Jennie W, Sheila, TJ
This is done to reduce the coupling we get to length from having off-centre spot positions on the mirrors.
The script can be found in userapps/isc/common/scripts/decoup/a2l_min_generic_LHO.py .
See the steps the script runs in the bottom two plots and the reponse of the ADS demodulated signals in the top plots.
I ran ETMX P and Y first by calling the script with
python a2l_min_generic_LHO ETMX BOTH
changed P and Y
H1:SUS-ETMX_L2_DRIVEALIGN_P2L_SPOT_GAIN => 3.22
H1:SUS-ETMX_L2_DRIVEALIGN_Y2L_SPOT_GAIN => 4.99
ETMY
both P and Y changed
H1:SUS-ETMY_L2_DRIVEALIGN_P2L_SPOT_GAIN => 4.3
H1:SUS-ETMY_L2_DRIVEALIGN_Y2L_SPOT_GAIN => 0.92
ITMX
both P and Y changed
H1:SUS-ITMX_L2_DRIVEALIGN_P2L_SPOT_GAIN => -0.99
H1:SUS-ITMX_L2_DRIVEALIGN_Y2L_SPOT_GAIN => 2.88
ITMY
H1:SUS-ITMY_L2_DRIVEALIGN_P2L_SPOT_GAIN => -0.36
H1:SUS-ITMY_L2_DRIVEALIGN_Y2L_SPOT_GAIN => -2.5
16:35:52 UTC all A2L gains set and script finished.
CHARD_Y coupling was still bad so we reran Y degree of freedom for all test masses.
ETMX
Want to change gain from 4.99 to 4.98, rounded to 2 decimal places. St.Div is 0.925. Change of 0.01
H1:SUS-ETMX_L2_DRIVEALIGN_Y2L_SPOT_GAIN => 4.98
ETMY
Want to change gain from 0.92 to 0.93, rounded to 2 decimal places. St.Div is 0.145. Change of -0.007
H1:SUS-ETMY_L2_DRIVEALIGN_Y2L_SPOT_GAIN => 0.93
ITMY
Want to change gain from -2.5 to -2.5, rounded to 2 decimal places. St.Div is 1.0. Change of -0.001
Gain did not change.
3 A2Ls changed by 17:33:32 UTC.
ITMX
Want to change gain from 2.88 to 2.87, rounded to 2 decimal places. St.Div is 0.496. Change of 0.01
H1:SUS-ITMX_L2_DRIVEALIGN_Y2L_SPOT_GAIN => 2.87
3 A2Ls changed by 17:33:32 UTC.
I don't think these values made it into lscparams' dictionary a2l_gains['FINAL'] (starting around line 451 in lscparams.py), so they were reverted for the next lock, and they were accepted as the previous values in alog 78383.