I got the time information of the blasting from Yokozawa-san. So, I checked the recent blasting between 2025/05/22 18:30 JST (we could recovered the DC READOUT at that time klog33869) and 2025/05/28 14:30 JST (the last recorded time in the document).
In total, there were 16 blasting.
- 2 times: the interferometer survived the blasting at OBSERVATION state (as shown in Figure 1 and 2)
- suvival ratio: 50% = 2/4
- In the case of Figure 1, the amount of the bomb was 37.6 which is typical value. Even though the amplitude of the seismic motion is comparable with the threshold to make the IMC oscillation, the lockloss didn't happen.
- In the case of Figure 2, the amount of the bomb was 11.6 which is relatively small. The amplitude of the seismic motion was smaller than the threshold to make the IMC oscillation.
- 2 times: lockloss occurred from OBSERVATION state (as shown in Figure 3 and 4)
- In both cases, the amplitude of the seismic motion was comparable with the threshold to make the IMC oscillation.
- 3 times: the interferometer survived the blasting at RF_LOCKED state
- suvival ratio: 42% = 3/7
- 4 times: lockloss occurred from RF_LOCKED state
- 5 times: interferometer was down
There is a hope to survive the interferometer from the blasting.
