kiwamu.izumi@LIGO.ORG - posted 16:47, Thursday 12 May 2016 - last comment - 11:27, Tuesday 07 June 2016(27150)
SUS ETMY L3 stage compensation filters updated to more accurate ones
I updated the ETMY L3 stage digital compensation filters (FM2, FM6 and FM7 of ETMY_L3_ESDOUTF_{UL,LL,UR,LR}_GAIN) to the more accurate ones which are based on the recent measurements by Evan and Jeff. The coefficients are already loaded, but we have not gotten a chance to use the ETMY ESD yet.
To minimize possible errors for editing the foton file, I wrote a python script which automatically populate the filters, rather than editing the file by hand. The script is in the SVN at
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER9/H1/Scripts/SUS/setETMYLVVNcompensations.py
This is to note the measured state of the ETMY ESD electronics and the compensation (7 June 2016)
Measured analog electronics:
Diff Receiver Summing Node LP1 LP2 Overall DC Gain
(z:p) [Hz] (z:p) [Hz] (z:p) [Hz] (z:p) [Hz] [V/V]
UL 117e3:25.9e3 :3158.93 42.32:2.16 54.20:2.16 1.882
LL 167e3:27.6e3 :3229.11 42.93:2.08 49.73:2.09 1.881
UR 140e3:26.0e3 :3269.85 47.79:2.15 47.87:2.16 1.881
LR 160e3:26.7e3 :3323.42 47.17:2.06 47.61:2.20 1.881
Compensation filters:
AntiLP AntiAcq
(z:p) [Hz] (z) [Hz]
UL [2.1580;2.1590], [42.3160;54.2020] 3158.9340
LL [2.0810;2.0870], [42.9260;49.7260] 3229.1150
UR [2.1500;2.1570], [47.7850;47.8680] 3269.8530
LR [2.0640;2.1970], [47.1660;47.6100] 3323.4210
So the only uncompensated part of the anlog electronics is the zero-pole pair above 20 kHz.