NetNews Usenet Archive 1992 #18/NN_1992_18.iso/spool/sci/physics/fusion/2019

Text File | 1992-08-13 | 5.3 KB | 102 lines

Newsgroups: sci.physics.fusion
Path: sparky!uunet!coplex!chuck
From: [e-mail] (Chuck Sites)
Subject: Deterium Resonance
Organization: Copper Electronics, Inc.
Date: Thu, 13 Aug 1992 21:05:11 GMT
Message-ID: <[e-mail]>
Summary: Just a collection of thoughts
Keywords: Ying resonance deterium low energy
Lines: 90

   The past couple of weeks have been a learning experience for me
because of the discussions on Ying and the the D + gamma interaction.
The focus has been that one interaction "D + gamma" and after considering
all the comments by this group, it seems like another tract must
be pursued.  I think the approach Robert Euchus is following is quite
interesting.  Paul Dietz's comments about the gamma+D cross section
are important too, however, I would like to point out, in response to
Paul, that cross sections for interaction are inherently dependent
on the energy of the interacting particles.  The only real way to
show that PdD(x) is no different from D2 with respect to a gamma+D
cross section is by experiment.  Right now, I don't know anyone
that has done that type of systematic study.

   My initial concept of the low energy gamma D interaction
was one of a low energy S to D state being stimulated by gamma.
Pure singlet to triplet state parity transition causing and enhancement
of the exchange potential.  The deeper one looks at the D+gamma interaction,
the deeper one is pushed into QED and high energy meson theory, for
guidance.  But then this may be a forest from the trees problem.

   In that vain, we know D+gamma must interact by means of electric and
magnetic moments.  The D nucleus is cigar shaped, and that appears in
scattering experiments, as the quadrupole moment. It is only the proton
within the D nuclei that has an electric moment.  So any low energy
(E<B) gamma absorption must deal with this.  However,  both n & p react
to the magnetic moment, thus to effect the nuclear exchange between the
two, the E/M wave has to be in phase with the moments of the pair.  Low
energy neutron scattering off the protons becomes important to the model
here, because ultra-low momentum energy neutrons interact with protons
by giving off gamma at 2.224MeV.  (See F.Close & D.Blue comments on
the P&F gamma spectrum a month or so back).  What this implies, is that
for the reverse to occur is the energy of the absorbed gamma must be
2.224MeV or greater for the reverse to occur.  I agree totally with that
contention.  From reading, I gather the maximum cross section for
D + gamma -> p + n occurs at close to twice that value 4.6MeV.

   My bit of speculation evolved around, whether there are states
in a deuteron, where gamma of (E<B) could excite a below (B = binding
energy) strong force interaction state change.  Basically in the standard
nuclear model, with D and gamma, it's all or nothing for a gamma initiated
strong force state change as J. Carr and others have pointed out. Still
I'm left wondering if there may be pertribation in the D (E<B) state, if
one considers the gamma could effect the nuclear exchange force directly.
For example, if the pion, has even the smallest magnetic or electric moment,
it might allow for an (E<B) D* state.  Also let us not forget the DeBrogle
in all this. In low momentum high energy interacting systems, like a
n -pion- p nucleus, charge can exchange. Even in quantumness, time
is important, as the coincidence of an interaction is probabilistic.
So if the electric dipole moment is exchanged with the pi meson and
happens to be caught in the exchange by a gamma, some interesting
interactions might take place.

   The other possibility is that a gamma doesn't stimulate a single D
by itself, but interacts with the pair.  This would be like a dipole
resonance.  Unlike D2 gas, PdD(x) has some geometrical aspects that
may allow for such a scheme.  That is, while D in Pd is pretty mobile,
it's constrained to certain directions of mobility by the lattice.
Because electron-gamma interactions are at best a small pertribation
to the overall gamma energy, there is no problem with gamma reaching
the pair. However there is the question of how strongly a D dipole
would interact and how the paired exchange forces react to the
instantaneous oscillation of a photon D pair impact.  Actually a full
description would probably require QED to describe the initial
dynamics, but then a good approximation might be had with normal
EM.  Also, if there are components of the exchange force that couple
to such a paired transition it may be do-able.  Conceptually
this would be like microwave oven, the glass cup doesn't get hot,
but the water does.

   Obviously, someone needs to put a good sintilation spectrometer
next to a Ying cell.  If nothing more than to satisfy this groups
curiosity ;-).

-------------------------------------------------------------------

Two other things unrelated to the above.

  1st.  Frank Close has a nice review of Huizenga's book in the July
23 issue Nature.  Way to go Frank!  As a TB, I may argue against some
of your positions, but I won't argue with your history of CF.

 2nd.  If you get a chance, see the movie "Mind Walk".  It is nothing
short of a terrific argument between a physicist, a politician, and
poet.  The physicist's argument was one of the best descriptions of
QM I've heard. The poet wasn't bad either.  Scale: weak to awesome.
Word: Awesome.


Have fun,
Chuck