Georgia, Sheila, Jenne

Operators have been noting that PRC align hasn't worked in the last few days.  PRX was locking OK in length, but as soon as the alignment loops from REFL WFS to PRM came on the cavity would unlock.  We were using REFLA9Q for the PRM sensor in this state, but we rephased these WFS on Friday (49172).  

We looked at REFL, POP and AS WFS while moving PRM, and found that REFLB9 had less noisy signals than A for both pitch and yaw, however the zero crossing of REFL B Y was not maximizing the POP build up.  We changed the pitch sensor to REFLB9I and the yaw sensor to REFLA9I, and reduced the gain for both pitch and yaw.  This is in the ALIGN_IFO guardian now, and worked fine the one time that we ran through it.