TITLE: 06/17 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 140Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY:

IFO is in NLN and OBSERVING as of 22:26 UTC

TUES Maintenance Activities:

We had a very productive maintenance day during which the following was completed

• LVEA Laser SAFE Transition - OPS
• RCG Upgrade and misc CDS work - CDS
  • WP 12624, WP 12625, WP 12626, WP 12627
  • Alog 85120, 
• VAC Channel Work - CDS 
  • Alog 85134
• Anchor drill work - VAC
• Laser Curtains around HAM1 replaced
  • Alog 85125
• Gauge replacement prep - VAC 
• ISCT7 Poke Homodyne - ISC
  • Alog 85116
• HAM ISI Measurements - SEI - 
• FAC Work (Bees, Tech Cleaning, Inventory, Lifts, Monitors) 
• 3IFO Visit Support - 3IFO
  • WP 12628

LVEA was swept - alog 85128

*Only listing completed WP’s - close your permits if work is done.

Lock Reacquisition:

Lock recovery was quite rough due to a few issues

1. ITMY Oscillation - Whilst locking ALSY, we noticed that it was oscillating at ~3Hz. No alarms had sounded other than the CDS/Maint work’s ISI/SUS trips expected earlier in the morning that were since successfully reverted. Ryan C discovered that the L1 BOSEMs were also oscillating independently of ALS WFs (which was the initial hypothesis). Then we found a worrying increase in the IY reaction chain gain (which showed an apparent increase of a few ten thousand!). This appears to have started when the CDS upgrade was done even though the right values were save into the SDF SAFE files. CDS advised that any signals from this time are not to be trusted, but clearly something must have moved since the 3Hz signal we were still getting was still ringing (albeit ringing down for the last 3 hrs). We managed to find the appropriate filter banks, IY_R0_L2DAMP_R_GAIN and IY_R0_L2DAMP_P_GAIN and identified them as the culprits, turning them off. After the involvement of Ryan C, Tony, Sheila, Elenna, Keita, Jonathan, Dave, EJ, Oli and myself, we came to the conclusion that we were going to test turning on the gain (nominally set to 1.5 and -2.5 not 10k) with a ramp. We did this and there were no issues. Weird. So essentially CDS is saying that there was no gain and power cycling the gain fixed the IY motion which was seen IY L2, IY L1 OSEMs as well as ALSY during ALS. Elenna still thinks something is weird with IY Reaction Chain so is investigating. Picture of Tony’s IY Power Spectrum Below. (alog 85135)
2. ALS Y Fault during ScanAlign. ALSY Faulted during scan-align causing a guardian node error. I had to manual out to continue locking. This is now a known issue whereby ALS scan align (not specific to X or Y) fails due to an AWG issue. The SUSCHARGE and ALS guardians will be restarted by Oli once we have our next Lockloss. (alog 85130)
3. IMC Locking Issues. The CDS work today threw the IMC out of alignment so we had to move MC1, MC2, MC3 and PZT sliders to a time where we were successfully auto-locking.
4. SEI states, PSL and SUS were all transitioned to their SAFE (Safe State Transition Wiki) and then transition out (Safe State De-transition Wiki)
5. SDF Screenshots Linked

LOG: