J. Kissel, L. Dartez S2300002 D2200215-v1 Chassis assembly D2200044-v2 Primary Whitening Circuit Before it's installation (LHO:66980), I used a setup virtually identical to the test setup described in LHO:62181 (save some adjustments to the source amplitude, response channel input ranges, and averaging parameters in the SR785) to get really high quality measurements of the new D2200215-flavor of OMC Whitening Chassis S2300002. I attach the measurement notes. The raw data can be found in the calibration svn under /ligo/svncommon/CalSVN/aligocalibration/trunk/Common/Electronics/H1/DCPDWhitening/OMCA/S2300002/20230124/Data/ Processed results and fit zeros and poles will be attached in the comments below.
The fit results for OMC Whitening Chassis S2300002 are below Chan A: Fit Zeros: [0.990741] Hz Fit Poles: [4.450068e+04 9.822735e+00] Hz Chan B: Fit Zeros: [0.993224] Hz Fit Poles: [4.457508e+04 9.850719e+00] Hz Processing script: /ligo/gitcommon/Calibration/ifo/scripts/electronics/omcwhitening/fits/fit_H1_OMC_Whitening_D2200215.py Plots showing the fit results are at /ligo/svncommon/CalSVN/aligocalibration/trunk/Common/Electronics/H1/DCPDWhitening/OMCA/S2300002/20230124/Results/2023-01-24_OMCDCPDWhitening_report.pdf. The first four pages in the pdf file linked above show bode plots of the measured & fitted OMC Whitening chassis transfer function on the left and the residual (measured data / fit) on the right in the following order: ChanA:WhiteningON, ChanA:WhiteningOFF, ChanB:WhiteningON, ChanB:WhiteningOFF. The last page contains a Bode Plot of just the transfer function from the amplifier test box used for all measurements. This is divided out before analysis. Full results are at /ligo/svncommon/aligocalibration/trunk/Common/Electronics/H1/DCPDWhitening/OMCA/S2300002/20230124/Results/
We verified that the response function systematic error due to the difference between the OMC whitening chassis fit and measurement is not significant. We follow the calculation outlined in G2200551, and the code for this calculation leverages new functionality in pydarm and lives on CIT: /home/ethan.payne/calibration/ifo/scripts/electronics/omcwhitening/models/Jan2023_H1_OMC_Whitening.py (this code can be easily updated for newer measurements by just replacing the detector configuration file, and the relevant measurement files). Plots for the sensing and response systematic errors are shown in eta_C_full.pdf and eta_R_full_reduced_freq_range.pdf, respectively. The ~1 deg advance in the response systematic error is due to previously measured behavior in the TIA systematic error (again see G2200551), and has been addressed with a 2.5e-6 s delay.