[Giacomo, Paul]
Yesterday we made some preliminary tests of the HAM AUX suspensions in the HAM2 chamber. We released the earthquake stops and checked that we could read sensible data from the OSEMs, and actuate the mirrors too - all of them looked fine, so the questionable cable connection mentioned in entry 4593 doesn't appear to be a problem. We then put the earthquake stops back in place and moved the HAM AUXs into the middle of the table to keep them out of the way for the moment (since we don't have dog-clamps to hold them down). We pulled the OSEMs out to make open light measurements (see comment from Giacomo in the near future). At first glance these look fine.
These are the measured open light values for the HAUX AOSEMs (10 seconds average):
These are to be compared with the (approximate) ones recorded at the end of August (see post 4004). It appears that most of them have gon down in magnitude, with a few going below the 25000 threshold and one even below 20000. Not sure what the reason for and impact of this is...
Also, we measured the open light noise to look for excess noise of other strange thing, but we found none (good!). See attached image (input filters have for this measurements have offsets and gains based on the above open light values, as well as de-withening filters and nominal counts->um conversion factor).
It turns out that all the out of vacuum cables were swapped during this measurements, so these values cannot be directly compared to the ones measured in August, as different channels were reading different physical OSEMs (see entry 4697)