AdV-COM (AdV commissioning (1st part) )mwas - 14:00 Wednesday 30 January 2019 (44619)
Print this reportComment to 52 Mpc!!!!!! (44544)Edit:
Found that the analysis below included a loud glitch in the middle (that causes a range drop). Shortening the data to avoid the glitch makes the 56MHz RIN subtraction work at most frequencies (still breaks down around the 50Hz and the violin modes)
Figure 3, shows the sensitivity before and after subtraction, with a small improvement visible between 80Hz and 200Hz.
Figure 4, shows the ratio between after cleaning and before cleaning, and there is up to 5% improvement in sensitivity in that band.
Computing the range, the cleaning gives a 2% improvement, so going from 52Mpc to 53Mpc.
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An additional note about the 56MHz RIN while at 52 Mpc.
Figure 1, as reported previously the measured coupling is about a factor 3 below the sensitivity curve. Using the B1s1 signal the 56MHz RIN can be removed, this is what makes the blue curve slightly below the red curve.
Figure 2, shows the ratio of h(t) after and before the subtraction of 56MHz RIN using the B1s1 signal. Below 100Hz the subtraction is clearly not working well, and is actually adding noise, but around 150Hz the noise is reduced by 3% because of the subtraction. Assuming the subtraction can be fixed, to have the same improvement above 100Hz without adding any noise below 100Hz, the impact on the range is still minimal. Even in that case the subtraction improves the range by only 0.7%, so from 52Mpc to 52.3Mpc. In other words the 56MHz RIN was not a large limitation last Saturday.