Tanaka, Miyoki, Uchiyama, Yuzu, Takase,
[Summary]
The stuck existed in the Adjuster BD.
[What we did]
After the STM2 cable cut and the STM1 cable fixing, we restarted the search for the stuck position in the water path in the BDs chiller path in the PSL room.
We replaced the Adjuster BD with 30W detectable power detector. Because the water tubes that are attached to the Adjuster BD were fixed on the ceiling metal mesh above around the center of the optical table, we scarcely could move the Adjuster BD just above the edge of the optical table.
At this position, we removed the yellow tube that directly went to the chiller return side above a water basket. We found there was almost no water in the yellow tube. When we injected air by using air duster can into this yellow tube, the return side had also slight water and air. In this sense, this yellow tube had no stuck.
After that, we checked the Adjuste BD itself. We injected air by using the air duster can to the water input where the transparent tube was connected (this tube came from the PMC BD), and checked whether the air could come out from the other side water input where the yellow tube was connected or not. Consequently, there was no airflow could path through the Adjuster BD even though I tried 3 times. After that, I retried the same air injection from the other side. The first trial failed to the air pass through. However, the second trial succeeded in letting the air pass through the BD with some dirty pieces as shown in the photo. After this first air conduction, all air injection trials have succeeded in passing through the BD. So we concluded that, at least this Adjuster BD had stuck.
After that, we injected air to the transparent tube that was connected to the PMC BD to check the airflow to the output side of the chiller through the shutter BD and several tubes. Then we obtained the expected airflow! So we concluded that there was no stuck in PMC BD and Shutter BD and their tubes.