Yesterday (sunday March 3rd), I injected a low frequency line (0.1 Hz) on SDB1 and on SDB2 from the top stage of the suspensions, along the Z degree of freedom of the benches. The purpose of these injections is to re-evaluate the scattered light coupling factors (analysis will be posted later). Note that these injections were performed with the SDB1 FI shutter closed. The times of the injections are provided below:
SDB1 low frequency line injection:
- 13h52m00 utc (5 min): reference quiet data (purple spectrum in the attached figures)
- 13h57m20 utc: SDB1 Z moving by +/-10um
- 13h59m40 utc (5 min): SDB1 Z moving by +/-15 um (see Fig.1)
- 14h05m40 utc (3 min): SDB1 Z moving by +/-18 um (see Fig.2)
- 14h09m09 utc: SDB2 LC tracking loop open. Taking 3 min of data with the injection on SDB1 still on (see Fig.3)
- 14h13m00 utc: Taking 4 min of data without injection, and with the tracking loop still open.
- SDB2 tracking loop closed at 14h17m32
SDB2 low frequency line injection:
- 15h03m50 utc (5 min): SDB2 bench moving by +/- 18 um (see Fig.4)
