Following the IMC round-trip losses calculated before the INJ power increase, we have repeated the measurements as well after the power increase (on 21/11/2020 #50015). We have used the same equations and the same method described in #50086.

However, the last data set presented a problem with the data PSTAB_PD2_DC. We can see here a bump when the signal decreases, making the fit not a good estimate of the data (Fig. 1 and Fig. 2). A possible difference with respect to the last time is the PSTAB loop which was forgotten closed.

INJ_IMC_REFL was our choice this time, even if it was not possible to obtain a good fit with most of the measurements as well, as the data was not very "clean" (from a set of 6 measurements, just one measurement was analyzed, the other 5 could not be fitted well). We were able to have a good fit only with one measure, which gave us the following result (Fig. 3):

- Pole = 494 Hz

- Finesse = 1058

- Round trip losses = 204 ppm

- Throughput = 93%

To be noted that the PSTAB was activated in the moment of the measurements, and we are not sure until what extent it could have some influence. Analyzing the data, however, it does not seem the case that the flaws in the curves come from this fact. In any case, this measurement does not seem very reliable.