Though the resonant frequencies were cahnged a little, the GAS TFs are healthy. The condition is better than the reference.

I think we can close the chamber.

The third plot is not for the IP-L but the IP-T (duplicated). 

• I have added some figures showing the comparison between the measured ITMX TFs and ITMY ones to the log. I've also included some simulated GAS-TFs when the F0 is mechanically locked. The resonant frequencies  in the simulation model are *NOT* tuned though.
  • Based on those, the ITMY-GAS transfer functions look healthy now. For the further check, we will want to measure the TFs with smaller band-width (and lager averaging time), however, at least GAS filters are much healthier than previous.
  • I would say BF-yaw is healthy now as well. Thus for the tower part, I agree with takahashi-san's comment. (Actually it is found that the GAS filters of ITMX might have problem, rather than ITMY.)

(with the help of Yoshinori and Aso-san)

Yesterday and Today,  I started to check the transfer functions of the tower part.

During all measuremens the optical levers signals were in the range.

Pic 1, Pic2, Pic3 show the IP transfer functions: today TFs (red curves) vs Sat 03 08 2019: The IP is healthy.

Pic 4 shows the BF_Y TF : Today TF (red curve) vs 03 08  2019 (blue curve): BF_Y body looks not touching and not rubbing (healthy).

I also measured the GAS TFs and compared with the old ones measured last saturday (yellow curve).

• GAS filters: F1 (pic5), F2 (pic6) , F3 (pic7), BF (pic8, and pic9)

The GAS TF for F2  and BF (Pic6, Pic8), are quite different from the reference (DC gain and peak): this because of the drift due to the pump down.

To recover the correct shape I moved the fishind rod of the BF and F2:

• the BF recovery was succefully (Pic9 show the TF after the keyston position adjustment with the motors)
•  when I tried to  move the F2 keystone (to recover it I moved along positive direction the F2 motors), somenthing strange happens: at the beginning the behavior of the motor was correct but at some point It start to push the GAS filter in the opposite direction (see Pic10).. to be investigate.

The .xml file of the measurements  are stored in:

• users/VISsvn/TypeAtower/ITMY/measuremnt/TF/20190806
• users/VIS/TypeAtower/measuremnt/ITMY/TF/20190806
• users/VIS/TypeAtower/measuremnt/ITMY/TF/20190806/GASTF

I turned on all IP and BF_Y loops.

Concernig the GAS loops  I changed the GAS SETpoints and I turned on only F1, F2 and F3. BF GAS loop is open because I need to investigate about a strange behavior.

F2  old= 190 new=-572

F3  old=-553 new=-740

BF old=- 2237 new=-2537

* Note

As reported in the klog 9766, in F1 and BF GAS Filt the sensor polarity were not correct: Today I changed them

F1  old= + --> now -

BF old= -  --> now +