1. Silent run
2023/05/26 05:45:00 - 06:05:00 (JST)
2. wide frequency injection, 2000 cnt
2023/05/26 06:10:00 - 06:30:00 (JST)
During this run, I turned off the BPC ITMX and ITMY
3. wide frequency injection, 1500 cnt
2023/05/26 06:30:00 - 06:49:00 (JST)
During this run, I turned off the BPC ITMX and ITMY
4. Silent run
2023/05/26 06:50:00 - 07:09:00 (JST)
5. wide frequency injection, 1000 cnt
2023/05/26 07:10:00 - 07:29:00 (JST)
During this run, I turned off the BPC ITMX and ITMY
6. 89.6 Hz injection with 50 cnt
2023/05/26 07:30:00 - 07:49:00 (JST)
7. 90.8 Hz injection with 50 cnt
2023/05/26 07:50:00 - 08:09:00 (JST)
6. 89.6 Hz injection with 50 cnt
2023/05/26 08:10:00 - 08:30:00 (JST)
After this measurement, I requested to OBSERVATION state.
Fig.1. shows the preliminary result for measurement 2,3 and 5
Fig.2. shows the preliminary result for measurement 6,7 and 8
We performed the detail analysis for acoustic injection to OMC area with three frequencies.
The detail is summarized in JGWDoc15910 by Sato-san(NiigataU) (Sorry in Japanese).
Measurement setups
Injection information klog25709 (original log of this klog)
89.6, 90.8 and 91.1 Hz
As you already know, when we performed the acoustic injection in those frequencies, the frequency conversion noise was detected in DARM.
- Sideband like signal
There were many sideband frequencies around injection frequency, he picked up all signals for each injection.
Then we recognized the difference between main frequency and sideband frequency is almost consist for each three frequencies (Page6)
Fig.1. showed the lists of the frequencies.
+/- 1.68 Hz
+/- 4.17 Hz
+/- 6.0 Hz
+/- 8.34 Hz
+/- 17.18 Hz
+/- 21.6 Hz
+/- 23.9 Hz
...
- Comb frequency
There were also large peaks in the harmonics frequencies (2 times from 89.6, 90.8 and 91.1 Hz) the wide peak shapes were also consistent after adjusting the frequency(Page7)
- Time-frequency plot
We can see the interesting topic, the excess with increasing the frequency was detected, the injecting frequency is minus tilt for time.
