[Koji, Manasa, Annalisa]
I made several trials to scan the arm on the IR TEM00 resonance while the PRMI was held with REFL165I&Q.
It was so hectic to keep multiple systems running correctly. We talked about how it should be automated.
We'll gradually offload the switching works on scripts.
In a good alignment condition, when I swept on the resonance, everytime the PRMI lost the lock. It reacquired
once the arm passed the resonance.
Lately I got difficulty to acquire lock of the PRMI while the arm is waiting at its off resonance.
If I change the ALS offset I got a stable lock in a certain offset, and did not get in another offset
so there could be something systematic. (The arm was in between the carrier resonance and the next sideband (55MHz) resonance).
- Run LSCoffset script.
- Misalign PRM. Lock and align the arms with ASS.
- Go into the tables. Align the oplevs for ETMX/Y, ITMX/Y, and BS. (Very important for alignment stability)
- Align PRMI and lock PRMI. Unlock once.
- Go into the BS/PRM table. Align the oplev for PRM.
- Misalign PRM by -0.2
- Find the beat note at around 50MHz by changing the Yarm SLOW control. Today the PSL SLOW was ~0.24, and the Yarm SLOW was -10981.
- Reset Phase Tracker History (Important)
- Engage Yarm ALS with FM5. Tested the sign of the servo by giving 0.01 or -0.01. In my case, the negative number worked fine.
Gradually increase the gain up to -10. Turn on FM2/3/6/7/10.
- Use Filter module "C1ALS-OFFSETTER2" to give the ALS sweep. I used FM1 (30mHz LPF). Change the offset while looking at the IR TRY and POY11 error signal.
- Once the resonance is found, shift the beat note by giving +10 or -10 offset.
- While the arm is kept off resonance, align PRM.
- Lock PRMI with REFL33I and AS55Q. Turn on PRM ASC.
- Once the stable lock is obtained, switch the input signals to REFL165I&Q. I used REF33I x1.0->REFL165I x0.8 and AS55Q x1.0 -> REFL165Q x0.5
[PRMI + one arm]
- Revert the ALS offset by 10 to bring the arm on the resonance the see what happens.