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Wed Sep 6 01:09:11 2017, johannes, Update, Computer Scripts / Programs, New set of loss measurements 
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Mon Sep 11 12:56:40 2017, johannes, Update, Computer Scripts / Programs, lossmap attempts
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Mon Sep 11 16:46:09 2017, Steve, Update, PEM, earthquakes
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Tue Sep 19 14:00:41 2017, Steve, Update, PEM, earthquakes
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Fri Oct 27 09:34:20 2017, Steve, Update, PEM, earthquakes
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Fri Nov 10 13:46:26 2017, Steve, Update, PEM, M3.1 local earthquake
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Mon Apr 9 08:39:39 2018, Steve, Update, PEM, M5.3 eq Souther CA  
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Thu Jan 25 08:27:25 2018, Steve, Update, PEM, earthquakes  
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Mon Sep 25 17:56:33 2017, johannes, Update, Computer Scripts / Programs, transmitted power during lossmap
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Thu Oct 11 13:40:51 2018, yuki, Update, Computer Scripts / Programs, loss measurements
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Fri Oct 12 12:29:34 2018, yuki, Update, Computer Scripts / Programs, loss measurements
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Fri Oct 12 20:20:29 2018, yuki, Update, Computer Scripts / Programs, loss measurements
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Sat Oct 13 20:11:10 2018, yuki, Update, Computer Scripts / Programs, loss measurements
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Mon Oct 15 10:32:13 2018, yuki, Update, Computer Scripts / Programs, loss measurements 
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Tue Oct 16 00:44:29 2018, yuki, Update, Computer Scripts / Programs, loss measurements
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Fri Nov 2 19:25:16 2018, gautam, Update, Computer Scripts / Programs, loss measurements
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Mon Oct 15 12:52:54 2018, yuki, Update, Computer Scripts / Programs, additional comments
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Fri Nov 2 16:42:31 2018, aaron, Update, Computer Scripts / Programs, arm loss measuremenents
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Mon Nov 5 13:52:18 2018, aaron, Update, Computer Scripts / Programs, arm loss measuremenents
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Tue Nov 6 10:19:26 2018, aaron, Update, Computer Scripts / Programs, arm loss measuremenents
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Tue Nov 6 15:23:48 2018, gautam, Update, IOO, IMC problematic
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Tue Nov 6 19:02:35 2018, aaron, Update, IOO, IMC problematic
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Sat Nov 10 17:40:00 2018, aaron, Update, IOO, IMC problematic
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Mon Nov 12 13:53:20 2018, rana, Update, IOO, loss measurement: oscope vs CDS DAQ
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Thu Nov 15 10:21:07 2018, aaron, Update, IOO, IMC problematic 
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Fri Nov 16 10:53:07 2018, aaron, Update, IOO, IMC problematic
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Sat Nov 17 18:59:01 2018, aaron, Update, IOO, IMC problematic
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Wed Nov 7 05:16:16 2018, yuki, Update, Computer Scripts / Programs, arm loss measuremenents
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Message ID: 14254
Entry time: Mon Oct 15 10:32:13 2018
In reply to: 14251
Reply to this: 14258
14269
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Author: |
yuki |
Type: |
Update |
Category: |
Computer Scripts / Programs |
Subject: |
loss measurements |
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I used these values for measuring armloss:
- Transmissivitity of ITM = 1.384e-2 * (1 +/- 1e-2)
- Transmissivitity of ETM = 13.7e-6 * (1 +/- 5e-2)
- Mode-Matching efficiency of XARM = 0.912 * (1 +/- 2e-2)
- Mode-Matching efficiency of YARM = 0.867 * (1 +/- 2e-2)
- modulation depth m1 (11MHz) = 0.179 * (1 +/- 2e-2)
- modulation depth m2 = 0.226 * (1 +/- 2e-2),
then the uncertainties reported by the individual measurements are on the order of 6 ppm (~6.2 for the XARM, ~6.3 for the YARM). This accounts for fluctuations of the data read from the scope and uncertainties in mode-matching and modulation depths in the EOM. I made histograms for the 20 datapoints taken for each arm: the standard deviation of the spread is over 6ppm. We end up with something like:
XARM: 123 +/- 50 ppm
YARM: 152+/- 50 ppm
This result has about 40% of uncertaintities in XARM and 33% in YARM (so big... ).
In the previous measurement, the fluctuation of each power was 0.1% and the fluctuation of P(Locked)/P(misaligned) was also 0.1%. Then the uncertainty was small. On the other hand in my measurement, the fluctuation of power is about 2% and the fluctuation of P(Locked)/P(misaligned) is 2%. That's why the uncertainty became big.
We want to measure tiny value of loss (~100ppm). So the fluctuation of P(Locked)/P(misaligned) must be smaller than 1.6%.
(Edit on 10/23)
I think the error is dominated by systematic error in scope. The data of beam power had only 3 degits. If P(Locked) and P(misaligned) have 2% error, then
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You have to check the configuration of scope. |
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