Date: 2022/1/13

Members: Dan, Terrence, Yokozawa

Summary

ETMY was aligned with GreenY, and we got the reflected beam at POS PD (K1: ALS-Y_ARM_REFL_IN1_DQ).
Oplev for ETMY was activated and centered. The optimal values are (P, Y) = (0.0064, -0.30) = K1:VIS-ETMY_TM_OPLEV_TILT_(VER, HOR)_INMON.

Detail

1. We covered EYA flange (+Y side) with Al foil with a big hole (~20*20 cm^2) to pass the GreenY from center. (fig 1, 2)
   1. With this condition, we roughly aligned ETMY.
2. At this point, we set the opleve.
3. We made the pass hole smaller (~1.5*15. cm^2) and adjusted ETMY alignment again. (fig 3)
4. After that, we made the pass hole even smaller (~0.5*0.5 cm^2) and adjusted ETMY alignment again. (fig 4, 5, 6)
5. We removed the Al foil and monitored the output of the RFPD on POS table, then we got the signal.
   1. We got signals from POS PD. When we blocked the GreenY at EYA area, the POS PD signal disappeared. (fig 7, 8, 9)
      1. We blocked GreenY between -14s ~ -9s on the figure of "IN1_DQ = fig 7", and between -17.5s ~ -14s on the figure of "OUT_DQ = fig 9"
   2. The best condition at the last:
      1. K1:VIS-ETMY_TM_OPLEV_TILT_VER_INMON = 0.0064
      2. K1:VIS-ETMY_TM_OPLEV_TILT_HOR_INMON = -0.30
      3. K1:VIS-ETMY_TM_DAMP_L_INMON = -532.3
      4. K1:VIS-ETMY_TM_IP_BLEND_LVDTL_INMON = 0.069
      5. K1:VIS-ETMY_TM_IP_BLEND_LVDTY_INMON = 7.2
   3. The signal on POS PD
      1. K1:ALS_Y_ARM_REFL_OUT_DQ = 0.8 (this was 0.6 when the GreenY was blocked at EYA area.)