This is the (delayed due to conference travel) summary of my DQ shift for 12-15 June mentored by Andy L, the detailed report is at https://wiki.ligo.org/viewauth/DetChar/DataQuality/DQShiftLHO20150612
Friday 12th: No science data
Saturday 13th: Few minutes of science data
Several blip glitches occurred during that time, eg this one
DAC glitches were noticed in LSC-MCL_IN1, these seem to come from SUS-MC2_M3 as shown by the lineup plot :
Sunday 14th: Several hours lock, several hours of science data
Much of the data was clean with good sensitivity - but there were significant bad periods of excess broadband and/or low frequency noise during hour 8 UTC (spectrogram link) and hour 10 UTC (link) which killed inspiral range. The excess noise appears also in a large number of ASC and LSC channels but no clear cause. Does anyone have an idea what could have been going on at these times?
One curious feature was a band of excess noise over 60-75 Hz appearing at almost exactly 12:00 and gradually moving up and down in frequency until hour 17 UTC when it suddenly disappeared. See spectrogram link for an overview. Again this is mysterious and any clues from on side would be welcome.
It is clear from the spectrograms and omicron triggers that there were a few (about 1 per hour) really loud glitches - SNR > 1000. It has been suggested these are related to beam tube cleaning and its aftermath (e.g. particles loosened & falling through the beam). See omega scan of the loudest
Another feature seen previously is a set of near-periodic glitches at 60Hz, approximately every 72 minutes. These are associated with activity in the SUS-ETMY_L2 auxiliary channel, 'something happening' at the Y arm end station with ~4300s period.
Monday 15th: Tiny amount of data
