Please ignore my post below. I confused the earlier work with the
present experiment.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
On Feb 1, 2009, at 6:46 AM, Horace Heffner wrote:
On Jan 31, 2009, at 2:36 PM, Michel Jullian wrote:
2009/1/27 Jed Rothwell <[email protected]>:
...
This paper is slightly revised:
Celani, F., et al. Deuteron Electromigration in Thin Pd Wires
Coated With
Nano-Particles: Evidence for Ultra-Fast Deuterium Loading and
Anomalous,
Large Thermal Effects. in ICCF-14 International Conference on
Condensed
Matter Nuclear Science. 2008. Washington, DC.
http://lenr-canr.org/acrobat/CelaniFdeuteronel.pdf
I was wondering, could the electromigration pressure possibly induce
deuterium desorption at the negative end of the Pd wire, anyone
knows?
Michel
P.S. typo: "braded" should be braided.
I would expect there to be periodiic desorption along the entire
length of the cathode wire because both the electromigration and
loading is driven by 1-2 microsecond pulses, to maximums of 300 V
and 150 A, applied at a rate of up to 30 kHz. This implies to me
the concentration in the surface of the *entire cathode wire*
increases for about 1 microsecond of each pulse and decreases for
the interim rest period. I think this is true whether or not the
cathode potential is sustained below some maximum negative voltage,
i.e. sustained as a cathode throughout each cycle.
Celani states the electromigration reaches/creates a [longitudinal]
equilibrium concentration gradient. However, since the loading
current itself drives the entire process, once the loading process
completes by reaching equilibrium I would expect the peak
instantaneous radial electromigration each cycle to far exceed the
peak instantaneous longitudinal migration, both positively and
negatively. Almost the entire 300 V potential is applied radially
to the wire surface, while the longitudinal potential drop through
the wire itself, i.e. the longitudinal i*R drop, is comparatively
small, and the internal longitudinal field strength very small.
Also notable is the fact the vast majority of the longitudinal
current through the wire is via electrons. The net longitudinal
electromigration current is thus very small. I think the hydrogen
component of the electromigration current is essentially a purely
AC current once equilibrium is reached, and that the radial
pressure driven (or concentration driven) component of hydrogen
flux far exceeds the longitudinally driven electromigration
component of the hydrogen flux.
I would think it might be more effective (to isolate and determine
the actual effects of electromigration itself) to drive the
longitudinal electromigration via an A/C process via an A/C
potential applied through the cathode wire directly, while
maintaining loading by sustaining the cathode at a high DC
potential. BTW, it has been known since early on that pulsed DC,
i.e. pulsed A/C imposed over the DC cathodic current was more
effective at generating excess heat, though use of this technique
caused a lot of controversy regarding power measurements.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
