aLIGO LHO Logbook

H1 SEI

sheila.dwyer@LIGO.ORG - posted 14:38, Saturday 28 February 2015 - last comment - 15:55, Monday 02 March 2015(16998)

seismic configuration for end stations for windy days

The wind gusts are at around 30mph, we could see from the ALS control signals that the arms are moving more than usual, so I changed the end stations to the high blends and we are using BRS sensor correction at end X. (configuration described in alog 16583)

Comments related to this report

sheila.dwyer@LIGO.ORG - 19:06, Saturday 28 February 2015 (17004)

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we are back to 45mHz blends, since the wind has died down, but the BRS sensor correction is still on.

jeffrey.kissel@LIGO.ORG - 09:21, Monday 02 March 2015 (17015)

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S. Dwyer, J. Kissel

Speaking with Sheila this morning, the improvement in the ALS performance was "not as clear" as the last time, when the winds were 40 [mph] at EY (i.e. LHO aLOG 16526). This could be that the wind only got to roughly ~30 [mph] during the above configuration switch.

Recall that in LHO aLOG 16526, the X-end was *not* changed, and the wind amplitude was large only at the Y-end.

jim.warner@LIGO.ORG - 15:55, Monday 02 March 2015 (17026)

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I was checking ISI configurations this morning and found that X&Y sensor correction at EX was actually OFF on the ISI, but it was turned off at a different point in the path than I usually try to steer commissioners and operators toward using.This would have made it look like sensor correction was on, when no STS signal was actually going to the ISI. I hope this explains some of why "the improvement was not as good as before". I've been meaning to make some edits to Hugo's new SensCor MEDM to make this clearer, but haven't gotten around to it. I also found a few other configuration errors, but I didn't bother writing them down. Time to get more serious about SDF's, I guess.