We worked following hammering test after the IFI work (klog24274), we performed the tapping test around IMC/IFI area.
1. tapping the +Y side of IFI chamber
In the previous tapping test, the large noise appeared, but this event disappeared by easy check.
2. tapping the leg of IFI chamber
Compared with previous tapping test, the effect of the vibration of the leg of the IFI chamber became larger.
We will summarize the vibration injection test later.
3. Tapping the IMC chamber
This would be another issue from IFI work, but large effect were detected. We will summarize in other report
4. Tapping the REFL table leg
The noise increasing were detected when we tapped the leg of REFL table.
We performed the vibration injection test, we will summarized in other report
5. Tapping whole area in center area
Akutsu-san tried to tap the whole area in center area.
The diaggui files are placed in
/users/yokozawa/Data/DARM/230307/
Fig.1. 50 -1000 Hz white injection
Two peaks appeared(?)
Fig.2. 50 - 100 Hz white injection
Increased the noise floor below 150 Hz, but unknown due to this work or not.
Fig.3. 100 - 200 Hz white injection
Increased the noise floor around 120 Hz
Fig.4. 200 - 300 Hz white injection
Peaks appeared!
Fig.5. 300 - 400 Hz white injection
No special peak appeared.
Fig.6. 400 - 500 Hz white injection
Some coherent peak appeared, but not so large (Two order larger vibration injected compared from environment)
Fig.7. 500 - 600 Hz white injection
Large peak appeared.
So at least 200-300 Hz, we may need to do scattering-light mitigation more seriously on the REFL table, as the excited peaks seemingly resembles the reference. In fact, the spectral floor varies in time, or unstable, so there would be another difficulty regarding what is the reference, though.
On the other hand, the non-coherence would mean no relation, or would be just due to several coupling paths are overlapped.
The diaggui files are placed in
/users/yokozawa/Data/DARM/230307/
Fig.1. 50 -1000 Hz white injection
No special peak appeared.
Fig.2. 50 - 100 Hz white injection
70 Hz, 90 - 100 Hz coherence appeared
Fig.3. 100 - 200 Hz white injection
Two large peaks (108 and 127 Hz) appeared
Fig.4. 200 - 300 Hz white injection
Two large peaks(217 and 268 Hz) appeared
Fig.5. 300 - 400 Hz white injection
No special peak appeared.
Fig.6. 400 - 400 Hz white injection
No special peak appeared.
Fig.7. 121 Hz solo injection
Large linear peak appeared.
Swept sine shaker injection for the MCF chamber body:
13:51 - 14:00 JST, 80 - 580 Hz, the amplitude was reduced around 175Hz
Fig.1: Spectrogram for the DARM and ACC (portable)
Fig.2: ASDs for 3.5min (141Hz) -> Many harmonics in the ACC signal -> Resonant of the chamber itself?
Fig.3: ASDs for 4min (162Hz) -> Many harmonics only in the DARM signal -> Resonant of something invac?
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When we tapped the -X side of the IMC refl chamber, the larger noise 50 - 1kHz appeared in DARM.
We checked the several interesting signal with high sampling rate
In many spectrum, the peak of the 4.12, 8.27 and 12.4 Hz appeared.
In the IMMT1 trans QPD2 signals(Both pitch and Yaw), similar noise shape appeared, that imply the when we tapped the IMC chamber, beam jitter happened.
In the IMC oplev signal, the peaks (4.12, 8.27 and 12.4 Hz) in pitch became larger compared with yaw at MCi and MCo (MCo became more larger??)
Both MCE trans QPD and MC refl QPD detected the increasing the peak (4.12, 8.27 and 12.4 Hz)
I analyzed the Shaker injection for the REFL table, by assuming the Coupling Function model (linear coupling).
510-520Hz peak is close to the current sensitivity.
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I analyzed the shaker injection data on the IMF chamber, -X side.
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