From: Jed Rothwell <72240.1256@compuserve.com>
Subject: Origin of heat
Reply-To: Jed Rothwell <72240.1256@compuserve.com>
Organization: Sci.physics.fusion/Mail Gateway
Date: Thu, 12 Nov 1992 15:31:11 GMT

To: >INTERNET:fusion@zorch.SF-Bay.ORG

Jim Batka asks:

"Have you [Tom Droege] (or anyone else that you know of) tried to localize
where the heat production (if any) is taking place?  It seems to me that
everyone is assuming it is taking place at the Palladium anode but no one
has bothered to check." [I assume this is a typo for "at the cathode."]

This was discussed informally at the Nagoya Conference. Some people thought
about using things like heat sensing cameras, to make videos or still photos
of working cells in plastic or glass cells; other people suggested that
thermocouple probes might be placed right next to the cathodes. That would be
a tight fit, and the probe might disrupt the process if it touched the metal.
That is the same problem people face when they try to measure loading by
measuring resistance.

The best evidence we have is that all of the heat originates in the cathode:

1. Close up videos and photos of P&F's vigorously boiling cells show that
virtually all of the bubbles are coming from the cathode. Actually, the anode
shows very few signs of bubbling at all, not even the usual amount you would
expect from electrolysis, which is interesting.

2. Other people who have observed boiling cells have noted vigorous activity
around the cathode, and nowhere else. There is a lot to be said for old
fashioned 'look and see' observations. I recommend glass or plastic cells with
old fashioned mercury thermometers in them, like the ones used by P&F,
Takahashi, Storms and me. I also recommend safety glasses, and heavy
plexiglass in front of the cells! A bright lamp helps. You can see a great
deal if you just *look*; you can answer questions about mixing, cleanliness,
and the condition of the platinum black on the palladium cathode. I say, look
at the cell and *think* before you go off on a tangent staring at the numbers
from a computer data collection device, or worse, from a computer simulation.
These experiments make much more sense when you confront something like
Notoya's cell with a multimeter, a thermometer, and a little common sense.

3. Cells with multiple thermocouples, like mine, show that the temperature of
the electrolyte is fairly uniform, and it must be much cooler than the
cathode. When you turn up the power and increase the joule heating, you can
sometimes see "waves" of heat hitting the thermocouples closest to the cathode
first.

4. Our top thermocouple was frequently out of the water, in the 'head space.'
It showed that the gas up there was close to ambient temperature. However, we
were not getting any excess heat, so that may not prove anything.

I do not know any CF workers who have postulated that the reaction takes place
anywhere but in the cathode, either at the surface, or in the bulk. The people
who want to make videos of the cathode to look for the heat are asking: Is the
heat spread uniformly throughout the cathode, or is it concentrated in local
hot spots? Does the heat start up in one part of the cathode and linger there,
or does it come and go in different parts? Answering this will be a difficult,
challenging job.

- Jed

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