Jennie W, Elenna, Jenne, TJ
We have been having trouble locking and keep falling out during the MAX_POWER state of ISC_LOCK as we power up (a and b are examples showing MICH and DHARD during two of these four locklosses).
During some of these we noticed that MICH or DHARD could be ringing up.
We measured MICH open loop gain with Elenna's template which I have saved a version of in /ligo/home/jennifer.wright/Documents/ASC/MICH_P_OLG_broadband_shaped.xml. We foudn the gain to be about 10% too low so increased the loop gain from -2.4 to -2.7 in the loop servo. We also measured DHARD open loop gain with the template in this folder DHARD_2W_P_OLG_broadband_shaped.xml and found it looks normal.
Investigations ongoing...