Aso, Komori, Tanaka

This morning, Aso-san and Komori-san tried to perform releasing ITMX by applying the DC offset. Sorry, I did not join this work this morning so I'm not sure of the detail (They will report about this later, I hope.). However the situation seems not to be changed, unfortunately.

From this afternoon, we tried to identify the touching point by measuring DC responces from the excitation to oplev signals, and by comparing IX's responces with IY's ones. The reason why we used oplev signals is that the calibration factor of the photosensor responce may be changed by cooling and the amount of the change may be difference between IX and IY. As for MN, we measured the DC responces from MN_SUMOUT_{L,P,R}_OUT to MN_MNOLDAMP_{L,P,R}_IN1 at 300mHz. And we measured the DC responce from MN_SUMOUT_Y_OUT to MN_MNOLDAMP_Y_IN1 at 100mHz because 300mHz was yaw resonance frequency so we avoided it. As for IM, we measured the DC responces from IM_SUMOUT_{L,P,Y}_OUT to TM_WIT_{L,P,Y} at 100 mHz. At that time, we centered the MN(TM) oplev with when we measured the responces with MN(TM) oplev with BF Yaw DC control and moving masses for PIT/Roll.

Fig.1,2,3,4 show the DC responces about MN {L,R,P,Y} and Fig.5,6,7,8 show the timeseries of IX/IY MN oplevs {L,R,P,Y} when we excited them. Fig.9,10,11 show the DC responces about IM and Fig.12,13,14 show the timeseries of IX/IY IM oplevs when we excited them. Following table is the summary of the DC responces at the excitation frequency and the difference between IX and IY.

According to the result, the discrepancy of the responces of IM horizontal directions seem to be larger than MN ones. So somewhere IM in horizontal direction is touched?