Celani presented one of the most interesting
results at ICCF-14, which I have been anxious to
send to Martin Fleischmann, who is interested in
electromigration. Unfortunately, the paper only
arrived yesterday. I hope to finish editing it soon. Here is a sneak preview.
The title and abstract from the paper:
Deuteron Electromigration in Thin Pd Wires Coated
With Nano-Particles: Evidence for Ultra-Fast
Deuterium Loading and Anomalous, Large Thermal Effects
Lots of authors!
Francesco Celani 1, A. Spallone 1, E. Righi 1, G.
Trenta 1, V. Andreassi 1, A. Marmigi 1, G.
Cappuccio 1, D. Hampai 1, P. Marini 2, V. Di
Stefano 2, M. Nakamura 2, F. Todarello 2, E.
Purchi 2, U. Mastromatteo 3, A. Mancini 4, F.
Falcioni 5, M. Marchesini 5, P. Di Biagio 5, U.
Martini 5, P. G. Sona 6, F. Fontana 7, L. Gamberale 7, D. Garbelli 7
. . .
Abstract
Large excess heat (about 400 J/g of Pd) was
measured by isoperibolic calorimetry when a thin
(50 m) and long (60 cm) Pd wire was heated with
up to 1 A of direct current in D2 gas atmosphere.
The D+ deuterons, in the Pd lattice, are forced
to move toward the most cathodic end of the wire
because of the voltage drop along the wire (the
Cöhn effect). The Pd wire was previously coated
with thin layers of Pd nano-particles, stabilized
and made adherent to the wire surface by heating
it in air up to about 800°C. The excess heat is
generated in coincidence with the phase change
from (a + b) phase to a phase of the Pd-D phase
diagram, and is directly proportional to the
current density (and to the corresponding voltage drop) flowing into the wire.
Here is the Abstract from the Book of Abstracts, which is already on line:
A new procedure has been developed at Frascati
National Laboratories of Istituto Nazionale di
Fisica Nucleare for the production and detection
of anomalous thermal effects on long (50-150 cm)
and thin (50 m) Pd wires. The wires surface was
previously coated with a complex mixture of salts
and nanomaterials, capable to produce, after high
temperatures heating in air, a thin layer of
nanometric materials. The wires, put in a
stainless steel chamber pressurised with
Deuterium gas, were Joule heated by a dc current
(J=5000-50000 A/cm2); the combined effect of high
electric field and high temperature caused a
large deuterons electromigration in the wires.
After applying D2 pressure of 5 bar the following has been observed:
* Extremely short loading time (6-12s) to
achieve the R/Ro value of 2 at temperatures (from
23°C) peaked to 45°C, for few seconds, during
Deuterium intake. The steady state D/Pd ratio was about 0.8 at 23°C;
* Anomalous thermal effects when large
electromigration current was applied.
In our experimental set-up, at the moment, an
isoperibolic calorimeter is used for the
assessment of possible anomalous thermal effects
because fast response time (about 1500s) and
simplicity. Such anomalous effects seem to be
related to a trigger temperature of about 120°C
and tend to increase in magnitude by increasing
wire temperature. Up to now, with a Pd wire of
14mg of weight, an anomalous power of over 3W at
about 300°C was detected: such value is
equivalent to a power density of over 200W/g of Pd.
The anomalous thermal effects are proportional to
the intensity of the current flowing along the
wire and increase with the increasing of the current density.
- Jed
