Like a mythical Phoenix, the dual vertical cells have each been reborn from their own ashes. Well, maybe not ashes, exactly, but after a good day and a half we have refurbished each cell and we are ready to start a test or two again. The process was quite involved and demands a great many pictures.
First step: Taking the cells into the assembly room from the lab. Malachi's nice smile here is actually an indication of his fierce determination to make bring this beast back to life.
Once in the assembly room we got a good look at the damage. It was actually kind of pretty with what I would call a copper-striped-mechano-tubular-tiger look.
Cell 1.0 definitely had more of a black color to it.
When we opened up the cell, we could see the nice plating on the mica in cell 1.0. Again, cell 1.1 definitely looked more black. Besides changing the IR absorption of the wire supports, we found that this thin metal coating was very conductive. This meant we had to replace the mica and the Macor.
The glass looked very nice, too. Anybody wanna make a nice lamp?
Then we got to work rebuilding everything. We had one last pyrex tube in stock and an extra set of the Macor and the mica pieces that were to be used in other cells.
The new mica supports had to have the binder baked out of them, so we improvised this process.
The nozzle of hte heat gun fit inside the quartz tube. Then, the heat gun was set to about 530C and the mica was left to cook inside the tube with air blowing over it for about 4 hours. The binder in the mica as well as in the mineral wool insulation made quite a stink as it cooked out.
Meanwhile, after a few hours we started to get the cells together again.
While we used all new macor, we did learn that a little buffer could polish off most of the metal. And Wes finished cleaning them with a short bath in Muriatic acid. We will use that set of supports for the stainless clad test cell that will go in the air flow calorimeter.
Finally, we mounted the cells back in the stand and re-attached all the wires and plumbing. We are definitely getting better at all the mechanics involved.
Tadah!! All ready to test.
After this, we pulled a vacuum on each cell. It took cell 1.0 a while to off gas a bunch of ethanol that was left inside it. Cell 1.1 pumped down more quickly.
Then we loaded with Helium for a first test. The reasoning is that if we establish a run with helium, then when we put in the Celani Wire we can test it in Helium and assure ourselves that the unloaded Celani wire is in the same configuration and behaves similarly to the control Isotan44 wire.
After the Helium, we will run a test in 1 bar H2 and see if the rebuilt cells perform near the center of the confidence intervals from last week's data. If it does, we are golden and can move on to putting in new Celani wires. Otherwise, we will have to spend several days running new calibration tests.
In other news, as we were waiting for some glue to cure and some mica to bake out, we got a chance to play with some pieces and try out a slightly different idea for wire supports. We got some 0.6mm mica sheet, much like what Mathieu used when he rebuilt his cell. I am hoping to make a denser smaller core that further isolates the hot part from the flanges. After a little fine machining with a dremel tool...
It would look something like this.
But that experiment will have to wait till we get the first ones rolling.