Fusion Message Board

In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.

Subject: Re: p-B11 + other Alt Fusion Fuel Web Site
Date: Jun 24, 00:53 am
Poster: Richard Hull

On Jun 24, 00:53 am, Richard Hull wrote:

YES! You will need at least 123kev to get this reaction lit and that is the starting point! As we know the 15kev for DD is just a tiny trikle of neutrons. The reaction really doesn't really cook until ~100kev!

The D-D reaction is a poor one due to the small collisional cross section (<1 barn). However, it is all we have to work with unless we have 100,000 bucks or so to develop a more interesting fuel reactor.

P-B11 is nice in that it is a DIRECT CONVERSION process (ideal of ideals). However, as mentioned below and in other posts, it is for very ambitious investigators sucking off the federal tit. To my knowledge it is not being done currently.

Richard Hull

> fuel T(keV) /T^2
> ---- ------ -------------
> DT 13.6 1.24e-24
> DD 15 1.28e-26
> DHe3 58 2.24e-26
> pLi6 66 1.46e-27
> pB11 123 3.01e-27 "
>Anyone know if this means 123 keV needed for pB11 reaction compared to 15keV for DD reaction?
>Just for interest;
> Relative natural abundance of Boron are
>Boron 10 19.78%
>Boron 11 80.22%
>Boron 8, 12 the rest
>And Boron 11 is what you want, so natural Boron is not too bad.
>But note Richard Hull's posting
>Subject: The physics of neutron production
> Date: Mar 23, 10:00 am
> Poster: Richard Hull
>In that posting, he points out (among other things) the problems caused by "extra" atoms or molecules in the reaction zone. That is, they cause unwanted collisions which tend to convert the high velocity reactants to just a uniform temperature hot gas which produces fewer of the desired high velocity impacts needed for fusion. So you should avoid having atoms (or molecules) such as boron 10 or anything else in the reaction zone that are not going to be at very high velocity and fusing.