Reports until 09:19, Tuesday 18 March 2025
H1 SUS
oli.patane@LIGO.ORG - posted 09:19, Tuesday 18 March 2025 (83425)
Bandpass filters for PI24 and PI31 updated

Sheila, Oli

Vlad had mentioned in the last commissioning meeting that our bandpass filters for our PIs were too wide, so I looked and sure enough, they are way too wide (up to 6 Hz wide!) and contained part/most of other peaks.

Since PI24 and PI31 are the two that we care about the most right now, I went in and narrowed them as well as shifted the band location to actually be centered on those modes (h1susprocpi diffs, accepted 83421).

I'll be taking a look at PI28 and PI29's bandpasses and adjusting those to what makes sense.

Table below shows before and after locations of the band passes (the values are after the downconversion, which is why they are in the 400 Hz range instead of the 10.4 kHz range)(the before/after links show the bandpasses on the bottom plot using vertical lines)

Mode Peak Location Before Now
PI 24 431.75 428.5 - 433.5 430.75 - 432.75
PI 31 428.625 425 - 431 427.125 - 430.125
Images attached to this report