As we recently confirmed, the coil driver analog circuits are not accurately compensated in the suspension front end model (see alog 21189 for EY L3 stage, alog 21189 for EY L1 stage, and Darkhan is making alog about the EY L2 stage). This results in an extra frequency dependent response in the actuators which would be flat if the compensation was perfect. Since we will run the interferometer in this way without accurately compensating the coil driver responses, we need a correction filter to take this into account in CAL-CS. So I made a matlab script to pick up the latest DARMOLGTF model, which already includes the precise measurement of the analog coil drivers, and then install them in CAL-CS_DARM_ANALOG_ETMY filters.

The script can be found at:

aligocalibration/trunk/Runs/ER8/H1/Scripts/CALCS/quack_coilmismatch_into_calcs.m

The script simply loads the latest DARM open loop model by calling a matlab function, H1DARMOLGTFmodel_ER8, and then processes the mismatch into one digital filter for each stage by combining the digital compensation filter and corresponding analog responses. Currently it handles only L2 and L3 stages since we are still working on the L1 stage. Using autoquack, it is going to install the mismatch filters into CALCS. I have ran this code multiple times and seemed to run without an issue so far. The filters are already installed at the end of the actuator chain as seen in the attached plot -- FM6 of each stage is the one. Note that they are not enabled yet since we need to install the latest suspension model in CAL-CS in order to be accurate.