I've been looking at:
Letts, D. and P.L. Hagelstein. Stimulation of Optical Phonons in
Deuterated Palladium. in ICCF-14 International
Conference on Condensed Matter Nuclear Science. 2008. Washington, DC.
http://lenr-canr.org/acrobat/LettsDstimulatio.pdf
This work has not received adequate attention.
There is more at http://www.iscmns.org/CMNS/JCMNS-Vol3.pdf -- page 59
et seq. (PDF page 65)
Summary:
A cathode of palladium foil is prepared, according to a protocoal
which Letts has found has high success at producing excess heat. The
cathode is loaded to perhaps 85% (?), then an alternate anode of gold
is energized, and gold is thus plated onto the cathode. Electrolysis
power is maintained after the loading period and through the experiment.
The cathode is illuminated at a spot with two lasers, tuned to
produce beat frequencies in the range of 3-22 THz.
Many experimental issues remain to be explored. However, aside from
some unlikely possibilities, it appears that there is a strong
response to stimulation, such that when there is, under the
experimental conditions, no laser stimulation, or stimulation
off-resonance, there is little or no XP. The response appears to be
quantitatively predictable. Further, that there would be such a
response was predicted from theory by Hagelstein. However, it is not
my purpose here to go into the Hagelstein's theory and its
implications, except to note that this work may be helping to
elucidate conditions under which cold fusion takes place. It is the
level of control that is important.
(One of the problems in the field is that there may be alternate
conditions, there is not necessarily just one mechanism. We need to
keep that in mind. For example, the Letts work generally involves
using a strong magnetic field, whereas other work shows XP without a
strong field. On the other hand, perhaps only a weak field is needed!
Such as that of the earth. Field orinetation might matter! One of the
avenues of approach here is to explore the effect across a range of
magnetic field strengths and orientations. Obviously, as well, laser
stimulation is not a necessary cause of XP under all conditions. The
Letts cells may be, I can speculate, held at a loading level under
that where the normal FPHE arises; but the THz stimulation shoves
them into activity.)
In order to replicate this work, THz stimulation is required. To do
it as Letts did it is expensive.
How can stimulation, perhaps at 14.8 THz or 21.78 THz, be arranged?
It may be possible to obtain inexpensive laser diodes chosen in pairs
to produce these frequencies, or close enough. (How close is
necessary is a matter to be explored). The power need not be high,
there are signs that the triggering threshold may be below 1 mW per
laser. It may be possible to tune inexpensive diodes by controlling
their temperature, over a limited range.
Filters in the THz region might also be obtained or fabricated.
For general interest, I'll add some results of prior discussion. The
gold deposit appears to be necessary for laser stimulation to have an
effect. It is that layer, perhaps, that mixes the two laser
frequencies, producing the effective beat frequency.
Plans are underway to analyze cell atmosphere and used cathodes for
helium, and, at least at first, this could be an important aspect of
this work. There is speculation that the resonance above 20 THz is
due to hydrogen, and so the product from that stimulation might not
be helium! It is conceivable that the cathode design with a gold
deposit traps helium, better than an open cathode would. If so, full
analysis of the cathode might reveal a great deal of information
about reaction site as well as, perhaps, better determination of
reaction Q (heat/helium) than has previously been obtained.
Any brainstorming, especially informed, on how to generate the THz
stimulation will be appreciated. My goal, generally, has been to
lower the entry cost for doing important cold fusion experimental work.
