[Sheila, Varun, Camilla, Jenne]
- Plan:
- Reduce ADS lines, then one-by-one increase the ADS loop gains. (Since the gain increase caused a lockloss a few days ago).
- Do the coil driver switching, but have the test masses stay at the intermediate state 1 (at least for our first try).
- DC couple the ISS
- Measure CARM so we can think about boosts.
- Run calibration sweeps
- Marc plugged in the SR785 to the CARM common mode board, so we can measure the CARM loop in prep for some boosting / gain increases in LaserNoiseSuppression.
- Varun lowered the ADS line amplitudes as lownoiseASC would do, from 1600 to 30. Seems fine.
- Compensating gain increase (turn off FM1) for pit3 and yaw3, okay.
- SKIPPING the extra FM8 for PIT3.
- Compensating gain increase (turn on FM2) for pit4, pit5 okay. Guardian does not do any yaw4 or yaw5 increases
- Uncommented these things from Guardian, so it will do them next time (still skipping pit3's FM8).
- Ran through SLOWNOISE_COIL_DRIVERS, leaving the test masses' L2 drivers in intermediate state 1.
- Worked nicely, although the attached first screenshot shows that we probably can't go to the lowest noise state 3 at this time.
- Having the ADS amplitudes down is good, but we'll probably have to be able to turn on the more aggressive ASC cutoffs before we can go all the way to the lowest noise state.
- The second screenshot shows the digital versions of the coil driver states. So, if we engage the analog versions of those, the digital compensation will add some gain. By going from state 2 to state 1, we added ~18dB of gain at 24 Hz. We probably can't really afford the next ~20dB of digital gain that would happen going to state 3.
- Sheila is putting SLOWNOISE_COIL_DRIVERS into the guardian path (instead of LOWNOISE_COIL_DRIVERS).
- Worked nicely, although the attached first screenshot shows that we probably can't go to the lowest noise state 3 at this time.
- ESD transition went smoothly.
- LownoiseLengthControl went smoothly.
- Camilla is setting up to do calibration sweeps.
Calibration sweeps saved to /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O3/H1/Measurements/FullIFOActuationTFs
2021-04-16_H1SUSETMX_L1_iEXC2DARM_25min.xml
2021-04-16_H1SUSETMX_L1_PCAL2DARM_8min.xml
2021-04-16_H1SUSETMX_L2_iEXC2DARM_12min.xml
2021-04-16_H1SUSETMX_L2_PCAL2DARM_6min.xml
2021-04-16_H1SUSETMX_L3_iEXC2DARM_12min.xml
2021-04-16_H1SUSETMX_L3_PCAL2DARM_6min.xml
I mixed up the labels between state 1 and 2 in the first attachment to Jenne's post.
Jeff pointed us to his plot of the different coil driver states for the PUM on the third page here: T1100507
We had another lockloss which looked like CARM/IMC glitches, seen in LSC-REFL_CTRL and IMC_REFL (1302655800) and another that seemed like and ADS excursion (1302662068), causing the arm powers to tank over ~10 seconds. Earlier in the day the ADS clock gains were reduced from 1600 to 30 in LOWNOISE_ASC. I edited the guardian so it would only reduce the gains to 300, and removed the overall loop gain increase. We’ll keep an eye on the ADS and see if that helps.
Craig and I lowered the IMC gain by 3 dB - he stepped the IMC IN1 and IMC IN2 gains together, from 5dB to 2dB and -22dB to -25dB respectively. Hopefully this helps with the glitches we've been seeing before lockloss.
Craig ran the SRCL OLG template and I stepped the CHARD P gain from 1 to 0.8, since that still has some coherence with DARM at ~35 Hz.
Attaching a nice DARM spectrum (we haven't updated the calibration yet though).
