From: alexo+@cs.cmu.edu (Alex Orenshteyn)
Newsgroups: sci.physics.fusion
Subject: Re: What should I do next?
Date: 16 Apr 92 01:04:12 GMT
Organization: School of Computer Science, Carnegie Mellon

In article <920415153333.208015bd@FNALD.FNAL.GOV> ames!FNALD.FNAL.GOV!DROEGE writes:
>Thanks to all of you that have tried to teach me some electrochemistry.  I 
>have not replied as I would like, since I have to absorb (or is it adsorb) the 
>information. 
>
>The vote seems to be to keep up discussion in this open forum.  So I would 
>like to interact with you all in the same way that I would with colleagues in 
>the halls and lunchroom if I were anywhere else but Fermilab with 500 hostile 
>physicists. 
>
>My present problem is what to do next.  At 35 days into a run that per P&F 
>might take 70 mean days to show heat, I suspect that this might not be the 
>best way to use my calorimeter.
>
>There has been from the start the suspicion that time to first "anomalous 
>heat" might go as the square of the smallest dimension.  Note that Appleby got 
>results in a rather short time with fine wires.  Also now Takahashi found heat 
>in 5 days with a 1 mm thick plate.  
>
>Some of you have supported the symmetry argument to achieve high loading.  
>Dieter Britz suggested (FD 233) "..., with the important proviso that the top 
>and the bottom of the cathode are flush with the cell top and bottom and not 
>electrochemically accessible."  How does one do this.  At the "enormous 
>fugacity" (I guess this means pressure) won't the gas just blow out the top 
>and bottom no matter what is used as a seal?  Note there have been some 
>reports of success with one sided plates with a different metal on one side.  
>But wouldn't this just blow off.  My favorite reference, G.A. Moore's 1939 
>princeton thesis has pictures of absorbed H lifting off sections of metal.  
>Some of the reports indicate plated seals.  My brother, an electroplater, does 
>not think a plated surface would seal anything, as it tends to be made up of 
>dendritic spongy growths.  
>
>So what do you all think of using long, fine, wires.  The idea would be to 
>load them faster than the gas can work its way out the ends which are 
>necessarily not sealed.  I would argue that this is why Takahashi was able to 
>achieve high loading.  His plate was 1 mm by 25 mm sq.  So maybe only the 
>center spot was loaded.
>
>Moore used 100 mm lengths of 0.05 mm wire.  A very high aspect ratio.  Things 
>were still changing after 10 hours of charging.  He thought he achieved 
>loadings of 2+ to 1.  What could take so long??  If a linear effect then my 
>present 3 mm cylinder should take 600 hours to stop changing.  But if higher 
>order, say a square effect as implied by rumor, then changes could still be 
>going on for 36000 hours.  We are presently at about hour 860.  
>
>I have a Takahashi style cell almost built (by Cam Tibbals who will do a 
>precision job).  This cell will have a 1 cm by 1 cm by 1mm cathode.  I also 
>have some 0.5 mm wire coming.  
>
>By loading the electrolyte after the calorimeter has been closed up, one sigma 
>error is about 100 microwatts.  This means that 2 or 3 milliwats would be 
>fairly convincing, but would take a minimum of one day to measure.  10 to 20 
>milliwats would be visible in an hour or so.  If we assume that 20 watts per 
>cc is the going performance, then a .5mm by 50 mm wire would give 200 mw and 
>be well above our sensitivity.  
>
>So here are some of the possibilities, act like I have cornered you in the 
>hall and react: 
>
>1) Keep running the present cell.  3 mm dia by aprox. 12 mm long cathode with 
>spherical ends.  How long to run before giving up?
>
>2) Run the Takahashi style cell when I get it.  
>
>3) Run the Takahashi style cell but machine the plate thinner to get a higher 
>aspect ratio.  How thin?
>
>4) Run the Takahashi style cell with a thin plate of the Pd-Ag alloy provided
>by Mark Hugo
>
>5) Run a long thin wire, .5 mm by 50 mm.
>
>Wile I would welcome a collaborator or two, here is an opportunity to tell me 
>what to do without being responsible.  
>
>Tom Droege


As long as you are asking for suggestions, I repeat mine: "Run the
cells with liquid D2", this should simplify the accounting.
Newsgroups: sci.physics.fusion