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Reports until 19:04, Wednesday 06 September 2017
H1 ISC (ISC)
thomas.vo@LIGO.ORG - posted 19:04, Wednesday 06 September 2017 - last comment - 17:11, Monday 11 September 2017(38540)
Back to NLN after ETMY Discharge

Patrick, Daniel, Hang, Sheila, TVo

We are back at NLN with a range of about 55 MPC.

Good news, it seems like the ETMY TMDS slightly lowered the noise floor in the 15-55 Hz band!

Attached is a spectra comparing a few different times, the first 3 are just to get a rough reference about what the noise floor was before the discharge measurement but after the Montana EQ.

It seems like ETMX discharge also helped a bit but it wasn't obvious unless you take on the order of hundreds of averages, this still doesn't reconcile all of the mystery noise but there is some progress.

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hang.yu@LIGO.ORG - 21:16, Wednesday 06 September 2017 (38541)

We also looked at the spectra before/after discharging with jitter noise removed. Instead of running Jenne's code with time-domain causal filters, we just did a rough freq domain subtraction. The results are attached.  

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sheila.dwyer@LIGO.ORG - 22:20, Wednesday 06 September 2017 (38544)

We'll try to check the calibration in the morning.

jeffrey.kissel@LIGO.ORG - 17:11, Monday 11 September 2017 (38607)
J. Kissel, S. Dwyer, T. Vo,

Just in case any one is mistrusting that the changes in actuation strength of the ETMY from discharging were not covered by the time-dependent correction factors (i.e. kappa_TST), we show a zoom of the ~35 Hz PCAL calibration line. The largest discrepancy between line heights is 5%, which is within the stated limit of uncertainty and systematic error for 68% confidence interval. So, no need to mistrust the calibration here. 

We've decided against making a full sweep given that we're so crunched for time on this last night with the O1-O2-like H1 interferometer. May we come back more sensitive than ever!
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