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 - the answer???
Date: Nov 16, 9:18 am
Poster: Richard Hull

On Nov 16, 9:18 am, Richard Hull wrote:

My question regarding the stripping of neutrons is answered,.........I think........ sorta'........ kinda'....... maybe, not really.

I have included below, my original question, and below that, the answer. It appears the confusion on this issue is universal and multiple guess.
We must live with the possibility, the retort, and the embarrassment of striping for all of our days with no hard and fast data it seems. Yes, we know the exact binding energy is way beyond our energy levels, but it is hinted that special instances can have stripping occur below the binding energy.

With this seemingly simple issue floating about the cosmos, unanswered in text or brains of the "informed", can we really rely on the validity of quarks, charmed, flavored and colored.......the neutrino.... the higgs boson and the plethora of particles that must "certainly exist" in the standard model????!!!!!

They are articles of faith in the new church of nuclear physics tended by the hand waving preisthood of the dutifully annointed telling the faithful how it really is.

Pardon my negativism. I am but an out of favor, pragmatic, empiricist. (from Missouri)

Richard Hull

The promised Q and A

The question.............

In the fusion Quest where deuterium-deuterium fusion is the goal, there is
an often mentioned caveat regarding "stripping". It appears that one might
be deceived if one were using a neutron signature to announce fusion in the
above scenario if neutrons are stripped from the deuteron in a collisional

First, what is the normal energy required to effect stripping? What
particles are canidates for this action? With deuterons colliding head on
with deuterons, what might be the EV energy range where stripping would
begin to be seen? The d-d cross section allows for small amounts of real
fusion in focused, colliding, beams of deuterons at energies as low as
10kev. Would stripping be going on here too, muddying the attempt at
measuring fusion rates with a neutron counter (assuming good neutron
measuring techniques)?

The process is found mentioned in several texts I have consulted, but no
details are given.

The reply...................

Your question was answered by:
Donald Howard Staff, Nuclear Engineering, Retired

You are correct in that there is little information about deuterium, at
least in this country - perhaps in Canada there is more, so I can't quote
ev levels for these reactions.

Without wandering to deeply into D-D fusion, I worked at a critical
facility for a heavy water reactor, and almost anything can strip neutrons
from deuterons. The standard light water reactor has a nominal six groups
of delayed neutrons, but the heavy water moderated type has nine groups,
the longest at about a 100,000 second average life. Those extra groups
are tied to fission product gamma, kicking photoneutrons out of the

The stuff is that unstable.

Whether the photoneutrons were produced at below 10 kev was and maybe
still is unknown. All that was discussed were "groups" of delayed
neutrons, know by their time-dependent behavior, not by which isotopes
contributed to a particular group.

Using a neutron monitor to monitor the fusion reaction might work if you
could look exclusively for those 14 Mev neutrons that come directly from
the reaction. We fission types always thought that any fusion reactor
should be surrounded by a U-238 blanket so we could use those wasted
neutrons to breed Pu-239 to fuel our power producers.


It appears that a fissioneer was the only guy willing to step up to the plate and with little info to impart. Still, he gave it a shot. I wish I could have been in the minds of the two prior canidates who kicked the question back into the pool.