{Mark, Tyler, Gerardo, Kyle, Chandra}

Outstanding group effort today in vacuum department. Mark and Tyler installed chevron baffle + newly rebuilt IP6 ion pump (replaced a temporary blank on IP6 isolation gate valve); Kyle, Gerardo, Chandra leak checked.  In summary we think the assembly is leak tight but there was some uncertainty because of leaky vent port on turbo plus multitude of KF joints. We saw a He signal in e-7 Torr-L/s range, but quickly discovered it was coming from the vent port on small turbo pump (vent port o-ring may be wrong size). We sprayed the vent port with instrument air and still saw a rise in He signal from background of 2e-9 Torr-L/s, into low e-8 Torr range, so we tried a few tests by toggling the right angle valve (RAV) on IP6. I sprayed the baffle flanges with the RAV closed (i.e. isolating the leak checker + external turbo from IP6 body) and we observed a rise in pressure. Similarly, while spraying the baffle flanges with valve closed while simultaneously spraying turbo area with instrument air, and then quickly opening the right angle valve to expose IP6 body to leak checker, there was no rise in He signal. 

We finished late, so we will need to resume pumping on IP6 before we can turn its high volts on. It is currently pumped out and valved out. Leak checker was left on mezzanine. We will clean up our mess asap.

A few notes:

• I sprayed the chevron baffle louvers with "top gun" N2 dionizer in LVEA this morning before installation.
• The baffle was installed on IP6 at ground level and then the total assembly was installed on isolation GV via crane.
• IP6 was vented with N2 yesterday to give us a head start since it takes ~30 min. to vent. It was tested for high volts last week.
• Tyler noticed a white goo on the threaded joint (thread to KF adapter) of external He calibration leak so we replaced it with another unit before we started leak checking. Suspicious about this "wet" white substance found on a vacuum component. It was not visible from the inside, but plentiful on external surface.
• Gerardo hack sawed off a stripped bolt on one of the HV feedthru connectors on IP6 and replaced with new bolt. Both HV feedthrus are attached along with grounding cable.

Appreciate everyone's patience today as we used a full maintenance day....and then some. :)

Soon we will have not four, but six ion pumps valved into corner station.