(Jordan V., Travis S., Gerardo M.)
Installation of the relay tube that connects HAM5 to HAM7 is done. For the installation we started with the flange on the HAM7 side, only hand tighten the bolts, then moved to the HAM5 side flange. For that side the compression tool made it easy to handle the bellows, however when we released the bellows no spring back was noted from the bellows because we noticed a gap between both of the flanges involved, the gap was not noted during the removal of the relay tube, we had to compress the bellows some to be able to separate the flanges. Once the flanges were closed and torqued the volume of the relay tube was pumpdown with a small can turbo backed with a leak detector. The pressure internal to the relay tube dropped fast, and yesterday afternoon the pressure was low enough to allow us to leak test the joints with the new copper gaskets, and no helium signal was detected by the leak detector above the background that was <1.0X10-10 Torr*l/sec.
Taking the relay tube volume to a lower pressure
After more relay tube pumping the pressure was low enough to incorporate the its volume to HAM7, this configuration took the pressure down at the the relay tube without affecting much the pressure inside HAM7, see attached plot. At this time we introduced its ion pump to HAM7, while pumping with the turbo pump, this configuration remained over night. Today we checked the pressure at the relay tube and it was low enough to change the configuration again, we isolated the relay tube from HAM7 and introduced its volume to HAM5 + main vacuum volume, this is noted on the attached plot. This was done remove the scattering that RV1 causes to the interferometer.
HAM7 Pumpdown
Today to help the pumpdown at HAM7, and proceed to a nominal configuration, we isolated the turbo pump and allowed its main ion pump to try and maintain the vacuum pressure on the chamber, at the same time we included the volume of section FC-A by opening FC-V1 to aide with its additional 150 ion pump, FC-A section still has FC-V2 closed at BSC3. As of this afternoon the vacuum pressure at HAM7 leveled and it is turning around.
