[Aritomi, Tanaka, Hirose]

This work is a continuation of klog37318. We try to perform WFS for DRMI. So we start the preparation for WFS.

Our goal is to improve the alignment by switching the alignment control from ADS to WFS while the interferometer is in the DRMI1f lock state (with ADS IMMT2, PRM, SRM).

As a preparation for the WFS commissioning, we introduced dark offsets for the DC, I, and Q signals of the WFS QPDs. The applied offset values are summarized in Fig. 1-4.

After introducing the offsets, we enabled the DC centering loops(Fig. 5).  We created the ENGAGE_WFSDC_DRMI" state pathing DRMI ADS on the ASC_LOCK guardian. However, the error signal of AS_QPDA2 Yaw showed no response to the PZT feedback, suggesting that the signal path may not be properly connected. In addition, REFL_QPDA3 appears to receive little or no light.

We also performed a rough excitation of the BS to obtain preliminary responses.(Fig. 6)

For the next session, we will first check the cabling of AS_QPDA2 Yaw and REFL_QPDA3, and then repeat the measurements after confirming that the signals are properly connected.