Julia, Georgia, Sheila, Camilla, Elenna
This might be out of date already as some ASC input matrices have already been updated.
On Sunday we had some locklosses as we powered up from a 0.02Hz oscillation. One known issue is we have taken out some gain out of our CHARD loops. We wanted to check our sensing (input) matrices CHARD, INP1 (which both use the refl wfs) and PRC2 (which uses new in vac pop_x).
We sat at 10W, with the input matrix Sheila found last week:
| DOF | REFL_A_RF9_I | REFL_A_RF45_I | REFL_B_RF9_I | REFL_B_RF45_I | POP_X_I |
| INP1_P | 1 | 1 | |||
| CHARD_P | -1 | -0.5 | |||
| PRC2_P | -1 | ||||
| INP1_Y | 1 | 1 | |||
| CHARD_Y | -1 | 1 | |||
| PRC2_Y | -1 |
While Elenna measured the phasing using an 8 Hz line, Julia and I added offsets into the loops and looked at the responses in the different sensors.
- When we stepped INP1_P, we saw a differential response in REFL_A and REFL_B RF45 (first screenshot)
- When we stepped INP1_Y, we saw a small common response in REFL_A and REFL_B RF45 (second screenshot), and maybe a small response in RF9 (which is what was in loop)
- When we stepped CHARD_P, we saw a differential response in REFL_A and REFL_B RF45, same as INP1_P (third screenshot) and a small response in REFL_A and REFL_B RF9 in the Q quadrature (sad)
- When we stepped CHARD_Y, we saw a small differential response in REFL_A and REFL_B RF45 and perhaps also in RF9 (fourth screenshot)
- When we stepped PRC2_P, we saw a differential response in REFL_A and REFL_B RF45, RF9, and a step in POP_X (a bit weak?) (fifth screenshot)
- When we stepped PRC2_Y, saw saw a strong response in REFL_A and REFL_B RF9, and POP_X (fifth screenshot)
Some of this is a bit different to what Sheila saw last week, but our ifo alignment has changed. We want to find intrixes that are sensitive to each DOF and ideally are insensitive to the other DOFs.
- It seems like RF9 is not a good sensor of INP1
- For some reason our steps showed a similar repsonse in A and B RF45 to INP1 and CHARD in P, which was the opposite of what Elenna saw in her radar plots?
- POP_X is good at only sensing PRC2, but PRC2 yaw shows up in other sensors...
While writing this another input matrix for INP and CHARD has been put in - https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=84711 - and seems to be working so stay tuned.
We plan to work on our gain heirarchy and hopefully power up further soon!
These are my radar plots for my 8 Hz dither sensing matrix.
