Kiwamu, Dan, Alexa, Rana, Sheila

Today we spent most of the day working on PRMI sideband locked, we had trouble acquiring lock, Kiwamu thinks this is a problem with MICH.

• We measured the gain and phase of REFL 45 I and Q compared to REFL 9 I and ASAIR 45 Q (we would like to switch to using REFL 45 I +Q for PRCL and MICH)
  • REFL 9 I/REFL 45 I = 0.2
  • REFL 45 Q/ ASAIR 45Q = -0.108
  • we were able to transition PRCL to REFL 45, but didn't get a chance to try transitioning MICH.
• We noticed that the alignment of PRM that gives the best build up of PRX isn't a good alignment for PRMI.
• Using PRX, we tried changing our filters for PRM, we lowered our cross over to something like 4.5 Hz, we only have something like 30 degrees of phase there. At 3 Hz the model of the suspension says that there is a resonance.  We are now using distributed control on PRM, and not using the plant inversion filter.  (Screen shot of configuration attached.)  Kiwamu will attach open loop gain.  We are still using PR2, no changes to those filters.