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
Date: Jun 14, 12:53 pm
Poster: Jim Lux

On Jun 14, 12:53 pm, Jim Lux wrote:

>The D-D reaction cross section, at our energy levels of 80KEV, (20kv applied - see earlier posts), is about 10 millibarns (very low). The
>
>The D-T reaction displays a uniform nearly 400X increase over the D-D reaction!!! At our current


Which is why the neutron generator folks at MFPhysics use tritiated targets, no doubt. Their web site (and other research papers that I found when doing a web search for such devices) indicates they use a few curies of T. How much is this, in practical terms? T half life is pretty short compared to radium, so mass wise it isn't a huge amount (about 2 mg/curie (3.3E-5 mol)), or about 0.7 cc at STP. I'll bet this is a bunch more than is in a tritiated gun sight or equivalent. And, to put it in perspective, I think generating it yourself is probably hopeless, because that few curies is still >1E19 atoms, which, if you are generating 1e5 neuts/second will take 1e14 seconds, MINIMUM, to generate.

Of course once you have a little bit of T, then the neuts from that reaction will help make more, etc....

And, if you are running at 10 microns pressure in a 1 liter volume, and you want a 50% mix, you really only need 1/100,000 of a liter (at STP), which is (assuming my number of .7cc/C is right), or around .013 curie.. So, is 10 milliCurie of T a lot or a little?