KAGRA Logbook

VIS (EY)

ryutaro.takahashi - 21:08 Wednesday 03 February 2021 (15919)

Setup of BF

[Takahashi, Sato, Horiuchi, Miyo(remote)]

Calibrated the LVDT in BF again. Blue line in the plot #4 shows new measurement.
Measured the TF without the cup. The resonant frequency was ~0.35Hz.
Closed the cup. Then the keystone went down.
Removed some ballast weight (440g x 3 + 60g = 1380g).
Measured the TF with the cup. The resonant frequency was ~0.2Hz.
Hung the F3 by the crane. Then the keystone went down.
Removed some ballast weight (86g + 44g + 62g = 192g)
Measured the TF with the cup hung. The resonant frequency was ~0.2Hz.

Images attached to this report

Comments to this report:

kouseki.miyo - 10:54 Thursday 04 February 2021 (15926)

We confirmed the double GAS filters chain including F3 and BF is installed properly as the double pendulum.

Today, we checked the TF of double GAS filter chain with F3 and BF. Check for single F3 filter was done by klog#15910 in yesterday.
Dtt file is here: /users/Miyo/dropbox/LOG/210204/f3_tuning.xml.

Images attached to this comment

ryutaro.takahashi - 19:56 Thursday 04 February 2021 (15931)

Sorry, but the title is not "Setup of BF" but "Setup of F3". We calibrated the LVDT again in not BF but F3.