In 86964 I ran a side by side comparison of the powers at various ports before and after the power outage so we could determine what, if anything had changed. Although it generally seemed like we had regained or even increased the powers everywhere, kappa C has indicated that the optical gain reduced. Our current kappa C has been consistently near 0.98 since the outage.

However, I calculated the full optical gain value today from the most recent calibration report (20251012T200500Z) and the current exported report on August 23 (20250823T183838Z). Each report lists H_c in ct/m. I also chose a time just before each report was measured to calculate the OMC-DCPD_SUM/LSC-DARM_IN1 transfer function that provides the mA/ct calibration value.

It seems like our optical gain between these two times has actually stayed the same to much less than a percent. I'm not sure what to make of this with regards to the calibration, given that the calibration report suggests an overall magnitude change in the sensing function (that we are correcting in the TDCFs), but in actuality the magnitude of the sensing function has remained constant.