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: "Stripping" reactions
Date: Aug 10, 2:32 pm
Poster: Jones Beene

On Aug 10, 2:32 pm, Jones Beene wrote:

Stripping: The following is an edited version of information on neutron “stripping” from my files. Stripping, like spallation, is technically not purely a themonuclear reaction, but can be called a quasinuclear reaction.

A lot of the following information began as dialog on the vortex forum in 1997 between Michael Schaffer of General Atomics (Schaffer@gav.gat.com) and others with input from George Miley by way of his lab assistant. Let’s begin with the most basic difference of opinion which goes to the very nature of these phenomena.

Schaffer believes that “The production of neutrons with an arc discharge in deuterium is almost trivial. You can buy thyatrons that do just this. But most of the neutrons [in the Fusors as well] come from stripping, not from fusion.”

OTH , Miley and his followers (including Richard, I beleive) feel that most of the neutrons from the fusor are fusion neutrons on “Boltzman’s” tail, i.e. the long statistical tail of the Maxwellian distribution which shows a “threshold” which should be far higher than what is observed.

No one, to my knowledge, has ever resolved this issue by actually plotting the expected tail against actual observation or even tried to measure thermal neutrons from a fusor (very difficult). Schaffer believes that , if done, the actual neutron production from a fusor would be several orders of magnitude greater than theory predicts - thereforet most of them do NOT derive from fusion. That Coulomb barrier _is_ a barrier to all who would exploit fusion reactions, be they of the hot team, or the cold, or the luke warm (Fusor).

Although the neutron binding energy in the deuteron appears to be 2.2 MeV, collisions at ~20 keV and less knock neutrons out of deuterons in such a way that the neutron goes free. That much is not in doubt. The free "fusion" neutron should possess an average 2.5 MeV if it comes from D+D fusion, however, but if it comes from a stripping reaction, it can be instantly thermalized but will often emerge with up to 1 MeV of energy. This doesn’t help, because if you are measuring neuts at 1 MeV then either side can claim them. Miley would say they have partially thermalized from 2.5.

Miley states that it is stripping which has the “low cross section” (ie reaction probably) compared to D-D at these energies! He also feels that stripping would also give an entirely different neutron energy spectrum. “In our case we ckecked neutron energies and scaling with voltage - both of which agree with D-D fusion. “

However, in followup, it was later determined that Miley did not, in fact , even look for thermal neutrons and has no capability for doing so, but only that the high energy neutrons he found did scale with voltage.

Nature is occasionally kind. It was discovered (I think first by experiment, rather than by calculation from theory, but I do not know the history that well) that the kinetic and electrostatic interaction between ions and electrons in these systems can sometimes produce multi-humped potential distributions. (Other examples of self-organized multi-humped potentials are well known in plasma physics and electrochemistry.) This phenomenon appears to be exploitable to account for fusion neutrons in electrostatic confinement.

Also, the particle distribution can oscillate, either freely or upon being driven. Oscillation modes can have very large amplitudes in the convergence region, leading to periodic short bursts of enhanced fusion. It remains to be seen if any of these or as yet undiscovered or uninvented effects can improve electrostatic confinement sufficiently to yield net fusion power or if the oscillations, in effect, are performing MHD surgery, i.e. stripping.

What is of interest is that, assuming the neutron and proton are somewhat isolated in the D nucleus, as is generally accepted, it may be possible to stimulate one relative to the other. Here is some frequency data at 1 Tesla (CRC HAndbook):

Isotope Freq.

1n 29.1639
1H 42.5764
2H 6.53573
3H 45.4137
2He 32.4352

Therfore, if you are stimulating D at 29.1639 MHz with RF energy in a low energy magnetically polarized plasma then you might tend to catalytically torque the neutron away from the proton, which keeps the extra energy to heat the plasma further.

Currently in the USA there is a small, but fruitful, amount of theory, experiment and development alactivity. The largest group I know of (a couple of people) is at Los Alamos Nat Lab. Presently they are trying to exploit the oscillations. They also are studying combined electrostatic and magnetic confinement of spherically converging ions in a Penning trap.

I have more information scattered about but I don’t know how large the mail files can be on this forum, so I will add more latter if anyone is interested.