Reports until 09:54, Saturday 07 July 2012
H1 ISC
matthew.evans@LIGO.ORG - posted 09:54, Saturday 07 July 2012 - last comment - 10:19, Saturday 07 July 2012(3350)
SUS work for OAT - R0 damping in place

As a first step to making the L1 and L2 sensors useful, I brought the reaction chain damping up to speed.  It now matches the main chain on both the ITM and ETM.  I also spent some time playing with M0 gains and filters, but without any definitive success.  Some directions to explore:

  1. decouple long-pit drives
  2. add L1 damping loops
  3. add optical lever damping
  4. improve SEI performance in 0.3-2Hz band

I'll poke at the first of these today.

Comments related to this report
matthew.evans@LIGO.ORG - 10:19, Saturday 07 July 2012 (3351)
Link

In the process I added a new filter for L damping: 0.43HzBoost2.  It just adds a little more gain around 0.43Hz, which flattens more the peak there.  It does what it should, but had little effect on the motion seen at the L1 and L2 levels.