[Mio, Nakano]

The PSL was operated with the full power of the fiber amp.!!

- First, the power was increased up to 10 W, and confirm if there are undamped ghost beams and scattered lights by using the IR viewer and the IR camera. Then, we put several beam dumps.
- After that, the laser power was increased up to full power. The PMC, the FSS, the MZM was operated with that power. The ISS was not locked since the PD cannot receive the power.
- The output power from the PSL is about 19 W. Therefore, the power loss on the PSL is 50 %. 10 % for the PMC, 10 % for the ISS, and we are not sure other 30 %. We need to investigate where the power goes.

We are ready to provide the full power light to the IMC with "Mio-sensei's osumitsuki" (see Fig.1)

Fig.1 The mirror with the soot. When we check the ghost beam, the sensor card was burned at the front of the mirror and the soot was attached on the mirror. This mirror is placed before the PMC. The mirror was replaced to the new one and the laser beam aligned with the PMC. So there is no problem anymore. However, this picture tells us the danger of the high power laser. We need to be careful.