Bevan Moss wrote:

Over the period of July 20-21st TM1 had several repairs completed and tested. The easiest of the repairs was the installation of a gasket and a blank off. The next repair was to replace the 2 oring on the side panels that were removed for inspection and repair. The instrument panel oring was replaced again and the previous one measured. Both were found to have the correct diameter of 0.131 inches for the seal groove. When attempting to cut the thermocouple line back to an acceptable distance it detached from the stainless tube running down the high voltage chase. It was discovered that it was only being held in place with heat shrink and that the bend consisted of a hand made copper tube that was flared slightly, a truly poor electrical and mechanical connection. Also discovered was the thermocouple wire was left in the tube, this too was removed. The stainless steel tube was then secured to the tube heater (C) lines with a PEEK tie wrap. The port where the thermocouple line was then blanked off. The extraction electrode and mounting plate feed through stem repair went as practiced and no unexpected events occurred. One thing of note is that because the lines are twisted and some of the tube was removed the quick connects are no longer facing the same direction they were before. During these repairs the Ion gauge screen contacted a filament and caused a fault, this was repaired by edi who rotated the gauge. Roughing was started at ~10 am on July 21st and the turbo pumps turned on at 10:45.  At 13:20 all of the lines and external seals were tested and no leaks were found. The module was at a pressure of 2.9 x 10^-5 Torr (IMG) and 1.4 x 10^-5 Torr (ION). The leak test cart was at a pressure of ~2.7 x 10^-2 Torr and a leak rate of 1.1 x 10^-2 atm cc/sec for the external leak test and the repaired lines. A small response was found in the Tube heater (D) where the leak increased to 2.1 x 10^-8 atm cc/sec. The leak test cart would then no longer drop below 1.9 x 10^-8 atm cc/sec and there was no response measured for lines C, B, and A. Over all very positive results! After 6 hours of pumping down the pressures were 2.0 X 10^-5 Torr (IMG) and 9.7 x 10^-6 Torr (Ion).

 I again checked the TM this morning (July 22) at 10:00 am (24 hours of pumping), There is no external leaks carts pressure was 0.0x10^-4 Torr and leak rate was 0.0X10^-9 atm cc/sec. The IMG gauge was reading 6.8 x 10^-6 Torr and ION gauge was reading 3.1 x 10^-6 Torr. The lowest we have yet to record on the IMG gauge was 6.6 x10^-6 Torr and that was when the ION gauge was reading 1.2 x 10^-6 Torr and there were several leaks. This is a very good sign. I will continue to check the vacuum throughout the day. 

One more thing of note is that the copper feed thru stems have a design flaw, the holes for the locating pins are too large. As such a custom step pin had to be made. It work functionally the same but is not as intended.