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- From: DROEGE@fnald.fnal.gov
- Subject: Status #7 Cell 4A3
- Message-ID: <930106131352.20c082a7@FNALD.FNAL.GOV>
- Sender: scott@zorch.SF-Bay.ORG (Scott Hazen Mueller)
- Reply-To: DROEGE@fnald.fnal.gov
- Organization: Sci.physics.fusion/Mail Gateway
- Date: Wed, 6 Jan 1993 20:07:25 GMT
- Lines: 63
-
- Status #7 Cell 4A3
-
- We are presently running a Takahashi style Pons and Fleischmann "cold fusion"
- experiment. Cell 4A3 contains a 1 cm by 1 cm by 1mm Pd cathode. The cathode
- was squeezed down to 1 mm thickness from a 3mm thick coin bar in a high
- pressure hydraulic press. Fill is 30 cc of .47 M D2O. Cell is running with a
- Pt dummy electrode at a 300 microampere bias current positioned off to one
- side of the anode grid. The Pt anode is wound around the cathode like the
- grid in a 6AS7 vacuum tube. (I might as well say positioned like the tongue
- in a Plesiosarus for all most of you would know.) A glass tube down the
- center of the cell supports the teflon anode/cathode structure at its end.
- The tube contains two solid state thermometers. One where the tube is
- surrounded by the liquid measures the cell temperature. A second is located
- above where the tube is surrounded by gas in the vicinity of the catalyst.
- The glass tube between the two thermometers is stuffed with foam to reduce
- coupling. The catalyst is Engelhard Palladium Catalyst D, which is Palladium
- based. The catalyst is formed as small cylinders which are 0.1" in diameter
- by 0.1" long. The catalyst is located in eight sodium glass tubes which are
- supported in the top of the cell by teflon spacers. The glass tubes are
- mounted vertically with the bottoms slightly closed to keep the cylinders in
- place. This allows condensate to drip out the bottoms of the tubes. About 15
- of the catalyst cylinders are in each of eight tubes. The cell is sealed with
- "O" rings external to the cell volume and any excess gas is removed to an
- atmospheric pressure motor driven syringe. The cell was assembled in an Argon
- filled glove bag after an appropriate cleaning ritual. The cell is operated
- in a null balance calorimeter of my design with a one sigma calibration for
- this run of 0.035 watts. (We will repeat this summary from time to time for
- new readers.)
-
- We are presently operating at 800 ma which results in a cell voltage of 4.5
- volts. Present calorimeter balance is at 7.300 watts. Peak to peak changes
- over the last several hundred hours are consistent with the 0.035 mw one sigma
- calibration. But there is an offset from the December calibration with only
- probable cause due to high temperature TED creep. Remember to get the
- temperature range we are operating with the shell servo off and floating. A
- curious observation is that we are more sensitive to the outside air
- temperature than to the room temperature. So while the room temperature is
- relatively constant, the calorimeter "sees" the outside through the dewar, 1
- 1/2" of foam, a (now) floating aluminum radiation shield, 1 1/2" foam, 10' of
- air, and an R19 house wall or R30 roof.
-
- After about 350 hours of charging, we have accumulated enough (presumed
- oxygen) gas to indicate that the cathode has absorbed D2 gas to an apparent
- 3.0 to 1 D/Pd.
-
- At this point, I guess I favor the "Trickle Down" gas theory. While running
- at one ampere there was a gas run away where the catalyst could not keep up.
- Backing down the cell current to 0.8 ampere gives stable operation, but there
- are still gas bumps. Looks like previously we were running right on the edge
- of what the catalyst could convert. The gas volume is observed to bump up
- slowly 5 cc or so over 15 minutes. Then it decays back to the baseline. This
- is accompanied by a cooling of the catalyst. They are mirror images of each
- other - gas goes up/catalyst goes down.
-
- This still does not explain why there is so much gas in the syringe. 3/1 is a
- lot but for comfort I have the Moore thesis where he found 2.3/1.
-
- For the first week or so the cell voltage had been slowly rising. Now it is
- quite stable so there is every indication that we will be able to run here for
- a long time.
-
- Tom Droege
-
-