sheila.dwyer@LIGO.ORG - posted 14:48, Friday 06 February 2015 - last comment - 09:16, Monday 02 March 2015(16526)
high winds at End Y
Jim, Krishna, Ryan, Jeff, Sheila, Alexa, Evan, everyone
We have been having trouble keeping the Y arm locked with green, due to cavity motion of about 10 um in about 10 seconds. The winds at end Y are approaching 40 mph, and have been climbing for an hour and a half. We have copied the 90mHz blends for X and Y from the ETMX ISI into ETMY and blending high has allowed us to lock ALS for now.
The attached screen shot shows the Y arm control signal (from the end station PDH with no slow feedback on) in beige, and the X arm in yellow. The blends were switchd at about -21 minutes.
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Here are a few more PEM screenshots of the wind and what it has been doing.
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J. Kissel, S. Dwyer For the record, Sheila only remembers changing the blend configuration for ISI ETMY, which is why only the brown trace (ALS-Y_REFL_CTRL) gets visibly better in the StripTool.