Michimura, TTanaka, Yokozawa
We placed the accelerometers to the foot of the OMC chamber.
K1:PEM-SENSOR_RACK_OMC1_DSUB(0-2)_OUT_DW
Also, we placed the oscillator near the dsub2 accelerometer because the excitation of the noise is larger when we hummered the OMC chamber foot.
By the way, tapping OMC chamber foot gave less excess noise injection compared with tapping foot of OMC optical table. Blocking AS RF beam at AS viewport didn't change the sensitivity much. These suggest back reflection from AS optical table and AS viewport have less impact to the sensitivity than the effect from something happening on the OMC optical table.
Also, illuminating inside the vacuum chamber with LED from AS viewport didn't change the sensitivity much. This suggests that ambient light is not affecting the sensitivity much. May be we don't need AS tube between OMC chamber and AS optical table at this point.
