Calibration parameters were updated after exchanging the coil drive chassis for ETMY TM (klog12970),
Assumption in old calibration:
- Actuator efficiency of ETMX (A_etmx) is roughly same as ETMY (A_etmy).
=> A_etmy = A_etmx = 9.812e-12
=> Optical gain = (DARM2_OUT / DARM1_IN1) / (A_etmx + A_etmy) = 1.3547e+7
Measurement result before exchange coil driver chassis:
- A_etmx / A_etmy = 0.471 (see klog12965)
=> A_etmy = 9.812e-12
=> A_etmx = 4.621e-12
=> Optical gain = 1.8423e+7
Latest calibration (Measurement result after exchange coil driver chassis):
- A_etmy / A_etmx = 0.866 (see fig1)
=> A_etmx = 4.621e-12
=> A_etmy = 4.002e-12
- TM_SUMOUT_L_GAIN for Type-A suspensions were changed from 1.0 to 1.5 for balancing DARM control,
=> Optical gain = (DARM2_OUT / DARM1_IN1) / (1.5*A_etmx + 1.5*A_etmy) = 2.0557e+7
Additional measurement: (see fig2)
- A_itmx / A_etmx = 0.880 (with ALS_LOCKED_WITH_IR on XARM guardian)
- A_itmy / A_etmy = 1.563 (with ALS_LOCKED_WITH_IR on YARM guardian)
