Now that HAM7 is at sufficient pressure (6.4E-7 Torr as of this post) we helium leak checked the two re-installed 12" CF blanks removed for table locking and the entire relay tube assembly which had been removed for the viewport adapter on HAM5.
The Helium background was unstable, so we turned on the HAM7 cleanroom (on 2/18 afternoon) to help flush the area of helium overnight.
Today the background stabilized around 1.5E-10 Torr-l/s, so we were able to continue leak checking. No significant helium signal observed above the leak detector background which hovered between 1.5&2E-10 Torr-l/s during leak checking.
HAM7 continues to pump down with the turbopump, next steps are chamber RGA scans.
HAM7 RGA scans and scan information posted to T2600064. RGA is dirty, but the chamber comparison to last pumpdown (Mar 2024) is posted.
Late entry.
Last Tuesday, 2/24/2026, HAM7 ion pump was introduced to the chamber's main volume, and currently the chamber is pumped with both; the ion pump and the turbo pump. Attached is a trend snap of the chamber's pressure since the introduction of the ion pump.
