[K. Nagano, Hasegawa, Tanioka, Shimoda, Miyazaki, Kita, Takano, H. Tanaka ,Hayama]

Today, we performed (a part of) noise injection test to ETMY, magnetic and acoustic injection.
Although detail analysis will be reported later, we could not see any excess in Michelson signal.
After this test, we originally planed to performe hummering test with CRY group.
However, there are earthquake (M=6) in Philippines around 15:30 (JST) and Michelson could not be locked after that.
Thus, the hummering test was postponed to tomorrow.

Magnetic injection
We injected magnetic field with a coil whose diameter is 1 m.
Comb wave at 9.2 Hz and filtered white noise (DC - 30 Hz and 30 - 300 Hz) were injected.
In all cases, we could not see any excess in Michelson sensitivity although the magnetic field was excessed from background by three order of magnitude.
This is good.
The spectra during 30 - 300 Hz injection are shown.
(The correspondence between channel name and sensors are explained in klog4940 and reference spectra are ones without injection)

Acoustic injection
We injected sound with a speaker.
Comb wave at 23 Hz and filtered white noise (30 - 500 Hz) were injected.
In both cases, we could not see excess in Michelson sensitivity.
This is good.
The spectra during 30 - 500 Hz injection are shown as follows.

Conclusion
ETMY may have small coupling with magnetic field and environmental sound.