GTS meeting 9 25 15

• Sheep chamber

In order to bake the cathode prep chamber along with the gun vacuum chamber, it needs to be under vacuum. We can start installing components such as effusion sources and viewports if we know their location. If not, we can use for now blanks. The ion pumps for both chambers need to be connected to the bake ion pump through a common "T". We need to find a flexible vacuum hose of proper length. An ion pump was connected to the cathode prep chamber a few days after the picture below was taken.

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• Electrode polishing (Bubba)
  • Shed (John's design): has polished to 1 micron DPP. Bubba is running a test on this piece using 3 micron diamond slurry on the barrel polisher. He discovered that the marks done by the 3 micron diamond are deeper than expected. He realized this is due to the weight of the piece, ie more force per unit area is exerted compared to the lighter electrode ball. After another 20 hr in the barrel polisher with 3-micron diamond solution, the shed is out, with no evident improvements. Bubba is almost done re-polishing on the potter's wheel with diamond paste.
  • Ball. Sections of the ball were polished with 600-grit hard sand paper, and some with 600-grit soft sand paper. Then the ball was placed in the barrel polisher with 3-micron diamond slurry. Bubba discovered that the barrel polishing does remove the 600-grit soft sand paper marks, but not the 600-grit hard paper marks. The ball is back in the barrel polishing with 3-micron diamond slurry. Afterwards, Bubba expects to finish diamond paste polishing in about one week.
  • Back-end pice. Started polishing by hand.
  • Barrel polishing is looking promising, but we need to do tests and studies for developing a recipe.

• The perks of Barrel Polishing:

-"Hey, this looks like...mmmhhhh....oatmeal!" -"Yeah, right, like "oatmeal"