I have been trying to familiarize myself with Rai's "hydrocarbon" RGA (software and apparatus) which is mounted on the East door of HAM3 and have included some preliminary scans taken today.  These aren't intended to contribute to the eventual analysis but are interesting nonetheless.  It looks to me like the lack of distinct hydrocarbon peaks will necessitate an accumulation on the RGA's 80K "cryo finger".  We may need to compare scans with and without CP2.  

Rai has already used this same setup to quantify the hydrocarbon partial pressures at the Y-end and has commented on the expected impact on aLIGO mirrors (see T1100561, T1100642, T1200021 and T1200395). 

Note: these .pdfs contain "sticky notes" without which these scans won't have much meaning