[Ushiba]
Curently, Nakano-kun modified the damping filter and guardian for Type-A suspension for the gentle alignment and mis-alignment.
So, I copied the consept of these modifications to ETMX suspension.
The work is not completed but at least guardian request works now.
I will continue to work on this tomorrow.
[Ushiba]
I continued the yesterday work of ETMX.
I finished the damping filter modification of ETMX and now guardian works well.
One remaining thing is to measure the transfer function of each damping filters.
This work will be done when the suspension will be available (maybe tomorrow).
Note: during the work, I changed the TM OpLev YAW set point from -2 to -22 in order not to flash the cavity.
So, before initial alignment, please change the TM OpLev YAW set point of ETMX.
[Ushiba]
I continued damping modification work of ETMX.
Today, I measured the transfer function of photosensor loop and compaired with ETMY transfer function.
Then, I found that if I adjust the gain so as to match the TF of ETMX and ETMY, the ETMX has about 40 times larger fluctuation than ETMY.
So, I decided to reduce the gain of PS loop of ETMX.
Current TM OpLev spectrum is attached (red shows before modification and blue shows after modification).
We can see peak around 9 Hz on TM Pitch motion but all L, P, and Y RMS is reduced from precious damping filter.
If something happen, please let me know.
