17:15-17:49 ITF on LN3_SQZ, SQZ alignment optimized maximizing the 4MHz beat note magnitude on B1 by moving SQB1_LC_X
17:49:09 First configuration: LN3_SQZ and SQZ AA loop open. We start shaking SQB1 at 0.1Hz:
• 17:51:29 line weight=5
• 17:52:29 line weight=10
• 17:54:00 line weight=20
• 17:56:09 line weight=50
• 17:58:08 line weight=100. This line weight correspond to an oscillation of SQB1 on about 60 micrometers pesk to peak (figure1) and its effect is visible on the ITF sensitivity curve (figure2).
18:06:49 Second configuration LN3_SQZ and SQZ AA closed
• 18:07:18 line weight=20
• 18:15:20 line weight=50 (figure3)
• 18:17:41 line weight=100 (figure4)
18:29 Third configuration LN3
• 18:38:50 line weight=20
• 18:42:22 line weight=50
• 18:45:26 line weight=100 (figure5)
At 18:50:54 injection stopped (line weight=0)
The purpose of the second part of the shift is to evaluate the sensitivity of the interferometer with SQZ injected as a function of the angle of the SR mirror
19:00 ITF in LN3
19:24:15 start of the CC phase scan (duration about 1250 sec.). the phase scan results are shown in figure6 ,7. Compared to usual the level of generated squeezing is low and consequently the effects on sensitivity are less evident.
20:23 the ITF automation set in the LN3_SQZ state
20:46:56 the squeezing angle is set at 2.9 rad (change made “by hand” on the VPM and not in the config file)
20:50 ITF unlock.
we decide to interrupt the shift and resume it after restoring the usual squeezing level
