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: Stripping - the answer???
Date: Nov 18, 5:39 pm
Poster: Richard Hester

On Nov 18, 5:39 pm, Richard Hester wrote:

A couple of small points:

1) The tail of the cross section curve for the D-D reaction is reasonably significant at a couple of tens of kev, such that one could not distinguish between a low energy stripping reaction (if such exists, which I doubt) and fusion, if one is simply looking for neutrons with the likes of a BF3 counter. The mega fusion folks with their Tokamaks and such are operating with plasmas of mean ion temperature even farther down on the curve, making it imperative for them to use the D-T reaction for "practical" results, but even they can get some D-D neutrons from one scheme or the other.

2) The method to distinguish between products of a low energy stripping reaction and D-D fusion would be to look at the energy of the neutrons emitted. In a way, one is already doing so with the BC-270 detector, since it is looking at proton recoil, and the proton energy will not be sufficient to provide much energy into the scintillator (remember,the proton has to bull its way from its production zone to the phosphor, making electron-ion pairs all the way...) unless the energy of the incoming neutrons is considerable.

If a low stripping reaction is somehow magically creating high energy neutrons, it really doesn't matter whether you call it fusion or stripping, for our purposes. I doubt this is happening, though. The cross sections for fusion on the low energy side of the tail have been exhaustively investigated (and indeed are vital for conventional efforts). The possibility for d-d reaction exists at >10kev energies, and has been demonstrated and documented.

I too, will ignore the nay-sayers and get on with business. I'll be looking for high energy protons with a semiconductor detector, so I will be able to directly detect and measure energy of reaction products, as pulse height is a direct function of energy for these detectors. Given the way things are going, I'm not expecting results until some time next year, but even the plodders get there eventually.....

Richard Hester