KAGRA Logbook

[Tanaka, Komori]

We performed openloop transfer functions and measured the UGF of the whole control loop and the crossover frequency between laser PZT control and EOM control as follows.

```
UGF: ~100 kHz
```
```
Crossover: ~ 14 kHz
```

These are almost the same result of the previous measurement (klog:26820).
The attached figures show the transfer functions of G1+G2 (Fig.1), G1/(1+G2) (Fig.2), and G2/(1+G1) (Fig.3), where G1 and G2 are openloop transfer functions of the laser PZT control and the EOM control.
To measure them, we measured the transfer function from TEST 1 to TEST 2 with excitation at EXC A, EXC B connected to the slow path, and EXC B connected to the fast path, respectively, in IMC common mode servo.

Measured data are stored at /Measurements/IOO/2024/TFs in KAGRA dropbox.