Rana, Evan, Kiwamu, Alexa
Tonight we worked on the ASC WFS again. We noticed that the P,Y had different integrators loaded even though they were named the same thing. There was also a high frequency gain of -30dB in the integretor. We have adjusted this filter (see attached photo of the new filter FM1, and second image with FM1 and FM2 on). We also aborbed some of the overall filter gain in FM1, so that the gains are not as small as before. We can now close the loops for PRMI, and they are stable. The configuration is as follows:
PRCL | MICH | |
Signal | RELF_A_RF9_I | ASC_A_RF45_Q |
Gain (P.Y) | (-0.01,-0.01) | (-0.0003,0.0003) |
Optic | PRM | BS |
Settle time | 1 min | 10 sec |
We noticed that there is a bit of coupling between the REFL_A_RF9_I pitch and yaw signal; however if the DC alignment is suffeciently good the loop is still stable. The ASC WFS then bring POPAIR_B_RF18_I_MON to ~170cts. These changes are reflected in the guardian. (The old gains are commented out, and the old FM1 filters remain in the SRCL loop in case we need to revert anything).
We continued on to DRMI. The PRCL loop worked fine. However, the above configurations for MICH failed. The loops would drive the BS cntrl too far off too quickly, and we would lose lock. Unfortunately, the DRMI lock acquisition time is extremely long, and trying to adjust this loop was difficult. We got tired....