentially a waste product for the DD Polywell. So, even if P B11 could not be made to work (but the DD can), you would still have aviable the possibility of a low neutron, direct conversion reactor for mobile applications and at costs comparable to the DD machines!

Dan Tibbets

From the B10 fision you get Li7.
And after that n+Li may produce T.

Torulf2 wrote:From the B10 fision you get Li7.
And after that n+Li may produce T.

After reading your comment, I thought - why did I think B10 fission produced tritium directly? Of course you are right. It produces Li 7 + alpha particle + gamma ray (I think). So, unless a significant percentage of the B10 present was first fissioned, there would not be much lithium 7 present to proceed to tritium production. It might become a concern (or oppertunity) depending on how large a neutron flux the B10 layer was exposed to before being removed.
The tritium and helium3 I was refering to would come directly from the two dominate reactions of DD fusion.

D. Tibbets