stefan.ballmer@LIGO.ORG - posted 00:02, Wednesday 02 November 2016 - last comment - 13:12, Wednesday 02 November 2016(31103)
A2L DRIVEALIGN gains over the last 14 days
Notes:
0) A2L gains of order two are getting suspicious, because it essentially means some coils are shut off.
1) ITMY_Y2L was always large (~-2) , but since 10/29 7UTC it is even bigger.
2) ITMX_Y2L also got big (~2) on 10/29 7UTC
Not sure what to make of this...
Images attached to this report
Comments related to this report
Tagging SUS.We should check functionality of coils.EDIT: Checked the functionality of the coils by taking a quick transfer function between COILOUT_EXC channels (OSEM basis excitation channels closest to the DAC output), and the various coil driver monitor channels. Though I've not taken the time to calibrate or understand the signals, I see no differences between the quadrants, and plenty of coherence between all drives and responses. I don't think there's anything wrong with the ITM L2 actuators. Note to self -- next time include OSEM sensors and optical levers in your template for those who don't trust the functionality of the coil driver monitor channels. The templates (attached) live here: /ligo/home/jeffrey.kissel/2016-11-02/ (apologies for my laziness -- I figured it would be faster to just create new templates than to find the one's Ed used to characterize the monitor signals that are likely committed to the SusSVN. #slapsownwrist) Also note that - The IFO was DOWN during this measurement. - I turned off the PIT optical lever damping during the measurement so as to not confuse anything.
Images attached to this comment
Non-image files attached to this comment
