I have processed all the data which Jeff Kissel and I measured last Tuesday on ITMX, ITMY and ETMY Reaction chain (R0). The results are attached below. The motivation was to look into their damping and understand the 3.4Hz mystery peak issue. See alog 68398 and 68405 for templates.
Results for ITMX Reaction chain:-
File no.1 compares the measurements with R0 Damping OFF - orange trace, R0 Damping ON (L2 WIT DAMP OFF) - black trace and R0 Damping ON (L2 WIT DAMP ON) - magenta trace.
File no.2 shows the individual osem performance during all R0damping OFF
File no.3 shows the individual osem performance during R0 Damping ON (L2 WIT DAMP OFF).
File no.4 shows the individual osem performance during R0 Damping ON (L2 WIT DAMP ON)
Results for ITMY Reaction chain:-
File no.5 compares the measurements with R0 Damping OFF - orange trace, R0 Damping ON (L2 WIT DAMP OFF) - black trace and R0 Damping ON (L2 WIT DAMP ON) - magenta trace.
File no.6 shows the individual osem performance during all R0damping OFF
File no.7 shows the individual osem performance during R0 Damping ON (L2 WIT DAMP OFF).
File no.8 shows the individual osem performance during R0 Damping ON (L2 WIT DAMP ON)
Results for ETMY Reaction chain:-
File no.9 compares the measurements with R0 Damping OFF - magenta trace, R0 Damping ON (L2 WIT DAMP OFF) - black trace and R0 Damping ON (L2 WIT DAMP ON) - orange trace.
File no.10 shows the individual osem performance during all R0damping OFF
File no.11 shows the individual osem performance during R0 Damping ON (L2 WIT DAMP OFF).
File no.12 shows the individual osem performance during R0 Damping ON (L2 WIT DAMP ON)
Conclusions:-
For all three Reaction chain suspensions, P dof looks to be over damped, and V_dof & Y_dof damping can be improved as well. I am still analyzing the individual osem data posted below to look for cross couplings etc.
