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Message ID: 195     Entry time: Tue Dec 18 00:51:39 2007
Author: Andrey 
Type: Update 
Category: Computer Scripts / Programs 
Subject: Results of Saturday overnight measurements 

As I indicated in the previous e-log entry (#194), I made overnight measurements in XARM in the night from Saturday to Sunday.

Root-mean-square values of the peaks in calibrated spectra were calculated, and I plotted them as functions of suspension gains in ITMX and ETMX "position" degrees of freedom.
More specifically, Q_ITMX means the value in the channel "C1:SUS-ITMX_SUSPOS_GAIN", while Q_ETMX means the value in the channel "C1:SUS-ETMX_SUSPOS_GAIN".

Root-mean-square values (RMS) were calculated during that night in three intervals:

1) around 0.8 HZ in the interval (0.6 Hz <-> 1.0 Hz);

2) around 3.0 Hz in the interval (2.0 Hz <-> 3.6 Hz);

3) in the broad interval from 0.6Hz to 3.6Hz.

I plotted three results for RMS in the abovementioned three intervals in three different ways:

1) view from the top in the axes (Q_{ITMX}+Q_{ETMX})/2 and (Q_{ITMX}-Q_{ETMX}) -> first three graphs (attachments 1 -3);

2) view from the side in the same sum- and difference-axes -> next three graphs (attachments 4-6);

3) view from the side in Q_{ITMX} and Q_{ETMX} axes -> next three graphs (attachments 7-9), above accelerometer spectra (attachments 10-11).

Also, I compared the ground noise level by comparing spectra of accelerometer signals at different times during that night. As a reminder, before my disease I installed one accelerometer near ITMX and another accelerometer near ETMX (see entries 161 and 172 in ELOG). The plots of ratios of accelerometer signals at different times (pairs of times that were used: 12AM and 3AM, 12AM and 6AM, 12AM and 9AM) are given below, see attachments 10-11.

Tomorrow I will try to compare the results with the second measurements that are being taken tonight.
Attachment 1: RMS_08Hz_top_view.png  16 kB  | Show | Show all
Attachment 2: RMS_3Hz_top_view.png  23 kB  | Show | Show all
Attachment 3: RMS_broad_top_view.png  16 kB  | Show | Show all
Attachment 4: RMS_08Hz_Qsum-Qdiff-axes.png  12 kB  | Show | Show all
Attachment 5: RMS_3Hz_Qsum-Qdiff-axes.png  15 kB  | Show | Show all
Attachment 6: RMS_broad_Qsum-Qdiff-axes.png  12 kB  | Show | Show all
Attachment 7: RMS_08Hz_Qaxes.png  12 kB  | Show | Show all
Attachment 8: RMS_3Hz_Qaxes.png  17 kB  | Show | Show all
Attachment 9: RMS_broad_Qaxes.png  13 kB  | Show | Show all
Attachment 10: Accel_ITMX.png  14 kB  | Show | Show all
Attachment 11: Accel_ETMX.png  11 kB  | Show | Show all
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