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Final Live Run on V2.0 Protocol

Scritto da Ryan Hunt on .

We are about to commence the final live run on the Celani wire in the US Cell 1.3A.  The wire has been loading in hydrogen very slowly for a couple of weeks, now.  It currently sits at R/R0=0.839.  It is not the lowest resistance we have seen with this wire, but it is definitely not dropped in a long time.

We will be dropping the pressure to approx 1 millibar and heating through the active wire to 25 watts (within calibration conditions).  We will be watching for behavior similar to earlier runs where the indicated output power exceeded the confidence interval (approx 0.5W) PLUS the indicated excess power out from Cell B, the control with no hydrogen present running at the same power.  

Doing this protocol, we had some interesting results in the first few runs.  Celani was explaining that he saw something similar after loading at higher pressure and then going down to 0.5 bar or 0.2 bar.  Much like we saw in earlier tests where the resistance of the wire increased, and the vacuum level dropped from 1.9 mbar to 1.1 mbar over the same period, he believes that running at lower pressures causes the necessary hydrogen flux to drive the reaction.  Because he was running at a mild negative pressure, his off gassing lasted much, much longer, giving a larger total energy produced before the flux, and the effect stopped.

After this live run we will compile a summary of the results we have seen running the V2.0 protocol.  Then, we will transition the cells to run in a differential mode where we can simply tell how much hotter the active cell is than the control cell.  The advantage is that we will be able to explore different pressure and temperature regimes.  We will still use the original V2.0 Protocol calibrations, but we will only be able to use that as a reference instead of a hard value.

As usual, updates will be posted here for a while. 

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0 #12 Ecco 2013-08-14 19:31
@MFMP: I see you've started the differential test. Are you going to ramp up power as if the cell were being calibrated? It will be interesting checking out if plotting temperature/pow er curves will yield different results than calibrations.

The active cell (B) should over a certain threshold show a significantly larger increase in temperatures than one would normally expect.
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0 #11 Malachi Heder 2013-08-12 21:22
@ Ecco

We were checking for vacuum tightness. We are hesitant to degass the wires.
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0 #10 Ecco 2013-08-12 20:33
@MFMP: from the experiment log:

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...The cells are hooked back up and vacuuming now...
As a reminder, if what you're trying to accomplish at this moment is removing trace gases from the cells, unless you apply heat during the operation, that is not going to be a very efficient process.

An idea, if you want to experiment next time: you could try applying medium power (10-15W) on both wires under mild vacuum (1-2 mbar) to remove oxides and trace gases from the entire cell, then, rather low power to them (for example ~1-2W) under the most powerful vacuum you can apply (0.01 mbar, I think), to degas the wires thoroughly. It would be useful if you were able to measure wire temperature with the IR sensor and tried to adjust power so that wire temperature would not exceed 350-400 °C during high vacuum degassing.
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0 #9 Ecco 2013-08-12 15:23
@MFMP: if you're going to operate the cells in differential mode, putting only inert wires on one cell and only active wires on the other would allow you to use hydrogen for both cells and consequently put to rest criticisms about the different thermal conductivity of the residual gases under vacuum (or under pressurized conditions for what matters).
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0 #8 Ecco 2013-08-07 22:30
For some reason resistance readings for the active wire in Cell US 1.3 A became smooth in the past 30 minutes or so. Weird.


i.imgur.com/E2Fz55B.png
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0 #7 Ecco 2013-08-07 21:46
@Edwin Pell: I asked Ryan to test changing input power from 25W on the active wire to 12.5W on the active wire + 12.5W on the heating wire. This caused changes in active wire resistance.
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0 #6 Edwin Pell 2013-08-07 21:42
Was that glitch on the input power intentional? Either way can you glitch the input power again?
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0 #5 Ecco 2013-08-07 21:42
@Ryan Hunt: thanks for performing that test on Cell A. Temperatures increased more than I expected. I was hoping that calibrations would still be usable when applying power to both wires at the same time, in order to explore higher temperatures under the same vacuum without frying them. Too bad.

This leads to a possible future test when both cells will be set up for differential mode operation. You might remember the temperature/exc ess heat correlation graph from STM I posted a while back on another blog post (this one: i.imgur.com/5IozJC9.png ). That graph showed two bumps in excess power, one at about 230°C and another at about 335°C.

If you start increasing power (and therefore temperatures) little by little on both cells, and if the active cell is indeed active, it should show similar bumps, while the inactive cell shouldn't. This should happen at temperatures higher than they currently are.

Whether the cells are calibrated or not for dual wire heating conditions, shouldn't matter for this test as we would only be watching for changes in temperatures, not the actual values.

To avoid damaging the glass tube or the wires under vacuum I would limit maximum input power to 2x25W or T_Ext temperature to 270°C, whichever occurs first.
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0 #4 Edwin Pell 2013-08-07 21:33
What happened at 21:08? Now the resistance is going down.
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0 #3 Ecco 2013-08-07 20:57
@Ryan Hunt: if you're about to declare this a null result, could you perform a short test?

Instead of applying 25W to the active wire, try applying 12.5W to both wires at the same time, if possible, so that the total would still be 25W. I'm curious to see what will be the Delta T at which T_Ext1 will settle and how it will compare to the calibration values here:

docs.google.com/.../...
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0 #2 Ryan Hunt 2013-08-07 20:34
Cell B is at 25.8. Cell A is at 26.25. 0.45 watts is approximately the 95% confidence interval. Unless it keep rising, it looks like a null result.
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0 #1 Ecco 2013-08-07 19:03
Not much going on after almost 2 hours since the test started, at least at the current indirect power level of 25W. Temperatures might be too low and wire performance might have degraded since its first run.
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