Sheila, Vicky, Camilla
We have turned back on the SQZ angle servo using the ADF at 322Hz. Last briefly tried while testing ADS alignment in ADS in 80194. Turned on ADF and used 'python setADF.py -f 322'. Then set H1:SQZ-ADF_OMC_TRANS_PHASE to get H1:SQZ-ADF_OMC_TRANS_SQZ_ANG close to zero and checked by stepping the SQZ angle that there is a zero crossing in the ADF measured SQZ angle, plot attached.
- Accepted attached sdfs.
- Edited SQZ_ANG_ADJUST nominal state to ADJUST_SQZ_ANG_ADF and reloaded.
- Changed sqzparams flag use_sqz_angle_adjust = True and reloaded SQZ_MANGER GRD.
- Made to edit SQZ_MANGER to turn on SQZ_ANG_ADJUST once we get to FREQ_DEP_SQZ and to turn it off at the start of SCAN_SQZ_ANG and SCAN_ALIGNMENT. We tested by going though scan sqz ang.
The servo adjusts the SQZ angle (H1:SQZ-CLF_REFL_RF6_PHASE_PHASEDEG) via keeping the ADF measured angle (H1:SQZ-ADF_OMC_TRANS_SQZ_ANG) at zero. Setpoint can be adjusted using the ADF phase (H1:SQZ-ADF_OMC_TRANS_PHASE).
Tagging Detchar: ADF is now on at 322Hz. It was turned all the way off in 79573 by Alan. We can adjust the frequency 50-500Hz if there is a better place for a line.
Note to operators: if you want to run SCAN_SQZANG, the ADF servo will now overwrite the sqz angle. So BEFORE going back to FREQ_DEP_SQZ you'll want to tweak H1:SQZ-ADF_OMC_TRANS_PHASE (via sqz overview > ADF) to make H1:SQZ-ADF_OMC_TRANS_SQZ_ANG close to zero. Or you can tweak H1:SQZ-ADF_OMC_TRANS_PHASE (via sqz overview > ADF) until the SQZ BLRMs/ DARM is best.
Trends of the ADF servo stabilizing the SQZ angle overnight. Looks good: the ADF SQZ ANGLE servo can hold the maximum squeezing level throughout the lock! Last night was running with the ADF SQZ angle servo + SQZ-IFO AS42 ASC together.
In the first lock of the screenshot, the ADF SQZ ANGLE servo is not yet running, and the squeezing level drifts quite a bit (~0.5-1 dB in ~2 hours, and ends up un-optimal). In the last 2 locks, the ADF SQZ ANGLE servo is running and successfully stabilizes the SQZ angle, though the 2 locks from last night stabilize at different SQZ angles (weird?). Note SQZ ASC is running in both of these locks, so it seems like ASC + ADF SQZ ANG servo work well when used together.
Naoki looked at sqz trends with/without the ADF servo before in LHO:75000. Looking at sqz trends for yesterday, the ADF servo stabilized the SQZ angle in the first ~25 minutes. Then over the first ~2 hours, the ADF servo needed to move the CLF_RF6 demod phase by 5-10 degrees to hold the SQZ angle stable. This implies something like, the optimal injected squeezing angle changed by about 2-5 degrees during IFO thermalization.
Also noting a reference to LHO:77292, where Naoki does an On/Off test with the ADF line at 322 Hz.
Checked against the 68139 list, can see that 322Hz is a good frequency for CW. We will look at trying to add this ADF line to the _CLEAN or _NOLINES subtractions.