Attached is an SEM (1500 volts) scan of the Y-end RGA following a multiday bakeout ( > 160C ) while still isolated from the Y-end and while being pumped by a ~60 l/s turbo which was bolted to the pump port (net pump speed 10 L/sec or less due to connection).  The suspect "dirty" Nitrogen and Krypton calibration gas isolation valves were open during the ramp up and heat soak portion of the bake but were then closed at the start of the cool down portion. The half of the calibration gas lecture bottles containing the pinched capillary tube was wrapped and heated along with the bottle isolation valves and the rest of the RGA components.  The calibration gas bottles were left isolated for this scan. 

Comments from vacuum folks?