From: ames!FNALD.FNAL.GOV!DROEGE
Subject: Cathode Loading
Reply-To: ames!FNALD.FNAL.GOV!DROEGE
Organization: Sci.physics.fusion/Mail Gateway
Date: Thu, 12 Nov 1992 20:44:09 GMT

More discussion on gas loading.

First I would like to say that I respect Tod Green's decision that resistance 
is the best way to measure gas loading.  While he is not posting his 
measurements as I am, it is obvious that he has done a lot of work.  It is 
just not possible to reach his level of understanding of the problems without 
trying a lot of things.  Also thanks to Dieter Britz for thinking with me.  
This is the reason I make these posts.  Some of you read them and think. 

The first thing to know, is that **all** of the electrolyzed D/H is absorbed 
by a fresh palladium cathode.  I would put this at 98 +/- 2%.  The palladium 
really wants that hydrogen!  This is when measured at relatively low current 
densities of 25 to 50 ma per sq cm.  I think it is also true at current 
densities of 600 ma per sq cm, but it is harder to make the measurement. 

1) The excess oxygen produced exactly matches the applied current.  This 
either means that the excess oxygen is that left over after all the D/H is 
absorbed or that there are two (or more - Why accept limits on miracles?*) 
processes going on that somehow exactly add to the expected result.  I think 
Occam's razor leads us to the simpler explanation.  This seems to hold between 
0% D/Pd and 60% D/Pd.  After this, the absorption percentage starts to 
decrease.  This from memory, I could generate a nice curve with a little 
effort. 

2) The closed calorimeter balance indicates that 1) is at least close.  The 
lost heat matches the expected difference between the heat lost because the 
absorbed D/H is not burned, and the heat of absorption of D/H by palladium.  
This measurement is at least good to 20% of the heat involved.  Some day I 
will run a large chunk of palladium and get a good measurement of heat of 
absorption versus loading.  

3) With a polished cathode we hit a limit at low current of about 0.94 D/Pd.  
Pushing up the current in steps gets to higher current loadings.  I suspect 
that this portion is adsorbed *note the d*.  Or at least that it is very near 
the surface.  A heavily loaded cathode often appears to bump gas in and out.  
Many small 1% D/Pd, but also as much as 10%.  But this is by the excess oxygen 
method.  What I observe is a sudden increase in gas volume.  By sudden I mean 
that with a .2 cc cathode, excess (presumed oxygen) gas accumulates at the 
rate of 1 cc per minute.  Sometimes as much as 10 to 15 cc are accumulated.  
Typically the gas is held by the cathode for an hour or so, then it is coughed 
back out at about the same rate.  I do not think that this is some funny 
artifact of the catalyst.  The above events are confirmed by a catalyst 
temperature reduction during gas ab/dsorption and a catalyst temperature 
increase when it is coughed back out.  Nothing much else seems to happen 
during these events.  

4)  The manufacture of "yellow crud" is not likely to affect the above 
measurements.  We charged the last sample (slightly less than 0.2 cc) at about 
100 ma.  This makes 20.9 cc of oxygen (and 41.8 cc D/H) an hour.  We got to 
0.94 in about six hours.  We are now running at 1 ampere and are losing about 
.3 cc per hour (of oxygen?).  If the oxygen eats the platinum, then the 
process would likely be proportional to current density.  So we would expect 
the loss of 0.03 cc of oxygen per hour at 100 ma.  This means that "yellow 
crud" formation is likely a 0.2% effect during charging.  At worst, if it is a 
constant effect independent of current, then it is still only a 2% effect.  
This is well within our likely error.  

Note that while I cannot say wonderful things about the precision of my gas 
measurement kludge, I can (and have) calibrated it against straight gas 
generation by current which I can measure *very* well.  Everything is good to 
within barometric pressure errors.  I do not correct for barometric pressure, 
but I do keep an eye on the Chicago weather.  

Note that the last 3 experiments all got to close to 0.94 initial loading.  I 
attribute this to surface grinding the samples, as previous cathodes did not 
load as high.  We have also achieved higher loading with ground flat plates 
than with ground rods.  Possibly Takahashi is right and there is something 
special about symmetrical loading of a flat plate.  One reason to believe the 
measurement is that many previous cathodes got to loadings like 0.65, 0.7. and 
0.86; more like the standard values.    This last one got to 1.05 during the 
steps up to high current.  The first cathode was 1 cm by 1 cm by 1 mm and was 
started with a D2 fill.  The second cell was a 1 cm by 2 cm by 1 mm cathode 
and was started with an Oxygen fill.  The present run was a re-run of the 1 cm 
by 2 cm by 1 mm cathode and was just filled with air.  

Tom Droege
____________________________________________________________________________
*Some of the critics have classified cold fusion phenomena by the number of 
miracles required.  Are there higher order miracles like there are higher 
order infinities?  Have the critics established that a seven miracle event is 
any less likely than a .5 miracle event?  I propose that since:

infinity + infinity = infinity

miracle + miracle + miracle + ... = miracle

So it is not as hard as some of the critics have proposed.  We just need one
miracle for cold fusion.