[Kyle, Chandra]

We opened back up GV6 this afternoon after closing it last Friday to leak hunt. Recap:  we checked the annulus systems on GV 5,6 & all in between for inner o-ring leaks (no leaks). We discovered 10" GV on CP1 was not tight and the volume capped by ISO flange was up to air, likely causing a slow leak into main volume. We did not spray GV 5,6, CP1, spool with helium.

We replaced the ISO with conflat reducing cross that can accommodate a turbo pump plus full range gauge and pump port. There seems to be a small (e-9 Torr-L/s) leak somewhere in this reducer cross but results are ambiguous and should not affect performance since it's behind the closed 10" valve.

The pressure reading on PT-124 (beam tube side of GV6) has dropped since tightening 10" GV, but value hasn't fallen below 5e-9 Torr which is where it is when isolated from leak. We may revisit this when we have access to the main YBM turbo for He leak checking. I would like to check the 10" GV gate seal and gappy flange at bottom of CP1.