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: Cross Sections (lithium, etc.)
Date: Jun 14, 9:50 pm
Poster: David Morgan

On Jun 14, 9:50 pm, David Morgan wrote:

>>I'm wondering if it's worthwhile to say Lithium.
>>Jim posted a 20-30 Barn thermal neutron cross-section for Li(6?) a while ago - It seems
>>How much extra tritium (and neutrons for the Li(7) reaction) would this make?
>Not many... even at 100K neuts/sec, and an infinite cross section, you'd need a long long time to make a substantial amount of Tritium.

I wasn't as concerned about making tritium as
a byproduct - just getting some use out of the neutrons to improve the energy output.

>>Is LiD a controlled substance?
>Why use LiD (other than for the novelty).. Just make a lithium ion injector, (that is, a tungsten filament with Li on it). the D is already in the chamber from the gas. If you wanted to, you could probably rig up some scheme to filter the ions to enrich either the Li6 or Li7 isotope, as desired (which might be interesting from a research standpoint).

I figured that using a little lump of LiD would be simpler than building an ion gun (assuming LiD
doesn't react with air.) Any other Li compounds would just pollute the chamber.

>>Also, if you put a nice thick, heavy, tamper around the fusor to keep the neutrons inside, the neutron flux could be increased substantially in the chamber for higher probability of Li+n reactions.
>Flux would be higher, but the number of neutrons is still pretty low.

Yeah, a tamper's the kind of thing you'd only use if you're pretty desparate. It would have to be made out of beryllium to be of much use without being enormous. Then we could add beryllium poisoning to our list of fusor hazards.