Daniel, Sheila

We have not been using REFL WFS to control PR3 in the last week or so because with somewhat high microseism this was making the IFO unstable.  Things got slightly better when we lowered the IMC WFS gain to avoid oscillating there. 

Tonight we started to look at the REFL centering loops, and re did them.  FIrst we started with diagonalizing them, the new matrix is in the screen shot.  Then we reshaped the loops a bit.  Before these changes the pitch loops were pretty close to unstable at 2.5 Hz with the ELF20s engaged, so we moved up the cut offs and moved the zeros down.  We have had trouble occasionally with CHARD loops ringing at 2.5 Hz, I hope this will be fixed now.

Since the microseism is down to around 0,4um/second, we tried the refl WFS again but lost the lock.  

The 260Hz peak was gone earlier tonight with an offset of 120 in DOF1P