[Miyamoto, Ohishi]
We have changed the configration of oplev for EXA from the original signal arm one to the folded arm one.(http://klog.icrr.u-tokyo.ac.jp/osl/?r=1406)
Thus, we did calibration again.
I calculated calibration factor(C2) of EXA Optical Lever
in the same way as the EYA ----> http://klog.icrr.u-tokyo.ac.jp/osl/?r=1374
C2 : calibration factor. C2 = 1/(8*L*C1) *10^6
Here L, δ, and C1 are as follows,
L : distance from mirror to QPD.(~1400mm)
δ : angle of mirror(Pitch or Yaw).
C1 : This factor transform output of QPD into displacement (mm) (http://klog.icrr.u-tokyo.ac.jp/osl/?r=1427)
Result
Updated calibration factors are,
K1:VIS-EX_TM_OPLEV_PIT_GAIN = 128.6
K1:VIS-EX_TM_OPLEV_YAW_GAIN = -131.1
Before the update, when the optical lever configuration was the original single arm, calibration factors of EXA
( http://klog.icrr.u-tokyo.ac.jp/osl/?r=988 ) are as follows,
K1:VIS-EX_TM_OPLEV_PIT_GAIN = -223
k1:VIS-EX_TM_OPLEV_YAW_GAIN = 255.
The definition of the signs of P/Y gain seems to be different.
Therefore, We changed the sign of the control gain
K1:VIS-EX_TM_OLDAMP_P_GAIN : -3000 --> 3000
K1:VIS-EX_TM_OLDAMP_Y_GAIN : -150 --> 150
