Reports until 17:46, Thursday 07 November 2019
H1 ISC (ISC)
sudarshan.karki@LIGO.ORG - posted 17:46, Thursday 07 November 2019 (53073)
Notching the ADS lines did not improve noise in DARM

S. Dwyer, S. Karki

We noticed yesterday that the ADS lines running at ETMY were showing up in ETMX and eventually into the DARM (attached plot- The dither lines are at : ETMX: P= 20.131, Y= 22.347 amd ETMY: P:20.789, Y=21.9 ). We thought we could reduce this coupling by notching these ADS lines in DHARD. We tested this today by  applying the notch at both the DHARD pitch and yaw. After notching the lines and opening the ADS servo loops we tried to see if we can reduce these lines in the DARM by changing the A2L gain. We tried both pitch and yaw at ETMY and didnot see any significant difference.

 

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