Cont'd work 2
Actuator efficiency of ETMX TM by pcal
With the same manner of estimating actuator efficiency ratio between two suspensions,
Actuator efficiency of ETMX TM was also estimated from the two transfer functions from Pcal-X and ETMX TM to DARM error signals.
A ratio between these transfer function represents
where A_{etmx,tm} contains actuator efficiency, filterbanks from DRIVEALIGN to COILOUTF, digital AI, 61us digital delay between VIS and IOP, DAC, analog AI, coil driver and pendulum response,
and also A_{pcal} contains pcal efficiency, pendulum response, optical loss of pcal, analog AA, ADC, digital AA.
(Detailed components and calculation theory are described in JGW-T2113446.)
Pcal actuator efficiency is already know by the laser power calibration by integration spheres as 7.521e-12/f^2 [m/W]
(This value already contains the optical loss between ETM and RxPD).
Two transfer functions and residual of them are shown in Fig.1 and Fig.2, respectively.
Pcal-X pushes ETMX to AR direction and the definition of DARM is Lx - Ly.
So "+" (push) direction of Pcal is "+DARM" direction (= "-L" direction of ETMX suspension).
As a results, actuator efficiency of ETMX TM was estimated as (-3.5185 +/- 0.0085)e-12 / f^2.
(Total systematic errors of Pcal haven't been taken into account yet.)
Summary
| ETMX to DARM | ITMX to DARM | BS to MICH | PRM to PRCL | klog | |
| '23/04/26 Pcal | (-3.5185+/-0.0085)e-12 | (-2.8774+/-0.0097)e-12 | (6.080+/-0.033)e-11 | (-8.326+/-0.091)e-10 | This post |
| '23/04/26 FSM (*1) | (-3.031 +/- 0.045)e-12 | (-2.479+/-0.036)e-12 | (5.238+/-0.074)e-11 | (-7.17+/-0.12)e-10 | klog#24969, #24980 |
| '22/10/22 OpLev | -6.96e-10 | (*2) | |||
| '22/10/11 Gr AOM | -3.524e-12 | klog#22434, #21630 | |||
| '22/08/03 FSM (*1) | 5.9e-11 | klog#21676 | |||
| '20/06/17 FSM Post O3GK (*1) | 6.28e-11 | -2.98e-9 | klog#14557, #14555 | ||
| '20/04/21 FSM O3GK (*1) | -4.46e-12 (*3) | -5.17e-12 (*3) | 5.63e-11 | klog#14194 | |
| '20/04/21 Pcal O3GK | -4.59e-12 (*3) | klog#14554, #14265 | |||
| '20/04/16 Pcal O3GK | -4.71e-12 (*3) | klog#14194 | |||
| '20/04/07 Pcal O3GK | -4.66e-12 (*3) | klog#14073 | |||
| '20/02/18 FSM Pre O3GK (*1) | 6.02e-11 | -1.01e-9 | klog#11754, #13020 |
(*1) Because FSM method cannot decide the sign of actuator efficiency, sign is decided based on suspension L direction defined by VIS/CRY groups.
(*2) I fitted /kagra/Dropbox/Measurements/VIS/PLANT/PRM/2022/07/PLANT_PRM_ISOLATED_TM_TEST_L_202207251949.xml and set it on filterbank on 2022-10-22 by my personal memo.
I couldn't find the klog post about this. So I forgot it...
(*3) Actuator efficiency is ~1.33 times different between O3 and O4 because convention in CAL (SUMOUT_GAIN=1.5 was included in efficiency during O3), and
in VIS/CRY (EUL2COIL and COILOUTF_GAIN were changed from 1.0 to 0.25 and from ~0.5 to ~1.0, respectively) were changed.
