[Dr. Richardson, Aiden] Large Update

Removed most of the insulation on the chamber in order to pull back some of the heater tape to get to the flange connecting the bypass line to the valve under the RGA line. Most of the heater tape on the bottom half of the chamber was pulled off and the rest will need to be removed as well in order to place the start of the heater tape on the barrel of the chamber rather than one of the flanges.

Engaged the valve under the RGA line to prevent it from getting more contaminated. Turned off the turbo pump. Turned off the scroll pump. Let the turbo pump sit for a few minutes to let the fans stop. Then leaked the turbo pump volume by turning the knob slowly on top of the turbo. Then proceeded to unscrew the bypass line after done leaking the volume. Replaced the copper gasket and then proceeded to screw it on while maintaining a circular path to ensure equal pressure on the gasket. BEWARE THAT REUSING SILVER PLATED SCREWS HAS A HIGH CHANCE OF STRIPPING THE SCREW AND WILL RESULT IN A LOT OF WORK TO GET THEM OFF. IT IS RECOMMENDED TO USE NEW SILVER SCREWS. HOWEVER WE HAVE NONE LEFT SO DO NOT TRY TO REUSE ANY SCREWS UNTIL WE HAVE SPARES. We were able to use the remaining two spare screws to tighten the flange to a point where it will not tighten anymore.

Then the lid was removed in order to inspect the inside of the chamber and the Viton O-Ring. The chamber had no physical damage and the viton had some visual damage that may correlate to the failure observed during bake 3. Note that some metal chips were found inside of the o-ring groove and needed to be removed. We changed out the o-ring for a new one and placed the old one inside of an anti static bag labeled "Viton O-Ring". Put the lid back on after inspecting for damage and put the bolts on hand tightened. Started to pump down again by turning on the scroll pump first until full range gauge 1 read below 1 torr and then began to turbo pump. The turbo pump was running for 1.5 hours until it plateaued around 3e-4 torr. We then realized the bolts on the lid needed to be tightened more with a wrench. After further tightening the pressure quickly dropped to 6e-6 torr. In the future the bolts should be tightened with a wrench from the begining.

Then proceeded to Helium leak test every weld, flange, and valve. Two of the flanges needed a little more tightening such as the 2 6" flanges. Other than that the only noticeable leak was from the flange just fixed today, however the leak is 10 times less than how it was yesterday and will most likely not hold the chamber back from reaching low 10e-8 torr pressures.