GTS meeting 10 31 16

• Gun high voltage chamber is under vacuum
  • The electrode was checked by S&A in their lab, while Bubba was tightening the 10" top CF flange. The center of the spherical electrode is about 1.5 mm high, we left it at that.
  • The gun chamber is now under vacuum, after Phil and Bubba made all vacuum piping connections to the bake pump, replaced the 40 l/s ion pump with a smaller 25 l/s ion pump so that the connector could fit with Riad's magnet in nominal position. Phil also added a right angle valve to the Kr line, and the extractor gauge is mounted on a 1" double side flange to prevent the filament from protruding in the gun chamber (this is bad for high voltage conditioning).
  • the bellows spool piece was completed, Bubba and Phil installed it and now Riad's coil magnet is trapped between the gun and the valve. The chamber was evacuated and preliminary leak checks shows both gate valves are leak tight.
  • Bubba and Phil found an issue with the concept of the sliding solenoid coil. For baking configuration, the solenoid coil does not go towards the beam line far enough, the actual beam line 80/20 prevents it to go any further. The 80/20 beam line holds the mount for the first beam line focusing solenoid, and to hold this solenoid at the specified distance (22") from the cathode, the 80/20 beam line has to be at such position that prevents the solenoid coil move further downstream, leaving little room for the oven.

Once more, Bubba and Phil devised a solution. The added a 'sliding shelf' allowing the 80/20 beam line to be placed far enough from the gun to slide the solenoid coil far enough for the bake, and when the focusing solenoid needs to be placed into its specified location, the 'sliding shelf' is moved towards the gun, with the focusing solenoid mount on it. Clever! This is something we all should have recognized from the design, my asking the designers to generate a model with the two solenoid magnets in the bake and in the nominal configurations.

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• Cathode prep chamber is almost ready
  • Mamun and Yan are making great progress, they have added six pucks, one extra Cs effusion source, and even TC to measure the source temperature at its tip and to measure the puck temperature.